diff mbox series

[v21,2/3] Input: mt6779-keypad - Add MediaTek keypad driver

Message ID 20220303154302.252041-3-mkorpershoek@baylibre.com (mailing list archive)
State Accepted
Commit f28af984e771efd1ded81b865b50fa13b69bcde5
Headers show
Series Add matrix keypad driver support for Mediatek SoCs | expand

Commit Message

Mattijs Korpershoek March 3, 2022, 3:43 p.m. UTC
From: "fengping.yu" <fengping.yu@mediatek.com>

This patch adds matrix keypad support for Mediatek SoCs.

Signed-off-by: fengping.yu <fengping.yu@mediatek.com>
Reviewed-by: Marco Felsch <m.felsch@pengutronix.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
---
 drivers/input/keyboard/Kconfig         |  12 ++
 drivers/input/keyboard/Makefile        |   1 +
 drivers/input/keyboard/mt6779-keypad.c | 215 +++++++++++++++++++++++++
 3 files changed, 228 insertions(+)
 create mode 100644 drivers/input/keyboard/mt6779-keypad.c

Comments

AngeloGioacchino Del Regno March 4, 2022, 10:31 a.m. UTC | #1
Il 03/03/22 16:43, Mattijs Korpershoek ha scritto:
> From: "fengping.yu" <fengping.yu@mediatek.com>
> 
> This patch adds matrix keypad support for Mediatek SoCs.
> 
> Signed-off-by: fengping.yu <fengping.yu@mediatek.com>
> Reviewed-by: Marco Felsch <m.felsch@pengutronix.de>
> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
> Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>

Hello Mattijs,
thanks for the patch!

However, to make it perfect, there's something to improve....

> ---
>   drivers/input/keyboard/Kconfig         |  12 ++
>   drivers/input/keyboard/Makefile        |   1 +
>   drivers/input/keyboard/mt6779-keypad.c | 215 +++++++++++++++++++++++++
>   3 files changed, 228 insertions(+)
>   create mode 100644 drivers/input/keyboard/mt6779-keypad.c
> 
> diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig
> index 0c607da9ee10..03a9530f620e 100644
> --- a/drivers/input/keyboard/Kconfig
> +++ b/drivers/input/keyboard/Kconfig
> @@ -779,6 +779,18 @@ config KEYBOARD_BCM
>   	  To compile this driver as a module, choose M here: the
>   	  module will be called bcm-keypad.
>   
> +config KEYBOARD_MT6779
> +	tristate "MediaTek Keypad Support"
> +	depends on ARCH_MEDIATEK || COMPILE_TEST
> +	select REGMAP_MMIO
> +	select INPUT_MATRIXKMAP
> +	help
> +	  Say Y here if you want to use the keypad on MediaTek SoCs.
> +	  If unsure, say N.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called mt6779-keypad.
> +
>   config KEYBOARD_MTK_PMIC
>   	tristate "MediaTek PMIC keys support"
>   	depends on MFD_MT6397
> diff --git a/drivers/input/keyboard/Makefile b/drivers/input/keyboard/Makefile
> index e3c8648f834e..721936e90290 100644
> --- a/drivers/input/keyboard/Makefile
> +++ b/drivers/input/keyboard/Makefile
> @@ -44,6 +44,7 @@ obj-$(CONFIG_KEYBOARD_MATRIX)		+= matrix_keypad.o
>   obj-$(CONFIG_KEYBOARD_MAX7359)		+= max7359_keypad.o
>   obj-$(CONFIG_KEYBOARD_MCS)		+= mcs_touchkey.o
>   obj-$(CONFIG_KEYBOARD_MPR121)		+= mpr121_touchkey.o
> +obj-$(CONFIG_KEYBOARD_MT6779)		+= mt6779-keypad.o
>   obj-$(CONFIG_KEYBOARD_MTK_PMIC) 	+= mtk-pmic-keys.o
>   obj-$(CONFIG_KEYBOARD_NEWTON)		+= newtonkbd.o
>   obj-$(CONFIG_KEYBOARD_NOMADIK)		+= nomadik-ske-keypad.o
> diff --git a/drivers/input/keyboard/mt6779-keypad.c b/drivers/input/keyboard/mt6779-keypad.c
> new file mode 100644
> index 000000000000..b207acdd1e2a
> --- /dev/null
> +++ b/drivers/input/keyboard/mt6779-keypad.c
> @@ -0,0 +1,215 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2022 MediaTek Inc.
> + * Author Fengping Yu <fengping.yu@mediatek.com>
> + */
> +#include <linux/bitops.h>
> +#include <linux/clk.h>
> +#include <linux/input/matrix_keypad.h>
> +#include <linux/interrupt.h>
> +#include <linux/module.h>
> +#include <linux/property.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +
> +#define MTK_KPD_NAME		"mt6779-keypad"
> +#define MTK_KPD_MEM		0x0004
> +#define MTK_KPD_DEBOUNCE	0x0018
> +#define MTK_KPD_DEBOUNCE_MASK	GENMASK(13, 0)
> +#define MTK_KPD_DEBOUNCE_MAX_MS	256
> +#define MTK_KPD_NUM_MEMS	5
> +#define MTK_KPD_NUM_BITS	136	/* 4*32+8 MEM5 only use 8 BITS */
> +
> +struct mt6779_keypad {
> +	struct regmap *regmap;
> +	struct input_dev *input_dev;
> +	struct clk *clk;
> +	void __iomem *base;
> +	u32 n_rows;
> +	u32 n_cols;
> +	DECLARE_BITMAP(keymap_state, MTK_KPD_NUM_BITS);
> +};
> +
> +static const struct regmap_config mt6779_keypad_regmap_cfg = {
> +	.reg_bits = 32,
> +	.val_bits = 32,
> +	.reg_stride = sizeof(u32),
> +	.max_register = 36,

Are you sure that you can't use .fast_io = true?

