| Message ID | 20220511094024.175994-4-shreeya.patel@collabora.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | Add LTRF216A Driver | expand |
On Wed, May 11, 2022 at 1:11 PM Shreeya Patel <shreeya.patel@collabora.com> wrote: > > From: Zhigang Shi <Zhigang.Shi@liteon.com> > > Add initial support for ltrf216a ambient light sensor. > Datasheet: gitlab.steamos.cloud/shreeya/iio/-/blob/main/LTRF216A.pdf What is the protocol? https? git? ssh? ... > +obj-$(CONFIG_LTRF216A) += ltrf216a.o I believe alphabetically it goes after the below one. > obj-$(CONFIG_LTR501) += ltr501.o ... > +#include <linux/bitfield.h> + bits.h ... > +static const int ltrf216a_int_time_available[5][2] = { You may drop 5 here and below, correct? > + {0, 400000}, > + {0, 200000}, > + {0, 100000}, > + {0, 50000}, > + {0, 25000}, > +}; ... > +/* open air. need to update based on TP transmission rate. */ I didn't get the small letters in conjunction with the period in the middle of the phrase. Can you update grammar or spell the shortened form of "air." fully? > +#define WIN_FAC 1 Can it be namespaced? ... > +static const struct iio_chan_spec ltrf216a_channels[] = { > + { > + .type = IIO_LIGHT, > + .info_mask_separate = > + BIT(IIO_CHAN_INFO_PROCESSED) | > + BIT(IIO_CHAN_INFO_INT_TIME), > + .info_mask_separate_available = > + BIT(IIO_CHAN_INFO_INT_TIME), > + } + Comma. > +}; ... > +static int ltrf216a_set_int_time(struct ltrf216a_data *data, int itime) > +{ > + int i, ret, index = -1; Redundant assignment, and actually not needed variable 'index', see below. > + u8 reg_val; > + > + for (i = 0; i < ARRAY_SIZE(ltrf216a_int_time_available); i++) { > + if (ltrf216a_int_time_available[i][1] == itime) { > + index = i; > + break; > + } if (...) break; > + } > + You can drop this blank line in order to show the tough connection between for-loop and if-cond. > + if (index < 0) > + return -EINVAL; if (i == ARRAY_SIZE(...)) return ... And use i here, which actually can be typed as unsigned int above. > + reg_val = ltrf216a_int_time_reg[index][1]; > + data->int_time_fac = ltrf216a_int_time_reg[index][0]; > + > + ret = i2c_smbus_write_byte_data(data->client, LTRF216A_ALS_MEAS_RES, reg_val); > + if (ret < 0) > + return ret; > + > + data->int_time = itime; > + > + return 0; > +} ... > +static int ltrf216a_read_data(struct ltrf216a_data *data, u8 addr) > +{ > + int ret = -1, tries = 25; No need to assign ret. And please avoid assigning returned values to some negative values that may be misinterpreted as error codes. > + u8 buf[3]; > + > + while (tries--) { > + ret = i2c_smbus_read_byte_data(data->client, LTRF216A_MAIN_STATUS); > + if (ret < 0) > + return ret; > + if (ret & LTRF216A_ALS_DATA_STATUS) > + break; > + msleep(20); > + } NIH of a macro from iopoll.h. Use the appropriate one. > + ret = i2c_smbus_read_i2c_block_data(data->client, addr, sizeof(buf), buf); > + if (ret < 0) > + return ret; > + > + return get_unaligned_le24(&buf[0]); > +} ... > + greendata = ltrf216a_read_data(data, LTRF216A_ALS_DATA_0); > + cleardata = ltrf216a_read_data(data, LTRF216A_CLEAR_DATA_0); > + > + if (greendata < 0 || cleardata < 0) > + return -EINVAL; I am expecting that each of them may contain the actual error code, so, please decouple the condition and return the actual error codes. ... > + switch (mask) { > + case IIO_CHAN_INFO_PROCESSED: > + ret = ltrf216a_get_lux(data); > + if (ret < 0) { > + mutex_unlock(&data->mutex); > + return ret; Wouldn't 'break' suffice? > + } > + *val = ret; > + ret = IIO_VAL_INT; > + break; > + case IIO_CHAN_INFO_INT_TIME: > + ret = ltrf216a_get_int_time(data, val, val2); > + break; > + default: > + ret = -EINVAL; Missed break;. > + } > + > + mutex_unlock(&data->mutex); > + > + return ret; ... > + ret = ltrf216a_init(indio_dev); > + if (ret < 0) > + return dev_err_probe(&client->dev, ret, > + "ltrf216a chip init failed\n"); One line? Esp. if you create a temporary variable to hold a device pointer. ... > + ret = devm_add_action_or_reset(&client->dev, als_ltrf216a_disable, > + indio_dev); Ditto. > + if (ret < 0) > + return ret; ... > +static struct i2c_driver ltrf216a_driver = { > + .driver = { > + .name = LTRF216A_DRV_NAME, > + .pm = pm_sleep_ptr(<rf216a_pm_ops), > + .of_match_table = ltrf216a_of_match, > + }, > + .probe_new = ltrf216a_probe, > + .id_table = ltrf216a_id, > +}; > + Redundant blank line. > +module_i2c_driver(ltrf216a_driver);
Hello Shreeya, ... > +#include <linux/init.h> > +#include <linux/mod_devicetable.h> You may safely remove these includes because module.h always provides them. > +#include <linux/module.h> > +#include <linux/mutex.h> > +#include <linux/pm.h> > +#include <linux/iio/iio.h> > +#include <asm/unaligned.h> > + > +#define LTRF216A_DRV_NAME "ltrf216a" This define doesn't bring much benefits, you may use "ltrf216a" directly in the code. > +#define LTRF216A_MAIN_CTRL 0x00 > + > +#define LTRF216A_ALS_DATA_STATUS BIT(3) > +#define LTRF216A_ALS_ENABLE_MASK BIT(1) > + > +#define LTRF216A_ALS_MEAS_RES 0x04 > +#define LTRF216A_MAIN_STATUS 0x07 > +#define LTRF216A_CLEAR_DATA_0 0x0A > + Is any reason for separating these regs with a newline? If no, then you may remove this newline. > +#define LTRF216A_ALS_DATA_0 0x0D > + ... > +struct ltrf216a_data { > + struct i2c_client *client; > + u32 int_time; > + u16 int_time_fac; > + u8 als_gain_fac; > + /* > + * Ensure cached value of integration time is consistent > + * with hardware setting and remains constant during a > + * measurement of Lux. > + */ > + struct mutex mutex; I'd rename the "mutex" -> "lock". > +}; > + > +/* open air. need to update based on TP transmission rate. */ > +#define WIN_FAC 1 Usually all defines are placed before the code. You may move this define before struct ltrf216a_data. ... > +static int ltrf216a_init(struct iio_dev *indio_dev) > +{ > + int ret; > + struct ltrf216a_data *data = iio_priv(indio_dev); Reverse Xmas tree is a common coding style in kernel for the function variables. ****** **** ** Will be great if you could use the same coding style everywhere in this source file, i.e. like this: struct ltrf216a_data *data = iio_priv(indio_dev); int ret; > + ret = i2c_smbus_read_byte_data(data->client, LTRF216A_MAIN_CTRL); > + if (ret < 0) { > + dev_err(&data->client->dev, "Error reading LTRF216A_MAIN_CTRL\n"); > + return ret; > + } > + > + /* enable sensor */ > + ret |= FIELD_PREP(LTRF216A_ALS_ENABLE_MASK, 1); > + ret = i2c_smbus_write_byte_data(data->client, LTRF216A_MAIN_CTRL, ret); > + if (ret < 0) { > + dev_err(&data->client->dev, "Error writing LTRF216A_MAIN_CTRL\n"); This message doesn't tell us the error code, which usually is very handy to know. I'd also change all the error messages in this driver to tell which action failed, like this: dev_err(dev, "Failed