[RFC,2/4] input: touchscreen: add core support for Goodix Berlin Touchscreen IC

Commit Message

Neil Armstrong June 6, 2023, 2:31 p.m. UTC

Add initial support for the new Goodix "Berlin" touchscreen ICs.

These touchscreen ICs support SPI, I2C and I3C interface, up to
10 finger touch, stylus and gestures events.

This initial driver is derived from the Goodix goodix_ts_berlin
available at [1] and [2] and only supports the GT9916 IC
present on the Qualcomm SM8550 MTP & QRD touch panel.

The current implementation only supports BerlinD, aka GT9916.

Support for advanced features like:
- Firmware & config update
- Stylus events
- Gestures events
- Previous revisions support (BerlinA or BerlinB)
is not included in current version.

The current support will work with currently flashed firmware
and config, and bail out if firmware or config aren't flashed yet.

[1] https://github.com/goodix/goodix_ts_berlin
[2] https://git.codelinaro.org/clo/la/platform/vendor/opensource/touch-drivers

Signed-off-by: Neil Armstrong <[e-mail]>
---
 drivers/input/touchscreen/Kconfig              |   5 +
 drivers/input/touchscreen/Makefile             |   1 +
 drivers/input/touchscreen/goodix_berlin.h      | 228 ++++++
 drivers/input/touchscreen/goodix_berlin_core.c | 935 +++++++++++++++++++++++++
 4 files changed, 1169 insertions(+)

Comments

Jeff LaBundy June 12, 2023, 4:45 a.m. UTC | #1

Hi Neil,

On Tue, Jun 06, 2023 at 04:31:57PM +0200, Neil Armstrong wrote:
> Add initial support for the new Goodix "Berlin" touchscreen ICs.
> 
> These touchscreen ICs support SPI, I2C and I3C interface, up to
> 10 finger touch, stylus and gestures events.
> 
> This initial driver is derived from the Goodix goodix_ts_berlin
> available at [1] and [2] and only supports the GT9916 IC
> present on the Qualcomm SM8550 MTP & QRD touch panel.
> 
> The current implementation only supports BerlinD, aka GT9916.
> 
> Support for advanced features like:
> - Firmware & config update
> - Stylus events
> - Gestures events
> - Previous revisions support (BerlinA or BerlinB)
> is not included in current version.
> 
> The current support will work with currently flashed firmware
> and config, and bail out if firmware or config aren't flashed yet.
> 
> [1] https://github.com/goodix/goodix_ts_berlin
> [2] https://git.codelinaro.org/clo/la/platform/vendor/opensource/touch-drivers
> 
> Signed-off-by: Neil Armstrong <[e-mail]>
> ---
>  drivers/input/touchscreen/Kconfig              |   5 +
>  drivers/input/touchscreen/Makefile             |   1 +
>  drivers/input/touchscreen/goodix_berlin.h      | 228 ++++++
>  drivers/input/touchscreen/goodix_berlin_core.c | 935 +++++++++++++++++++++++++
>  4 files changed, 1169 insertions(+)
> 
> diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
> index c2cbd332af1d..1a6f6f6da991 100644
> --- a/drivers/input/touchscreen/Kconfig
> +++ b/drivers/input/touchscreen/Kconfig
> @@ -416,6 +416,11 @@ config TOUCHSCREEN_GOODIX
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called goodix.
>  
> +config TOUCHSCREEN_GOODIX_BERLIN_CORE
> +	depends on GPIOLIB || COMPILE_TEST
> +	depends on REGMAP
> +	tristate
> +
>  config TOUCHSCREEN_HIDEEP
>  	tristate "HiDeep Touch IC"
>  	depends on I2C
> diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
> index 159cd5136fdb..29cdb042e104 100644
> --- a/drivers/input/touchscreen/Makefile
> +++ b/drivers/input/touchscreen/Makefile
> @@ -47,6 +47,7 @@ obj-$(CONFIG_TOUCHSCREEN_EGALAX_SERIAL)	+= egalax_ts_serial.o
>  obj-$(CONFIG_TOUCHSCREEN_EXC3000)	+= exc3000.o
>  obj-$(CONFIG_TOUCHSCREEN_FUJITSU)	+= fujitsu_ts.o
>  obj-$(CONFIG_TOUCHSCREEN_GOODIX)	+= goodix_ts.o
> +obj-$(CONFIG_TOUCHSCREEN_GOODIX_BERLIN_CORE)	+= goodix_berlin_core.o
>  obj-$(CONFIG_TOUCHSCREEN_HIDEEP)	+= hideep.o
>  obj-$(CONFIG_TOUCHSCREEN_HYNITRON_CSTXXX)	+= hynitron_cstxxx.o
>  obj-$(CONFIG_TOUCHSCREEN_ILI210X)	+= ili210x.o
> diff --git a/drivers/input/touchscreen/goodix_berlin.h b/drivers/input/touchscreen/goodix_berlin.h
> new file mode 100644
> index 000000000000..83f16201c354
> --- /dev/null
> +++ b/drivers/input/touchscreen/goodix_berlin.h
> @@ -0,0 +1,228 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later */
> +/*
> + * Goodix Touchscreen Driver
> + * Copyright (C) 2020 - 2021 Goodix, Inc.
> + * Copyright (C) 2023 Linaro Ltd.
> + *
> + * Based on goodix_berlin_berlin driver.
> + */
> +
> +#ifndef __GOODIX_BERLIN_H_
> +#define __GOODIX_BERLIN_H_
> +
> +#include <linux/input.h>
> +#include <linux/of_gpio.h>
> +#include <linux/input/touchscreen.h>
> +#include <linux/regulator/consumer.h>
> +
> +#define GOODIX_MAX_TOUCH 10
> +#define GOODIX_MAX_FRAMEDATA_LEN 1700
> +
> +#define GOODIX_NORMAL_RESET_DELAY_MS 100
> +#define GOODIX_HOLD_CPU_RESET_DELAY_MS 5
> +
> +enum CHECKSUM_MODE {
> +	CHECKSUM_MODE_U8_LE,
> +	CHECKSUM_MODE_U16_LE,
> +};

These don't seem to be used anywhere.

Understanding that vendor drivers are typically saddled with lots of cruft
as a result of having supported many different ICs and customers, please
prune the driver for these kinds of things for v1.

> +
> +#define MAX_SCAN_FREQ_NUM	8
> +#define MAX_SCAN_RATE_NUM	8
> +#define MAX_FREQ_NUM_STYLUS	8
> +
> +#define IRQ_EVENT_HEAD_LEN	8
> +#define BYTES_PER_POINT		8
> +#define COOR_DATA_CHECKSUM_SIZE 2
> +
> +#define GOODIX_TOUCH_EVENT	BIT(7)
> +#define GOODIX_REQUEST_EVENT	BIT(6)
> +#define GOODIX_GESTURE_EVENT	BIT(5)
> +
> +#define POINT_TYPE_STYLUS_HOVER	0x01
> +#define POINT_TYPE_STYLUS	0x03
> +
> +#define DEV_CONFIRM_VAL		0xAA
> +#define BOOTOPTION_ADDR		0x10000
> +#define FW_VERSION_INFO_ADDR	0x10014
> +
> +#define GOODIX_IC_INFO_MAX_LEN	1024
> +#define GOODIX_IC_INFO_ADDR	0x10070
> +
> +enum brl_request_code {
> +	BRL_REQUEST_CODE_CONFIG = 1,
> +	BRL_REQUEST_CODE_REF_ERR = 2,
> +	BRL_REQUEST_CODE_RESET = 3,
> +	BRL_REQUEST_CODE_CLOCK = 4,
> +};
> +
> +struct goodix_fw_version {
> +	u8 rom_pid[6]; /* rom PID */

This comment is obvious and noisy; there are similar instances below.

> +	u8 rom_vid[3]; /* Mask VID */
> +	u8 rom_vid_reserved;
> +	u8 patch_pid[8]; /* Patch PID */
> +	u8 patch_vid[4]; /* Patch VID */
> +	u8 patch_vid_reserved;
> +	u8 sensor_id;
> +	u8 reserved[2];
> +	u16 checksum;
> +} __packed;
> +
> +struct goodix_ic_info_version {
> +	u8 info_customer_id;
> +	u8 info_version_id;
> +	u8 ic_die_id;
> +	u8 ic_version_id;
> +	u32 config_id;
> +	u8 config_version;
> +	u8 frame_data_customer_id;
> +	u8 frame_data_version_id;
> +	u8 touch_data_customer_id;
> +	u8 touch_data_version_id;
> +	u8 reserved[3];
> +} __packed;
> +
> +struct goodix_ic_info_feature { /* feature info*/
> +	u16 freqhop_feature;
> +	u16 calibration_feature;
> +	u16 gesture_feature;
> +	u16 side_touch_feature;
> +	u16 stylus_feature;
> +} __packed;
> +
> +struct goodix_ic_info_param { /* param */
> +	u8 drv_num;
> +	u8 sen_num;
> +	u8 button_num;
> +	u8 force_num;
> +	u8 active_scan_rate_num;
> +	u16 active_scan_rate[MAX_SCAN_RATE_NUM];
> +	u8 mutual_freq_num;
> +	u16 mutual_freq[MAX_SCAN_FREQ_NUM];
> +	u8 self_tx_freq_num;
> +	u16 self_tx_freq[MAX_SCAN_FREQ_NUM];
> +	u8 self_rx_freq_num;
> +	u16 self_rx_freq[MAX_SCAN_FREQ_NUM];
> +	u8 stylus_freq_num;
> +	u16 stylus_freq[MAX_FREQ_NUM_STYLUS];
> +} __packed;
> +
> +struct goodix_ic_info_misc { /* other data */
> +	u32 cmd_addr;
> +	u16 cmd_max_len;
> +	u32 cmd_reply_addr;
> +	u16 cmd_reply_len;
> +	u32 fw_state_addr;
> +	u16 fw_state_len;
> +	u32 fw_buffer_addr;
> +	u16 fw_buffer_max_len;
> +	u32 frame_data_addr;
> +	u16 frame_data_head_len;
> +	u16 fw_attr_len;
> +	u16 fw_log_len;
> +	u8 pack_max_num;
> +	u8 pack_compress_version;
> +	u16 stylus_struct_len;
> +	u16 mutual_struct_len;
> +	u16 self_struct_len;
> +	u16 noise_struct_len;
> +	u32 touch_data_addr;
> +	u16 touch_data_head_len;
> +	u16 point_struct_len;
> +	u16 reserved1;
> +	u16 reserved2;
> +	u32 mutual_rawdata_addr;
> +	u32 mutual_diffdata_addr;
> +	u32 mutual_refdata_addr;
> +	u32 self_rawdata_addr;
> +	u32 self_diffdata_addr;
> +	u32 self_refdata_addr;
> +	u32 iq_rawdata_addr;
> +	u32 iq_refdata_addr;
> +	u32 im_rawdata_addr;
> +	u16 im_readata_len;
> +	u32 noise_rawdata_addr;
> +	u16 noise_rawdata_len;
> +	u32 stylus_rawdata_addr;
> +	u16 stylus_rawdata_len;
> +	u32 noise_data_addr;
> +	u32 esd_addr;
> +} __packed;
> +
> +struct goodix_ic_info {
> +	u16 length;
> +	struct goodix_ic_info_version version;
> +	struct goodix_ic_info_feature feature;
> +	struct goodix_ic_info_param parm;
> +	struct goodix_ic_info_misc misc;
> +} __packed;
> +
> +/* interrupt event type */
> +enum ts_event_type {
> +	EVENT_INVALID,
> +	EVENT_TOUCH, /* finger touch event */
> +	EVENT_REQUEST,
> +};

Please consistently namespace all of these, i.e. goodix_berlin_...

> +
> +enum ts_request_type {
> +	REQUEST_TYPE_RESET,
> +};

And here.

> +
> +enum touch_point_status {
> +	TS_NONE,
> +	TS_RELEASE,
> +	TS_TOUCH,
> +};
> +
> +/* coordinate package */
> +struct goodix_berlin_coords {
> +	int status; /* NONE, RELEASE, TOUCH */

	enum touch_point_status status; (without comment, and namespace fixed)

> +	unsigned int x, y, w, p;
> +};
> +
> +/* touch event data */
> +struct goodix_touch_data {
> +	int touch_num;
> +	struct goodix_berlin_coords coords[GOODIX_MAX_TOUCH];
> +};
> +
> +/* touch event struct */
> +struct goodix_berlin_event {
> +	enum ts_event_type event_type;
> +	u8 request_code; /* represent the request type */
> +	struct goodix_touch_data touch_data;
> +};
> +
> +struct goodix_berlin_core {
> +	struct device *dev;
> +	struct regmap *regmap;

It is just my opinion, but I find these newlines to be unnecessary.

> +
> +	struct regulator *avdd;
> +	struct regulator *iovdd;
> +	struct gpio_desc *reset_gpio;
> +
> +	struct touchscreen_properties props;
> +
> +	struct goodix_fw_version fw_version;
> +	struct goodix_ic_info ic_info;
> +
> +	struct input_dev *input_dev;
> +	struct goodix_berlin_event ts_event;
> +
> +	int irq;
> +
> +	struct dentry *debugfs_root;
> +};
> +
> +u32 goodix_append_checksum(u8 *data, int len, int mode);
> +int checksum_cmp(const u8 *data, int size, int mode);
> +int is_risk_data(const u8 *data, int size);
> +u32 goodix_get_file_config_id(u8 *ic_config);
> +void goodix_rotate_abcd2cbad(int tx, int rx, s16 *data);
> +
> +int goodix_berlin_probe(struct device *dev, int irq, const struct input_id *id,
> +			struct regmap *regmap);
> +int goodix_berlin_remove(struct device *dev);
> +
> +extern const struct dev_pm_ops goodix_berlin_pm_ops;
> +
> +#endif
> diff --git a/drivers/input/touchscreen/goodix_berlin_core.c b/drivers/input/touchscreen/goodix_berlin_core.c
> new file mode 100644
> index 000000000000..0719690a5bd3
> --- /dev/null
> +++ b/drivers/input/touchscreen/goodix_berlin_core.c
> @@ -0,0 +1,935 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Goodix Touchscreen Driver
> + * Copyright (C) 2020 - 2021 Goodix, Inc.
> + * Copyright (C) 2023 Linaro Ltd.
> + *
> + * Based on goodix_ts_berlin driver.
> + */
> +#include <linux/regmap.h>
> +#include <linux/input/mt.h>
> +#include <linux/input/touchscreen.h>
> +#include <linux/debugfs.h>

Please sort these alphabetically.

> +
> +#include "goodix_berlin.h"
> +
> +/*
> + * Goodix "Berlin" Touchscreen ID driver
> + *
> + * Currently only handles Multitouch events with already
> + * programmed firmware and "config" for "Revision D" Berlin IC.
> + *
> + * Support is missing for:
> + * - ESD Management
> + * - Firmware update/flashing
> + * - "Config" update/flashing
> + * - PEN Events

What is "PEN"; is it "stylus" as written elsewhere?

> + * - Gesture Events
> + * - Support for older revisions (A, B & C)
> + */
> +
> +static bool goodix_berlin_check_checksum(const u8 *data, int size)
> +{
> +	u32 cal_checksum = 0;
> +	u32 r_checksum = 0;
> +	u32 i;
> +
> +	if (size < COOR_DATA_CHECKSUM_SIZE)
> +		return false;
> +
> +	for (i = 0; i < size - COOR_DATA_CHECKSUM_SIZE; i++)
> +		cal_checksum += data[i];
> +
> +	r_checksum += data[i++];
> +	r_checksum += (data[i] << 8);
> +
> +	return (cal_checksum & 0xFFFF) == r_checksum;
> +}
> +
> +static bool goodix_berlin_is_risk_data(struct goodix_berlin_core *cd,
> +				       const u8 *data, int size)
> +{
> +	int zero_count = 0;
> +	int ff_count = 0;
> +	int i;
> +
> +	for (i = 0; i < size; i++) {
> +		if (data[i] == 0)
> +			zero_count++;
> +		else if (data[i] == 0xff)
> +			ff_count++;
> +	}
> +	if (zero_count == size || ff_count == size) {
> +		dev_warn(cd->dev, "warning data is all %s\n",
> +			 zero_count == size ? "zero" : "0xff");
> +		return true;
> +	}
> +
> +	return false;
> +}
> +
> +static int goodix_berlin_dev_confirm(struct goodix_berlin_core *cd)
> +{
> +	u8 tx_buf[8] = { 0 };
> +	u8 rx_buf[8] = { 0 };
> +	int retry = 3;
> +	int ret = 0;

No need to initialize 'ret' here.

Please note however that in input, return values which can either return
zero (success) or an error code are typically called 'error' since we are
quite literally evaluating an error code. Therefore:

	int error;

	memset(...);
	while (...) {
		error = ...;
		if (error)
			return error;

		[...]
	}

> +
> +	memset(tx_buf, DEV_CONFIRM_VAL, sizeof(tx_buf));
> +	while (retry--) {
> +		ret = regmap_raw_write(cd->regmap, BOOTOPTION_ADDR, tx_buf,
> +				       sizeof(tx_buf));
> +		if (ret < 0)
> +			return ret;
> +		ret = regmap_raw_read(cd->regmap, BOOTOPTION_ADDR, rx_buf,
> +				      sizeof(rx_buf));
> +		if (ret < 0)
> +			return ret;
> +		if (!memcmp(tx_buf, rx_buf, sizeof(tx_buf)))
> +			break;
> +		usleep_range(5000, 5100);
> +	}
> +
> +	if (retry < 0) {
> +		ret = -EINVAL;
> +		dev_err(cd->dev, "device confirm failed, rx_buf: %*ph\n", 8, rx_buf);
> +	}
> +
> +	return ret;
> +}
> +
> +static int goodix_berlin_power_on(struct goodix_berlin_core *cd, bool on)
> +{
> +	int ret = 0;
> +
> +	if (on) {
> +		ret = regulator_enable(cd->iovdd);
> +		if (ret < 0) {
> +			dev_err(cd->dev, "Failed to enable iovdd: %d\n", ret);
> +			goto power_off;

This initially struck me as an imbalance; can you let me know in case I have
misunderstood? If we fail here, we will disable both regulators despite only
have attempted to enable the first.

Also, I do not believe failing to enable a regulator is sufficient evidence
to subsequently disable it.

> +		}
> +

Let us have a comment to explain why 3 ms is special.

> +		usleep_range(3000, 3100);
> +
> +		ret = regulator_enable(cd->avdd);
> +		if (ret < 0) {
> +			dev_err(cd->dev, "Failed to enable avdd: %d\n", ret);
> +			goto power_off;
> +		}
> +
> +		usleep_range(15000, 15100);

And here.

> +
> +		gpiod_set_value(cd->reset_gpio, 0);
> +
> +		usleep_range(4000, 4100);
> +
> +		ret = goodix_berlin_dev_confirm(cd);
> +		if (ret < 0)
> +			goto power_off;
> +
> +		msleep(GOODIX_NORMAL_RESET_DELAY_MS);
> +
> +		return 0;
> +	}
> +
> +power_off:
> +	gpiod_set_value(cd->reset_gpio, 1);
> +	regulator_disable(cd->iovdd);
> +	regulator_disable(cd->avdd);
> +	return ret;
> +}
> +
> +static int goodix_berlin_do_suspend(struct goodix_berlin_core *cd)
> +{
> +	if (goodix_berlin_power_on(cd, 0))
> +		dev_err(cd->dev, "failed power off\n");
> +
> +	return 0;
> +}
> +
> +static int goodix_berlin_do_resume(struct goodix_berlin_core *cd)
> +{
> +	int ret = 0;
> +
> +	ret = goodix_berlin_power_on(cd, 1);
> +	if (ret) {
> +		dev_err(cd->dev, "failed power on\n");
> +		return ret;
> +	}
> +
> +	return ret;
> +}
> +
> +static int goodix_berlin_reset(struct goodix_berlin_core *cd, int delay)
> +{
> +	gpiod_set_value(cd->reset_gpio, 1);
> +	usleep_range(2000, 2100);
> +	gpiod_set_value(cd->reset_gpio, 0);
> +
> +	if (delay < 20)
> +		usleep_range(delay * 1000, delay * 1000 + 100);
> +	else
> +		msleep(delay);

This seems to duplicate fsleep. That being said, why is this logic necessary
at all? This function seems to only be called once; there is no need to make
a decision based on the delay...you already know the value.