Another version for the same question:
Are you sure that you need to lock with a mutex here, and not with a spinlock?

Since you're performing reads over a MMIO, I think that there's a very good
chance that you can use fast_io.

> +};
> +
> +static irqreturn_t mt6779_keypad_irq_handler(int irq, void *dev_id)
> +{
> +	struct mt6779_keypad *keypad = dev_id;
> +	unsigned short *keycode = keypad->input_dev->keycode;
> +	DECLARE_BITMAP(new_state, MTK_KPD_NUM_BITS);
> +	DECLARE_BITMAP(change, MTK_KPD_NUM_BITS);
> +	int bit_nr;
> +	int pressed;
> +	unsigned short code;
> +	int row, col;
> +	int row_shift = get_count_order(keypad->n_cols);
> +
> +	regmap_bulk_read(keypad->regmap, MTK_KPD_MEM,
> +			 new_state, MTK_KPD_NUM_MEMS);
> +
> +	bitmap_xor(change, new_state, keypad->keymap_state, MTK_KPD_NUM_BITS);
> +
> +	for_each_set_bit(bit_nr, change, MTK_KPD_NUM_BITS) {
> +	/* For 32bits register, only bits [15:0] use to indicate key status */
> +		if (bit_nr % 32 >= 16)
> +			continue;
> +
> +		/* 1: not pressed, 0: pressed */
> +		pressed = !test_bit(bit_nr, new_state);
> +		dev_dbg(&keypad->input_dev->dev, "%s",
> +			pressed ? "pressed" : "released");
> +
> +		row = bit_nr / 32;
> +		col = bit_nr % 32;
> +
> +		code = keycode[MATRIX_SCAN_CODE(row, col, row_shift)];
> +
> +		input_report_key(keypad->input_dev, code, pressed);
> +		input_sync(keypad->input_dev);
> +
> +		dev_dbg(&keypad->input_dev->dev,
> +			"report Linux keycode = %d\n", code);
> +	}
> +
> +	bitmap_copy(keypad->keymap_state, new_state, MTK_KPD_NUM_BITS);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static void mt6779_keypad_clk_disable(void *data)
> +{
> +	clk_disable_unprepare(data);
> +}
> +
> +static int mt6779_keypad_pdrv_probe(struct platform_device *pdev)
> +{
> +	struct mt6779_keypad *keypad;
> +	unsigned int irq;
> +	u32 debounce;
> +	bool wakeup;
> +	int error;
> +
> +	keypad = devm_kzalloc(&pdev->dev, sizeof(*keypad), GFP_KERNEL);
> +	if (!keypad)
> +		return -ENOMEM;
> +
> +	keypad->base = devm_platform_ioremap_resource(pdev, 0);
> +	if (IS_ERR(keypad->base))
> +		return PTR_ERR(keypad->base);
> +
> +	keypad->regmap = devm_regmap_init_mmio(&pdev->dev,
> +					       keypad->base,
> +					       &mt6779_keypad_regmap_cfg);

Please use dev_err_probe() to simplify error handling in probe functions: you've
done a great job with adding a devm action for the error cases, avoiding gotos to
get out cleanly.. it would be a pity to not finish this to perfection.

I'll give you two examples for this, so that you'll be all set.

	if (IS_ERR(keypad->regmap))
		return dev_err_probe(&pdev->dev, PTR_ERR(keypad->regmap),
				     "regmap init failed\n");

P.S.: No need for %pe here, as dev_err_probe prints the error number for you!

> +	if (IS_ERR(keypad->regmap)) {
> +		dev_err(&pdev->dev,
> +			"regmap init failed:%pe\n", keypad->regmap);
> +		return PTR_ERR(keypad->regmap);
> +	}
> +
> +	bitmap_fill(keypad->keymap_state, MTK_KPD_NUM_BITS);
> +
> +	keypad->input_dev = devm_input_allocate_device(&pdev->dev);

	if (!keypad->input_dev)
		return dev_err_probe(&pdev->dev, -ENOMEM,
				     "Cannot allocate input device\n");