to enable sensor: %d\n", ret); > + return ret; > + } > + > + return 0; > +} > + > +static int ltrf216a_disable(struct iio_dev *indio_dev) > +{ > + int ret; > + struct ltrf216a_data *data = iio_priv(indio_dev); > + > + ret = i2c_smbus_write_byte_data(data->client, LTRF216A_MAIN_CTRL, 0); > + if (ret < 0) > + dev_err(&data->client->dev, "Error writing LTRF216A_MAIN_CTRL\n"); Please add error code to the message here too and reword it. This is exactly the same error message as in ltrf216a_init(), so you can't distinguish whether it's enabling or disabling that failed. > + return ret; > +} > + > +static void als_ltrf216a_disable(void *data) > +{ > + struct iio_dev *indio_dev = data; > + > + ltrf216a_disable(indio_dev); > +} > + > +static int ltrf216a_set_int_time(struct ltrf216a_data *data, int itime) > +{ > + int i, ret, index = -1; > + u8 reg_val; > + > + for (i = 0; i < ARRAY_SIZE(ltrf216a_int_time_available); i++) { > + if (ltrf216a_int_time_available[i][1] == itime) { > + index = i; > + break; > + } > + } > + > + if (index < 0) > + return -EINVAL; > + > + reg_val = ltrf216a_int_time_reg[index][1]; > + data->int_time_fac = ltrf216a_int_time_reg[index][0]; > + > + ret = i2c_smbus_write_byte_data(data->client, LTRF216A_ALS_MEAS_RES, reg_val); > + if (ret < 0) > + return ret; Won't hurt to add error message here for consistency. > + data->int_time = itime; > + > + return 0; > +} > + > +static int ltrf216a_get_int_time(struct ltrf216a_data *data, int *val, int *val2) > +{ > + *val = 0; > + *val2 = data->int_time; > + return IIO_VAL_INT_PLUS_MICRO; > +} > + > +static int ltrf216a_read_data(struct ltrf216a_data *data, u8 addr) > +{ > + int ret = -1, tries = 25; No need to initialize the ret variable. > + u8 buf[3]; > + > + while (tries--) { > + ret = i2c_smbus_read_byte_data(data->client, LTRF216A_MAIN_STATUS); > + if (ret < 0) > + return ret; Need error message > + if (ret & LTRF216A_ALS_DATA_STATUS) > + break; > + msleep(20); > + } > + > + ret = i2c_smbus_read_i2c_block_data(data->client, addr, sizeof(buf), buf); > + if (ret < 0) > + return ret; Same here .. > +MODULE_AUTHOR("Shi Zhigang <Zhigang.Shi@liteon.com>"); Driver could have multiple MODULE_AUTHOR(), you may add yourself here: MODULE_AUTHOR("Shreeya Patel <shreeya.patel@collabora.com>")
11.05.2022 12:40, Shreeya Patel пишет: > +static int ltrf216a_probe(struct i2c_client *client) > +{ > + struct ltrf216a_data *data; > + struct iio_dev *indio_dev; > + int ret; > + > + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); > + if (!indio_dev) > + return -ENOMEM; > + > + data = iio_priv(indio_dev); > + i2c_set_clientdata(client, indio_dev); > + data->client = client; > + > + mutex_init(&data->mutex); > + > + indio_dev->info = <rf216a_info; > + indio_dev->name = LTRF216A_DRV_NAME; > + indio_dev->channels = ltrf216a_channels; > + indio_dev->num_channels = ARRAY_SIZE(ltrf216a_channels); > + indio_dev->modes = INDIO_DIRECT_MODE; > + > + ret = ltrf216a_init(indio_dev); > + if (ret < 0) > + return dev_err_probe(&client->dev, ret, > + "ltrf216a chip init failed\n"); Is it possible to enable sensor only when measurement is made for more power savings? Light sensor shouldn't consume much power, but nevertheless. You'll need to add msleep(power_on_delay + resolution_rate_delay) after enabling sensor and before reading the measurement to wait until measurement is made by h/w.