> +
> +	return 0;
> +}
> +
> +static int goodix_berlin_irq_enable(struct goodix_berlin_core *cd, bool enable)
> +{
> +	if (enable)
> +		enable_irq(cd->irq);
> +	else
> +		disable_irq(cd->irq);

Why to wrap this logic? While I agree doing so is common for vendor drivers,
that does not make it correct.

> +
> +	return 0;
> +}
> +
> +static int goodix_berlin_read_version(struct goodix_berlin_core *cd,
> +				      struct goodix_fw_version *version)
> +{
> +	u8 buf[sizeof(struct goodix_fw_version)] = { 0 };

Same comment here with regard to initialization of immediately overwritten
variables.

> +	int ret, i;
> +
> +	for (i = 0; i < 2; i++) {
> +		ret = regmap_raw_read(cd->regmap, FW_VERSION_INFO_ADDR, buf, sizeof(buf));
> +		if (ret) {
> +			dev_dbg(cd->dev, "read fw version: %d, retry %d\n", ret, i);
> +			usleep_range(5000, 5100);
> +			continue;
> +		}
> +
> +		if (goodix_berlin_check_checksum(buf, sizeof(buf)))
> +			break;
> +
> +		dev_dbg(cd->dev, "invalid fw version: checksum error\n");
> +
> +		ret = -EINVAL;
> +		usleep_range(10000, 11000);

Let us optimize this logic here; no need to sleep for 10 ms only to fail
upon the last try.

> +	}
> +
> +	if (ret) {
> +		dev_err(cd->dev, "failed to get fw version");
> +		return ret;
> +	}
> +
> +	memcpy(version, buf, sizeof(*version));
> +
> +	return 0;
> +}
> +
> +static int goodix_berlin_fw_version_show(struct seq_file *s, void *unused)
> +{
> +	struct goodix_berlin_core *cd = s->private;
> +	struct goodix_fw_version *version = &cd->fw_version;
> +	u8 temp_pid[9] = { 0 };

And here, with regard to initialization.

> +
> +	memcpy(temp_pid, version->rom_pid, sizeof(version->rom_pid));
> +	temp_pid[sizeof(version->rom_pid)] = '\0';
> +
> +	seq_printf(s, "rom_pid: %s\n", temp_pid);
> +	seq_printf(s, "rom_vid: %*ph\n",
> +		   (int)sizeof(version->rom_vid),
> +		   version->rom_vid);
> +
> +	memcpy(temp_pid, version->patch_pid, sizeof(version->patch_pid));
> +	temp_pid[sizeof(version->patch_pid)] = '\0';
> +
> +	seq_printf(s, "patch_pid: %s\n", temp_pid);
> +	seq_printf(s, "patch_vid: %*ph\n",
> +		   (int)sizeof(version->patch_vid),
> +		   version->patch_vid);
> +	seq_printf(s, "sensor_id: %d\n",
> +		   version->sensor_id);
> +
> +	return 0;
> +}
> +
> +DEFINE_SHOW_ATTRIBUTE(goodix_berlin_fw_version);
> +
> +static int goodix_berlin_convert_ic_info(struct goodix_berlin_core *cd,
> +					 struct goodix_ic_info *info,
> +					 const u8 *data)
> +{
> +	int i;
> +	struct goodix_ic_info_version *version = &info->version;
> +	struct goodix_ic_info_feature *feature = &info->feature;
> +	struct goodix_ic_info_param *parm = &info->parm;
> +	struct goodix_ic_info_misc *misc = &info->misc;
> +
> +	info->length = le16_to_cpup((__le16 *)data);
> +
> +	data += 2;
> +	memcpy(version, data, sizeof(*version));
> +	version->config_id = le32_to_cpu(version->config_id);
> +
> +	data += sizeof(struct goodix_ic_info_version);
> +	memcpy(feature, data, sizeof(*feature));
> +	feature->freqhop_feature = le16_to_cpu(feature->freqhop_feature);
> +	feature->calibration_feature =
> +		le16_to_cpu(feature->calibration_feature);
> +	feature->gesture_feature = le16_to_cpu(feature->gesture_feature);
> +	feature->side_touch_feature = le16_to_cpu(feature->side_touch_feature);
> +	feature->stylus_feature = le16_to_cpu(feature->stylus_feature);
> +
> +	data += sizeof(struct goodix_ic_info_feature);
> +	parm->drv_num = *(data++);
> +	parm->sen_num = *(data++);
> +	parm->button_num = *(data++);
> +	parm->force_num = *(data++);
> +	parm->active_scan_rate_num = *(data++);
> +
> +	if (parm->active_scan_rate_num > MAX_SCAN_RATE_NUM) {
> +		dev_err(cd->dev, "invalid scan rate num %d > %d\n",
> +			parm->active_scan_rate_num, MAX_SCAN_RATE_NUM);
> +		return -EINVAL;
> +	}
> +
> +	for (i = 0; i < parm->active_scan_rate_num; i++)
> +		parm->active_scan_rate[i] =
> +			le16_to_cpup((__le16 *)(data + i * 2));
> +
> +	data += parm->active_scan_rate_num * 2;
> +	parm->mutual_freq_num = *(data++);
> +
> +	if (parm->mutual_freq_num > MAX_SCAN_FREQ_NUM) {
> +		dev_err(cd->dev, "invalid mntual freq num %d > %d\n",
> +			parm->mutual_freq_num, MAX_SCAN_FREQ_NUM);
> +		return -EINVAL;
> +	}
> +
> +	for (i = 0; i < parm->mutual_freq_num; i++)
> +		parm->mutual_freq[i] = le16_to_cpup((__le16 *)(data + i * 2));
> +
> +	data += parm->mutual_freq_num * 2;
> +	parm->self_tx_freq_num = *(data++);
> +
> +	if (parm->self_tx_freq_num > MAX_SCAN_FREQ_NUM) {
> +		dev_err(cd->dev, "invalid tx freq num %d > %d\n",
> +			parm->self_tx_freq_num, MAX_SCAN_FREQ_NUM);
> +		return -EINVAL;
> +	}
> +
> +	for (i = 0; i < parm->self_tx_freq_num; i++)
> +		parm->self_tx_freq[i] = le16_to_cpup((__le16 *)(data + i * 2));
> +
> +	data += parm->self_tx_freq_num * 2;
> +	parm->self_rx_freq_num = *(data++);
> +
> +	if (parm->self_rx_freq_num > MAX_SCAN_FREQ_NUM) {
> +		dev_err(cd->dev, "invalid rx freq num %d > %d\n",
> +			parm->self_rx_freq_num, MAX_SCAN_FREQ_NUM);
> +		return -EINVAL;
> +	}
> +
> +	for (i = 0; i < parm->self_rx_freq_num; i++)
> +		parm->self_rx_freq[i] = le16_to_cpup((__le16 *)(data + i * 2));
> +
> +	data += parm->self_rx_freq_num * 2;
> +	parm->stylus_freq_num = *(data++);
> +
> +	if (parm->stylus_freq_num > MAX_FREQ_NUM_STYLUS) {
> +		dev_err(cd->dev, "invalid stylus freq num %d > %d\n",
> +			parm->stylus_freq_num, MAX_FREQ_NUM_STYLUS);
> +		return -EINVAL;
> +	}
> +
> +	for (i = 0; i < parm->stylus_freq_num; i++)
> +		parm->stylus_freq[i] = le16_to_cpup((__le16 *)(data + i * 2));
> +
> +	data += parm->stylus_freq_num * 2;
> +	memcpy(misc, data, sizeof(*misc));
> +	misc->cmd_addr = le32_to_cpu(misc->cmd_addr);
> +	misc->cmd_max_len = le16_to_cpu(misc->cmd_max_len);
> +	misc->cmd_reply_addr = le32_to_cpu(misc->cmd_reply_addr);
> +	misc->cmd_reply_len = le16_to_cpu(misc->cmd_reply_len);
> +	misc->fw_state_addr = le32_to_cpu(misc->fw_state_addr);
> +	misc->fw_state_len = le16_to_cpu(misc->fw_state_len);
> +	misc->fw_buffer_addr = le32_to_cpu(misc->fw_buffer_addr);
> +	misc->fw_buffer_max_len = le16_to_cpu(misc->fw_buffer_max_len);
> +	misc->frame_data_addr = le32_to_cpu(misc->frame_data_addr);
> +	misc->frame_data_head_len = le16_to_cpu(misc->frame_data_head_len);
> +
> +	misc->fw_attr_len = le16_to_cpu(misc->fw_attr_len);
> +	misc->fw_log_len = le16_to_cpu(misc->fw_log_len);
> +	misc->stylus_struct_len = le16_to_cpu(misc->stylus_struct_len);
> +	misc->mutual_struct_len = le16_to_cpu(misc->mutual_struct_len);
> +	misc->self_struct_len = le16_to_cpu(misc->self_struct_len);
> +	misc->noise_struct_len = le16_to_cpu(misc->noise_struct_len);
> +	misc->touch_data_addr = le32_to_cpu(misc->touch_data_addr);
> +	misc->touch_data_head_len = le16_to_cpu(misc->touch_data_head_len);
> +	misc->point_struct_len = le16_to_cpu(misc->point_struct_len);
> +	misc->mutual_rawdata_addr = le32_to_cpu(misc->mutual_rawdata_addr);
> +	misc->mutual_diffdata_addr = le32_to_cpu(misc->mutual_diffdata_addr);
> +	misc->mutual_refdata_addr = le32_to_cpu(misc->mutual_refdata_addr);
> +	misc->self_rawdata_addr = le32_to_cpu(misc->self_rawdata_addr);
> +	misc->self_diffdata_addr = le32_to_cpu(misc->self_diffdata_addr);
> +	misc->self_refdata_addr = le32_to_cpu(misc->self_refdata_addr);
> +	misc->iq_rawdata_addr = le32_to_cpu(misc->iq_rawdata_addr);
> +	misc->iq_refdata_addr = le32_to_cpu(misc->iq_refdata_addr);
> +	misc->im_rawdata_addr = le32_to_cpu(misc->im_rawdata_addr);
> +	misc->im_readata_len = le16_to_cpu(misc->im_readata_len);
> +	misc->noise_rawdata_addr = le32_to_cpu(misc->noise_rawdata_addr);
> +	misc->noise_rawdata_len = le16_to_cpu(misc->noise_rawdata_len);
> +	misc->stylus_rawdata_addr = le32_to_cpu(misc->stylus_rawdata_addr);
> +	misc->stylus_rawdata_len = le16_to_cpu(misc->stylus_rawdata_len);
> +	misc->noise_data_addr = le32_to_cpu(misc->noise_data_addr);
> +	misc->esd_addr = le32_to_cpu(misc->esd_addr);

What is all of this stuff for? The beginning of the driver explicitly states
that ESD recovery is not supported; please consider stripping all of this if
its only purpose is to support noise in the logs or sysfs attributes that we
cannot reasonably react to.

> +
> +	return 0;
> +}
> +
> +/* Convert to debugfs */

This comment is unnecessary.

> +static int goodix_berlin_ic_info_show(struct seq_file *s, void *unused)
> +{
> +	struct goodix_berlin_core *cd = s->private;
> +	struct goodix_ic_info_version *version = &cd->ic_info.version;
> +	struct goodix_ic_info_feature *feature = &cd->ic_info.feature;
> +	struct goodix_ic_info_param *parm = &cd->ic_info.parm;
> +	struct goodix_ic_info_misc *misc = &cd->ic_info.misc;
> +
> +	seq_printf(s, "ic_info_length:                %d\n", cd->ic_info.length);
> +	seq_printf(s, "info_customer_id:              0x%01X\n",
> +		   version->info_customer_id);
> +	seq_printf(s, "info_version_id:               0x%01X\n",
> +		   version->info_version_id);
> +	seq_printf(s, "ic_die_id:                     0x%01X\n",
> +		   version->ic_die_id);
> +	seq_printf(s, "ic_version_id:                 0x%01X\n",
> +		   version->ic_version_id);
> +	seq_printf(s, "config_id:                     0x%4X\n",
> +		   version->config_id);
> +	seq_printf(s, "config_version:                0x%01X\n",
> +		   version->config_version);
> +	seq_printf(s, "frame_data_customer_id:        0x%01X\n",
> +		   version->frame_data_customer_id);
> +	seq_printf(s, "frame_data_version_id:         0x%01X\n",
> +		   version->frame_data_version_id);
> +	seq_printf(s, "touch_data_customer_id:        0x%01X\n",
> +		   version->touch_data_customer_id);
> +	seq_printf(s, "touch_data_version_id:         0x%01X\n",
> +		   version->touch_data_version_id);
> +	seq_printf(s, "freqhop_feature:               0x%04X\n",
> +		   feature->freqhop_feature);
> +	seq_printf(s, "calibration_feature:           0x%04X\n",
> +		   feature->calibration_feature);
> +	seq_printf(s, "gesture_feature:               0x%04X\n",
> +		   feature->gesture_feature);
> +	seq_printf(s, "side_touch_feature:            0x%04X\n",
> +		   feature->side_touch_feature);
> +	seq_printf(s, "stylus_feature:                0x%04X\n",
> +		   feature->stylus_feature);
> +	seq_printf(s, "Drv*Sen,Button,Force num:      %d x %d, %d, %d\n",
> +		   parm->drv_num, parm->sen_num, parm->button_num, parm->force_num);
> +	seq_printf(s, "Cmd:                           0x%04X, %d\n",
> +		   misc->cmd_addr, misc->cmd_max_len);
> +	seq_printf(s, "Cmd-Reply:                     0x%04X, %d\n",
> +		   misc->cmd_reply_addr, misc->cmd_reply_len);
> +	seq_printf(s, "FW-State:                      0x%04X, %d\n",
> +		   misc->fw_state_addr, misc->fw_state_len);
> +	seq_printf(s, "FW-Buffer:                     0x%04X, %d\n",
> +		   misc->fw_buffer_addr, misc->fw_buffer_max_len);
> +	seq_printf(s, "Touch-Data:                    0x%04X, %d\n",
> +		   misc->touch_data_addr, misc->touch_data_head_len);
> +	seq_printf(s, "point_struct_len:              %d\n",
> +		   misc->point_struct_len);
> +	seq_printf(s, "mutual_rawdata_addr:           0x%04X\n",
> +		   misc->mutual_rawdata_addr);
> +	seq_printf(s, "mutual_diffdata_addr:          0x%04X\n",
> +		   misc->mutual_diffdata_addr);
> +	seq_printf(s, "self_rawdata_addr:             0x%04X\n",
> +		   misc->self_rawdata_addr);
> +	seq_printf(s, "self_diffdata_addr:            0x%04X\n",
> +		   misc->self_diffdata_addr);
> +	seq_printf(s, "stylus_rawdata_addr:           0x%04X, %d\n",
> +		   misc->stylus_rawdata_addr, misc->stylus_rawdata_len);
> +	seq_printf(s, "esd_addr:                      0x%04X\n",
> +		   misc->esd_addr);
> +
> +	return 0;
> +}
> +
> +DEFINE_SHOW_ATTRIBUTE(goodix_berlin_ic_info);
> +
> +static int goodix_berlin_get_ic_info(struct goodix_berlin_core *cd,
> +				     struct goodix_ic_info *ic_info)
> +{
> +	int ret, i;
> +	u16 length = 0;
> +	u32 ic_addr;
> +	u8 afe_data[GOODIX_IC_INFO_MAX_LEN] = { 0 };
> +
> +	ic_addr = GOODIX_IC_INFO_ADDR;
> +
> +	for (i = 0; i < 3; i++) {
> +		ret = regmap_raw_read(cd->regmap, ic_addr, (u8 *)&length, sizeof(length));
> +		if (ret) {
> +			dev_info(cd->dev, "failed get ic info length, %d\n", ret);
> +			usleep_range(5000, 5100);
> +			continue;
> +		}
> +
> +		length = le16_to_cpu(length);
> +		if (length >= GOODIX_IC_INFO_MAX_LEN) {
> +			dev_info(cd->dev, "invalid ic info length %d, retry %d\n", length, i);
> +			continue;
> +		}
> +
> +		ret = regmap_raw_read(cd->regmap, ic_addr, afe_data, length);
> +		if (ret) {
> +			dev_info(cd->dev, "failed get ic info data, %d\n", ret);
> +			usleep_range(5000, 5100);
> +			continue;
> +		}
> +
> +		/* judge whether the data is valid */
> +		if (goodix_berlin_is_risk_data(cd, (const uint8_t *)afe_data,
> +					       length)) {
> +			dev_info(cd->dev, "fw info data invalid\n");
> +			usleep_range(5000, 5100);
> +			continue;
> +		}
> +
> +		if (!goodix_berlin_check_checksum((const uint8_t *)afe_data, length)) {
> +			dev_info(cd->dev, "fw info checksum error\n");
> +			usleep_range(5000, 5100);
> +			continue;
> +		}
> +
> +		break;
> +	}
> +	if (i == 3) {
> +		dev_err(cd->dev, "failed get ic info\n");
> +		return -EINVAL;
> +	}
> +
> +	ret = goodix_berlin_convert_ic_info(cd, ic_info, afe_data);
> +	if (ret) {
> +		dev_err(cd->dev, "error converting ic info\n");
> +		return ret;
> +	}
> +
> +	/* check some key info */
> +	if (!ic_info->misc.cmd_addr || !ic_info->misc.fw_buffer_addr ||
> +	    !ic_info->misc.touch_data_addr) {
> +		dev_err(cd->dev, "cmd_addr fw_buf_addr and touch_data_addr is null\n");
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
> +static int goodix_berlin_after_event_handler(struct goodix_berlin_core *cd)
> +{
> +	struct goodix_ic_info_misc *misc = &cd->ic_info.misc;
> +	u8 sync_clean = 0;
> +
> +	return regmap_raw_write(cd->regmap, misc->touch_data_addr, &sync_clean, 1);
> +}
> +
> +static void goodix_berlin_parse_finger(struct goodix_berlin_core *cd,
> +				       struct goodix_touch_data *touch_data,
> +				       u8 *buf, int touch_num)
> +{
> +	unsigned int id = 0, x = 0, y = 0, w = 0;
> +	u8 *coor_data;
> +	int i;
> +
> +	coor_data = &buf[IRQ_EVENT_HEAD_LEN];
> +
> +	for (i = 0; i < touch_num; i++) {
> +		id = (coor_data[0] >> 4) & 0x0F;
> +
> +		if (id >= GOODIX_MAX_TOUCH) {
> +			dev_warn(cd->dev, "invalid finger id %d\n", id);
> +
> +			touch_data->touch_num = 0;
> +			return;
> +		}
> +
> +		x = le16_to_cpup((__le16 *)(coor_data + 2));
> +		y = le16_to_cpup((__le16 *)(coor_data + 4));
> +		w = le16_to_cpup((__le16 *)(coor_data + 6));
> +
> +		touch_data->coords[id].status = TS_TOUCH;
> +		touch_data->coords[id].x = x;
> +		touch_data->coords[id].y = y;
> +		touch_data->coords[id].w = w;
> +
> +		coor_data += BYTES_PER_POINT;
> +	}
> +
> +	touch_data->touch_num = touch_num;
> +}
> +
> +static int goodix_berlin_touch_handler(struct goodix_berlin_core *cd,
> +				       u8 *pre_buf, u32 pre_buf_len)
> +{
> +	static u8 buffer[IRQ_EVENT_HEAD_LEN + BYTES_PER_POINT * GOODIX_MAX_TOUCH + 2];
> +	struct goodix_touch_data *touch_data = &cd->ts_event.touch_data;
> +	struct goodix_ic_info_misc *misc = &cd->ic_info.misc;
> +	u8 point_type = 0;
> +	u8 touch_num = 0;
> +	int ret = 0;
> +
> +	/* clean event buffer */
> +	memset(&cd->ts_event, 0, sizeof(cd->ts_event));
> +
> +	/* copy pre-data to buffer */
> +	memcpy(buffer, pre_buf, pre_buf_len);
> +
> +	touch_num = buffer[2] & 0x0F;
> +
> +	if (touch_num > GOODIX_MAX_TOUCH) {
> +		dev_warn(cd->dev, "invalid touch num %d\n", touch_num);
> +		return -EINVAL;
> +	}
> +
> +	/* read more data if more than 2 touch events */
> +	if (unlikely(touch_num > 2)) {
> +		ret = regmap_raw_read(cd->regmap,
> +				      misc->touch_data_addr + pre_buf_len,
> +				      &buffer[pre_buf_len],
> +				      (touch_num - 2) * BYTES_PER_POINT);
> +		if (ret) {
> +			dev_err(cd->dev, "failed get touch data\n");
> +			return ret;
> +		}
> +	}
> +
> +	/* read done */
> +	goodix_berlin_after_event_handler(cd);
> +
> +	if (touch_num == 0)
> +		return 0;
> +
> +	point_type = buffer[IRQ_EVENT_HEAD_LEN] & 0x0F;
> +
> +	/* TOFIX: Not handled */

Same here; this comment is unnecessary as the print makes it obvious.

