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References: <20220714091312.838152-1-shreeya.patel@collabora.com> <20220714091312.838152-3-shreeya.patel@collabora.com>
In-Reply-To: <20220714091312.838152-3-shreeya.patel@collabora.com>
From:   Andy Shevchenko <andy.shevchenko@gmail.com>
Date:   Thu, 14 Jul 2022 15:06:57 +0200
Message-ID: <CAHp75Vdmg_hf0VbQXshWSfRuBRo7LgP8J5pM7iKhjBu0ON0qQA@mail.gmail.com>
Subject: Re: [PATCH v8 2/2] iio: light: Add support for ltrf216a sensor
To:     Shreeya Patel <shreeya.patel@collabora.com>
Cc:     Jonathan Cameron <jic23@kernel.org>,
        Lars-Peter Clausen <lars@metafoo.de>,
        Rob Herring <robh+dt@kernel.org>,
        Dmitry Osipenko <dmitry.osipenko@collabora.com>,
        Zhigang.Shi@liteon.com, krisman@collabora.com,
        linux-iio <linux-iio@vger.kernel.org>,
        devicetree <devicetree@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Collabora Kernel ML <kernel@collabora.com>,
        alvaro.soliverez@collabora.com
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On Thu, Jul 14, 2022 at 11:14 AM Shreeya Patel
<shreeya.patel@collabora.com> wrote:
>
> Add initial support for ltrf216a ambient light sensor.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

> Datasheet: https://gitlab.steamos.cloud/shreeya/iio/-/blob/main/LTRF216A.pdf
> Co-developed-by: Zhigang Shi <Zhigang.Shi@liteon.com>
> Signed-off-by: Zhigang Shi <Zhigang.Shi@liteon.com>
> Co-developed-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
> Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
> Signed-off-by: Shreeya Patel <shreeya.patel@collabora.com>
> ---
>
> Note :-
>
> This patch generates the below mentioned warnings due to not documenting
> the 'ltr' string in vendors-prefix.yaml and liteon,ltrf216a.yaml files.
> The thread for the discussion of not documenting 'ltr' as deprecated
> prefix can be found here.
> https://lore.kernel.org/lkml/20220511094024.175994-2-shreeya.patel@collabora.com/
>
> There are released devices which uses ltr216a light sensor and exposes the
> vendor prefix name as 'ltr' through ACPI. Hence, we would like to add
> this string under compatible property which would help probe the light sensor
> driver.
>
> WARNING: DT compatible string "ltr,ltrf216a" appears un-documented
> -- check ./Documentation/devicetree/bindings/
> #474: FILE: drivers/iio/light/ltrf216a.c:421:
> +       { .compatible = "ltr,ltrf216a", },
>
> WARNING: DT compatible string vendor "ltr" appears un-documented
> -- check ./Documentation/devicetree/bindings/vendor-prefixes.yaml
> #474: FILE: drivers/iio/light/ltrf216a.c:421:
> +       { .compatible = "ltr,ltrf216a", },
>
> Changes in v8
>   - Add caching mechanism to restore register state after h/w resume.
>   - Add callback functions and disable locking in regmap config.
>   - Update mutex comment as per it's current scope in the driver.
>   - Add Shreeya as author of the driver.
>   - Make some minor cleanups.
>
> Changes in v7
>   - Add regmap support.
>   - Fix runtime power management implementation.
>   - Fix the ordering of devm and non-devm functions.
>   - Use DEFINE_RUNTIME_DEV_PM_OPS macro
>
> Changes in v6
>   - Fix some errors reported by kernel test robot.
>   - Add protocol details for the datasheet link.
>   - Remove useless assignments.
>   - Add unit details for read data delay macro.
>   - Use pm_sleep_ptr().
>
> Changes in v5
>   - Add power management support.
>   - Add reset functionality.
>   - Use readx_poll_timeout() to get data.
>   - Cleanup some of the redundant code.
>   - Update int_time_fac after I2C write is successful.
>   - Rename mutex to lock.
>   - Use Reverse Xmas tree pattern for all variable definitions.
>   - Improve error handling messages and add error codes.
>   - Add one more MODULE_AUTHOR.
>   - Remove cleardata which was reading data for infrared light.
>
> Changes in v4
>   - Add more descriptive comment for mutex lock
>   - Fix mutex locking in read_raw()
>   - Use i2c_smbus_read_i2c_block_data()
>
> Changes in v3
>   - Use u16 instead of u8 for int_time_fac
>   - Reorder headers in ltrf216a.c file
>   - Remove int_time_mapping table and use int_time_available
>
> Changes in v2
>   - Add support for 25ms and 50ms integration time.
>   - Rename some of the macros as per names given in datasheet
>   - Add a comment for the mutex lock
>   - Use read_avail callback instead of attributes and set the
>     appropriate _available bit.
>   - Use FIELD_PREP() at appropriate places.
>   - Add a constant lookup table for integration time and reg val
>   - Use BIT() macro for magic numbers.