> +	if (!keypad->input_dev) {
> +		dev_err(&pdev->dev, "Failed to allocate input dev\n");
> +		return -ENOMEM;
> +	}
> +
> +	keypad->input_dev->name = MTK_KPD_NAME;
> +	keypad->input_dev->id.bustype = BUS_HOST;
> +
> +	error = matrix_keypad_parse_properties(&pdev->dev, &keypad->n_rows,
> +					       &keypad->n_cols);
> +	if (error) {
> +		dev_err(&pdev->dev, "Failed to parse keypad params\n");
> +		return error;
> +	}
> +
> +	if (device_property_read_u32(&pdev->dev, "debounce-delay-ms",
> +				     &debounce))
> +		debounce = 16;
> +
> +	if (debounce > MTK_KPD_DEBOUNCE_MAX_MS) {
> +		dev_err(&pdev->dev, "Debounce time exceeds the maximum allowed time %dms\n",
> +			MTK_KPD_DEBOUNCE_MAX_MS);
> +		return -EINVAL;
> +	}
> +
> +	wakeup = device_property_read_bool(&pdev->dev, "wakeup-source");
> +
> +	dev_dbg(&pdev->dev, "n_row=%d n_col=%d debounce=%d\n",
> +		keypad->n_rows, keypad->n_cols, debounce);
> +
> +	error = matrix_keypad_build_keymap(NULL, NULL,
> +					   keypad->n_rows,
> +					   keypad->n_cols,
> +					   NULL,
> +					   keypad->input_dev);
> +	if (error) {
> +		dev_err(&pdev->dev, "Failed to build keymap\n");
> +		return error;
> +	}
> +
> +	regmap_write(keypad->regmap, MTK_KPD_DEBOUNCE,
> +		     (debounce * (1 << 5)) & MTK_KPD_DEBOUNCE_MASK);
> +
> +	keypad->clk = devm_clk_get(&pdev->dev, "kpd");
> +	if (IS_ERR(keypad->clk))
> +		return PTR_ERR(keypad->clk);
> +
> +	error = clk_prepare_enable(keypad->clk);
> +	if (error) {
> +		dev_err(&pdev->dev, "cannot prepare/enable keypad clock\n");
> +		return error;
> +	}
> +
> +	error = devm_add_action_or_reset(&pdev->dev, mt6779_keypad_clk_disable, keypad->clk);
> +	if (error)
> +		return error;
> +
> +	irq = platform_get_irq(pdev, 0);
> +	if (irq < 0)
> +		return irq;
> +
> +	error = devm_request_threaded_irq(&pdev->dev, irq, NULL, mt6779_keypad_irq_handler,
> +					  IRQF_ONESHOT, MTK_KPD_NAME, keypad);
> +	if (error) {
> +		dev_err(&pdev->dev, "Failed to request IRQ#%d:%d\n", irq, error);
> +		return error;
> +	}
> +
> +	error = input_register_device(keypad->input_dev);
> +	if (error) {
> +		dev_err(&pdev->dev, "Failed to register device\n");
> +		return error;
> +	}
> +
> +	error =  device_init_wakeup(&pdev->dev, wakeup);

Whoops! Two spaces here! Please fix this typo.

P.S.: Please add my email to the Cc's when you'll send the next version, so that
       I will be able to timely give you a R-b tag.

Cheers,
Angelo
Andy Shevchenko March 4, 2022, 12:38 p.m. UTC | #2
On Fri, Mar 04, 2022 at 11:31:38AM +0100, AngeloGioacchino Del Regno wrote:
> Il 03/03/22 16:43, Mattijs Korpershoek ha scritto:
> > From: "fengping.yu" <fengping.yu@mediatek.com>
> > 
> > This patch adds matrix keypad support for Mediatek SoCs.

> > +struct mt6779_keypad {
> > +	struct regmap *regmap;
> > +	struct input_dev *input_dev;
> > +	struct clk *clk;

> > +	void __iomem *base;

Not sure why you need this here.

> > +	u32 n_rows;
> > +	u32 n_cols;
> > +	DECLARE_BITMAP(keymap_state, MTK_KPD_NUM_BITS);
> > +};
> > +
> > +static const struct regmap_config mt6779_keypad_regmap_cfg = {
> > +	.reg_bits = 32,
> > +	.val_bits = 32,
> > +	.reg_stride = sizeof(u32),
> > +	.max_register = 36,
> 
> Are you sure that you can't use .fast_io = true?
> 
> Another version for the same question:
> Are you sure that you need to lock with a mutex here, and not with a spinlock?
> 
> Since you're performing reads over a MMIO, I think that there's a very good
> chance that you can use fast_io.
> 
> > +};

...

> Please use dev_err_probe() to simplify error handling in probe functions: you've
> done a great job with adding a devm action for the error cases, avoiding gotos to
> get out cleanly.. it would be a pity to not finish this to perfection.
> 
> I'll give you two examples for this, so that you'll be all set.
> 
> 	if (IS_ERR(keypad->regmap))
> 		return dev_err_probe(&pdev->dev, PTR_ERR(keypad->regmap),
> 				     "regmap init failed\n");
> 
> P.S.: No need for %pe here, as dev_err_probe prints the error number for you!

Maintainer of the input subsystem is strongly against dev_err_probe() API. See
other files there. Ditto for other cases you mentioned below.
Dmitry Torokhov March 5, 2022, 11:04 p.m. UTC | #3
On Fri, Mar 04, 2022 at 11:31:38AM +0100, AngeloGioacchino Del Regno wrote:
> Il 03/03/22 16:43, Mattijs Korpershoek ha scritto:
> > From: "fengping.yu" <fengping.yu@mediatek.com>
> > +
> > +static const struct regmap_config mt6779_keypad_regmap_cfg = {
> > +	.reg_bits = 32,
> > +	.val_bits = 32,
> > +	.reg_stride = sizeof(u32),
> > +	.max_register = 36,
> 
> Are you sure that you can't use .fast_io = true?
> 
> Another version for the same question:
> Are you sure that you need to lock with a mutex here, and not with a spinlock?
> 
> Since you're performing reads over a MMIO, I think that there's a very good
> chance that you can use fast_io.