> +	if (point_type == POINT_TYPE_STYLUS || point_type == POINT_TYPE_STYLUS_HOVER) {
> +		dev_warn_once(cd->dev, "Stylus event type not handled\n");
> +		return 0;
> +	}
> +
> +	if (!goodix_berlin_check_checksum(&buffer[IRQ_EVENT_HEAD_LEN],
> +					  touch_num * BYTES_PER_POINT + 2)) {
> +		dev_dbg(cd->dev, "touch data checksum error\n");
> +		dev_dbg(cd->dev, "data: %*ph\n",
> +			touch_num * BYTES_PER_POINT + 2, &buffer[IRQ_EVENT_HEAD_LEN]);
> +		return -EINVAL;
> +	}
> +
> +	cd->ts_event.event_type = EVENT_TOUCH;
> +	goodix_berlin_parse_finger(cd, touch_data, buffer, touch_num);
> +
> +	return 0;
> +}
> +
> +static int goodix_berlin_event_handler(struct goodix_berlin_core *cd)
> +{
> +	struct goodix_ic_info_misc *misc = &cd->ic_info.misc;
> +	int pre_read_len;
> +	u8 pre_buf[32];
> +	u8 event_status;
> +	int ret;
> +
> +	pre_read_len = IRQ_EVENT_HEAD_LEN + BYTES_PER_POINT * 2 +
> +		       COOR_DATA_CHECKSUM_SIZE;
> +
> +	ret = regmap_raw_read(cd->regmap, misc->touch_data_addr, pre_buf,
> +			      pre_read_len);
> +	if (ret) {
> +		dev_err(cd->dev, "failed get event head data\n");
> +		return ret;
> +	}
> +
> +	if (pre_buf[0] == 0x00)
> +		return -EINVAL;
> +
> +	if (!goodix_berlin_check_checksum(pre_buf, IRQ_EVENT_HEAD_LEN)) {
> +		dev_warn(cd->dev, "touch head checksum err : %*ph\n",
> +			 IRQ_EVENT_HEAD_LEN, pre_buf);
> +		return -EINVAL;
> +	}
> +
> +	event_status = pre_buf[0];
> +	if (event_status & GOODIX_TOUCH_EVENT)
> +		return goodix_berlin_touch_handler(cd, pre_buf, pre_read_len);
> +
> +	if (event_status & GOODIX_REQUEST_EVENT) {
> +		cd->ts_event.event_type = EVENT_REQUEST;
> +		if (pre_buf[2] == BRL_REQUEST_CODE_RESET)
> +			cd->ts_event.request_code = REQUEST_TYPE_RESET;
> +		else
> +			dev_warn(cd->dev, "unsupported request code 0x%x\n", pre_buf[2]);
> +	}
> +
> +	goodix_berlin_after_event_handler(cd);
> +
> +	return 0;
> +}
> +
> +static void goodix_berlin_report_finger(struct goodix_berlin_core *cd)
> +{
> +	struct goodix_touch_data *touch_data = &cd->ts_event.touch_data;
> +	int i;
> +
> +	mutex_lock(&cd->input_dev->mutex);
> +
> +	for (i = 0; i < GOODIX_MAX_TOUCH; i++) {
> +		if (touch_data->coords[i].status == TS_TOUCH) {
> +			dev_dbg(cd->dev, "report: id[%d], x %d, y %d, w %d\n", i,
> +				touch_data->coords[i].x,
> +				touch_data->coords[i].y,
> +				touch_data->coords[i].w);
> +
> +			input_mt_slot(cd->input_dev, i);
> +			input_mt_report_slot_state(cd->input_dev,
> +						   MT_TOOL_FINGER, true);
> +			touchscreen_report_pos(cd->input_dev, &cd->props,
> +					       touch_data->coords[i].x,
> +					       touch_data->coords[i].y, true);
> +			input_report_abs(cd->input_dev, ABS_MT_TOUCH_MAJOR,
> +					 touch_data->coords[i].w);
> +		} else {
> +			input_mt_slot(cd->input_dev, i);
> +			input_mt_report_slot_state(cd->input_dev,
> +						   MT_TOOL_FINGER, false);
> +		}
> +	}
> +
> +	input_mt_sync_frame(cd->input_dev);
> +	input_sync(cd->input_dev);
> +
> +	mutex_unlock(&cd->input_dev->mutex);
> +}
> +
> +static int goodix_berlin_request_handle(struct goodix_berlin_core *cd)
> +{
> +	/* TOFIX: Handle more request codes */
> +	if (cd->ts_event.request_code != REQUEST_TYPE_RESET) {
> +		dev_info(cd->dev, "can't handle request type 0x%x\n",
> +			 cd->ts_event.request_code);
> +		return -EINVAL;
> +	}
> +
> +	return goodix_berlin_reset(cd, GOODIX_NORMAL_RESET_DELAY_MS);

This is confusing; can you add some comments here? Under what conditions
would we bail and reset the device? Surely this is unlikely?

> +}
> +
> +static irqreturn_t goodix_berlin_threadirq_func(int irq, void *data)
> +{
> +	struct goodix_berlin_core *cd = data;
> +	int ret;
> +
> +	ret = goodix_berlin_event_handler(cd);
> +	if (likely(!ret)) {
> +		switch (cd->ts_event.event_type) {
> +		case EVENT_TOUCH:
> +			goodix_berlin_report_finger(cd);
> +			break;
> +
> +		case EVENT_REQUEST:
> +			goodix_berlin_request_handle(cd);
> +			break;
> +
> +		/* TOFIX: Handle more request types */
> +		case EVENT_INVALID:
> +			break;
> +		}
> +	}
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int goodix_berlin_input_dev_config(struct goodix_berlin_core *cd,
> +					  const struct input_id *id)
> +{
> +	struct input_dev *input_dev = devm_input_allocate_device(cd->dev);

Please break this assignment into its own line.

> +
> +	if (!input_dev)
> +		return -ENOMEM;
> +
> +	cd->input_dev = input_dev;
> +	input_set_drvdata(input_dev, cd);
> +
> +	input_dev->name = "Goodix Berlin Capacitive TouchScreen";
> +	input_dev->phys = "input/ts";
> +	input_dev->dev.parent = cd->dev;
> +
> +	memcpy(&input_dev->id, id, sizeof(*id));
> +
> +	/* set input parameters */
> +	input_set_abs_params(cd->input_dev, ABS_MT_POSITION_X, 0, SZ_64K - 1, 0, 0);
> +	input_set_abs_params(cd->input_dev, ABS_MT_POSITION_Y, 0, SZ_64K - 1, 0, 0);
> +	input_set_abs_params(cd->input_dev, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0);
> +
> +	/* Override with DT */

This comment is unnecessary; furthermore touchscreen_parse_properties() is not
limited to OF.

> +	touchscreen_parse_properties(cd->input_dev, true, &cd->props);
> +
> +	input_mt_init_slots(cd->input_dev, GOODIX_MAX_TOUCH, INPUT_MT_DIRECT);

Please check this function's return value and bail if negative.

> +
> +	return input_register_device(cd->input_dev);
> +}
> +
> +static void goodix_berlin_release_connects(struct goodix_berlin_core *cd)
> +{
> +	struct input_dev *input_dev = cd->input_dev;
> +	int i;
> +
> +	mutex_lock(&input_dev->mutex);
> +
> +	for (i = 0; i < GOODIX_MAX_TOUCH; i++) {
> +		input_mt_slot(input_dev, i);
> +		input_mt_report_slot_state(input_dev, MT_TOOL_FINGER, false);
> +	}
> +	input_mt_sync_frame(input_dev);
> +	input_sync(input_dev);
> +
> +	mutex_unlock(&input_dev->mutex);
> +}
> +
> +static int goodix_berlin_suspend(struct goodix_berlin_core *cd)
> +{
> +	/* disable irq */
> +	goodix_berlin_irq_enable(cd, false);
> +
> +	/* enter sleep mode or power off */
> +	goodix_berlin_do_suspend(cd);
> +
> +	goodix_berlin_release_connects(cd);

For my own understanding, why is this operation necessary? Do you expect
a platform to suspend if the user's fingers remain on the panel? I also
find it confusing that multiple entry points can call input_mt_sync_frame()
or input_sync(); typically these are limited to a common handler.

> +
> +	return 0;
> +}
> +
> +static int goodix_berlin_resume(struct goodix_berlin_core *cd)
> +{
> +	goodix_berlin_irq_enable(cd, false);
> +
> +	/* reset device or power on*/
> +	goodix_berlin_do_resume(cd);
> +
> +	/* enable irq */
> +	goodix_berlin_irq_enable(cd, true);
> +
> +	return 0;
> +}
> +
> +int goodix_berlin_pm_suspend(struct device *dev)
> +{
> +	struct goodix_berlin_core *cd = dev_get_drvdata(dev);
> +
> +	return goodix_berlin_suspend(cd);
> +}
> +
> +int goodix_berlin_pm_resume(struct device *dev)
> +{
> +	struct goodix_berlin_core *cd = dev_get_drvdata(dev);
> +
> +	return goodix_berlin_resume(cd);
> +}
> +
> +EXPORT_GPL_SIMPLE_DEV_PM_OPS(goodix_berlin_pm_ops,
> +			     goodix_berlin_pm_suspend,
> +			     goodix_berlin_pm_resume);
> +
> +int goodix_berlin_probe(struct device *dev, int irq, const struct input_id *id,
> +			struct regmap *regmap)
> +{
> +	struct goodix_berlin_core *cd;
> +	int ret;
> +
> +	if (irq <= 0)
> +		return -EINVAL;
> +
> +	cd = devm_kzalloc(dev, sizeof(*cd), GFP_KERNEL);
> +	if (!cd)
> +		return -ENOMEM;
> +
> +	cd->dev = dev;
> +	cd->regmap = regmap;
> +	cd->irq = irq;
> +
> +	cd->reset_gpio = devm_gpiod_get(cd->dev, "reset", GPIOF_OUT_INIT_HIGH);
> +	if (IS_ERR(cd->reset_gpio))
> +		return dev_err_probe(cd->dev, PTR_ERR(cd->reset_gpio),
> +				     "Failed to request reset gpio\n");

In my experience, the reset GPIO is the first to go in case the board designer
runs out of GPIO. Can it be optional?

> +
> +	cd->avdd = devm_regulator_get(cd->dev, "avdd");
> +	if (IS_ERR(cd->avdd))
> +		return dev_err_probe(cd->dev, PTR_ERR(cd->avdd),
> +				     "Failed to request avdd regulator\n");
> +
> +	cd->iovdd = devm_regulator_get(cd->dev, "iovdd");
> +	if (IS_ERR(cd->iovdd))
> +		return dev_err_probe(cd->dev, PTR_ERR(cd->iovdd),
> +				     "Failed to request iovdd regulator\n");
> +
> +	ret = goodix_berlin_input_dev_config(cd, id);
> +	if (ret < 0) {
> +		dev_err(cd->dev, "failed set input device");
> +		return ret;
> +	}
> +
> +	ret = devm_request_threaded_irq(dev, irq, NULL,
> +					goodix_berlin_threadirq_func,
> +					IRQF_ONESHOT, "goodix-berlin", cd);
> +	if (ret) {
> +		dev_err(dev, "request threaded irq failed: %d\n", ret);
> +		return ret;
> +	}
> +
> +	dev_set_drvdata(dev, cd);
> +
> +	ret = goodix_berlin_power_on(cd, true);

This seems like something that can be posted as an device-managed action
as opposed to having subsequent goto statements from here on.

> +	if (ret) {
> +		dev_err(cd->dev, "failed power on");
> +		goto err_out;
> +	}
> +
> +	ret = goodix_berlin_read_version(cd, &cd->fw_version);
> +	if (ret < 0) {
> +		dev_err(cd->dev, "failed to get version info");
> +		goto err_out;
> +	}
> +
> +	ret = goodix_berlin_get_ic_info(cd, &cd->ic_info);
> +	if (ret) {
> +		dev_err(cd->dev, "invalid ic info, abort");
> +		goto err_out;
> +	}
> +
> +	cd->debugfs_root = debugfs_create_dir(dev_name(dev), NULL);
> +	debugfs_create_file("fw_version", 0444, cd->debugfs_root,
> +			    cd, &goodix_berlin_fw_version_fops);
> +	debugfs_create_file("ic_info", 0444, cd->debugfs_root,
> +			    cd, &goodix_berlin_ic_info_fops);

We need not explicitly create attributes; consider the dev_groups member
of the device_driver struct instead.

> +
> +	dev_info(cd->dev, "Goodix Berlin %s Touchscreen Controller", cd->fw_version.patch_pid);

dev_dbg()

> +
> +	return 0;
> +
> +err_out:
> +	goodix_berlin_power_on(cd, false);
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(goodix_berlin_probe);
> +
> +int goodix_berlin_remove(struct device *dev)
> +{
> +	struct goodix_berlin_core *cd = dev_get_drvdata(dev);
> +
> +	goodix_berlin_release_connects(cd);
> +
> +	goodix_berlin_irq_enable(cd, false);
> +
> +	goodix_berlin_power_on(cd, false);
> +
> +	debugfs_remove(cd->debugfs_root);
> +
> +	return 0;

I suspect much of this is unnecessary if you adopt modern primitives. Once
you wrap regulator disables with device-managed actions, you should be able
to get rid of the remove callback altogether.

> +}
> +EXPORT_SYMBOL_GPL(goodix_berlin_remove);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_DESCRIPTION("Goodix Berlin Core Touchscreen driver");
> +MODULE_AUTHOR("Neil Armstrong <[e-mail]>");
> 
> -- 
> 2.34.1
> 

Kind regards,
Jeff LaBundy

Neil Armstrong June 12, 2023, 8:37 a.m. UTC | #2

Hi Jeff,

On 12/06/2023 06:45, Jeff LaBundy wrote:
> Hi Neil,
> 
> On Tue, Jun 06, 2023 at 04:31:57PM +0200, Neil Armstrong wrote:
>> Add initial support for the new Goodix "Berlin" touchscreen ICs.
>>
>> These touchscreen ICs support SPI, I2C and I3C interface, up to
>> 10 finger touch, stylus and gestures events.
>>
>> This initial driver is derived from the Goodix goodix_ts_berlin
>> available at [1] and [2] and only supports the GT9916 IC
>> present on the Qualcomm SM8550 MTP & QRD touch panel.
>>
>> The current implementation only supports BerlinD, aka GT9916.
>>
>> Support for advanced features like:
>> - Firmware & config update
>> - Stylus events
>> - Gestures events
>> - Previous revisions support (BerlinA or BerlinB)
>> is not included in current version.
>>
>> The current support will work with currently flashed firmware
>> and config, and bail out if firmware or config aren't flashed yet.
>>
>> [1] https://github.com/goodix/goodix_ts_berlin
>> [2] https://git.codelinaro.org/clo/la/platform/vendor/opensource/touch-drivers
>>
>> Signed-off-by: Neil Armstrong <[e-mail]>
>> ---
>>   drivers/input/touchscreen/Kconfig              |   5 +
>>   drivers/input/touchscreen/Makefile             |   1 +
>>   drivers/input/touchscreen/goodix_berlin.h      | 228 ++++++
>>   drivers/input/touchscreen/goodix_berlin_core.c | 935 +++++++++++++++++++++++++
>>   4 files changed, 1169 insertions(+)
>>
>> diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
>> index c2cbd332af1d..1a6f6f6da991 100644
>> --- a/drivers/input/touchscreen/Kconfig
>> +++ b/drivers/input/touchscreen/Kconfig
>> @@ -416,6 +416,11 @@ config TOUCHSCREEN_GOODIX
>>   	  To compile this driver as a module, choose M here: the
>>   	  module will be called goodix.
>>   
>> +config TOUCHSCREEN_GOODIX_BERLIN_CORE
>> +	depends on GPIOLIB || COMPILE_TEST
>> +	depends on REGMAP
>> +	tristate
>> +
>>   config TOUCHSCREEN_HIDEEP
>>   	tristate "HiDeep Touch IC"
>>   	depends on I2C
>> diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
>> index 159cd5136fdb..29cdb042e104 100644
>> --- a/drivers/input/touchscreen/Makefile
>> +++ b/drivers/input/touchscreen/Makefile
>> @@ -47,6 +47,7 @@ obj-$(CONFIG_TOUCHSCREEN_EGALAX_SERIAL)	+= egalax_ts_serial.o
>>   obj-$(CONFIG_TOUCHSCREEN_EXC3000)	+= exc3000.o
>>   obj-$(CONFIG_TOUCHSCREEN_FUJITSU)	+= fujitsu_ts.o
>>   obj-$(CONFIG_TOUCHSCREEN_GOODIX)	+= goodix_ts.o
>> +obj-$(CONFIG_TOUCHSCREEN_GOODIX_BERLIN_CORE)	+= goodix_berlin_core.o
>>   obj-$(CONFIG_TOUCHSCREEN_HIDEEP)	+= hideep.o
>>   obj-$(CONFIG_TOUCHSCREEN_HYNITRON_CSTXXX)	+= hynitron_cstxxx.o
>>   obj-$(CONFIG_TOUCHSCREEN_ILI210X)	+= ili210x.o
>> diff --git a/drivers/input/touchscreen/goodix_berlin.h b/drivers/input/touchscreen/goodix_berlin.h
>> new file mode 100644
>> index 000000000000..83f16201c354
>> --- /dev/null
>> +++ b/drivers/input/touchscreen/goodix_berlin.h
>> @@ -0,0 +1,228 @@
>> +/* SPDX-License-Identifier: GPL-2.0-or-later */
>> +/*
>> + * Goodix Touchscreen Driver
>> + * Copyright (C) 2020 - 2021 Goodix, Inc.
>> + * Copyright (C) 2023 Linaro Ltd.
>> + *
>> + * Based on goodix_berlin_berlin driver.
>> + */
>> +
>> +#ifndef __GOODIX_BERLIN_H_
>> +#define __GOODIX_BERLIN_H_
>> +
>> +#include <linux/input.h>
>> +#include <linux/of_gpio.h>
>> +#include <linux/input/touchscreen.h>
>> +#include <linux/regulator/consumer.h>
>> +
>> +#define GOODIX_MAX_TOUCH 10
>> +#define GOODIX_MAX_FRAMEDATA_LEN 1700
>> +
>> +#define GOODIX_NORMAL_RESET_DELAY_MS 100
>> +#define GOODIX_HOLD_CPU_RESET_DELAY_MS 5
>> +
>> +enum CHECKSUM_MODE {
>> +	CHECKSUM_MODE_U8_LE,
>> +	CHECKSUM_MODE_U16_LE,
>> +};
> 
> These don't seem to be used anywhere.
> 
> Understanding that vendor drivers are typically saddled with lots of cruft
> as a result of having supported many different ICs and customers, please
> prune the driver for these kinds of things for v1.

Thanks for your very advanced review, I already gone though a very
heavy cleanup of the vendor driver but seems I missed some pieces
and namings. I'll make sure all the remaining unused stuff is pruned
on v2.