>   - Improve error handling at few places.
>   - Use get_unaligned_le24() and div_u64()
>   - Use probe_new() callback and devm functions
>   - Return errors in probe using dev_err_probe()
>   - Use DEFINE_SIMPLE_DEV_PM_OPS()
>   - Correct the formula for lux to use 0.45 instead of 0.8
>
>
>  drivers/iio/light/Kconfig    |  11 +
>  drivers/iio/light/Makefile   |   1 +
>  drivers/iio/light/ltrf216a.c | 522 +++++++++++++++++++++++++++++++++++
>  3 files changed, 534 insertions(+)
>  create mode 100644 drivers/iio/light/ltrf216a.c
>
> diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
> index 8537e88f02e3..7cf6e8490123 100644
> --- a/drivers/iio/light/Kconfig
> +++ b/drivers/iio/light/Kconfig
> @@ -331,6 +331,17 @@ config LTR501
>           This driver can also be built as a module.  If so, the module
>           will be called ltr501.
>
> +config LTRF216A
> +       tristate "Liteon LTRF216A Light Sensor"
> +       depends on I2C
> +       select REGMAP_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 LV0104CS
>         tristate "LV0104CS Ambient Light Sensor"
>         depends on I2C
> diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile
> index d10912faf964..6f23817fae6f 100644
> --- a/drivers/iio/light/Makefile
> +++ b/drivers/iio/light/Makefile
> @@ -31,6 +31,7 @@ obj-$(CONFIG_ISL29125)                += isl29125.o
>  obj-$(CONFIG_JSA1212)          += jsa1212.o
>  obj-$(CONFIG_SENSORS_LM3533)   += lm3533-als.o
>  obj-$(CONFIG_LTR501)           += ltr501.o
> +obj-$(CONFIG_LTRF216A)         += ltrf216a.o
>  obj-$(CONFIG_LV0104CS)         += lv0104cs.o
>  obj-$(CONFIG_MAX44000)         += max44000.o
>  obj-$(CONFIG_MAX44009)         += max44009.o
> diff --git a/drivers/iio/light/ltrf216a.c b/drivers/iio/light/ltrf216a.c
> new file mode 100644
> index 000000000000..fd0c5dd5ffa0
> --- /dev/null
> +++ b/drivers/iio/light/ltrf216a.c
> @@ -0,0 +1,522 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * LTRF216A Ambient Light Sensor
> + *
> + * Copyright (C) 2022 Collabora, Ltd.
> + * Author: Shreeya Patel <shreeya.patel@collabora.com>
> + *
> + * 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/bits.h>
> +#include <linux/delay.h>
> +#include <linux/i2c.h>
> +#include <linux/init.h>
> +#include <linux/iopoll.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/pm.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/regmap.h>
> +
> +#include <linux/iio/iio.h>
> +
> +#include <asm/unaligned.h>
> +
> +#define LTRF216A_ALS_RESET_MASK                BIT(4)
> +#define LTRF216A_ALS_DATA_STATUS       BIT(3)
> +#define LTRF216A_ALS_ENABLE_MASK       BIT(1)
> +#define LTRF216A_MAIN_CTRL             0x00
> +#define LTRF216A_ALS_MEAS_RES          0x04
> +#define LTRF216A_ALS_GAIN              0x05
> +#define LTRF216A_PART_ID               0x06
> +#define LTRF216A_MAIN_STATUS           0x07
> +#define LTRF216A_ALS_CLEAR_DATA_0      0x0a
> +#define LTRF216A_ALS_CLEAR_DATA_1      0x0b
> +#define LTRF216A_ALS_CLEAR_DATA_2      0x0c
> +#define LTRF216A_ALS_DATA_0            0x0d
> +#define LTRF216A_ALS_DATA_1            0x0e
> +#define LTRF216A_ALS_DATA_2            0x0f
> +#define LTRF216A_INT_CFG               0x19
> +#define LTRF216A_INT_PST               0x1a
> +#define LTRF216A_ALS_THRES_UP_0                0x21
> +#define LTRF216A_ALS_THRES_UP_1                0x22
> +#define LTRF216A_ALS_THRES_UP_2                0x23
> +#define LTRF216A_ALS_THRES_LOW_0       0x24
> +#define LTRF216A_ALS_THRES_LOW_1       0x25
> +#define LTRF216A_ALS_THRES_LOW_2       0x26
> +#define LTRF216A_ALS_READ_DATA_DELAY_US        20000
> +
> +static const int ltrf216a_int_time_available[][2] = {
> +       { 0, 400000 },
> +       { 0, 200000 },
> +       { 0, 100000 },
> +       { 0,  50000 },
> +       { 0,  25000 },
> +};
> +
> +static const int ltrf216a_int_time_reg[][2] = {
> +       { 400, 0x03 },
> +       { 200, 0x13 },
> +       { 100, 0x22 },
> +       {  50, 0x31 },
> +       {  25, 0x40 },
> +};
> +
> +/*
> + * Window Factor is needed when the device is under Window glass
> + * with coated tinted ink. This is to compensate for the light loss
> + * due to the lower transmission rate of the window glass and helps
> + * in calculating lux.