I think there are good ideas here, but they are not critical (this is a
keypad we are dealing with) and so can be investigated at a later time.

I added reporting of EV_MSC/MSC_SCAN as it is customary for
keyboard/keypad drivers, and applied the patch.

Thank you.
Mattijs Korpershoek March 14, 2022, 7:57 a.m. UTC | #4
On ven., mars 04, 2022 at 11:31, AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> wrote:

> Il 03/03/22 16:43, Mattijs Korpershoek ha scritto:
>> From: "fengping.yu" <fengping.yu@mediatek.com>
>> 
>> This patch adds matrix keypad support for Mediatek SoCs.
>> 
>> Signed-off-by: fengping.yu <fengping.yu@mediatek.com>
>> Reviewed-by: Marco Felsch <m.felsch@pengutronix.de>
>> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
>> Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
>> Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
>
> Hello Mattijs,
> thanks for the patch!
>
> However, to make it perfect, there's something to improve....
Hi Angelo,

Thank you for your detailed review, It's really appreciated!
>
>> ---
>>   drivers/input/keyboard/Kconfig         |  12 ++
>>   drivers/input/keyboard/Makefile        |   1 +
>>   drivers/input/keyboard/mt6779-keypad.c | 215 +++++++++++++++++++++++++
>>   3 files changed, 228 insertions(+)
>>   create mode 100644 drivers/input/keyboard/mt6779-keypad.c
>> 
>> diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig
>> index 0c607da9ee10..03a9530f620e 100644
>> --- a/drivers/input/keyboard/Kconfig
>> +++ b/drivers/input/keyboard/Kconfig
>> @@ -779,6 +779,18 @@ config KEYBOARD_BCM
>>   	  To compile this driver as a module, choose M here: the
>>   	  module will be called bcm-keypad.
>>   
>> +config KEYBOARD_MT6779
>> +	tristate "MediaTek Keypad Support"
>> +	depends on ARCH_MEDIATEK || COMPILE_TEST
>> +	select REGMAP_MMIO
>> +	select INPUT_MATRIXKMAP
>> +	help
>> +	  Say Y here if you want to use the keypad on MediaTek SoCs.
>> +	  If unsure, say N.
>> +
>> +	  To compile this driver as a module, choose M here: the
>> +	  module will be called mt6779-keypad.
>> +
>>   config KEYBOARD_MTK_PMIC
>>   	tristate "MediaTek PMIC keys support"
>>   	depends on MFD_MT6397
>> diff --git a/drivers/input/keyboard/Makefile b/drivers/input/keyboard/Makefile
>> index e3c8648f834e..721936e90290 100644
>> --- a/drivers/input/keyboard/Makefile
>> +++ b/drivers/input/keyboard/Makefile
>> @@ -44,6 +44,7 @@ obj-$(CONFIG_KEYBOARD_MATRIX)		+= matrix_keypad.o
>>   obj-$(CONFIG_KEYBOARD_MAX7359)		+= max7359_keypad.o
>>   obj-$(CONFIG_KEYBOARD_MCS)		+= mcs_touchkey.o
>>   obj-$(CONFIG_KEYBOARD_MPR121)		+= mpr121_touchkey.o
>> +obj-$(CONFIG_KEYBOARD_MT6779)		+= mt6779-keypad.o
>>   obj-$(CONFIG_KEYBOARD_MTK_PMIC) 	+= mtk-pmic-keys.o
>>   obj-$(CONFIG_KEYBOARD_NEWTON)		+= newtonkbd.o
>>   obj-$(CONFIG_KEYBOARD_NOMADIK)		+= nomadik-ske-keypad.o
>> diff --git a/drivers/input/keyboard/mt6779-keypad.c b/drivers/input/keyboard/mt6779-keypad.c
>> new file mode 100644
>> index 000000000000..b207acdd1e2a
>> --- /dev/null
>> +++ b/drivers/input/keyboard/mt6779-keypad.c
>> @@ -0,0 +1,215 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * Copyright (C) 2022 MediaTek Inc.
>> + * Author Fengping Yu <fengping.yu@mediatek.com>
>> + */
>> +#include <linux/bitops.h>
>> +#include <linux/clk.h>
>> +#include <linux/input/matrix_keypad.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/module.h>
>> +#include <linux/property.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/regmap.h>
>> +
>> +#define MTK_KPD_NAME		"mt6779-keypad"
>> +#define MTK_KPD_MEM		0x0004
>> +#define MTK_KPD_DEBOUNCE	0x0018
>> +#define MTK_KPD_DEBOUNCE_MASK	GENMASK(13, 0)
>> +#define MTK_KPD_DEBOUNCE_MAX_MS	256
>> +#define MTK_KPD_NUM_MEMS	5
>> +#define MTK_KPD_NUM_BITS	136	/* 4*32+8 MEM5 only use 8 BITS */
>> +
>> +struct mt6779_keypad {
>> +	struct regmap *regmap;
>> +	struct input_dev *input_dev;
>> +	struct clk *clk;
>> +	void __iomem *base;
>> +	u32 n_rows;
>> +	u32 n_cols;
>> +	DECLARE_BITMAP(keymap_state, MTK_KPD_NUM_BITS);
>> +};
>> +
>> +static const struct regmap_config mt6779_keypad_regmap_cfg = {
>> +	.reg_bits = 32,
>> +	.val_bits = 32,
>> +	.reg_stride = sizeof(u32),
>> +	.max_register = 36,
>
> Are you sure that you can't use .fast_io = true?
I am not sure at all. I did not think twice about this.
>
> Another version for the same question:
> Are you sure that you need to lock with a mutex here, and not with a spinlock?
>
> Since you're performing reads over a MMIO, I think that there's a very good
> chance that you can use fast_io.
Thank you for this suggestion. I might send a follow-up series with this
improvement included.
Will cc you if I do.