> 
>> +
>> +#define MAX_SCAN_FREQ_NUM	8
>> +#define MAX_SCAN_RATE_NUM	8
>> +#define MAX_FREQ_NUM_STYLUS	8
>> +
>> +#define IRQ_EVENT_HEAD_LEN	8
>> +#define BYTES_PER_POINT		8
>> +#define COOR_DATA_CHECKSUM_SIZE 2
>> +
>> +#define GOODIX_TOUCH_EVENT	BIT(7)
>> +#define GOODIX_REQUEST_EVENT	BIT(6)
>> +#define GOODIX_GESTURE_EVENT	BIT(5)
>> +
>> +#define POINT_TYPE_STYLUS_HOVER	0x01
>> +#define POINT_TYPE_STYLUS	0x03
>> +
>> +#define DEV_CONFIRM_VAL		0xAA
>> +#define BOOTOPTION_ADDR		0x10000
>> +#define FW_VERSION_INFO_ADDR	0x10014
>> +
>> +#define GOODIX_IC_INFO_MAX_LEN	1024
>> +#define GOODIX_IC_INFO_ADDR	0x10070
>> +
>> +enum brl_request_code {
>> +	BRL_REQUEST_CODE_CONFIG = 1,
>> +	BRL_REQUEST_CODE_REF_ERR = 2,
>> +	BRL_REQUEST_CODE_RESET = 3,
>> +	BRL_REQUEST_CODE_CLOCK = 4,
>> +};
>> +
>> +struct goodix_fw_version {
>> +	u8 rom_pid[6]; /* rom PID */
> 
> This comment is obvious and noisy; there are similar instances below.
> 
>> +	u8 rom_vid[3]; /* Mask VID */
>> +	u8 rom_vid_reserved;
>> +	u8 patch_pid[8]; /* Patch PID */
>> +	u8 patch_vid[4]; /* Patch VID */
>> +	u8 patch_vid_reserved;
>> +	u8 sensor_id;
>> +	u8 reserved[2];
>> +	u16 checksum;
>> +} __packed;
>> +
>> +struct goodix_ic_info_version {
>> +	u8 info_customer_id;
>> +	u8 info_version_id;
>> +	u8 ic_die_id;
>> +	u8 ic_version_id;
>> +	u32 config_id;
>> +	u8 config_version;
>> +	u8 frame_data_customer_id;
>> +	u8 frame_data_version_id;
>> +	u8 touch_data_customer_id;
>> +	u8 touch_data_version_id;
>> +	u8 reserved[3];
>> +} __packed;
>> +
>> +struct goodix_ic_info_feature { /* feature info*/
>> +	u16 freqhop_feature;
>> +	u16 calibration_feature;
>> +	u16 gesture_feature;
>> +	u16 side_touch_feature;
>> +	u16 stylus_feature;
>> +} __packed;
>> +
>> +struct goodix_ic_info_param { /* param */
>> +	u8 drv_num;
>> +	u8 sen_num;
>> +	u8 button_num;
>> +	u8 force_num;
>> +	u8 active_scan_rate_num;
>> +	u16 active_scan_rate[MAX_SCAN_RATE_NUM];
>> +	u8 mutual_freq_num;
>> +	u16 mutual_freq[MAX_SCAN_FREQ_NUM];
>> +	u8 self_tx_freq_num;
>> +	u16 self_tx_freq[MAX_SCAN_FREQ_NUM];
>> +	u8 self_rx_freq_num;
>> +	u16 self_rx_freq[MAX_SCAN_FREQ_NUM];
>> +	u8 stylus_freq_num;
>> +	u16 stylus_freq[MAX_FREQ_NUM_STYLUS];
>> +} __packed;
>> +
>> +struct goodix_ic_info_misc { /* other data */
>> +	u32 cmd_addr;
>> +	u16 cmd_max_len;
>> +	u32 cmd_reply_addr;
>> +	u16 cmd_reply_len;
>> +	u32 fw_state_addr;
>> +	u16 fw_state_len;
>> +	u32 fw_buffer_addr;
>> +	u16 fw_buffer_max_len;
>> +	u32 frame_data_addr;
>> +	u16 frame_data_head_len;
>> +	u16 fw_attr_len;
>> +	u16 fw_log_len;
>> +	u8 pack_max_num;
>> +	u8 pack_compress_version;
>> +	u16 stylus_struct_len;
>> +	u16 mutual_struct_len;
>> +	u16 self_struct_len;
>> +	u16 noise_struct_len;
>> +	u32 touch_data_addr;
>> +	u16 touch_data_head_len;
>> +	u16 point_struct_len;
>> +	u16 reserved1;
>> +	u16 reserved2;
>> +	u32 mutual_rawdata_addr;
>> +	u32 mutual_diffdata_addr;
>> +	u32 mutual_refdata_addr;
>> +	u32 self_rawdata_addr;
>> +	u32 self_diffdata_addr;
>> +	u32 self_refdata_addr;
>> +	u32 iq_rawdata_addr;
>> +	u32 iq_refdata_addr;
>> +	u32 im_rawdata_addr;
>> +	u16 im_readata_len;
>> +	u32 noise_rawdata_addr;
>> +	u16 noise_rawdata_len;
>> +	u32 stylus_rawdata_addr;
>> +	u16 stylus_rawdata_len;
>> +	u32 noise_data_addr;
>> +	u32 esd_addr;
>> +} __packed;
>> +
>> +struct goodix_ic_info {
>> +	u16 length;
>> +	struct goodix_ic_info_version version;
>> +	struct goodix_ic_info_feature feature;
>> +	struct goodix_ic_info_param parm;
>> +	struct goodix_ic_info_misc misc;
>> +} __packed;
>> +
>> +/* interrupt event type */
>> +enum ts_event_type {
>> +	EVENT_INVALID,
>> +	EVENT_TOUCH, /* finger touch event */
>> +	EVENT_REQUEST,
>> +};
> 
> Please consistently namespace all of these, i.e. goodix_berlin_...
> 
>> +
>> +enum ts_request_type {
>> +	REQUEST_TYPE_RESET,
>> +};
> 
> And here.
> 
>> +
>> +enum touch_point_status {
>> +	TS_NONE,
>> +	TS_RELEASE,
>> +	TS_TOUCH,
>> +};
>> +
>> +/* coordinate package */
>> +struct goodix_berlin_coords {
>> +	int status; /* NONE, RELEASE, TOUCH */
> 
> 	enum touch_point_status status; (without comment, and namespace fixed)
> 
>> +	unsigned int x, y, w, p;
>> +};
>> +
>> +/* touch event data */
>> +struct goodix_touch_data {
>> +	int touch_num;
>> +	struct goodix_berlin_coords coords[GOODIX_MAX_TOUCH];
>> +};
>> +
>> +/* touch event struct */
>> +struct goodix_berlin_event {
>> +	enum ts_event_type event_type;
>> +	u8 request_code; /* represent the request type */
>> +	struct goodix_touch_data touch_data;
>> +};
>> +
>> +struct goodix_berlin_core {
>> +	struct device *dev;
>> +	struct regmap *regmap;
> 
> It is just my opinion, but I find these newlines to be unnecessary.
> 
>> +
>> +	struct regulator *avdd;
>> +	struct regulator *iovdd;
>> +	struct gpio_desc *reset_gpio;
>> +
>> +	struct touchscreen_properties props;
>> +
>> +	struct goodix_fw_version fw_version;
>> +	struct goodix_ic_info ic_info;
>> +
>> +	struct input_dev *input_dev;
>> +	struct goodix_berlin_event ts_event;
>> +
>> +	int irq;
>> +
>> +	struct dentry *debugfs_root;
>> +};
>> +
>> +u32 goodix_append_checksum(u8 *data, int len, int mode);
>> +int checksum_cmp(const u8 *data, int size, int mode);
>> +int is_risk_data(const u8 *data, int size);
>> +u32 goodix_get_file_config_id(u8 *ic_config);
>> +void goodix_rotate_abcd2cbad(int tx, int rx, s16 *data);
>> +
>> +int goodix_berlin_probe(struct device *dev, int irq, const struct input_id *id,
>> +			struct regmap *regmap);
>> +int goodix_berlin_remove(struct device *dev);
>> +
>> +extern const struct dev_pm_ops goodix_berlin_pm_ops;
>> +
>> +#endif
>> diff --git a/drivers/input/touchscreen/goodix_berlin_core.c b/drivers/input/touchscreen/goodix_berlin_core.c
>> new file mode 100644
>> index 000000000000..0719690a5bd3
>> --- /dev/null
>> +++ b/drivers/input/touchscreen/goodix_berlin_core.c
>> @@ -0,0 +1,935 @@
>> +// SPDX-License-Identifier: GPL-2.0-or-later
>> +/*
>> + * Goodix Touchscreen Driver
>> + * Copyright (C) 2020 - 2021 Goodix, Inc.
>> + * Copyright (C) 2023 Linaro Ltd.
>> + *
>> + * Based on goodix_ts_berlin driver.
>> + */
>> +#include <linux/regmap.h>
>> +#include <linux/input/mt.h>
>> +#include <linux/input/touchscreen.h>
>> +#include <linux/debugfs.h>
> 
> Please sort these alphabetically.
> 
>> +
>> +#include "goodix_berlin.h"
>> +
>> +/*
>> + * Goodix "Berlin" Touchscreen ID driver
>> + *
>> + * Currently only handles Multitouch events with already
>> + * programmed firmware and "config" for "Revision D" Berlin IC.
>> + *
>> + * Support is missing for:
>> + * - ESD Management
>> + * - Firmware update/flashing
>> + * - "Config" update/flashing
>> + * - PEN Events
> 
> What is "PEN"; is it "stylus" as written elsewhere?

Yes, they use both terms in the vendor driver.

> 
>> + * - Gesture Events
>> + * - Support for older revisions (A, B & C)
>> + */
>> +
>> +static bool goodix_berlin_check_checksum(const u8 *data, int size)
>> +{
>> +	u32 cal_checksum = 0;
>> +	u32 r_checksum = 0;
>> +	u32 i;
>> +
>> +	if (size < COOR_DATA_CHECKSUM_SIZE)
>> +		return false;
>> +
>> +	for (i = 0; i < size - COOR_DATA_CHECKSUM_SIZE; i++)
>> +		cal_checksum += data[i];
>> +
>> +	r_checksum += data[i++];
>> +	r_checksum += (data[i] << 8);
>> +
>> +	return (cal_checksum & 0xFFFF) == r_checksum;
>> +}
>> +
>> +static bool goodix_berlin_is_risk_data(struct goodix_berlin_core *cd,
>> +				       const u8 *data, int size)
>> +{
>> +	int zero_count = 0;
>> +	int ff_count = 0;
>> +	int i;
>> +
>> +	for (i = 0; i < size; i++) {
>> +		if (data[i] == 0)
>> +			zero_count++;
>> +		else if (data[i] == 0xff)
>> +			ff_count++;
>> +	}
>> +	if (zero_count == size || ff_count == size) {
>> +		dev_warn(cd->dev, "warning data is all %s\n",
>> +			 zero_count == size ? "zero" : "0xff");
>> +		return true;
>> +	}
>> +
>> +	return false;
>> +}
>> +
>> +static int goodix_berlin_dev_confirm(struct goodix_berlin_core *cd)
>> +{
>> +	u8 tx_buf[8] = { 0 };
>> +	u8 rx_buf[8] = { 0 };
>> +	int retry = 3;
>> +	int ret = 0;
> 
> No need to initialize 'ret' here.
> 
> Please note however that in input, return values which can either return
> zero (success) or an error code are typically called 'error' since we are
> quite literally evaluating an error code. Therefore:
> 
> 	int error;
> 
> 	memset(...);
> 	while (...) {
> 		error = ...;
> 		if (error)
> 			return error;
> 
> 		[...]
> 	}
> 
>> +
>> +	memset(tx_buf, DEV_CONFIRM_VAL, sizeof(tx_buf));
>> +	while (retry--) {
>> +		ret = regmap_raw_write(cd->regmap, BOOTOPTION_ADDR, tx_buf,
>> +				       sizeof(tx_buf));
>> +		if (ret < 0)
>> +			return ret;
>> +		ret = regmap_raw_read(cd->regmap, BOOTOPTION_ADDR, rx_buf,
>> +				      sizeof(rx_buf));
>> +		if (ret < 0)
>> +			return ret;
>> +		if (!memcmp(tx_buf, rx_buf, sizeof(tx_buf)))
>> +			break;
>> +		usleep_range(5000, 5100);
>> +	}
>> +
>> +	if (retry < 0) {
>> +		ret = -EINVAL;
>> +		dev_err(cd->dev, "device confirm failed, rx_buf: %*ph\n", 8, rx_buf);
>> +	}
>> +
>> +	return ret;
>> +}
>> +
>> +static int goodix_berlin_power_on(struct goodix_berlin_core *cd, bool on)
>> +{
>> +	int ret = 0;
>> +
>> +	if (on) {
>> +		ret = regulator_enable(cd->iovdd);
>> +		if (ret < 0) {
>> +			dev_err(cd->dev, "Failed to enable iovdd: %d\n", ret);
>> +			goto power_off;
> 
> This initially struck me as an imbalance; can you let me know in case I have
> misunderstood? If we fail here, we will disable both regulators despite only
> have attempted to enable the first.

I problably missed this, I'll fix it.

> 
> Also, I do not believe failing to enable a regulator is sufficient evidence
> to subsequently disable it.
> 
>> +		}
>> +
> 
> Let us have a comment to explain why 3 ms is special.

I must say I have no idea why 3ms is needed since I don't
have access to any HW documentation, I'll probbaly write something
like :
/* Vendo waits 3ms here to wait for iovdd to settle */

> 
>> +		usleep_range(3000, 3100);
>> +
>> +		ret = regulator_enable(cd->avdd);
>> +		if (ret < 0) {
>> +			dev_err(cd->dev, "Failed to enable avdd: %d\n", ret);
>> +			goto power_off;
>> +		}
>> +
>> +		usleep_range(15000, 15100);
> 
> And here.
> 
>> +
>> +		gpiod_set_value(cd->reset_gpio, 0);
>> +
>> +		usleep_range(4000, 4100);
>> +
>> +		ret = goodix_berlin_dev_confirm(cd);
>> +		if (ret < 0)
>> +			goto power_off;
>> +
>> +		msleep(GOODIX_NORMAL_RESET_DELAY_MS);
>> +
>> +		return 0;
>> +	}
>> +
>> +power_off:
>> +	gpiod_set_value(cd->reset_gpio, 1);
>> +	regulator_disable(cd->iovdd);
>> +	regulator_disable(cd->avdd);
>> +	return ret;
>> +}
>> +
>> +static int goodix_berlin_do_suspend(struct goodix_berlin_core *cd)
>> +{
>> +	if (goodix_berlin_power_on(cd, 0))
>> +		dev_err(cd->dev, "failed power off\n");
>> +
>> +	return 0;
>> +}
>> +
>> +static int goodix_berlin_do_resume(struct goodix_berlin_core *cd)
>> +{
>> +	int ret = 0;
>> +
>> +	ret = goodix_berlin_power_on(cd, 1);
>> +	if (ret) {
>> +		dev_err(cd->dev, "failed power on\n");
>> +		return ret;
>> +	}
>> +
>> +	return ret;
>> +}
>> +
>> +static int goodix_berlin_reset(struct goodix_berlin_core *cd, int delay)
>> +{
>> +	gpiod_set_value(cd->reset_gpio, 1);
>> +	usleep_range(2000, 2100);
>> +	gpiod_set_value(cd->reset_gpio, 0);
>> +
>> +	if (delay < 20)
>> +		usleep_range(delay * 1000, delay * 1000 + 100);
>> +	else
>> +		msleep(delay);
> 
> This seems to duplicate fsleep. That being said, why is this logic necessary
> at all? This function seems to only be called once; there is no need to make
> a decision based on the delay...you already know the value.

Yep I'll inline it.

> 
>> +
>> +	return 0;
>> +}
>> +
>> +static int goodix_berlin_irq_enable(struct goodix_berlin_core *cd, bool enable)
>> +{
>> +	if (enable)
>> +		enable_irq(cd->irq);
>> +	else
>> +		disable_irq(cd->irq);
> 
> Why to wrap this logic? While I agree doing so is common for vendor drivers,
> that does not make it correct.