11.05.2022 12:40, Shreeya Patel пишет: > +static int ltrf216a_init(struct iio_dev *indio_dev) > +{ > + int ret; > + struct ltrf216a_data *data = iio_priv(indio_dev); > + > + ret = i2c_smbus_read_byte_data(data->client, LTRF216A_MAIN_CTRL); > + if (ret < 0) { > + dev_err(&data->client->dev, "Error reading LTRF216A_MAIN_CTRL\n"); > + return ret; > + } > + > + /* enable sensor */ > + ret |= FIELD_PREP(LTRF216A_ALS_ENABLE_MASK, 1); > + ret = i2c_smbus_write_byte_data(data->client, LTRF216A_MAIN_CTRL, ret); > + if (ret < 0) { > + dev_err(&data->client->dev, "Error writing LTRF216A_MAIN_CTRL\n"); > + return ret; > + } Couldn't you write "1" directly without reading? What about doing SW reset?
11.05.2022 12:40, Shreeya Patel пишет: > +static int ltrf216a_get_lux(struct ltrf216a_data *data) > +{ > + int greendata, cleardata; > + u64 lux, div; > + > + greendata = ltrf216a_read_data(data, LTRF216A_ALS_DATA_0); > + cleardata = ltrf216a_read_data(data, LTRF216A_CLEAR_DATA_0); Could you please explain what is cleardata?
11.05.2022 12:40, Shreeya Patel пишет: > +static int ltrf216a_get_lux(struct ltrf216a_data *data) > +{ > + int greendata, cleardata; > + u64 lux, div; > + > + greendata = ltrf216a_read_data(data, LTRF216A_ALS_DATA_0); > + cleardata = ltrf216a_read_data(data, LTRF216A_CLEAR_DATA_0); > + > + if (greendata < 0 || cleardata < 0) > + return -EINVAL; -EIO should be more appropriate error code here
11.05.2022 12:40, Shreeya Patel пишет: > +static int ltrf216a_set_int_time(struct ltrf216a_data *data, int itime) > +{ > + int i, ret, index = -1; > + u8 reg_val; > + > + for (i = 0; i < ARRAY_SIZE(ltrf216a_int_time_available); i++) { > + if (ltrf216a_int_time_available[i][1] == itime) { > + index = i; > + break; > + } > + } > + > + if (index < 0) > + return -EINVAL; > + > + reg_val = ltrf216a_int_time_reg[index][1]; > + data->int_time_fac = ltrf216a_int_time_reg[index][0]; > + > + ret = i2c_smbus_write_byte_data(data->client, LTRF216A_ALS_MEAS_RES, reg_val); > + if (ret < 0) > + return ret; Should the data->int_time_fac be updated only if I2C write was successful? I'm not sure what reading of LTRF216A_CLEAR_DATA reg does, but if it clears the measured data, then shouldn't the data be cleared after changing the config? > + data->int_time = itime; > + > + return 0; > +}
On 13/05/22 05:24, Dmitry Osipenko wrote: Hi Dmitry, > 11.05.2022 12:40, Shreeya Patel пишет: >> +static int ltrf216a_init(struct iio_dev *indio_dev) >> +{ >> + int ret; >> + struct ltrf216a_data *data = iio_priv(indio_dev); >> + >> + ret = i2c_smbus_read_byte_data(data->client, LTRF216A_MAIN_CTRL); >> + if (ret < 0) { >> + dev_err(&data->client->dev, "Error reading LTRF216A_MAIN_CTRL\n"); >> + return ret; >> + } >> + >> + /* enable sensor */ >> + ret |= FIELD_PREP(LTRF216A_ALS_ENABLE_MASK, 1); >> + ret = i2c_smbus_write_byte_data(data->client, LTRF216A_MAIN_CTRL, ret); >> + if (ret < 0) { >> + dev_err(&data->client->dev, "Error writing LTRF216A_MAIN_CTRL\n"); >> + return ret; >> + } > Couldn't you write "1" directly without reading? > > What about doing SW reset? I think we are doing a read here just to make sure device registers are ready and accessible without any issues. Also, why would we want to do a SW reset here? In the datasheet, I could see the following steps to enable the sensor Supply VDD to Sensor (Sensor in Standby Mode) ---> Wait 100 ms (min) - initial startup time ---> I2C Command (Write) To enable sensor to Active Mode Thanks, Shreeya Patel >