>
>> +};
>> +
>> +static irqreturn_t mt6779_keypad_irq_handler(int irq, void *dev_id)
>> +{
>> +	struct mt6779_keypad *keypad = dev_id;
>> +	unsigned short *keycode = keypad->input_dev->keycode;
>> +	DECLARE_BITMAP(new_state, MTK_KPD_NUM_BITS);
>> +	DECLARE_BITMAP(change, MTK_KPD_NUM_BITS);
>> +	int bit_nr;
>> +	int pressed;
>> +	unsigned short code;
>> +	int row, col;
>> +	int row_shift = get_count_order(keypad->n_cols);
>> +
>> +	regmap_bulk_read(keypad->regmap, MTK_KPD_MEM,
>> +			 new_state, MTK_KPD_NUM_MEMS);
>> +
>> +	bitmap_xor(change, new_state, keypad->keymap_state, MTK_KPD_NUM_BITS);
>> +
>> +	for_each_set_bit(bit_nr, change, MTK_KPD_NUM_BITS) {
>> +	/* For 32bits register, only bits [15:0] use to indicate key status */
>> +		if (bit_nr % 32 >= 16)
>> +			continue;
>> +
>> +		/* 1: not pressed, 0: pressed */
>> +		pressed = !test_bit(bit_nr, new_state);
>> +		dev_dbg(&keypad->input_dev->dev, "%s",
>> +			pressed ? "pressed" : "released");
>> +
>> +		row = bit_nr / 32;
>> +		col = bit_nr % 32;
>> +
>> +		code = keycode[MATRIX_SCAN_CODE(row, col, row_shift)];
>> +
>> +		input_report_key(keypad->input_dev, code, pressed);
>> +		input_sync(keypad->input_dev);
>> +
>> +		dev_dbg(&keypad->input_dev->dev,
>> +			"report Linux keycode = %d\n", code);
>> +	}
>> +
>> +	bitmap_copy(keypad->keymap_state, new_state, MTK_KPD_NUM_BITS);
>> +
>> +	return IRQ_HANDLED;
>> +}
>> +
>> +static void mt6779_keypad_clk_disable(void *data)
>> +{
>> +	clk_disable_unprepare(data);
>> +}
>> +
>> +static int mt6779_keypad_pdrv_probe(struct platform_device *pdev)
>> +{
>> +	struct mt6779_keypad *keypad;
>> +	unsigned int irq;
>> +	u32 debounce;
>> +	bool wakeup;
>> +	int error;
>> +
>> +	keypad = devm_kzalloc(&pdev->dev, sizeof(*keypad), GFP_KERNEL);
>> +	if (!keypad)
>> +		return -ENOMEM;
>> +
>> +	keypad->base = devm_platform_ioremap_resource(pdev, 0);
>> +	if (IS_ERR(keypad->base))
>> +		return PTR_ERR(keypad->base);
>> +
>> +	keypad->regmap = devm_regmap_init_mmio(&pdev->dev,
>> +					       keypad->base,
>> +					       &mt6779_keypad_regmap_cfg);
>
> Please use dev_err_probe() to simplify error handling in probe functions: you've
> done a great job with adding a devm action for the error cases, avoiding gotos to
> get out cleanly.. it would be a pity to not finish this to perfection.
>
> I'll give you two examples for this, so that you'll be all set.
>
> 	if (IS_ERR(keypad->regmap))
> 		return dev_err_probe(&pdev->dev, PTR_ERR(keypad->regmap),
> 				     "regmap init failed\n");
>
> P.S.: No need for %pe here, as dev_err_probe prints the error number for you!
I did not know about dev_err_probe(). As far as I understand, it's not
recommended to be used for input drivers, but I'll definitely use it for
other subsystems.