Ack

> 
>> +
>> +	return 0;
>> +}
>> +
>> +static int goodix_berlin_read_version(struct goodix_berlin_core *cd,
>> +				      struct goodix_fw_version *version)
>> +{
>> +	u8 buf[sizeof(struct goodix_fw_version)] = { 0 };
> 
> Same comment here with regard to initialization of immediately overwritten
> variables.
> 
>> +	int ret, i;
>> +
>> +	for (i = 0; i < 2; i++) {
>> +		ret = regmap_raw_read(cd->regmap, FW_VERSION_INFO_ADDR, buf, sizeof(buf));
>> +		if (ret) {
>> +			dev_dbg(cd->dev, "read fw version: %d, retry %d\n", ret, i);
>> +			usleep_range(5000, 5100);
>> +			continue;
>> +		}
>> +
>> +		if (goodix_berlin_check_checksum(buf, sizeof(buf)))
>> +			break;
>> +
>> +		dev_dbg(cd->dev, "invalid fw version: checksum error\n");
>> +
>> +		ret = -EINVAL;
>> +		usleep_range(10000, 11000);
> 
> Let us optimize this logic here; no need to sleep for 10 ms only to fail
> upon the last try.
> 
>> +	}
>> +
>> +	if (ret) {
>> +		dev_err(cd->dev, "failed to get fw version");
>> +		return ret;
>> +	}
>> +
>> +	memcpy(version, buf, sizeof(*version));
>> +
>> +	return 0;
>> +}
>> +
>> +static int goodix_berlin_fw_version_show(struct seq_file *s, void *unused)
>> +{
>> +	struct goodix_berlin_core *cd = s->private;
>> +	struct goodix_fw_version *version = &cd->fw_version;
>> +	u8 temp_pid[9] = { 0 };
> 
> And here, with regard to initialization.
> 
>> +
>> +	memcpy(temp_pid, version->rom_pid, sizeof(version->rom_pid));
>> +	temp_pid[sizeof(version->rom_pid)] = '\0';
>> +
>> +	seq_printf(s, "rom_pid: %s\n", temp_pid);
>> +	seq_printf(s, "rom_vid: %*ph\n",
>> +		   (int)sizeof(version->rom_vid),
>> +		   version->rom_vid);
>> +
>> +	memcpy(temp_pid, version->patch_pid, sizeof(version->patch_pid));
>> +	temp_pid[sizeof(version->patch_pid)] = '\0';
>> +
>> +	seq_printf(s, "patch_pid: %s\n", temp_pid);
>> +	seq_printf(s, "patch_vid: %*ph\n",
>> +		   (int)sizeof(version->patch_vid),
>> +		   version->patch_vid);
>> +	seq_printf(s, "sensor_id: %d\n",
>> +		   version->sensor_id);
>> +
>> +	return 0;
>> +}
>> +
>> +DEFINE_SHOW_ATTRIBUTE(goodix_berlin_fw_version);
>> +
>> +static int goodix_berlin_convert_ic_info(struct goodix_berlin_core *cd,
>> +					 struct goodix_ic_info *info,
>> +					 const u8 *data)
>> +{
>> +	int i;
>> +	struct goodix_ic_info_version *version = &info->version;
>> +	struct goodix_ic_info_feature *feature = &info->feature;
>> +	struct goodix_ic_info_param *parm = &info->parm;
>> +	struct goodix_ic_info_misc *misc = &info->misc;
>> +
>> +	info->length = le16_to_cpup((__le16 *)data);
>> +
>> +	data += 2;
>> +	memcpy(version, data, sizeof(*version));
>> +	version->config_id = le32_to_cpu(version->config_id);
>> +
>> +	data += sizeof(struct goodix_ic_info_version);
>> +	memcpy(feature, data, sizeof(*feature));
>> +	feature->freqhop_feature = le16_to_cpu(feature->freqhop_feature);
>> +	feature->calibration_feature =
>> +		le16_to_cpu(feature->calibration_feature);
>> +	feature->gesture_feature = le16_to_cpu(feature->gesture_feature);
>> +	feature->side_touch_feature = le16_to_cpu(feature->side_touch_feature);
>> +	feature->stylus_feature = le16_to_cpu(feature->stylus_feature);
>> +
>> +	data += sizeof(struct goodix_ic_info_feature);
>> +	parm->drv_num = *(data++);
>> +	parm->sen_num = *(data++);
>> +	parm->button_num = *(data++);
>> +	parm->force_num = *(data++);
>> +	parm->active_scan_rate_num = *(data++);
>> +
>> +	if (parm->active_scan_rate_num > MAX_SCAN_RATE_NUM) {
>> +		dev_err(cd->dev, "invalid scan rate num %d > %d\n",
>> +			parm->active_scan_rate_num, MAX_SCAN_RATE_NUM);
>> +		return -EINVAL;
>> +	}
>> +
>> +	for (i = 0; i < parm->active_scan_rate_num; i++)
>> +		parm->active_scan_rate[i] =
>> +			le16_to_cpup((__le16 *)(data + i * 2));
>> +
>> +	data += parm->active_scan_rate_num * 2;
>> +	parm->mutual_freq_num = *(data++);
>> +
>> +	if (parm->mutual_freq_num > MAX_SCAN_FREQ_NUM) {
>> +		dev_err(cd->dev, "invalid mntual freq num %d > %d\n",
>> +			parm->mutual_freq_num, MAX_SCAN_FREQ_NUM);
>> +		return -EINVAL;
>> +	}
>> +
>> +	for (i = 0; i < parm->mutual_freq_num; i++)
>> +		parm->mutual_freq[i] = le16_to_cpup((__le16 *)(data + i * 2));
>> +
>> +	data += parm->mutual_freq_num * 2;
>> +	parm->self_tx_freq_num = *(data++);
>> +
>> +	if (parm->self_tx_freq_num > MAX_SCAN_FREQ_NUM) {
>> +		dev_err(cd->dev, "invalid tx freq num %d > %d\n",
>> +			parm->self_tx_freq_num, MAX_SCAN_FREQ_NUM);
>> +		return -EINVAL;
>> +	}
>> +
>> +	for (i = 0; i < parm->self_tx_freq_num; i++)
>> +		parm->self_tx_freq[i] = le16_to_cpup((__le16 *)(data + i * 2));
>> +
>> +	data += parm->self_tx_freq_num * 2;
>> +	parm->self_rx_freq_num = *(data++);
>> +
>> +	if (parm->self_rx_freq_num > MAX_SCAN_FREQ_NUM) {
>> +		dev_err(cd->dev, "invalid rx freq num %d > %d\n",
>> +			parm->self_rx_freq_num, MAX_SCAN_FREQ_NUM);
>> +		return -EINVAL;
>> +	}
>> +
>> +	for (i = 0; i < parm->self_rx_freq_num; i++)
>> +		parm->self_rx_freq[i] = le16_to_cpup((__le16 *)(data + i * 2));
>> +
>> +	data += parm->self_rx_freq_num * 2;
>> +	parm->stylus_freq_num = *(data++);
>> +
>> +	if (parm->stylus_freq_num > MAX_FREQ_NUM_STYLUS) {
>> +		dev_err(cd->dev, "invalid stylus freq num %d > %d\n",
>> +			parm->stylus_freq_num, MAX_FREQ_NUM_STYLUS);
>> +		return -EINVAL;
>> +	}
>> +
>> +	for (i = 0; i < parm->stylus_freq_num; i++)
>> +		parm->stylus_freq[i] = le16_to_cpup((__le16 *)(data + i * 2));
>> +
>> +	data += parm->stylus_freq_num * 2;
>> +	memcpy(misc, data, sizeof(*misc));
>> +	misc->cmd_addr = le32_to_cpu(misc->cmd_addr);
>> +	misc->cmd_max_len = le16_to_cpu(misc->cmd_max_len);
>> +	misc->cmd_reply_addr = le32_to_cpu(misc->cmd_reply_addr);
>> +	misc->cmd_reply_len = le16_to_cpu(misc->cmd_reply_len);
>> +	misc->fw_state_addr = le32_to_cpu(misc->fw_state_addr);
>> +	misc->fw_state_len = le16_to_cpu(misc->fw_state_len);
>> +	misc->fw_buffer_addr = le32_to_cpu(misc->fw_buffer_addr);
>> +	misc->fw_buffer_max_len = le16_to_cpu(misc->fw_buffer_max_len);
>> +	misc->frame_data_addr = le32_to_cpu(misc->frame_data_addr);
>> +	misc->frame_data_head_len = le16_to_cpu(misc->frame_data_head_len);
>> +
>> +	misc->fw_attr_len = le16_to_cpu(misc->fw_attr_len);
>> +	misc->fw_log_len = le16_to_cpu(misc->fw_log_len);
>> +	misc->stylus_struct_len = le16_to_cpu(misc->stylus_struct_len);
>> +	misc->mutual_struct_len = le16_to_cpu(misc->mutual_struct_len);
>> +	misc->self_struct_len = le16_to_cpu(misc->self_struct_len);
>> +	misc->noise_struct_len = le16_to_cpu(misc->noise_struct_len);
>> +	misc->touch_data_addr = le32_to_cpu(misc->touch_data_addr);
>> +	misc->touch_data_head_len = le16_to_cpu(misc->touch_data_head_len);
>> +	misc->point_struct_len = le16_to_cpu(misc->point_struct_len);
>> +	misc->mutual_rawdata_addr = le32_to_cpu(misc->mutual_rawdata_addr);
>> +	misc->mutual_diffdata_addr = le32_to_cpu(misc->mutual_diffdata_addr);
>> +	misc->mutual_refdata_addr = le32_to_cpu(misc->mutual_refdata_addr);
>> +	misc->self_rawdata_addr = le32_to_cpu(misc->self_rawdata_addr);
>> +	misc->self_diffdata_addr = le32_to_cpu(misc->self_diffdata_addr);
>> +	misc->self_refdata_addr = le32_to_cpu(misc->self_refdata_addr);
>> +	misc->iq_rawdata_addr = le32_to_cpu(misc->iq_rawdata_addr);
>> +	misc->iq_refdata_addr = le32_to_cpu(misc->iq_refdata_addr);
>> +	misc->im_rawdata_addr = le32_to_cpu(misc->im_rawdata_addr);
>> +	misc->im_readata_len = le16_to_cpu(misc->im_readata_len);
>> +	misc->noise_rawdata_addr = le32_to_cpu(misc->noise_rawdata_addr);
>> +	misc->noise_rawdata_len = le16_to_cpu(misc->noise_rawdata_len);
>> +	misc->stylus_rawdata_addr = le32_to_cpu(misc->stylus_rawdata_addr);
>> +	misc->stylus_rawdata_len = le16_to_cpu(misc->stylus_rawdata_len);
>> +	misc->noise_data_addr = le32_to_cpu(misc->noise_data_addr);
>> +	misc->esd_addr = le32_to_cpu(misc->esd_addr);
> 
> What is all of this stuff for? The beginning of the driver explicitly states
> that ESD recovery is not supported; please consider stripping all of this if
> its only purpose is to support noise in the logs or sysfs attributes that we
> cannot reasonably react to.

Those are all the firmware parameters used by the driver, for now only a little
are used, we already read the entire struct so stripping isn't an option otherwise
the values will be shifted.

We only print those over debugfs se it won't fill any logs

> 
>> +
>> +	return 0;
>> +}
>> +
>> +/* Convert to debugfs */
> 
> This comment is unnecessary.
> 
>> +static int goodix_berlin_ic_info_show(struct seq_file *s, void *unused)
>> +{
>> +	struct goodix_berlin_core *cd = s->private;
>> +	struct goodix_ic_info_version *version = &cd->ic_info.version;
>> +	struct goodix_ic_info_feature *feature = &cd->ic_info.feature;
>> +	struct goodix_ic_info_param *parm = &cd->ic_info.parm;
>> +	struct goodix_ic_info_misc *misc = &cd->ic_info.misc;
>> +
>> +	seq_printf(s, "ic_info_length:                %d\n", cd->ic_info.length);
>> +	seq_printf(s, "info_customer_id:              0x%01X\n",
>> +		   version->info_customer_id);
>> +	seq_printf(s, "info_version_id:               0x%01X\n",
>> +		   version->info_version_id);
>> +	seq_printf(s, "ic_die_id:                     0x%01X\n",
>> +		   version->ic_die_id);
>> +	seq_printf(s, "ic_version_id:                 0x%01X\n",
>> +		   version->ic_version_id);
>> +	seq_printf(s, "config_id:                     0x%4X\n",
>> +		   version->config_id);
>> +	seq_printf(s, "config_version:                0x%01X\n",
>> +		   version->config_version);
>> +	seq_printf(s, "frame_data_customer_id:        0x%01X\n",
>> +		   version->frame_data_customer_id);
>> +	seq_printf(s, "frame_data_version_id:         0x%01X\n",
>> +		   version->frame_data_version_id);
>> +	seq_printf(s, "touch_data_customer_id:        0x%01X\n",
>> +		   version->touch_data_customer_id);
>> +	seq_printf(s, "touch_data_version_id:         0x%01X\n",
>> +		   version->touch_data_version_id);
>> +	seq_printf(s, "freqhop_feature:               0x%04X\n",
>> +		   feature->freqhop_feature);
>> +	seq_printf(s, "calibration_feature:           0x%04X\n",
>> +		   feature->calibration_feature);
>> +	seq_printf(s, "gesture_feature:               0x%04X\n",
>> +		   feature->gesture_feature);
>> +	seq_printf(s, "side_touch_feature:            0x%04X\n",
>> +		   feature->side_touch_feature);
>> +	seq_printf(s, "stylus_feature:                0x%04X\n",
>> +		   feature->stylus_feature);
>> +	seq_printf(s, "Drv*Sen,Button,Force num:      %d x %d, %d, %d\n",
>> +		   parm->drv_num, parm->sen_num, parm->button_num, parm->force_num);
>> +	seq_printf(s, "Cmd:                           0x%04X, %d\n",
>> +		   misc->cmd_addr, misc->cmd_max_len);
>> +	seq_printf(s, "Cmd-Reply:                     0x%04X, %d\n",
>> +		   misc->cmd_reply_addr, misc->cmd_reply_len);
>> +	seq_printf(s, "FW-State:                      0x%04X, %d\n",
>> +		   misc->fw_state_addr, misc->fw_state_len);
>> +	seq_printf(s, "FW-Buffer:                     0x%04X, %d\n",
>> +		   misc->fw_buffer_addr, misc->fw_buffer_max_len);
>> +	seq_printf(s, "Touch-Data:                    0x%04X, %d\n",
>> +		   misc->touch_data_addr, misc->touch_data_head_len);
>> +	seq_printf(s, "point_struct_len:              %d\n",
>> +		   misc->point_struct_len);
>> +	seq_printf(s, "mutual_rawdata_addr:           0x%04X\n",
>> +		   misc->mutual_rawdata_addr);
>> +	seq_printf(s, "mutual_diffdata_addr:          0x%04X\n",
>> +		   misc->mutual_diffdata_addr);
>> +	seq_printf(s, "self_rawdata_addr:             0x%04X\n",
>> +		   misc->self_rawdata_addr);
>> +	seq_printf(s, "self_diffdata_addr:            0x%04X\n",
>> +		   misc->self_diffdata_addr);
>> +	seq_printf(s, "stylus_rawdata_addr:           0x%04X, %d\n",
>> +		   misc->stylus_rawdata_addr, misc->stylus_rawdata_len);
>> +	seq_printf(s, "esd_addr:                      0x%04X\n",
>> +		   misc->esd_addr);
>> +
>> +	return 0;
>> +}
>> +
>> +DEFINE_SHOW_ATTRIBUTE(goodix_berlin_ic_info);
>> +
>> +static int goodix_berlin_get_ic_info(struct goodix_berlin_core *cd,
>> +				     struct goodix_ic_info *ic_info)
>> +{
>> +	int ret, i;
>> +	u16 length = 0;
>> +	u32 ic_addr;
>> +	u8 afe_data[GOODIX_IC_INFO_MAX_LEN] = { 0 };
>> +
>> +	ic_addr = GOODIX_IC_INFO_ADDR;
>> +
>> +	for (i = 0; i < 3; i++) {
>> +		ret = regmap_raw_read(cd->regmap, ic_addr, (u8 *)&length, sizeof(length));
>> +		if (ret) {
>> +			dev_info(cd->dev, "failed get ic info length, %d\n", ret);
>> +			usleep_range(5000, 5100);
>> +			continue;
>> +		}
>> +
>> +		length = le16_to_cpu(length);
>> +		if (length >= GOODIX_IC_INFO_MAX_LEN) {
>> +			dev_info(cd->dev, "invalid ic info length %d, retry %d\n", length, i);
>> +			continue;
>> +		}
>> +
>> +		ret = regmap_raw_read(cd->regmap, ic_addr, afe_data, length);
>> +		if (ret) {
>> +			dev_info(cd->dev, "failed get ic info data, %d\n", ret);
>> +			usleep_range(5000, 5100);
>> +			continue;
>> +		}
>> +
>> +		/* judge whether the data is valid */
>> +		if (goodix_berlin_is_risk_data(cd, (const uint8_t *)afe_data,
>> +					       length)) {
>> +			dev_info(cd->dev, "fw info data invalid\n");
>> +			usleep_range(5000, 5100);
>> +			continue;
>> +		}
>> +
>> +		if (!goodix_berlin_check_checksum((const uint8_t *)afe_data, length)) {
>> +			dev_info(cd->dev, "fw info checksum error\n");
>> +			usleep_range(5000, 5100);
>> +			continue;
>> +		}
>> +
>> +		break;
>> +	}
>> +	if (i == 3) {
>> +		dev_err(cd->dev, "failed get ic info\n");
>> +		return -EINVAL;
>> +	}
>> +
>> +	ret = goodix_berlin_convert_ic_info(cd, ic_info, afe_data);
>> +	if (ret) {
>> +		dev_err(cd->dev, "error converting ic info\n");
>> +		return ret;
>> +	}
>> +
>> +	/* check some key info */
>> +	if (!ic_info->misc.cmd_addr || !ic_info->misc.fw_buffer_addr ||
>> +	    !ic_info->misc.touch_data_addr) {
>> +		dev_err(cd->dev, "cmd_addr fw_buf_addr and touch_data_addr is null\n");
>> +		return -EINVAL;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static int goodix_berlin_after_event_handler(struct goodix_berlin_core *cd)
>> +{
>> +	struct goodix_ic_info_misc *misc = &cd->ic_info.misc;
>> +	u8 sync_clean = 0;
>> +
>> +	return regmap_raw_write(cd->regmap, misc->touch_data_addr, &sync_clean, 1);
>> +}
>> +
>> +static void goodix_berlin_parse_finger(struct goodix_berlin_core *cd,
>> +				       struct goodix_touch_data *touch_data,
>> +				       u8 *buf, int touch_num)
>> +{
>> +	unsigned int id = 0, x = 0, y = 0, w = 0;
>> +	u8 *coor_data;
>> +	int i;
>> +
>> +	coor_data = &buf[IRQ_EVENT_HEAD_LEN];
>> +
>> +	for (i = 0; i < touch_num; i++) {
>> +		id = (coor_data[0] >> 4) & 0x0F;
>> +
>> +		if (id >= GOODIX_MAX_TOUCH) {
>> +			dev_warn(cd->dev, "invalid finger id %d\n", id);
>> +
>> +			touch_data->touch_num = 0;
>> +			return;
>> +		}
>> +
>> +		x = le16_to_cpup((__le16 *)(coor_data + 2));
>> +		y = le16_to_cpup((__le16 *)(coor_data + 4));
>> +		w = le16_to_cpup((__le16 *)(coor_data + 6));
>> +
>> +		touch_data->coords[id].status = TS_TOUCH;
>> +		touch_data->coords[id].x = x;
>> +		touch_data->coords[id].y = y;
>> +		touch_data->coords[id].w = w;
>> +
>> +		coor_data += BYTES_PER_POINT;
>> +	}
>> +
>> +	touch_data->touch_num = touch_num;
>> +}
>> +
>> +static int goodix_berlin_touch_handler(struct goodix_berlin_core *cd,
>> +				       u8 *pre_buf, u32 pre_buf_len)
>> +{
>> +	static u8 buffer[IRQ_EVENT_HEAD_LEN + BYTES_PER_POINT * GOODIX_MAX_TOUCH + 2];
>> +	struct goodix_touch_data *touch_data = &cd->ts_event.touch_data;
>> +	struct goodix_ic_info_misc *misc = &cd->ic_info.misc;
>> +	u8 point_type = 0;
>> +	u8 touch_num = 0;
>> +	int ret = 0;
>> +
>> +	/* clean event buffer */
>> +	memset(&cd->ts_event, 0, sizeof(cd->ts_event));
>> +
>> +	/* copy pre-data to buffer */
>> +	memcpy(buffer, pre_buf, pre_buf_len);
>> +
>> +	touch_num = buffer[2] & 0x0F;
>> +
>> +	if (touch_num > GOODIX_MAX_TOUCH) {
>> +		dev_warn(cd->dev, "invalid touch num %d\n", touch_num);
>> +		return -EINVAL;
>> +	}
>> +
>> +	/* read more data if more than 2 touch events */
>> +	if (unlikely(touch_num > 2)) {
>> +		ret = regmap_raw_read(cd->regmap,
>> +				      misc->touch_data_addr + pre_buf_len,
>> +				      &buffer[pre_buf_len],
>> +				      (touch_num - 2) * BYTES_PER_POINT);
>> +		if (ret) {
>> +			dev_err(cd->dev, "failed get touch data\n");
>> +			return ret;
>> +		}
>> +	}
>> +
>> +	/* read done */
>> +	goodix_berlin_after_event_handler(cd);
>> +
>> +	if (touch_num == 0)
>> +		return 0;
>> +
>> +	point_type = buffer[IRQ_EVENT_HEAD_LEN] & 0x0F;
>> +
>> +	/* TOFIX: Not handled */
> 
> Same here; this comment is unnecessary as the print makes it obvious.
> 
>> +	if (point_type == POINT_TYPE_STYLUS || point_type == POINT_TYPE_STYLUS_HOVER) {
>> +		dev_warn_once(cd->dev, "Stylus event type not handled\n");
>> +		return 0;
>> +	}
>> +
>> +	if (!goodix_berlin_check_checksum(&buffer[IRQ_EVENT_HEAD_LEN],
>> +					  touch_num * BYTES_PER_POINT + 2)) {
>> +		dev_dbg(cd->dev, "touch data checksum error\n");
>> +		dev_dbg(cd->dev, "data: %*ph\n",
>> +			touch_num * BYTES_PER_POINT + 2, &buffer[IRQ_EVENT_HEAD_LEN]);
>> +		return -EINVAL;
>> +	}
>> +
>> +	cd->ts_event.event_type = EVENT_TOUCH;
>> +	goodix_berlin_parse_finger(cd, touch_data, buffer, touch_num);
>> +
>> +	return 0;
>> +}
>> +
>> +static int goodix_berlin_event_handler(struct goodix_berlin_core *cd)
>> +{
>> +	struct goodix_ic_info_misc *misc = &cd->ic_info.misc;
>> +	int pre_read_len;
>> +	u8 pre_buf[32];
>> +	u8 event_status;
>> +	int ret;
>> +
>> +	pre_read_len = IRQ_EVENT_HEAD_LEN + BYTES_PER_POINT * 2 +
>> +		       COOR_DATA_CHECKSUM_SIZE;
>> +
>> +	ret = regmap_raw_read(cd->regmap, misc->touch_data_addr, pre_buf,
>> +			      pre_read_len);
>> +	if (ret) {
>> +		dev_err(cd->dev, "failed get event head data\n");
>> +		return ret;
>> +	}
>> +
>> +	if (pre_buf[0] == 0x00)
>> +		return -EINVAL;
>> +
>> +	if (!goodix_berlin_check_checksum(pre_buf, IRQ_EVENT_HEAD_LEN)) {
>> +		dev_warn(cd->dev, "touch head checksum err : %*ph\n",
>> +			 IRQ_EVENT_HEAD_LEN, pre_buf);
>> +		return -EINVAL;
>> +	}
>> +
>> +	event_status = pre_buf[0];
>> +	if (event_status & GOODIX_TOUCH_EVENT)
>> +		return goodix_berlin_touch_handler(cd, pre_buf, pre_read_len);
>> +
>> +	if (event_status & GOODIX_REQUEST_EVENT) {
>> +		cd->ts_event.event_type = EVENT_REQUEST;
>> +		if (pre_buf[2] == BRL_REQUEST_CODE_RESET)
>> +			cd->ts_event.request_code = REQUEST_TYPE_RESET;
>> +		else
>> +			dev_warn(cd->dev, "unsupported request code 0x%x\n", pre_buf[2]);
>> +	}
>> +
>> +	goodix_berlin_after_event_handler(cd);
>> +
>> +	return 0;
>> +}
>> +
>> +static void goodix_berlin_report_finger(struct goodix_berlin_core *cd)
>> +{
>> +	struct goodix_touch_data *touch_data = &cd->ts_event.touch_data;
>> +	int i;
>> +
>> +	mutex_lock(&cd->input_dev->mutex);
>> +
>> +	for (i = 0; i < GOODIX_MAX_TOUCH; i++) {
>> +		if (touch_data->coords[i].status == TS_TOUCH) {
>> +			dev_dbg(cd->dev, "report: id[%d], x %d, y %d, w %d\n", i,
>> +				touch_data->coords[i].x,
>> +				touch_data->coords[i].y,
>> +				touch_data->coords[i].w);
>> +
>> +			input_mt_slot(cd->input_dev, i);
>> +			input_mt_report_slot_state(cd->input_dev,
>> +						   MT_TOOL_FINGER, true);
>> +			touchscreen_report_pos(cd->input_dev, &cd->props,
>> +					       touch_data->coords[i].x,
>> +					       touch_data->coords[i].y, true);
>> +			input_report_abs(cd->input_dev, ABS_MT_TOUCH_MAJOR,
>> +					 touch_data->coords[i].w);
>> +		} else {
>> +			input_mt_slot(cd->input_dev, i);
>> +			input_mt_report_slot_state(cd->input_dev,
>> +						   MT_TOOL_FINGER, false);
>> +		}
>> +	}
>> +
>> +	input_mt_sync_frame(cd->input_dev);
>> +	input_sync(cd->input_dev);
>> +
>> +	mutex_unlock(&cd->input_dev->mutex);
>> +}
>> +
>> +static int goodix_berlin_request_handle(struct goodix_berlin_core *cd)
>> +{
>> +	/* TOFIX: Handle more request codes */
>> +	if (cd->ts_event.request_code != REQUEST_TYPE_RESET) {
>> +		dev_info(cd->dev, "can't handle request type 0x%x\n",
>> +			 cd->ts_event.request_code);
>> +		return -EINVAL;
>> +	}
>> +
>> +	return goodix_berlin_reset(cd, GOODIX_NORMAL_RESET_DELAY_MS);
> 
> This is confusing; can you add some comments here? Under what conditions
> would we bail and reset the device? Surely this is unlikely?