On 13/05/22 19:10, Shreeya Patel wrote: > > On 13/05/22 05:24, Dmitry Osipenko wrote: > > Hi Dmitry, > >> 11.05.2022 12:40, Shreeya Patel пишет: >>> +static int ltrf216a_init(struct iio_dev *indio_dev) >>> +{ >>> + int ret; >>> + struct ltrf216a_data *data = iio_priv(indio_dev); >>> + >>> + ret = i2c_smbus_read_byte_data(data->client, LTRF216A_MAIN_CTRL); >>> + if (ret < 0) { >>> + dev_err(&data->client->dev, "Error reading >>> LTRF216A_MAIN_CTRL\n"); >>> + return ret; >>> + } >>> + >>> + /* enable sensor */ >>> + ret |= FIELD_PREP(LTRF216A_ALS_ENABLE_MASK, 1); >>> + ret = i2c_smbus_write_byte_data(data->client, >>> LTRF216A_MAIN_CTRL, ret); >>> + if (ret < 0) { >>> + dev_err(&data->client->dev, "Error writing >>> LTRF216A_MAIN_CTRL\n"); >>> + return ret; >>> + } >> Couldn't you write "1" directly without reading? >> >> What about doing SW reset? > > I think we are doing a read here just to make sure device registers > are ready and accessible > without any issues. > I just came to know that in I2C communication, writing a single bit requires reading the old value (whole byte), modifying the result (i.e. set or clear the bit one is interested in) and then write it back. So the above code writes the enable bit without modifying the other bits in the LTRF216A_MAIN_CTRL register. ( Thanks to Sebastian ) And you are right, we don't need to do a read here since we anyway want all other bits of LTRF216A_MAIN_CTRL to be 0. Thanks, Shreeya Patel > Also, why would we want to do a SW reset here? > > In the datasheet, I could see the following steps to enable the sensor > Supply VDD to Sensor (Sensor in Standby Mode) ---> Wait 100 ms (min) - > initial startup time > ---> I2C Command (Write) To enable sensor to Active Mode > > Thanks, > Shreeya Patel > >> >
13.05.2022 16:40, Shreeya Patel пишет: > Also, why would we want to do a SW reset here? > > In the datasheet, I could see the following steps to enable the sensor > Supply VDD to Sensor (Sensor in Standby Mode) ---> Wait 100 ms (min) - > initial startup time > ---> I2C Command (Write) To enable sensor to Active Mode For example, if you'll do kexec from other kernel, say downstream kernel, then the h/w state is undetermined for us. It's a common problem with downstream drivers that they rely on a specific state left from bootloader, which is often unacceptable for upstream. If we'll do the SW reset on probe, then we'll bring h/w into the predictable state and won't depend on state left from bootloader or anything else that touched h/w before us.
On Fri, 13 May 2022 02:40:41 +0300 Dmitry Osipenko <digetx@gmail.com> wrote: > Hello Shreeya, > > ... > > +#include <linux/init.h> > > +#include <linux/mod_devicetable.h> > > You may safely remove these includes because module.h always provides them. Safely yes, but generally I'd prefer direct include of mod_devicetable.h because of the direct use of elements from it in the driver. Jonathan