>
>> +	if (IS_ERR(keypad->regmap)) {
>> +		dev_err(&pdev->dev,
>> +			"regmap init failed:%pe\n", keypad->regmap);
>> +		return PTR_ERR(keypad->regmap);
>> +	}
>> +
>> +	bitmap_fill(keypad->keymap_state, MTK_KPD_NUM_BITS);
>> +
>> +	keypad->input_dev = devm_input_allocate_device(&pdev->dev);
>
> 	if (!keypad->input_dev)
> 		return dev_err_probe(&pdev->dev, -ENOMEM,
> 				     "Cannot allocate input device\n");
>
>> +	if (!keypad->input_dev) {
>> +		dev_err(&pdev->dev, "Failed to allocate input dev\n");
>> +		return -ENOMEM;
>> +	}
>> +
>> +	keypad->input_dev->name = MTK_KPD_NAME;
>> +	keypad->input_dev->id.bustype = BUS_HOST;
>> +
>> +	error = matrix_keypad_parse_properties(&pdev->dev, &keypad->n_rows,
>> +					       &keypad->n_cols);
>> +	if (error) {
>> +		dev_err(&pdev->dev, "Failed to parse keypad params\n");
>> +		return error;
>> +	}
>> +
>> +	if (device_property_read_u32(&pdev->dev, "debounce-delay-ms",
>> +				     &debounce))
>> +		debounce = 16;
>> +
>> +	if (debounce > MTK_KPD_DEBOUNCE_MAX_MS) {
>> +		dev_err(&pdev->dev, "Debounce time exceeds the maximum allowed time %dms\n",
>> +			MTK_KPD_DEBOUNCE_MAX_MS);
>> +		return -EINVAL;
>> +	}
>> +
>> +	wakeup = device_property_read_bool(&pdev->dev, "wakeup-source");
>> +
>> +	dev_dbg(&pdev->dev, "n_row=%d n_col=%d debounce=%d\n",
>> +		keypad->n_rows, keypad->n_cols, debounce);
>> +
>> +	error = matrix_keypad_build_keymap(NULL, NULL,
>> +					   keypad->n_rows,
>> +					   keypad->n_cols,
>> +					   NULL,
>> +					   keypad->input_dev);
>> +	if (error) {
>> +		dev_err(&pdev->dev, "Failed to build keymap\n");
>> +		return error;
>> +	}
>> +
>> +	regmap_write(keypad->regmap, MTK_KPD_DEBOUNCE,
>> +		     (debounce * (1 << 5)) & MTK_KPD_DEBOUNCE_MASK);
>> +
>> +	keypad->clk = devm_clk_get(&pdev->dev, "kpd");
>> +	if (IS_ERR(keypad->clk))
>> +		return PTR_ERR(keypad->clk);
>> +
>> +	error = clk_prepare_enable(keypad->clk);
>> +	if (error) {
>> +		dev_err(&pdev->dev, "cannot prepare/enable keypad clock\n");
>> +		return error;
>> +	}
>> +
>> +	error = devm_add_action_or_reset(&pdev->dev, mt6779_keypad_clk_disable, keypad->clk);
>> +	if (error)
>> +		return error;
>> +
>> +	irq = platform_get_irq(pdev, 0);
>> +	if (irq < 0)
>> +		return irq;
>> +
>> +	error = devm_request_threaded_irq(&pdev->dev, irq, NULL, mt6779_keypad_irq_handler,
>> +					  IRQF_ONESHOT, MTK_KPD_NAME, keypad);
>> +	if (error) {
>> +		dev_err(&pdev->dev, "Failed to request IRQ#%d:%d\n", irq, error);
>> +		return error;
>> +	}
>> +
>> +	error = input_register_device(keypad->input_dev);
>> +	if (error) {
>> +		dev_err(&pdev->dev, "Failed to register device\n");
>> +		return error;
>> +	}
>> +
>> +	error =  device_init_wakeup(&pdev->dev, wakeup);
>
> Whoops! Two spaces here! Please fix this typo.
It looks Dmitry fixed this already in his tree [1]

[1] https://git.kernel.org/pub/scm/linux/kernel/git/dtor/input.git/commit/?h=next&id=f28af984e771efd1ded81b865b50fa13b69bcde5

>
> P.S.: Please add my email to the Cc's when you'll send the next version, so that
>        I will be able to timely give you a R-b tag.
>
> Cheers,
> Angelo
Mattijs Korpershoek March 14, 2022, 8 a.m. UTC | #5
On ven., mars 04, 2022 at 14:38, Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote:

> On Fri, Mar 04, 2022 at 11:31:38AM +0100, AngeloGioacchino Del Regno wrote:
>> Il 03/03/22 16:43, Mattijs Korpershoek ha scritto:
>> > From: "fengping.yu" <fengping.yu@mediatek.com>
>> > 
>> > This patch adds matrix keypad support for Mediatek SoCs.
>
>> > +struct mt6779_keypad {
>> > +	struct regmap *regmap;
>> > +	struct input_dev *input_dev;
>> > +	struct clk *clk;
>
>> > +	void __iomem *base;
>
> Not sure why you need this here.
You are right. There is no point of keeping this __iomem region as part
of the structure, since it's only used in the probe() function to create
the regmap.

Will send an improvement part of a later series.

>
>> > +	u32 n_rows;
>> > +	u32 n_cols;
>> > +	DECLARE_BITMAP(keymap_state, MTK_KPD_NUM_BITS);
>> > +};
>> > +
>> > +static const struct regmap_config mt6779_keypad_regmap_cfg = {
>> > +	.reg_bits = 32,
>> > +	.val_bits = 32,
>> > +	.reg_stride = sizeof(u32),
>> > +	.max_register = 36,
>> 
>> Are you sure that you can't use .fast_io = true?
>> 
>> Another version for the same question:
>> Are you sure that you need to lock with a mutex here, and not with a spinlock?
>> 
>> Since you're performing reads over a MMIO, I think that there's a very good
>> chance that you can use fast_io.
>> 
>> > +};
>
> ...
>
>> Please use dev_err_probe() to simplify error handling in probe functions: you've
>> done a great job with adding a devm action for the error cases, avoiding gotos to
>> get out cleanly.. it would be a pity to not finish this to perfection.
>> 
>> I'll give you two examples for this, so that you'll be all set.
>> 
>> 	if (IS_ERR(keypad->regmap))
>> 		return dev_err_probe(&pdev->dev, PTR_ERR(keypad->regmap),
>> 				     "regmap init failed\n");
>> 
>> P.S.: No need for %pe here, as dev_err_probe prints the error number for you!
>
> Maintainer of the input subsystem is strongly against dev_err_probe() API. See
> other files there. Ditto for other cases you mentioned below.
>
> -- 
> With Best Regards,
> Andy Shevchenko
diff mbox series