I'll add comments, the current goodix.c has the same scheme where the firmwre
can ask for a reset.

> 
>> +}
>> +
>> +static irqreturn_t goodix_berlin_threadirq_func(int irq, void *data)
>> +{
>> +	struct goodix_berlin_core *cd = data;
>> +	int ret;
>> +
>> +	ret = goodix_berlin_event_handler(cd);
>> +	if (likely(!ret)) {
>> +		switch (cd->ts_event.event_type) {
>> +		case EVENT_TOUCH:
>> +			goodix_berlin_report_finger(cd);
>> +			break;
>> +
>> +		case EVENT_REQUEST:
>> +			goodix_berlin_request_handle(cd);
>> +			break;
>> +
>> +		/* TOFIX: Handle more request types */
>> +		case EVENT_INVALID:
>> +			break;
>> +		}
>> +	}
>> +
>> +	return IRQ_HANDLED;
>> +}
>> +
>> +static int goodix_berlin_input_dev_config(struct goodix_berlin_core *cd,
>> +					  const struct input_id *id)
>> +{
>> +	struct input_dev *input_dev = devm_input_allocate_device(cd->dev);
> 
> Please break this assignment into its own line.
> 
>> +
>> +	if (!input_dev)
>> +		return -ENOMEM;
>> +
>> +	cd->input_dev = input_dev;
>> +	input_set_drvdata(input_dev, cd);
>> +
>> +	input_dev->name = "Goodix Berlin Capacitive TouchScreen";
>> +	input_dev->phys = "input/ts";
>> +	input_dev->dev.parent = cd->dev;
>> +
>> +	memcpy(&input_dev->id, id, sizeof(*id));
>> +
>> +	/* set input parameters */
>> +	input_set_abs_params(cd->input_dev, ABS_MT_POSITION_X, 0, SZ_64K - 1, 0, 0);
>> +	input_set_abs_params(cd->input_dev, ABS_MT_POSITION_Y, 0, SZ_64K - 1, 0, 0);
>> +	input_set_abs_params(cd->input_dev, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0);
>> +
>> +	/* Override with DT */
> 
> This comment is unnecessary; furthermore touchscreen_parse_properties() is not
> limited to OF.
> 
>> +	touchscreen_parse_properties(cd->input_dev, true, &cd->props);
>> +
>> +	input_mt_init_slots(cd->input_dev, GOODIX_MAX_TOUCH, INPUT_MT_DIRECT);
> 
> Please check this function's return value and bail if negative.
> 
>> +
>> +	return input_register_device(cd->input_dev);
>> +}
>> +
>> +static void goodix_berlin_release_connects(struct goodix_berlin_core *cd)
>> +{
>> +	struct input_dev *input_dev = cd->input_dev;
>> +	int i;
>> +
>> +	mutex_lock(&input_dev->mutex);
>> +
>> +	for (i = 0; i < GOODIX_MAX_TOUCH; i++) {
>> +		input_mt_slot(input_dev, i);
>> +		input_mt_report_slot_state(input_dev, MT_TOOL_FINGER, false);
>> +	}
>> +	input_mt_sync_frame(input_dev);
>> +	input_sync(input_dev);
>> +
>> +	mutex_unlock(&input_dev->mutex);
>> +}
>> +
>> +static int goodix_berlin_suspend(struct goodix_berlin_core *cd)
>> +{
>> +	/* disable irq */
>> +	goodix_berlin_irq_enable(cd, false);
>> +
>> +	/* enter sleep mode or power off */
>> +	goodix_berlin_do_suspend(cd);
>> +
>> +	goodix_berlin_release_connects(cd);
> 
> For my own understanding, why is this operation necessary? Do you expect
> a platform to suspend if the user's fingers remain on the panel? I also
> find it confusing that multiple entry points can call input_mt_sync_frame()
> or input_sync(); typically these are limited to a common handler.

I don't know either, I can drop it if it's looks fishy.

> 
>> +
>> +	return 0;
>> +}
>> +
>> +static int goodix_berlin_resume(struct goodix_berlin_core *cd)
>> +{
>> +	goodix_berlin_irq_enable(cd, false);
>> +
>> +	/* reset device or power on*/
>> +	goodix_berlin_do_resume(cd);
>> +
>> +	/* enable irq */
>> +	goodix_berlin_irq_enable(cd, true);
>> +
>> +	return 0;
>> +}
>> +
>> +int goodix_berlin_pm_suspend(struct device *dev)
>> +{
>> +	struct goodix_berlin_core *cd = dev_get_drvdata(dev);
>> +
>> +	return goodix_berlin_suspend(cd);
>> +}
>> +
>> +int goodix_berlin_pm_resume(struct device *dev)
>> +{
>> +	struct goodix_berlin_core *cd = dev_get_drvdata(dev);
>> +
>> +	return goodix_berlin_resume(cd);
>> +}
>> +
>> +EXPORT_GPL_SIMPLE_DEV_PM_OPS(goodix_berlin_pm_ops,
>> +			     goodix_berlin_pm_suspend,
>> +			     goodix_berlin_pm_resume);
>> +
>> +int goodix_berlin_probe(struct device *dev, int irq, const struct input_id *id,
>> +			struct regmap *regmap)
>> +{
>> +	struct goodix_berlin_core *cd;
>> +	int ret;
>> +
>> +	if (irq <= 0)
>> +		return -EINVAL;
>> +
>> +	cd = devm_kzalloc(dev, sizeof(*cd), GFP_KERNEL);
>> +	if (!cd)
>> +		return -ENOMEM;
>> +
>> +	cd->dev = dev;
>> +	cd->regmap = regmap;
>> +	cd->irq = irq;
>> +
>> +	cd->reset_gpio = devm_gpiod_get(cd->dev, "reset", GPIOF_OUT_INIT_HIGH);
>> +	if (IS_ERR(cd->reset_gpio))
>> +		return dev_err_probe(cd->dev, PTR_ERR(cd->reset_gpio),
>> +				     "Failed to request reset gpio\n");
> 
> In my experience, the reset GPIO is the first to go in case the board designer
> runs out of GPIO. Can it be optional?

Sure, I need to make it optional in the bindings

> 
>> +
>> +	cd->avdd = devm_regulator_get(cd->dev, "avdd");
>> +	if (IS_ERR(cd->avdd))
>> +		return dev_err_probe(cd->dev, PTR_ERR(cd->avdd),
>> +				     "Failed to request avdd regulator\n");
>> +
>> +	cd->iovdd = devm_regulator_get(cd->dev, "iovdd");
>> +	if (IS_ERR(cd->iovdd))
>> +		return dev_err_probe(cd->dev, PTR_ERR(cd->iovdd),
>> +				     "Failed to request iovdd regulator\n");
>> +
>> +	ret = goodix_berlin_input_dev_config(cd, id);
>> +	if (ret < 0) {
>> +		dev_err(cd->dev, "failed set input device");
>> +		return ret;
>> +	}
>> +
>> +	ret = devm_request_threaded_irq(dev, irq, NULL,
>> +					goodix_berlin_threadirq_func,
>> +					IRQF_ONESHOT, "goodix-berlin", cd);
>> +	if (ret) {
>> +		dev_err(dev, "request threaded irq failed: %d\n", ret);
>> +		return ret;
>> +	}
>> +
>> +	dev_set_drvdata(dev, cd);
>> +
>> +	ret = goodix_berlin_power_on(cd, true);
> 
> This seems like something that can be posted as an device-managed action
> as opposed to having subsequent goto statements from here on.
> 
>> +	if (ret) {
>> +		dev_err(cd->dev, "failed power on");
>> +		goto err_out;
>> +	}
>> +
>> +	ret = goodix_berlin_read_version(cd, &cd->fw_version);
>> +	if (ret < 0) {
>> +		dev_err(cd->dev, "failed to get version info");
>> +		goto err_out;
>> +	}
>> +
>> +	ret = goodix_berlin_get_ic_info(cd, &cd->ic_info);
>> +	if (ret) {
>> +		dev_err(cd->dev, "invalid ic info, abort");
>> +		goto err_out;
>> +	}
>> +
>> +	cd->debugfs_root = debugfs_create_dir(dev_name(dev), NULL);
>> +	debugfs_create_file("fw_version", 0444, cd->debugfs_root,
>> +			    cd, &goodix_berlin_fw_version_fops);
>> +	debugfs_create_file("ic_info", 0444, cd->debugfs_root,
>> +			    cd, &goodix_berlin_ic_info_fops);
> 
> We need not explicitly create attributes; consider the dev_groups member
> of the device_driver struct instead.
> 
>> +
>> +	dev_info(cd->dev, "Goodix Berlin %s Touchscreen Controller", cd->fw_version.patch_pid);
> 
> dev_dbg()
> 
>> +
>> +	return 0;
>> +
>> +err_out:
>> +	goodix_berlin_power_on(cd, false);
>> +
>> +	return ret;
>> +}
>> +EXPORT_SYMBOL_GPL(goodix_berlin_probe);
>> +
>> +int goodix_berlin_remove(struct device *dev)
>> +{
>> +	struct goodix_berlin_core *cd = dev_get_drvdata(dev);
>> +
>> +	goodix_berlin_release_connects(cd);
>> +
>> +	goodix_berlin_irq_enable(cd, false);
>> +
>> +	goodix_berlin_power_on(cd, false);
>> +
>> +	debugfs_remove(cd->debugfs_root);
>> +
>> +	return 0;
> 
> I suspect much of this is unnecessary if you adopt modern primitives. Once
> you wrap regulator disables with device-managed actions, you should be able
> to get rid of the remove callback altogether.

Ack I'll try to reduce in order to remove this callback.

> 
>> +}
>> +EXPORT_SYMBOL_GPL(goodix_berlin_remove);
>> +
>> +MODULE_LICENSE("GPL");
>> +MODULE_DESCRIPTION("Goodix Berlin Core Touchscreen driver");
>> +MODULE_AUTHOR("Neil Armstrong <[e-mail]>");
>>
>> -- 
>> 2.34.1
>>
> 
> Kind regards,
> Jeff LaBundy

Jeff LaBundy June 12, 2023, 4:59 p.m. UTC | #3

Hi Neil,

[...]

> > > + * - PEN Events
> > 
> > What is "PEN"; is it "stylus" as written elsewhere?
> 
> Yes, they use both terms in the vendor driver.

I recommend using a common term throughout; as written, I first thought
"PEN" was an acronym.

[...]

> > > +	misc->fw_attr_len = le16_to_cpu(misc->fw_attr_len);
> > > +	misc->fw_log_len = le16_to_cpu(misc->fw_log_len);
> > > +	misc->stylus_struct_len = le16_to_cpu(misc->stylus_struct_len);
> > > +	misc->mutual_struct_len = le16_to_cpu(misc->mutual_struct_len);
> > > +	misc->self_struct_len = le16_to_cpu(misc->self_struct_len);
> > > +	misc->noise_struct_len = le16_to_cpu(misc->noise_struct_len);
> > > +	misc->touch_data_addr = le32_to_cpu(misc->touch_data_addr);
> > > +	misc->touch_data_head_len = le16_to_cpu(misc->touch_data_head_len);
> > > +	misc->point_struct_len = le16_to_cpu(misc->point_struct_len);
> > > +	misc->mutual_rawdata_addr = le32_to_cpu(misc->mutual_rawdata_addr);
> > > +	misc->mutual_diffdata_addr = le32_to_cpu(misc->mutual_diffdata_addr);
> > > +	misc->mutual_refdata_addr = le32_to_cpu(misc->mutual_refdata_addr);
> > > +	misc->self_rawdata_addr = le32_to_cpu(misc->self_rawdata_addr);
> > > +	misc->self_diffdata_addr = le32_to_cpu(misc->self_diffdata_addr);
> > > +	misc->self_refdata_addr = le32_to_cpu(misc->self_refdata_addr);
> > > +	misc->iq_rawdata_addr = le32_to_cpu(misc->iq_rawdata_addr);
> > > +	misc->iq_refdata_addr = le32_to_cpu(misc->iq_refdata_addr);
> > > +	misc->im_rawdata_addr = le32_to_cpu(misc->im_rawdata_addr);
> > > +	misc->im_readata_len = le16_to_cpu(misc->im_readata_len);
> > > +	misc->noise_rawdata_addr = le32_to_cpu(misc->noise_rawdata_addr);
> > > +	misc->noise_rawdata_len = le16_to_cpu(misc->noise_rawdata_len);
> > > +	misc->stylus_rawdata_addr = le32_to_cpu(misc->stylus_rawdata_addr);
> > > +	misc->stylus_rawdata_len = le16_to_cpu(misc->stylus_rawdata_len);
> > > +	misc->noise_data_addr = le32_to_cpu(misc->noise_data_addr);
> > > +	misc->esd_addr = le32_to_cpu(misc->esd_addr);
> > 
> > What is all of this stuff for? The beginning of the driver explicitly states
> > that ESD recovery is not supported; please consider stripping all of this if
> > its only purpose is to support noise in the logs or sysfs attributes that we
> > cannot reasonably react to.
> 
> Those are all the firmware parameters used by the driver, for now only a little
> are used, we already read the entire struct so stripping isn't an option otherwise
> the values will be shifted.
> 
> We only print those over debugfs se it won't fill any logs

I feel this is a lot of bloat to simply enable pretty printing of register
values. Some of these struct members aren't even used anywhere; others seem
to be related to functions this driver does not support. Do you realistically
expect one to read those values?

For registers that customers would in fact need to read for debugging, can
you not simply rely on regmap's natural debugfs facility? It seems you are
largely duplicating that here.

I understand that some parameters are used elsewhere and it may be efficient
to read the entire memory region as a packed struct, but there is no need to
unalign and store what is effectively padding in many cases.

[...]

Kind regards,
Jeff LaBundy

Patch

diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index c2cbd332af1d..1a6f6f6da991 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -416,6 +416,11 @@  config TOUCHSCREEN_GOODIX
 	  To compile this driver as a module, choose M here: the
 	  module will be called goodix.
 