On 13/05/22 06:00, Dmitry Osipenko wrote: > 11.05.2022 12:40, Shreeya Patel пишет: >> +static int ltrf216a_set_int_time(struct ltrf216a_data *data, int itime) >> +{ >> + int i, ret, index = -1; >> + u8 reg_val; >> + >> + for (i = 0; i < ARRAY_SIZE(ltrf216a_int_time_available); i++) { >> + if (ltrf216a_int_time_available[i][1] == itime) { >> + index = i; >> + break; >> + } >> + } >> + >> + if (index < 0) >> + return -EINVAL; >> + >> + reg_val = ltrf216a_int_time_reg[index][1]; >> + data->int_time_fac = ltrf216a_int_time_reg[index][0]; >> + >> + ret = i2c_smbus_write_byte_data(data->client, LTRF216A_ALS_MEAS_RES, reg_val); >> + if (ret < 0) >> + return ret; > Should the data->int_time_fac be updated only if I2C write was successful? Yes, thanks for pointing it out. It should be updated only if write is successful. > I'm not sure what reading of LTRF216A_CLEAR_DATA reg does, but if it > clears the measured data, then shouldn't the data be cleared after > changing the config? LTRF216A_CLEAR_DATA isn't used for clearing the measured data. Name is a bit confusing and even I assumed it is being used for clearing the data. But from the datasheet, it seems that clear data registers provides light intensity data related to infrared and ultravoilet. We are currently not using this anywhere in the driver so we could remove the cleardata readings for now. Thanks, Shreeya Patel >> + data->int_time = itime; >> + >> + return 0; >> +} >
diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig index a62c7b4b8678..33d2b24ba1da 100644 --- a/drivers/iio/light/Kconfig +++ b/drivers/iio/light/Kconfig @@ -318,6 +318,16 @@ config SENSORS_LM3533 changes. The ALS-control output values can be set per zone for the three current output channels. +config LTRF216A + tristate "Liteon LTRF216A Light Sensor" + depends on I2C + help + If you say Y or M here, you get support for Liteon LTRF216A + Ambient Light Sensor. + + If built as a dynamically linked module, it will be called + ltrf216a. + config LTR501 tristate "LTR-501ALS-01 light sensor" depends on I2C diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile index d10912faf964..8fa91b9fe5b6 100644 --- a/drivers/iio/light/Makefile +++ b/drivers/iio/light/Makefile @@ -30,6 +30,7 @@ obj-$(CONFIG_SENSORS_ISL29028) += isl29028.o obj-$(CONFIG_ISL29125) += isl29125.o obj-$(CONFIG_JSA1212) += jsa1212.o obj-$(CONFIG_SENSORS_LM3533) += lm3533-als.o +obj-$(CONFIG_LTRF216A) += ltrf216a.o obj-$(CONFIG_LTR501) += ltr501.o obj-$(CONFIG_LV0104CS) += lv0104cs.o obj-$(CONFIG_MAX44000) += max44000.o diff --git a/drivers/iio/light/ltrf216a.c b/drivers/iio/light/ltrf216a.c new file mode 100644 index 000000000000..05ae9912c854 --- /dev/null +++ b/drivers/iio/light/ltrf216a.c @@ -0,0 +1,346 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * LTRF216A Ambient Light Sensor + * + * Copyright (C) 2021 Lite-On Technology Corp (Singapore) + * Author: Shi Zhigang <Zhigang.Shi@liteon.com> + * + * IIO driver for LTRF216A (7-bit I2C slave address 0x53). + */ + +#include <linux/bitfield.h> +#include <linux/delay.h> +#include <linux/i2c.h> +#include <linux/init.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/pm.h> +#include <linux/iio/iio.h> +#include <asm/unaligned.h> + +#define LTRF216A_DRV_NAME "ltrf216a" + +#define LTRF216A_MAIN_CTRL 0x00 + +#define LTRF216A_ALS_DATA_STATUS BIT(3) +#define LTRF216A_ALS_ENABLE_MASK BIT(1) + +#define LTRF216A_ALS_MEAS_RES 0x04 +#define LTRF216A_MAIN_STATUS 0x07 +#define LTRF216A_CLEAR_DATA_0 0x0A + +#define LTRF216A_ALS_DATA_0 0x0D + +static const int ltrf216a_int_time_available[5][2] = { + {0, 400000}, + {0, 200000}, + {0, 100000}, + {0, 50000}, + {0, 25000}, +}; + +static const int ltrf216a_int_time_reg[5][2] = { + {400, 0x03}, + {200, 0x13}, + {100, 0x22}, + {50, 0x31}, + {25, 0x40}, +}; + +struct ltrf216a_data { + struct