Patch

diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig
index 0c607da9ee10..03a9530f620e 100644
--- a/drivers/input/keyboard/Kconfig
+++ b/drivers/input/keyboard/Kconfig
@@ -779,6 +779,18 @@  config KEYBOARD_BCM
 	  To compile this driver as a module, choose M here: the
 	  module will be called bcm-keypad.
 
+config KEYBOARD_MT6779
+	tristate "MediaTek Keypad Support"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	select REGMAP_MMIO
+	select INPUT_MATRIXKMAP
+	help
+	  Say Y here if you want to use the keypad on MediaTek SoCs.
+	  If unsure, say N.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called mt6779-keypad.
+
 config KEYBOARD_MTK_PMIC
 	tristate "MediaTek PMIC keys support"
 	depends on MFD_MT6397
diff --git a/drivers/input/keyboard/Makefile b/drivers/input/keyboard/Makefile
index e3c8648f834e..721936e90290 100644
--- a/drivers/input/keyboard/Makefile
+++ b/drivers/input/keyboard/Makefile
@@ -44,6 +44,7 @@  obj-$(CONFIG_KEYBOARD_MATRIX)		+= matrix_keypad.o
 obj-$(CONFIG_KEYBOARD_MAX7359)		+= max7359_keypad.o
 obj-$(CONFIG_KEYBOARD_MCS)		+= mcs_touchkey.o
 obj-$(CONFIG_KEYBOARD_MPR121)		+= mpr121_touchkey.o
+obj-$(CONFIG_KEYBOARD_MT6779)		+= mt6779-keypad.o
 obj-$(CONFIG_KEYBOARD_MTK_PMIC) 	+= mtk-pmic-keys.o
 obj-$(CONFIG_KEYBOARD_NEWTON)		+= newtonkbd.o
 obj-$(CONFIG_KEYBOARD_NOMADIK)		+= nomadik-ske-keypad.o
diff --git a/drivers/input/keyboard/mt6779-keypad.c b/drivers/input/keyboard/mt6779-keypad.c
new file mode 100644
index 000000000000..b207acdd1e2a
--- /dev/null
+++ b/drivers/input/keyboard/mt6779-keypad.c
@@ -0,0 +1,215 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2022 MediaTek Inc.
+ * Author Fengping Yu <fengping.yu@mediatek.com>
+ */
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/input/matrix_keypad.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/property.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#define MTK_KPD_NAME		"mt6779-keypad"
+#define MTK_KPD_MEM		0x0004
+#define MTK_KPD_DEBOUNCE	0x0018
+#define MTK_KPD_DEBOUNCE_MASK	GENMASK(13, 0)
+#define MTK_KPD_DEBOUNCE_MAX_MS	256
+#define MTK_KPD_NUM_MEMS	5
+#define MTK_KPD_NUM_BITS	136	/* 4*32+8 MEM5 only use 8 BITS */
+
+struct mt6779_keypad {
+	struct regmap *regmap;
+	struct input_dev *input_dev;
+	struct clk *clk;
+	void __iomem *base;
+	u32 n_rows;
+	u32 n_cols;
+	DECLARE_BITMAP(keymap_state, MTK_KPD_NUM_BITS);
+};
+
+static const struct regmap_config mt6779_keypad_regmap_cfg = {
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = sizeof(u32),
+	.max_register = 36,
+};
+
+static irqreturn_t mt6779_keypad_irq_handler(int irq, void *dev_id)
+{
+	struct mt6779_keypad *keypad = dev_id;
+	unsigned short *keycode = keypad->input_dev->keycode;
+	DECLARE_BITMAP(new_state, MTK_KPD_NUM_BITS);
+	DECLARE_BITMAP(change, MTK_KPD_NUM_BITS);
+	int bit_nr;
+	int pressed;
+	unsigned short code;
+	int row, col;
+	int row_shift = get_count_order(keypad->n_cols);
+
+	regmap_bulk_read(keypad->regmap, MTK_KPD_MEM,
+			 new_state, MTK_KPD_NUM_MEMS);
+
+	bitmap_xor(change, new_state, keypad->keymap_state, MTK_KPD_NUM_BITS);
+
+	for_each_set_bit(bit_nr, change, MTK_KPD_NUM_BITS) {
+	/* For 32bits register, only bits [15:0] use to indicate key status */
+		if (bit_nr % 32 >= 16)
+			continue;
+
+		/* 1: not pressed, 0: pressed */
+		pressed = !test_bit(bit_nr, new_state);
+		dev_dbg(&keypad->input_dev->dev, "%s",
+			pressed ? "pressed" : "released");
+
+		row = bit_nr / 32;
+		col = bit_nr % 32;
+
+		code = keycode[MATRIX_SCAN_CODE(row, col, row_shift)];
+
+		input_report_key(keypad->input_dev, code, pressed);
+		input_sync(keypad->input_dev);
+
+		dev_dbg(&keypad->input_dev->dev,