+config TOUCHSCREEN_GOODIX_BERLIN_CORE
+	depends on GPIOLIB || COMPILE_TEST
+	depends on REGMAP
+	tristate
+
 config TOUCHSCREEN_HIDEEP
 	tristate "HiDeep Touch IC"
 	depends on I2C
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 159cd5136fdb..29cdb042e104 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -47,6 +47,7 @@  obj-$(CONFIG_TOUCHSCREEN_EGALAX_SERIAL)	+= egalax_ts_serial.o
 obj-$(CONFIG_TOUCHSCREEN_EXC3000)	+= exc3000.o
 obj-$(CONFIG_TOUCHSCREEN_FUJITSU)	+= fujitsu_ts.o
 obj-$(CONFIG_TOUCHSCREEN_GOODIX)	+= goodix_ts.o
+obj-$(CONFIG_TOUCHSCREEN_GOODIX_BERLIN_CORE)	+= goodix_berlin_core.o
 obj-$(CONFIG_TOUCHSCREEN_HIDEEP)	+= hideep.o
 obj-$(CONFIG_TOUCHSCREEN_HYNITRON_CSTXXX)	+= hynitron_cstxxx.o
 obj-$(CONFIG_TOUCHSCREEN_ILI210X)	+= ili210x.o
diff --git a/drivers/input/touchscreen/goodix_berlin.h b/drivers/input/touchscreen/goodix_berlin.h
new file mode 100644
index 000000000000..83f16201c354
--- /dev/null
+++ b/drivers/input/touchscreen/goodix_berlin.h
@@ -0,0 +1,228 @@ 
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Goodix Touchscreen Driver
+ * Copyright (C) 2020 - 2021 Goodix, Inc.
+ * Copyright (C) 2023 Linaro Ltd.
+ *
+ * Based on goodix_berlin_berlin driver.
+ */
+
+#ifndef __GOODIX_BERLIN_H_
+#define __GOODIX_BERLIN_H_
+
+#include <linux/input.h>
+#include <linux/of_gpio.h>
+#include <linux/input/touchscreen.h>
+#include <linux/regulator/consumer.h>
+
+#define GOODIX_MAX_TOUCH 10
+#define GOODIX_MAX_FRAMEDATA_LEN 1700
+
+#define GOODIX_NORMAL_RESET_DELAY_MS 100
+#define GOODIX_HOLD_CPU_RESET_DELAY_MS 5
+
+enum CHECKSUM_MODE {
+	CHECKSUM_MODE_U8_LE,
+	CHECKSUM_MODE_U16_LE,
+};
+
+#define MAX_SCAN_FREQ_NUM	8
+#define MAX_SCAN_RATE_NUM	8
+#define MAX_FREQ_NUM_STYLUS	8
+
+#define IRQ_EVENT_HEAD_LEN	8
+#define BYTES_PER_POINT		8
+#define COOR_DATA_CHECKSUM_SIZE 2
+
+#define GOODIX_TOUCH_EVENT	BIT(7)
+#define GOODIX_REQUEST_EVENT	BIT(6)
+#define GOODIX_GESTURE_EVENT	BIT(5)
+
+#define POINT_TYPE_STYLUS_HOVER	0x01
+#define POINT_TYPE_STYLUS	0x03
+
+#define DEV_CONFIRM_VAL		0xAA
+#define BOOTOPTION_ADDR		0x10000
+#define FW_VERSION_INFO_ADDR	0x10014
+
+#define GOODIX_IC_INFO_MAX_LEN	1024
+#define GOODIX_IC_INFO_ADDR	0x10070
+
+enum brl_request_code {
+	BRL_REQUEST_CODE_CONFIG = 1,
+	BRL_REQUEST_CODE_REF_ERR = 2,
+	BRL_REQUEST_CODE_RESET = 3,
+	BRL_REQUEST_CODE_CLOCK = 4,
+};
+
+struct goodix_fw_version {
+	u8 rom_pid[6]; /* rom PID */
+	u8 rom_vid[3]; /* Mask VID */
+	u8 rom_vid_reserved;
+	u8 patch_pid[8]; /* Patch PID */
+	u8 patch_vid[4]; /* Patch VID */
+	u8 patch_vid_reserved;
+	u8 sensor_id;
+	u8 reserved[2];
+	u16 checksum;
+} __packed;
+
+struct goodix_ic_info_version {
+	u8 info_customer_id;
+	u8 info_version_id;
+	u8 ic_die_id;
+	u8 ic_version_id;
+	u32 config_id;
+	u8 config_version;
+	u8 frame_data_customer_id;
+	u8 frame_data_version_id;
+	u8 touch_data_customer_id;
+	u8 touch_data_version_id;
+	u8 reserved[3];
+} __packed;
+
+struct goodix_ic_info_feature { /* feature info*/
+	u16 freqhop_feature;
+	u16 calibration_feature;
+	u16 gesture_feature;
+	u16 side_touch_feature;
+	u16 stylus_feature;
+} __packed;
+
+struct goodix_ic_info_param { /* param */
+	u8 drv_num;
+	u8 sen_num;
+	u8 button_num;
+	u8 force_num;
+	u8 active_scan_rate_num;
+	u16 active_scan_rate[MAX_SCAN_RATE_NUM];
+	u8 mutual_freq_num;
+	u16 mutual_freq[MAX_SCAN_FREQ_NUM];
+	u8 self_tx_freq_num;
+	u16 self_tx_freq[MAX_SCAN_FREQ_NUM];
+	u8 self_rx_freq_num;
+	u16 self_rx_freq[MAX_SCAN_FREQ_NUM];
+	u8 stylus_freq_num;
+	u16 stylus_freq[MAX_FREQ_NUM_STYLUS];
+} __packed;
+
+struct goodix_ic_info_misc { /* other data */
+	u32 cmd_addr;
+	u16 cmd_max_len;
+	u32 cmd_reply_addr;
+	u16 cmd_reply_len;
+	u32 fw_state_addr;
+	u16 fw_state_len;
+	u32 fw_buffer_addr;
+	u16 fw_buffer_max_len;
+	u32 frame_data_addr;
+	u16 frame_data_head_len;
+	u16 fw_attr_len;
+	u16 fw_log_len;
+	u8 pack_max_num;
+	u8 pack_compress_version;
+	u16 stylus_struct_len;
+	u16 mutual_struct_len;
+	u16 self_struct_len;
+	u16 noise_struct_len;
+	u32 touch_data_addr;
+	u16 touch_data_head_len;
+	u16 point_struct_len;
+	u16 reserved1;
+	u16 reserved2;
+	u32 mutual_rawdata_addr;
+	u32 mutual_diffdata_addr;
+	u32 mutual_refdata_addr;
+	u32 self_rawdata_addr;
+	u32 self_diffdata_addr;
+	u32 self_refdata_addr;
+	u32 iq_rawdata_addr;
+	u32 iq_refdata_addr;
+	u32 im_rawdata_addr;
+	u16 im_readata_len;
+	u32 noise_rawdata_addr;
+	u16 noise_rawdata_len;
+	u32 stylus_rawdata_addr;
+	u16 stylus_rawdata_len;
+	u32 noise_data_addr;
+	u32 esd_addr;
+} __packed;
+
+struct goodix_ic_info {
+	u16 length;
+	struct goodix_ic_info_version version;
+	struct goodix_ic_info_feature feature;
+	struct goodix_ic_info_param parm;
+	struct goodix_ic_info_misc misc;
+} __packed;
+
+/* interrupt event type */
+enum ts_event_type {
+	EVENT_INVALID,
+	EVENT_TOUCH, /* finger touch event */
+	EVENT_REQUEST,
+};
+
+enum ts_request_type {
+	REQUEST_TYPE_RESET,
+};
+
+enum touch_point_status {
+	TS_NONE,
+	TS_RELEASE,
+	TS_TOUCH,
+};
+
+/* coordinate package */
+struct goodix_berlin_coords {
+	int status; /* NONE, RELEASE, TOUCH */
+	unsigned int x, y, w, p;
+};
+
+/* touch event data */
+struct goodix_touch_data {
+	int touch_num;
+	struct goodix_berlin_coords coords[GOODIX_MAX_TOUCH];
+};
+
+/* touch event struct */
+struct goodix_berlin_event {
+	enum ts_event_type event_type;
+	u8 request_code; /* represent the request type */
+	struct goodix_touch_data touch_data;
+};
+
+struct goodix_berlin_core {
+	struct device *dev;
+	struct regmap *regmap;
+
+	struct regulator *avdd;
+	struct regulator *iovdd;
+	struct gpio_desc *reset_gpio;
+
+	struct touchscreen_properties props;
+
+	struct goodix_fw_version fw_version;
+	struct goodix_ic_info ic_info;
+
+	struct input_dev *input_dev;
+	struct goodix_berlin_event ts_event;
+
+	int irq;
+
+	struct dentry *debugfs_root;
+};
+
+u32 goodix_append_checksum(u8 *data, int len, int mode);
+int checksum_cmp(const u8 *data, int size, int mode);
+int is_risk_data(const u8 *data, int size);
+u32 goodix_get_file_config_id(u8 *ic_config);
+void goodix_rotate_abcd2cbad(int tx, int rx, s16 *data);
+
+int goodix_berlin_probe(struct device *dev, int irq, const struct input_id *id,
+			struct regmap *regmap);
+int goodix_berlin_remove(struct device *dev);
+
+extern const struct dev_pm_ops goodix_berlin_pm_ops;
+
+#endif
diff --git a/drivers/input/touchscreen/goodix_berlin_core.c b/drivers/input/touchscreen/goodix_berlin_core.c
new file mode 100644
index 000000000000..0719690a5bd3
--- /dev/null
+++ b/drivers/input/touchscreen/goodix_berlin_core.c
@@ -0,0 +1,935 @@ 
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Goodix Touchscreen Driver
+ * Copyright (C) 2020 - 2021 Goodix, Inc.
+ * Copyright (C) 2023 Linaro Ltd.
+ *
+ * Based on goodix_ts_berlin driver.
+ */
+#include <linux/regmap.h>
+#include <linux/input/mt.h>
+#include <linux/input/touchscreen.h>
+#include <linux/debugfs.h>
+
+#include "goodix_berlin.h"
+
+/*
+ * Goodix "Berlin" Touchscreen ID driver
+ *
+ * Currently only handles Multitouch events with already
+ * programmed firmware and "config" for "Revision D" Berlin IC.
+ *
+ * Support is missing for:
+ * - ESD Management
+ * - Firmware update/flashing
+ * - "Config" update/flashing
+ * - PEN Events
+ * - Gesture Events
+ * - Support for older revisions (A, B & C)
+ */
+
+static bool goodix_berlin_check_checksum(const u8 *data, int size)
+{
+	u32 cal_checksum = 0;
+	u32 r_checksum = 0;
+	u32 i;
+
+	if (size < COOR_DATA_CHECKSUM_SIZE)
+		return false;
+
+	for (i = 0; i < size - COOR_DATA_CHECKSUM_SIZE; i++)
+		cal_checksum += data[i];
+
+	r_checksum += data[i++];
+	r_checksum += (data[i] << 8);
+
+	return (cal_checksum & 0xFFFF) == r_checksum;
+}
+
+static bool goodix_berlin_is_risk_data(struct goodix_berlin_core *cd,
+				       const u8 *data, int size)
+{
+	int zero_count = 0;
+	int ff_count = 0;
+	int i;
+
+	for (i = 0; i < size; i++) {
+		if (data[i] == 0)
+			zero_count++;
+		else if (data[i] == 0xff)
+			ff_count++;
+	}
+	if (zero_count == size || ff_count == size) {
+		dev_warn(cd->dev, "warning data is all %s\n",
+			 zero_count == size ? "zero" : "0xff");
+		return true;
+	}
+
+	return false;
+}
+
+static int goodix_berlin_dev_confirm(struct goodix_berlin_core *cd)
+{
+	u8 tx_buf[8] = { 0 };
+	u8 rx_buf[8] = { 0 };
+	int retry = 3;
+	int ret = 0;
+
+	memset(tx_buf, DEV_CONFIRM_VAL, sizeof(tx_buf));
+	while (retry--) {
+		ret = regmap_raw_write(cd->regmap, BOOTOPTION_ADDR, tx_buf,
+				       sizeof(tx_buf));
+		if (ret < 0)
+			return ret;
+		ret = regmap_raw_read(cd->regmap, BOOTOPTION_ADDR, rx_buf,
+				      sizeof(rx_buf));
+		if (ret < 0)
+			return ret;
+		if (!memcmp(tx_buf, rx_buf, sizeof(tx_buf)))
+			break;
+		usleep_range(5000, 5100);
+	}
+
+	if (retry < 0) {
+		ret = -EINVAL;
+		dev_err(cd->dev, "device confirm failed, rx_buf: %*ph\n", 8, rx_buf);
+	}
+
+	return ret;
+}
+
+static int goodix_berlin_power_on(struct goodix_berlin_core *cd, bool on)
+{
+	int ret = 0;
+
+	if (on) {
+		ret = regulator_enable(cd->iovdd);
+		if (ret < 0) {
+			dev_err(cd->dev, "Failed to enable iovdd: %d\n", ret);
+			goto power_off;
+		}
+
+		usleep_range(3000, 3100);
+
+		ret = regulator_enable(cd->avdd);
+		if (ret < 0) {
+			dev_err(cd->dev, "Failed to enable avdd: %d\n", ret);
+			goto power_off;
+		}
+
+		usleep_range(15000, 15100);
+
+		gpiod_set_value(cd->reset_gpio, 0);
+
+		usleep_range(4000, 4100);
+
+		ret = goodix_berlin_dev_confirm(cd);
+		if (ret < 0)
+			goto power_off;
+
+		msleep(GOODIX_NORMAL_RESET_DELAY_MS);
+
+		return 0;
+	}
+
+power_off:
+	gpiod_set_value(cd->reset_gpio, 1);
+	regulator_disable(cd->iovdd);
+	regulator_disable(cd->avdd);
+	return ret;
+}
+
+static int goodix_berlin_do_suspend(struct goodix_berlin_core *cd)
+{
+	if (goodix_berlin_power_on(cd, 0))
+		dev_err(cd->dev, "failed power off\n");
+
+	return 0;
+}
+
+static int goodix_berlin_do_resume(struct goodix_berlin_core *cd)
+{
+	int ret = 0;
+
+	ret = goodix_berlin_power_on(cd, 1);
+	if (ret) {
+		dev_err(cd->dev, "failed power on\n");
+		return ret;
+	}
+
+	return ret;
+}
+
+static int goodix_berlin_reset(struct goodix_berlin_core *cd, int delay)
+{
+	gpiod_set_value(cd->reset_gpio, 1);
+	usleep_range(2000, 2100);
+	gpiod_set_value(cd->reset_gpio, 0);
+
+	if (delay < 20)
+		usleep_range(delay * 1000, delay * 1000 + 100);
+	else
+		msleep(delay);
+
+	return 0;
+}
+
+static int goodix_berlin_irq_enable(struct goodix_berlin_core *cd, bool enable)
+{
+	if (enable)
+		enable_irq(cd->irq);
+	else
+		disable_irq(cd->irq);
+
+	return 0;
+}
+
+static int goodix_berlin_read_version(struct goodix_berlin_core *cd,
+				      struct goodix_fw_version *version)
+{
+	u8 buf[sizeof(struct goodix_fw_version)] = { 0 };
+	int ret, i;
+
+	for (i = 0; i < 2; i++) {
+		ret = regmap_raw_read(cd->regmap, FW_VERSION_INFO_ADDR, buf, sizeof(buf));
+		if (ret) {
+			dev_dbg(cd->dev, "read fw version: %d, retry %d\n", ret, i);
+			usleep_range(5000, 5100);
+			continue;
+		}
+
+		if (goodix_berlin_check_checksum(buf, sizeof(buf)))
+			break;
+
+		dev_dbg(cd->dev, "invalid fw version: checksum error\n");
+
+		ret = -EINVAL;
+		usleep_range(10000, 11000);
+	}
+
+	if (ret) {
+		dev_err(cd->dev, "failed to get fw version");
+		return ret;
+	}
+
+	memcpy(version, buf, sizeof(*version));
+
+	return 0;
+}
+
+static int goodix_berlin_fw_version_show(struct seq_file *s, void *unused)
+{
+	struct goodix_berlin_core *cd = s->private;
+	struct goodix_fw_version *version = &cd->fw_version;
+	u8 temp_pid[9] = { 0 };
+
+	memcpy(temp_pid, version->rom_pid, sizeof(version->rom_pid));
+	temp_pid[sizeof(version->rom_pid)] = '\0';
+
+	seq_printf(s, "rom_pid: %s\n", temp_pid);
+	seq_printf(s, "rom_vid: %*ph\n",
+		   (int)sizeof(version->rom_vid),
+		   version->rom_vid);
+
+	memcpy(temp_pid, version->patch_pid, sizeof(version->patch_pid));
+	temp_pid[sizeof(version->patch_pid)] = '\0';
+
+	seq_printf(s, "patch_pid: %s\n", temp_pid);
+	seq_printf(s, "patch_vid: %*ph\n",
+		   (int)sizeof(version->patch_vid),
+		   version->patch_vid);
+	seq_printf(s, "sensor_id: %d\n",
+		   version->sensor_id);
+
+	return 0;
+}
+
+DEFINE_SHOW_ATTRIBUTE(goodix_berlin_fw_version);
+
+static int goodix_berlin_convert_ic_info(struct goodix_berlin_core *cd,
+					 struct goodix_ic_info *info,
+					 const u8 *data)
+{
+	int i;
+	struct goodix_ic_info_version *version = &info->version;
+	struct goodix_ic_info_feature *feature = &info->feature;
+	struct goodix_ic_info_param *parm = &info->parm;
+	struct goodix_ic_info_misc *misc = &info->misc;
+
+	info->length = le16_to_cpup((__le16 *)data);
+
+	data += 2;
+	memcpy(version, data, sizeof(*version));
+	version->config_id = le32_to_cpu(version->config_id);
+
+	data += sizeof(struct goodix_ic_info_version);
+	memcpy(feature, data, sizeof(*feature));
+	feature->freqhop_feature = le16_to_cpu(feature->freqhop_feature);
+	feature->calibration_feature =
+		le16_to_cpu(feature->calibration_feature);
+	feature->gesture_feature = le16_to_cpu(feature->gesture_feature);
+	feature->side_touch_feature = le16_to_cpu(feature->side_touch_feature);
+	feature->stylus_feature = le16_to_cpu(feature->stylus_feature);
+
+	data += sizeof(struct goodix_ic_info_feature);
+	parm->drv_num = *(data++);
+	parm->sen_num = *(data++);
+	parm->button_num = *(data++);
+	parm->force_num = *(data++);
+	parm->active_scan_rate_num = *(data++);
+
+	if (parm->active_scan_rate_num > MAX_SCAN_RATE_NUM) {
+		dev_err(cd->dev, "invalid scan rate num %d > %d\n",
+			parm->active_scan_rate_num, MAX_SCAN_RATE_NUM);
+		return -EINVAL;
+	}
+
+	for (i = 0; i < parm->active_scan_rate_num; i++)
+		parm->active_scan_rate[i] =
+			le16_to_cpup((__le16 *)(data + i * 2));
+
+	data += parm->active_scan_rate_num * 2;
+	parm->mutual_freq_num = *(data++);
+
+	if (parm->mutual_freq_num > MAX_SCAN_FREQ_NUM) {
+		dev_err(cd->dev, "invalid mntual freq num %d > %d\n",
+			parm->mutual_freq_num, MAX_SCAN_FREQ_NUM);
+		return -EINVAL;
+	}
+
+	for (i = 0; i < parm->mutual_freq_num; i++)
+		parm->mutual_freq[i] = le16_to_cpup((__le16 *)(data + i * 2));
+
+	data += parm->mutual_freq_num * 2;
+	parm->self_tx_freq_num = *(data++);
+
+	if (parm->self_tx_freq_num > MAX_SCAN_FREQ_NUM) {
+		dev_err(cd->dev, "invalid tx freq num %d > %d\n",
+			parm->self_tx_freq_num, MAX_SCAN_FREQ_NUM);
+		return -EINVAL;
+	}
+
+	for (i = 0; i < parm->self_tx_freq_num; i++)
+		parm->self_tx_freq[i] = le16_to_cpup((__le16 *)(data + i * 2));
+
+	data += parm->self_tx_freq_num * 2;
+	parm->self_rx_freq_num = *(data++);
+
+	if (parm->self_rx_freq_num > MAX_SCAN_FREQ_NUM) {
+		dev_err(cd->dev, "invalid rx freq num %d > %d\n",
+			parm->self_rx_freq_num, MAX_SCAN_FREQ_NUM);
+		return -EINVAL;
+	}
+
+	for (i = 0; i < parm->self_rx_freq_num; i++)
+		parm->self_rx_freq[i] = le16_to_cpup((__le16 *)(data + i * 2));
+
+	data += parm->self_rx_freq_num * 2;
+	parm->stylus_freq_num = *(data++);
+
+	if (parm->stylus_freq_num > MAX_FREQ_NUM_STYLUS) {
+		dev_err(cd->dev, "invalid stylus freq num %d > %d\n",
+			parm->stylus_freq_num, MAX_FREQ_NUM_STYLUS);
+		return -EINVAL;
+	}
+
+	for (i = 0; i < parm->stylus_freq_num; i++)
+		parm->stylus_freq[i] = le16_to_cpup((__le16 *)(data + i * 2));
+
+	data += parm->stylus_freq_num * 2;
+	memcpy(misc, data, sizeof(*misc));
+	misc->cmd_addr = le32_to_cpu(misc->cmd_addr);
+	misc->cmd_max_len = le16_to_cpu(misc->cmd_max_len);
+	misc->cmd_reply_addr = le32_to_cpu(misc->cmd_reply_addr);
+	misc->cmd_reply_len = le16_to_cpu(misc->cmd_reply_len);
+	misc->fw_state_addr = le32_to_cpu(misc->fw_state_addr);
+	misc->fw_state_len = le16_to_cpu(misc->fw_state_len);
+	misc->fw_buffer_addr = le32_to_cpu(misc->fw_buffer_addr);
+	misc->fw_buffer_max_len = le16_to_cpu(misc->fw_buffer_max_len);
+	misc->frame_data_addr = le32_to_cpu(misc->frame_data_addr);
+	misc->frame_data_head_len = le16_to_cpu(misc->frame_data_head_len);
+
+	misc->fw_attr_len = le16_to_cpu(misc->fw_attr_len);
+	misc->fw_log_len = le16_to_cpu(misc->fw_log_len);
+	misc->stylus_struct_len = le16_to_cpu(misc->stylus_struct_len);
+	misc->mutual_struct_len = le16_to_cpu(misc->mutual_struct_len);
+	misc->self_struct_len = le16_to_cpu(misc->self_struct_len);
+	misc->noise_struct_len = le16_to_cpu(misc->noise_struct_len);
+	misc->touch_data_addr = le32_to_cpu(misc->touch_data_addr);
+	misc->touch_data_head_len = le16_to_cpu(misc->touch_data_head_len);
+	misc->point_struct_len = le16_to_cpu(misc->point_struct_len);
+	misc->mutual_rawdata_addr = le32_to_cpu(misc->mutual_rawdata_addr);
+	misc->mutual_diffdata_addr = le32_to_cpu(misc->mutual_diffdata_addr);
+	misc->mutual_refdata_addr = le32_to_cpu(misc->mutual_refdata_addr);
+	misc->self_rawdata_addr = le32_to_cpu(misc->self_rawdata_addr);
+	misc->self_diffdata_addr = le32_to_cpu(misc->self_diffdata_addr);