i2c_client *client; + u32 int_time; + u16 int_time_fac; + u8 als_gain_fac; + /* + * Ensure cached value of integration time is consistent + * with hardware setting and remains constant during a + * measurement of Lux. + */ + struct mutex mutex; +}; + +/* open air. need to update based on TP transmission rate. */ +#define WIN_FAC 1 + +static const struct iio_chan_spec ltrf216a_channels[] = { + { + .type = IIO_LIGHT, + .info_mask_separate = + BIT(IIO_CHAN_INFO_PROCESSED) | + BIT(IIO_CHAN_INFO_INT_TIME), + .info_mask_separate_available = + BIT(IIO_CHAN_INFO_INT_TIME), + } +}; + +static int ltrf216a_init(struct iio_dev *indio_dev) +{ + int ret; + struct ltrf216a_data *data = iio_priv(indio_dev); + + ret = i2c_smbus_read_byte_data(data->client, LTRF216A_MAIN_CTRL); + if (ret < 0) { + dev_err(&data->client->dev, "Error reading LTRF216A_MAIN_CTRL\n"); + return ret; + } + + /* enable sensor */ + ret |= FIELD_PREP(LTRF216A_ALS_ENABLE_MASK, 1); + ret = i2c_smbus_write_byte_data(data->client, LTRF216A_MAIN_CTRL, ret); + if (ret < 0) { + dev_err(&data->client->dev, "Error writing LTRF216A_MAIN_CTRL\n"); + return ret; + } + + return 0; +} + +static int ltrf216a_disable(struct iio_dev *indio_dev) +{ + int ret; + struct ltrf216a_data *data = iio_priv(indio_dev); + + ret = i2c_smbus_write_byte_data(data->client, LTRF216A_MAIN_CTRL, 0); + if (ret < 0) + dev_err(&data->client->dev, "Error writing LTRF216A_MAIN_CTRL\n"); + + return ret; +} + +static void als_ltrf216a_disable(void *data) +{ + struct iio_dev *indio_dev = data; + + ltrf216a_disable(indio_dev); +} + +static int ltrf216a_set_int_time(struct ltrf216a_data *data, int itime) +{ + int i, ret, index = -1; + u8 reg_val; + + for (i = 0; i < ARRAY_SIZE(ltrf216a_int_time_available); i++) { + if (ltrf216a_int_time_available[i][1] == itime) { + index = i; + break; + } + } + + if (index < 0) + return -EINVAL; + + reg_val = ltrf216a_int_time_reg[index][1]; + data->int_time_fac = ltrf216a_int_time_reg[index][0]; + + ret = i2c_smbus_write_byte_data(data->client, LTRF216A_ALS_MEAS_RES, reg_val); + if (ret < 0) + return ret; + + data->int_time = itime; + + return 0; +} + +static int ltrf216a_get_int_time(struct ltrf216a_data *data, int *val, int *val2) +{ + *val = 0; + *val2 = data->int_time; + return IIO_VAL_INT_PLUS_MICRO; +} + +static int ltrf216a_read_data(struct ltrf216a_data *data, u8 addr) +{ + int ret = -1, tries = 25; + u8 buf[3]; + + while (tries--) { + ret = i2c_smbus_read_byte_data(data->client, LTRF216A_MAIN_STATUS); + if (ret < 0) + return ret; + if (ret & LTRF216A_ALS_DATA_STATUS) + break; + msleep(20); + } + + ret = i2c_smbus_read_i2c_block_data(data->client, addr, sizeof(buf), buf); + if (ret < 0) + return ret; + + return get_unaligned_le24(&buf[0]); +} + +static int ltrf216a_get_lux(struct ltrf216a_data *data) +{ + int greendata, cleardata; + u64 lux, div; + + greendata = ltrf216a_read_data(data, LTRF216A_ALS_DATA_0); + cleardata = ltrf216a_read_data(data, LTRF216A_CLEAR_DATA_0); + + if (greendata < 0 || cleardata < 0) + return -EINVAL; + + lux = greendata * 45 * WIN_FAC * 100; + div = data->als_gain_fac * data->int_time_fac * 100; + + return div_u64(lux, div); +} + +static int ltrf216a_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, int *val, + int *val2, long mask) +{ + int ret; + struct ltrf216a_data *data = iio_priv(indio_dev); + + mutex_lock(&data->mutex); + + switch (mask) { + case