+			"report Linux keycode = %d\n", code);
+	}
+
+	bitmap_copy(keypad->keymap_state, new_state, MTK_KPD_NUM_BITS);
+
+	return IRQ_HANDLED;
+}
+
+static void mt6779_keypad_clk_disable(void *data)
+{
+	clk_disable_unprepare(data);
+}
+
+static int mt6779_keypad_pdrv_probe(struct platform_device *pdev)
+{
+	struct mt6779_keypad *keypad;
+	unsigned int irq;
+	u32 debounce;
+	bool wakeup;
+	int error;
+
+	keypad = devm_kzalloc(&pdev->dev, sizeof(*keypad), GFP_KERNEL);
+	if (!keypad)
+		return -ENOMEM;
+
+	keypad->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(keypad->base))
+		return PTR_ERR(keypad->base);
+
+	keypad->regmap = devm_regmap_init_mmio(&pdev->dev,
+					       keypad->base,
+					       &mt6779_keypad_regmap_cfg);
+	if (IS_ERR(keypad->regmap)) {
+		dev_err(&pdev->dev,
+			"regmap init failed:%pe\n", keypad->regmap);
+		return PTR_ERR(keypad->regmap);
+	}
+
+	bitmap_fill(keypad->keymap_state, MTK_KPD_NUM_BITS);
+
+	keypad->input_dev = devm_input_allocate_device(&pdev->dev);
+	if (!keypad->input_dev) {
+		dev_err(&pdev->dev, "Failed to allocate input dev\n");
+		return -ENOMEM;
+	}
+
+	keypad->input_dev->name = MTK_KPD_NAME;
+	keypad->input_dev->id.bustype = BUS_HOST;
+
+	error = matrix_keypad_parse_properties(&pdev->dev, &keypad->n_rows,
+					       &keypad->n_cols);
+	if (error) {
+		dev_err(&pdev->dev, "Failed to parse keypad params\n");
+		return error;
+	}
+
+	if (device_property_read_u32(&pdev->dev, "debounce-delay-ms",
+				     &debounce))
+		debounce = 16;
+
+	if (debounce > MTK_KPD_DEBOUNCE_MAX_MS) {
+		dev_err(&pdev->dev, "Debounce time exceeds the maximum allowed time %dms\n",
+			MTK_KPD_DEBOUNCE_MAX_MS);
+		return -EINVAL;
+	}
+
+	wakeup = device_property_read_bool(&pdev->dev, "wakeup-source");
+
+	dev_dbg(&pdev->dev, "n_row=%d n_col=%d debounce=%d\n",
+		keypad->n_rows, keypad->n_cols, debounce);
+
+	error = matrix_keypad_build_keymap(NULL, NULL,
+					   keypad->n_rows,
+					   keypad->n_cols,
+					   NULL,
+					   keypad->input_dev);
+	if (error) {
+		dev_err(&pdev->dev, "Failed to build keymap\n");
+		return error;
+	}
+
+	regmap_write(keypad->regmap, MTK_KPD_DEBOUNCE,
+		     (debounce * (1 << 5)) & MTK_KPD_DEBOUNCE_MASK);
+
+	keypad->clk = devm_clk_get(&pdev->dev, "kpd");
+	if (IS_ERR(keypad->clk))
+		return PTR_ERR(keypad->clk);
+
+	error = clk_prepare_enable(keypad->clk);
+	if (error) {
+		dev_err(&pdev->dev, "cannot prepare/enable keypad clock\n");
+		return error;
+	}
+
+	error = devm_add_action_or_reset(&pdev->dev, mt6779_keypad_clk_disable, keypad->clk);
+	if (error)
+		return error;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	error = devm_request_threaded_irq(&pdev->dev, irq, NULL, mt6779_keypad_irq_handler,
+					  IRQF_ONESHOT, MTK_KPD_NAME, keypad);
+	if (error) {
+		dev_err(&pdev->dev, "Failed to request IRQ#%d:%d\n", irq, error);
+		return error;
+	}
+
+	error = input_register_device(keypad->input_dev);
+	if (error) {
+		dev_err(&pdev->dev, "Failed to register device\n");
+		return error;
+	}
+
+	error =  device_init_wakeup(&pdev->dev, wakeup);
+	if (error)
+		dev_warn(&pdev->dev, "device_init_wakeup fail\n");
+
+	return 0;
+}
+
+static const struct of_device_id mt6779_keypad_of_match[] = {
+	{ .compatible = "mediatek,mt6779-keypad" },
+	{ .compatible = "mediatek,mt6873-keypad" },
+	{ /* sentinel */ }
+};
+
+static struct platform_driver mt6779_keypad_pdrv = {
+	.probe = mt6779_keypad_pdrv_probe,
+	.driver = {
+		   .name = MTK_KPD_NAME,
+		   .of_match_table = mt6779_keypad_of_match,
+	},
+};
+module_platform_driver(mt6779_keypad_pdrv);
+
+MODULE_AUTHOR("Mediatek Corporation");
+MODULE_DESCRIPTION("MTK Keypad (KPD) Driver");
+MODULE_LICENSE("GPL");