+	misc->self_refdata_addr = le32_to_cpu(misc->self_refdata_addr);
+	misc->iq_rawdata_addr = le32_to_cpu(misc->iq_rawdata_addr);
+	misc->iq_refdata_addr = le32_to_cpu(misc->iq_refdata_addr);
+	misc->im_rawdata_addr = le32_to_cpu(misc->im_rawdata_addr);
+	misc->im_readata_len = le16_to_cpu(misc->im_readata_len);
+	misc->noise_rawdata_addr = le32_to_cpu(misc->noise_rawdata_addr);
+	misc->noise_rawdata_len = le16_to_cpu(misc->noise_rawdata_len);
+	misc->stylus_rawdata_addr = le32_to_cpu(misc->stylus_rawdata_addr);
+	misc->stylus_rawdata_len = le16_to_cpu(misc->stylus_rawdata_len);
+	misc->noise_data_addr = le32_to_cpu(misc->noise_data_addr);
+	misc->esd_addr = le32_to_cpu(misc->esd_addr);
+
+	return 0;
+}
+
+/* Convert to debugfs */
+static int goodix_berlin_ic_info_show(struct seq_file *s, void *unused)
+{
+	struct goodix_berlin_core *cd = s->private;
+	struct goodix_ic_info_version *version = &cd->ic_info.version;
+	struct goodix_ic_info_feature *feature = &cd->ic_info.feature;
+	struct goodix_ic_info_param *parm = &cd->ic_info.parm;
+	struct goodix_ic_info_misc *misc = &cd->ic_info.misc;
+
+	seq_printf(s, "ic_info_length:                %d\n", cd->ic_info.length);
+	seq_printf(s, "info_customer_id:              0x%01X\n",
+		   version->info_customer_id);
+	seq_printf(s, "info_version_id:               0x%01X\n",
+		   version->info_version_id);
+	seq_printf(s, "ic_die_id:                     0x%01X\n",
+		   version->ic_die_id);
+	seq_printf(s, "ic_version_id:                 0x%01X\n",
+		   version->ic_version_id);
+	seq_printf(s, "config_id:                     0x%4X\n",
+		   version->config_id);
+	seq_printf(s, "config_version:                0x%01X\n",
+		   version->config_version);
+	seq_printf(s, "frame_data_customer_id:        0x%01X\n",
+		   version->frame_data_customer_id);
+	seq_printf(s, "frame_data_version_id:         0x%01X\n",
+		   version->frame_data_version_id);
+	seq_printf(s, "touch_data_customer_id:        0x%01X\n",
+		   version->touch_data_customer_id);
+	seq_printf(s, "touch_data_version_id:         0x%01X\n",
+		   version->touch_data_version_id);
+	seq_printf(s, "freqhop_feature:               0x%04X\n",
+		   feature->freqhop_feature);
+	seq_printf(s, "calibration_feature:           0x%04X\n",
+		   feature->calibration_feature);
+	seq_printf(s, "gesture_feature:               0x%04X\n",
+		   feature->gesture_feature);
+	seq_printf(s, "side_touch_feature:            0x%04X\n",
+		   feature->side_touch_feature);
+	seq_printf(s, "stylus_feature:                0x%04X\n",
+		   feature->stylus_feature);
+	seq_printf(s, "Drv*Sen,Button,Force num:      %d x %d, %d, %d\n",
+		   parm->drv_num, parm->sen_num, parm->button_num, parm->force_num);
+	seq_printf(s, "Cmd:                           0x%04X, %d\n",
+		   misc->cmd_addr, misc->cmd_max_len);
+	seq_printf(s, "Cmd-Reply:                     0x%04X, %d\n",
+		   misc->cmd_reply_addr, misc->cmd_reply_len);
+	seq_printf(s, "FW-State:                      0x%04X, %d\n",
+		   misc->fw_state_addr, misc->fw_state_len);
+	seq_printf(s, "FW-Buffer:                     0x%04X, %d\n",
+		   misc->fw_buffer_addr, misc->fw_buffer_max_len);
+	seq_printf(s, "Touch-Data:                    0x%04X, %d\n",
+		   misc->touch_data_addr, misc->touch_data_head_len);
+	seq_printf(s, "point_struct_len:              %d\n",
+		   misc->point_struct_len);
+	seq_printf(s, "mutual_rawdata_addr:           0x%04X\n",
+		   misc->mutual_rawdata_addr);
+	seq_printf(s, "mutual_diffdata_addr:          0x%04X\n",
+		   misc->mutual_diffdata_addr);
+	seq_printf(s, "self_rawdata_addr:             0x%04X\n",
+		   misc->self_rawdata_addr);
+	seq_printf(s, "self_diffdata_addr:            0x%04X\n",
+		   misc->self_diffdata_addr);
+	seq_printf(s, "stylus_rawdata_addr:           0x%04X, %d\n",
+		   misc->stylus_rawdata_addr, misc->stylus_rawdata_len);
+	seq_printf(s, "esd_addr:                      0x%04X\n",
+		   misc->esd_addr);
+
+	return 0;
+}
+
+DEFINE_SHOW_ATTRIBUTE(goodix_berlin_ic_info);
+
+static int goodix_berlin_get_ic_info(struct goodix_berlin_core *cd,
+				     struct goodix_ic_info *ic_info)
+{
+	int ret, i;
+	u16 length = 0;
+	u32 ic_addr;
+	u8 afe_data[GOODIX_IC_INFO_MAX_LEN] = { 0 };
+
+	ic_addr = GOODIX_IC_INFO_ADDR;
+
+	for (i = 0; i < 3; i++) {
+		ret = regmap_raw_read(cd->regmap, ic_addr, (u8 *)&length, sizeof(length));
+		if (ret) {
+			dev_info(cd->dev, "failed get ic info length, %d\n", ret);
+			usleep_range(5000, 5100);
+			continue;
+		}
+
+		length = le16_to_cpu(length);
+		if (length >= GOODIX_IC_INFO_MAX_LEN) {
+			dev_info(cd->dev, "invalid ic info length %d, retry %d\n", length, i);
+			continue;
+		}
+
+		ret = regmap_raw_read(cd->regmap, ic_addr, afe_data, length);
+		if (ret) {
+			dev_info(cd->dev, "failed get ic info data, %d\n", ret);
+			usleep_range(5000, 5100);
+			continue;
+		}
+
+		/* judge whether the data is valid */
+		if (goodix_berlin_is_risk_data(cd, (const uint8_t *)afe_data,
+					       length)) {
+			dev_info(cd->dev, "fw info data invalid\n");
+			usleep_range(5000, 5100);
+			continue;
+		}
+
+		if (!goodix_berlin_check_checksum((const uint8_t *)afe_data, length)) {
+			dev_info(cd->dev, "fw info checksum error\n");
+			usleep_range(5000, 5100);
+			continue;
+		}
+
+		break;
+	}
+	if (i == 3) {
+		dev_err(cd->dev, "failed get ic info\n");
+		return -EINVAL;
+	}
+
+	ret = goodix_berlin_convert_ic_info(cd, ic_info, afe_data);
+	if (ret) {
+		dev_err(cd->dev, "error converting ic info\n");
+		return ret;
+	}
+
+	/* check some key info */
+	if (!ic_info->misc.cmd_addr || !ic_info->misc.fw_buffer_addr ||
+	    !ic_info->misc.touch_data_addr) {
+		dev_err(cd->dev, "cmd_addr fw_buf_addr and touch_data_addr is null\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int goodix_berlin_after_event_handler(struct goodix_berlin_core *cd)
+{
+	struct goodix_ic_info_misc *misc = &cd->ic_info.misc;
+	u8 sync_clean = 0;
+
+	return regmap_raw_write(cd->regmap, misc->touch_data_addr, &sync_clean, 1);
+}
+
+static void goodix_berlin_parse_finger(struct goodix_berlin_core *cd,
+				       struct goodix_touch_data *touch_data,
+				       u8 *buf, int touch_num)
+{
+	unsigned int id = 0, x = 0, y = 0, w = 0;
+	u8 *coor_data;
+	int i;
+
+	coor_data = &buf[IRQ_EVENT_HEAD_LEN];
+
+	for (i = 0; i < touch_num; i++) {
+		id = (coor_data[0] >> 4) & 0x0F;
+
+		if (id >= GOODIX_MAX_TOUCH) {
+			dev_warn(cd->dev, "invalid finger id %d\n", id);
+
+			touch_data->touch_num = 0;
+			return;
+		}
+
+		x = le16_to_cpup((__le16 *)(coor_data + 2));
+		y = le16_to_cpup((__le16 *)(coor_data + 4));
+		w = le16_to_cpup((__le16 *)(coor_data + 6));
+
+		touch_data->coords[id].status = TS_TOUCH;
+		touch_data->coords[id].x = x;
+		touch_data->coords[id].y = y;
+		touch_data->coords[id].w = w;
+
+		coor_data += BYTES_PER_POINT;
+	}
+
+	touch_data->touch_num = touch_num;
+}
+
+static int goodix_berlin_touch_handler(struct goodix_berlin_core *cd,
+				       u8 *pre_buf, u32 pre_buf_len)
+{
+	static u8 buffer[IRQ_EVENT_HEAD_LEN + BYTES_PER_POINT * GOODIX_MAX_TOUCH + 2];
+	struct goodix_touch_data *touch_data = &cd->ts_event.touch_data;
+	struct goodix_ic_info_misc *misc = &cd->ic_info.misc;
+	u8 point_type = 0;
+	u8 touch_num = 0;
+	int ret = 0;
+
+	/* clean event buffer */
+	memset(&cd->ts_event, 0, sizeof(cd->ts_event));
+
+	/* copy pre-data to buffer */
+	memcpy(buffer, pre_buf, pre_buf_len);
+
+	touch_num = buffer[2] & 0x0F;
+
+	if (touch_num > GOODIX_MAX_TOUCH) {
+		dev_warn(cd->dev, "invalid touch num %d\n", touch_num);
+		return -EINVAL;
+	}
+
+	/* read more data if more than 2 touch events */
+	if (unlikely(touch_num > 2)) {
+		ret = regmap_raw_read(cd->regmap,
+				      misc->touch_data_addr + pre_buf_len,
+				      &buffer[pre_buf_len],
+				      (touch_num - 2) * BYTES_PER_POINT);
+		if (ret) {
+			dev_err(cd->dev, "failed get touch data\n");
+			return ret;
+		}
+	}
+
+	/* read done */
+	goodix_berlin_after_event_handler(cd);
+
+	if (touch_num == 0)
+		return 0;
+
+	point_type = buffer[IRQ_EVENT_HEAD_LEN] & 0x0F;
+
+	/* TOFIX: Not handled */
+	if (point_type == POINT_TYPE_STYLUS || point_type == POINT_TYPE_STYLUS_HOVER) {
+		dev_warn_once(cd->dev, "Stylus event type not handled\n");
+		return 0;
+	}
+
+	if (!goodix_berlin_check_checksum(&buffer[IRQ_EVENT_HEAD_LEN],
+					  touch_num * BYTES_PER_POINT + 2)) {
+		dev_dbg(cd->dev, "touch data checksum error\n");
+		dev_dbg(cd->dev, "data: %*ph\n",
+			touch_num * BYTES_PER_POINT + 2, &buffer[IRQ_EVENT_HEAD_LEN]);
+		return -EINVAL;
+	}
+
+	cd->ts_event.event_type = EVENT_TOUCH;
+	goodix_berlin_parse_finger(cd, touch_data, buffer, touch_num);
+
+	return 0;
+}
+
+static int goodix_berlin_event_handler(struct goodix_berlin_core *cd)
+{
+	struct goodix_ic_info_misc *misc = &cd->ic_info.misc;
+	int pre_read_len;
+	u8 pre_buf[32];
+	u8 event_status;
+	int ret;
+
+	pre_read_len = IRQ_EVENT_HEAD_LEN + BYTES_PER_POINT * 2 +
+		       COOR_DATA_CHECKSUM_SIZE;
+
+	ret = regmap_raw_read(cd->regmap, misc->touch_data_addr, pre_buf,
+			      pre_read_len);
+	if (ret) {
+		dev_err(cd->dev, "failed get event head data\n");
+		return ret;
+	}
+
+	if (pre_buf[0] == 0x00)
+		return -EINVAL;
+
+	if (!goodix_berlin_check_checksum(pre_buf, IRQ_EVENT_HEAD_LEN)) {
+		dev_warn(cd->dev, "touch head checksum err : %*ph\n",
+			 IRQ_EVENT_HEAD_LEN, pre_buf);
+		return -EINVAL;
+	}
+
+	event_status = pre_buf[0];
+	if (event_status & GOODIX_TOUCH_EVENT)
+		return goodix_berlin_touch_handler(cd, pre_buf, pre_read_len);
+
+	if (event_status & GOODIX_REQUEST_EVENT) {
+		cd->ts_event.event_type = EVENT_REQUEST;
+		if (pre_buf[2] == BRL_REQUEST_CODE_RESET)
+			cd->ts_event.request_code = REQUEST_TYPE_RESET;
+		else
+			dev_warn(cd->dev, "unsupported request code 0x%x\n", pre_buf[2]);
+	}
+
+	goodix_berlin_after_event_handler(cd);
+
+	return 0;
+}
+
+static void goodix_berlin_report_finger(struct goodix_berlin_core *cd)
+{
+	struct goodix_touch_data *touch_data = &cd->ts_event.touch_data;
+	int i;
+
+	mutex_lock(&cd->input_dev->mutex);
+
+	for (i = 0; i < GOODIX_MAX_TOUCH; i++) {
+		if (touch_data->coords[i].status == TS_TOUCH) {
+			dev_dbg(cd->dev, "report: id[%d], x %d, y %d, w %d\n", i,
+				touch_data->coords[i].x,
+				touch_data->coords[i].y,
+				touch_data->coords[i].w);
+
+			input_mt_slot(cd->input_dev, i);
+			input_mt_report_slot_state(cd->input_dev,
+						   MT_TOOL_FINGER, true);
+			touchscreen_report_pos(cd->input_dev, &cd->props,
+					       touch_data->coords[i].x,
+					       touch_data->coords[i].y, true);
+			input_report_abs(cd->input_dev, ABS_MT_TOUCH_MAJOR,
+					 touch_data->coords[i].w);
+		} else {
+			input_mt_slot(cd->input_dev, i);
+			input_mt_report_slot_state(cd->input_dev,
+						   MT_TOOL_FINGER, false);
+		}
+	}
+
+	input_mt_sync_frame(cd->input_dev);
+	input_sync(cd->input_dev);
+
+	mutex_unlock(&cd->input_dev->mutex);
+}
+
+static int goodix_berlin_request_handle(struct goodix_berlin_core *cd)
+{
+	/* TOFIX: Handle more request codes */
+	if (cd->ts_event.request_code != REQUEST_TYPE_RESET) {
+		dev_info(cd->dev, "can't handle request type 0x%x\n",
+			 cd->ts_event.request_code);
+		return -EINVAL;
+	}
+
+	return goodix_berlin_reset(cd, GOODIX_NORMAL_RESET_DELAY_MS);
+}
+
+static irqreturn_t goodix_berlin_threadirq_func(int irq, void *data)
+{
+	struct goodix_berlin_core *cd = data;
+	int ret;
+
+	ret = goodix_berlin_event_handler(cd);
+	if (likely(!ret)) {
+		switch (cd->ts_event.event_type) {
+		case EVENT_TOUCH:
+			goodix_berlin_report_finger(cd);
+			break;
+
+		case EVENT_REQUEST:
+			goodix_berlin_request_handle(cd);
+			break;
+
+		/* TOFIX: Handle more request types */
+		case EVENT_INVALID:
+			break;
+		}
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int goodix_berlin_input_dev_config(struct goodix_berlin_core *cd,
+					  const struct input_id *id)
+{
+	struct input_dev *input_dev = devm_input_allocate_device(cd->dev);
+
+	if (!input_dev)
+		return -ENOMEM;
+
+	cd->input_dev = input_dev;
+	input_set_drvdata(input_dev, cd);
+
+	input_dev->name = "Goodix Berlin Capacitive TouchScreen";
+	input_dev->phys = "input/ts";
+	input_dev->dev.parent = cd->dev;
+
+	memcpy(&input_dev->id, id, sizeof(*id));
+
+	/* set input parameters */
+	input_set_abs_params(cd->input_dev, ABS_MT_POSITION_X, 0, SZ_64K - 1, 0, 0);
+	input_set_abs_params(cd->input_dev, ABS_MT_POSITION_Y, 0, SZ_64K - 1, 0, 0);
+	input_set_abs_params(cd->input_dev, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0);
+
+	/* Override with DT */
+	touchscreen_parse_properties(cd->input_dev, true, &cd->props);
+
+	input_mt_init_slots(cd->input_dev, GOODIX_MAX_TOUCH, INPUT_MT_DIRECT);
+
+	return input_register_device(cd->input_dev);
+}
+
+static void goodix_berlin_release_connects(struct goodix_berlin_core *cd)
+{
+	struct input_dev *input_dev = cd->input_dev;
+	int i;
+
+	mutex_lock(&input_dev->mutex);
+
+	for (i = 0; i < GOODIX_MAX_TOUCH; i++) {
+		input_mt_slot(input_dev, i);
+		input_mt_report_slot_state(input_dev, MT_TOOL_FINGER, false);
+	}
+	input_mt_sync_frame(input_dev);
+	input_sync(input_dev);
+
+	mutex_unlock(&input_dev->mutex);
+}
+
+static int goodix_berlin_suspend(struct goodix_berlin_core *cd)
+{
+	/* disable irq */
+	goodix_berlin_irq_enable(cd, false);
+
+	/* enter sleep mode or power off */
+	goodix_berlin_do_suspend(cd);
+
+	goodix_berlin_release_connects(cd);
+
+	return 0;
+}
+
+static int goodix_berlin_resume(struct goodix_berlin_core *cd)
+{
+	goodix_berlin_irq_enable(cd, false);
+
+	/* reset device or power on*/
+	goodix_berlin_do_resume(cd);
+
+	/* enable irq */
+	goodix_berlin_irq_enable(cd, true);
+
+	return 0;
+}
+
+int goodix_berlin_pm_suspend(struct device *dev)
+{
+	struct goodix_berlin_core *cd = dev_get_drvdata(dev);
+
+	return goodix_berlin_suspend(cd);
+}
+
+int goodix_berlin_pm_resume(struct device *dev)
+{
+	struct goodix_berlin_core *cd = dev_get_drvdata(dev);
+
+	return goodix_berlin_resume(cd);
+}
+
+EXPORT_GPL_SIMPLE_DEV_PM_OPS(goodix_berlin_pm_ops,
+			     goodix_berlin_pm_suspend,
+			     goodix_berlin_pm_resume);
+
+int goodix_berlin_probe(struct device *dev, int irq, const struct input_id *id,
+			struct regmap *regmap)
+{
+	struct goodix_berlin_core *cd;
+	int ret;
+
+	if (irq <= 0)
+		return -EINVAL;
+
+	cd = devm_kzalloc(dev, sizeof(*cd), GFP_KERNEL);
+	if (!cd)
+		return -ENOMEM;
+
+	cd->dev = dev;
+	cd->regmap = regmap;
+	cd->irq = irq;
+
+	cd->reset_gpio = devm_gpiod_get(cd->dev, "reset", GPIOF_OUT_INIT_HIGH);
+	if (IS_ERR(cd->reset_gpio))
+		return dev_err_probe(cd->dev, PTR_ERR(cd->reset_gpio),
+				     "Failed to request reset gpio\n");
+
+	cd->avdd = devm_regulator_get(cd->dev, "avdd");
+	if (IS_ERR(cd->avdd))
+		return dev_err_probe(cd->dev, PTR_ERR(cd->avdd),
+				     "Failed to request avdd regulator\n");
+
+	cd->iovdd = devm_regulator_get(cd->dev, "iovdd");
+	if (IS_ERR(cd->iovdd))
+		return dev_err_probe(cd->dev, PTR_ERR(cd->iovdd),
+				     "Failed to request iovdd regulator\n");
+
+	ret = goodix_berlin_input_dev_config(cd, id);
+	if (ret < 0) {
+		dev_err(cd->dev, "failed set input device");
+		return ret;
+	}
+
+	ret = devm_request_threaded_irq(dev, irq, NULL,
+					goodix_berlin_threadirq_func,
+					IRQF_ONESHOT, "goodix-berlin", cd);
+	if (ret) {
+		dev_err(dev, "request threaded irq failed: %d\n", ret);
+		return ret;
+	}
+
+	dev_set_drvdata(dev, cd);
+
+	ret = goodix_berlin_power_on(cd, true);
+	if (ret) {
+		dev_err(cd->dev, "failed power on");
+		goto err_out;
+	}
+
+	ret = goodix_berlin_read_version(cd, &cd->fw_version);
+	if (ret < 0) {
+		dev_err(cd->dev, "failed to get version info");
+		goto err_out;
+	}
+
+	ret = goodix_berlin_get_ic_info(cd, &cd->ic_info);
+	if (ret) {
+		dev_err(cd->dev, "invalid ic info, abort");
+		goto err_out;
+	}
+
+	cd->debugfs_root = debugfs_create_dir(dev_name(dev), NULL);
+	debugfs_create_file("fw_version", 0444, cd->debugfs_root,
+			    cd, &goodix_berlin_fw_version_fops);
+	debugfs_create_file("ic_info", 0444, cd->debugfs_root,
+			    cd, &goodix_berlin_ic_info_fops);
+
+	dev_info(cd->dev, "Goodix Berlin %s Touchscreen Controller", cd->fw_version.patch_pid);
+
+	return 0;
+
+err_out:
+	goodix_berlin_power_on(cd, false);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(goodix_berlin_probe);
+
+int goodix_berlin_remove(struct device *dev)
+{
+	struct goodix_berlin_core *cd = dev_get_drvdata(dev);
+
+	goodix_berlin_release_connects(cd);
+
+	goodix_berlin_irq_enable(cd, false);
+
+	goodix_berlin_power_on(cd, false);
+
+	debugfs_remove(cd->debugfs_root);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(goodix_berlin_remove);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Goodix Berlin Core Touchscreen driver");
+MODULE_AUTHOR("Neil Armstrong <[e-mail]>");