IIO_CHAN_INFO_PROCESSED: + ret = ltrf216a_get_lux(data); + if (ret < 0) { + mutex_unlock(&data->mutex); + return ret; + } + *val = ret; + ret = IIO_VAL_INT; + break; + case IIO_CHAN_INFO_INT_TIME: + ret = ltrf216a_get_int_time(data, val, val2); + break; + default: + ret = -EINVAL; + } + + mutex_unlock(&data->mutex); + + return ret; +} + +static int ltrf216a_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, int val, + int val2, long mask) +{ + struct ltrf216a_data *data = iio_priv(indio_dev); + int ret; + + switch (mask) { + case IIO_CHAN_INFO_INT_TIME: + if (val != 0) + return -EINVAL; + mutex_lock(&data->mutex); + ret = ltrf216a_set_int_time(data, val2); + mutex_unlock(&data->mutex); + return ret; + default: + return -EINVAL; + } +} + +static int ltrf216a_read_available(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + const int **vals, int *type, int *length, + long mask) +{ + switch (mask) { + case IIO_CHAN_INFO_INT_TIME: + *length = ARRAY_SIZE(ltrf216a_int_time_available) * 2; + *vals = (const int *)ltrf216a_int_time_available; + *type = IIO_VAL_INT_PLUS_MICRO; + return IIO_AVAIL_LIST; + default: + return -EINVAL; + } +} + +static const struct iio_info ltrf216a_info = { + .read_raw = ltrf216a_read_raw, + .write_raw = ltrf216a_write_raw, + .read_avail = ltrf216a_read_available, +}; + +static int ltrf216a_probe(struct i2c_client *client) +{ + struct ltrf216a_data *data; + struct iio_dev *indio_dev; + int ret; + + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); + if (!indio_dev) + return -ENOMEM; + + data = iio_priv(indio_dev); + i2c_set_clientdata(client, indio_dev); + data->client = client; + + mutex_init(&data->mutex); + + indio_dev->info = <rf216a_info; + indio_dev->name = LTRF216A_DRV_NAME; + indio_dev->channels = ltrf216a_channels; + indio_dev->num_channels = ARRAY_SIZE(ltrf216a_channels); + indio_dev->modes = INDIO_DIRECT_MODE; + + ret = ltrf216a_init(indio_dev); + if (ret < 0) + return dev_err_probe(&client->dev, ret, + "ltrf216a chip init failed\n"); + + data->int_time = 100000; + data->int_time_fac = 100; + data->als_gain_fac = 3; + + ret = devm_add_action_or_reset(&client->dev, als_ltrf216a_disable, + indio_dev); + if (ret < 0) + return ret; + + return devm_iio_device_register(&client->dev, indio_dev); +} + +static int ltrf216a_suspend(struct device *dev) +{ + struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev)); + + return ltrf216a_disable(indio_dev); +} + +static int ltrf216a_resume(struct device *dev) +{ + struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev)); + + return ltrf216a_init(indio_dev); +} + +static DEFINE_SIMPLE_DEV_PM_OPS(ltrf216a_pm_ops, ltrf216a_suspend, ltrf216a_resume); + +static const struct i2c_device_id ltrf216a_id[] = { + { LTRF216A_DRV_NAME, 0 }, + {} +}; +MODULE_DEVICE_TABLE(i2c, ltrf216a_id); + +static const struct of_device_id ltrf216a_of_match[] = { + { .compatible = "liteon,ltrf216a", }, + { .compatible = "ltr,ltrf216a", }, + {} +}; +MODULE_DEVICE_TABLE(of, ltrf216a_of_match); + +static struct i2c_driver ltrf216a_driver = { + .driver = { + .name = LTRF216A_DRV_NAME, + .pm = pm_sleep_ptr(<rf216a_pm_ops), + .of_match_table = ltrf216a_of_match, + }, + .probe_new = ltrf216a_probe, + .id_table = ltrf216a_id, +}; + +module_i2c_driver(ltrf216a_driver); + +MODULE_AUTHOR("Shi Zhigang <Zhigang.Shi@liteon.com>"); +MODULE_DESCRIPTION("LTRF216A ambient light sensor driver"); +MODULE_LICENSE("GPL");