> + */
> +#define LTRF216A_WIN_FAC       1
> +
> +struct ltrf216a_data {
> +       struct regmap *regmap;
> +       struct i2c_client *client;
> +       u32 int_time;
> +       u16 int_time_fac;
> +       u8 als_gain_fac;
> +       /*
> +        * Protects regmap accesses and makes sure integration time
> +        * remains constant during the measurement of lux.
> +        */
> +       struct mutex lock;
> +};
> +
> +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 void ltrf216a_reset(struct iio_dev *indio_dev)
> +{
> +       struct ltrf216a_data *data = iio_priv(indio_dev);
> +
> +       /* reset sensor, chip fails to respond to this, so ignore any errors */
> +       regmap_write(data->regmap, LTRF216A_MAIN_CTRL, LTRF216A_ALS_RESET_MASK);
> +
> +       /* reset time */
> +       usleep_range(1000, 2000);
> +}
> +
> +static int ltrf216a_enable(struct iio_dev *indio_dev)
> +{
> +       struct ltrf216a_data *data = iio_priv(indio_dev);
> +       struct device *dev = &data->client->dev;
> +       int ret;
> +
> +       /* enable sensor */
> +       ret = regmap_set_bits(data->regmap,
> +                             LTRF216A_MAIN_CTRL, LTRF216A_ALS_ENABLE_MASK);
> +       if (ret) {
> +               dev_err(dev, "failed to enable sensor: %d\n", ret);
> +               return ret;
> +       }
> +
> +       /* sleep for one integration cycle after enabling the device */
> +       msleep(ltrf216a_int_time_reg[0][0]);
> +
> +       return 0;
> +}
> +
> +static int ltrf216a_disable(struct iio_dev *indio_dev)
> +{
> +       struct ltrf216a_data *data = iio_priv(indio_dev);
> +       struct device *dev = &data->client->dev;
> +       int ret;
> +
> +       ret = regmap_write(data->regmap, LTRF216A_MAIN_CTRL, 0);
> +       if (ret)
> +               dev_err(dev, "failed to disable sensor: %d\n", ret);
> +
> +       return ret;
> +}
> +
> +static int ltrf216a_set_int_time(struct ltrf216a_data *data, int itime)
> +{
> +       struct device *dev = &data->client->dev;
> +       unsigned int i;
> +       u8 reg_val;
> +       int ret;
> +
> +       for (i = 0; i < ARRAY_SIZE(ltrf216a_int_time_available); i++) {
> +               if (ltrf216a_int_time_available[i][1] == itime)
> +                       break;
> +       }
> +       if (i == ARRAY_SIZE(ltrf216a_int_time_available))
> +               return -EINVAL;
> +
> +       reg_val = ltrf216a_int_time_reg[i][1];
> +
> +       ret = regmap_write(data->regmap, LTRF216A_ALS_MEAS_RES, reg_val);
> +       if (ret) {
> +               dev_err(dev, "failed to set integration time: %d\n", ret);
> +               return ret;
> +       }
> +
> +       data->int_time_fac = ltrf216a_int_time_reg[i][0];
> +       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_set_power_state(struct ltrf216a_data *data, bool on)
> +{
> +       struct device *dev = &data->client->dev;
> +       int ret;
> +
> +       if (on) {
> +               ret = pm_runtime_resume_and_get(dev);
> +               if (ret) {
> +                       dev_err(dev, "failed to resume runtime PM: %d\n", ret);
> +                       return ret;
> +               }
> +       } else {
> +               pm_runtime_mark_last_busy(dev);
> +               pm_runtime_put_autosuspend(dev);
> +       }
> +
> +       return ret;
> +}
> +
> +static int ltrf216a_read_data(struct ltrf216a_data *data, u8 addr)
> +{
> +       struct device *dev = &data->client->dev;
> +       int ret, val;
> +       u8 buf[3];
> +
> +       ret = regmap_read_poll_timeout(data->regmap, LTRF216A_MAIN_STATUS,
> +                                      val, val & LTRF216A_ALS_DATA_STATUS,
> +                                      LTRF216A_ALS_READ_DATA_DELAY_US,
> +                                      LTRF216A_ALS_READ_DATA_DELAY_US * 50);
> +       if (ret) {
> +               dev_err(dev, "failed to wait for measurement data: %d\n", ret);
> +               return ret;
> +       }
> +
> +       ret = regmap_bulk_read(data->regmap, addr, buf, sizeof(buf));
> +       if (ret) {
> +               dev_err(dev, "failed to read measurement data: %d\n", ret);
> +               return ret;
> +       }
> +
> +       return get_unaligned_le24(&buf[0]);
> +}
> +
> +static int ltrf216a_get_lux(struct ltrf216a_data *data)
> +{
> +       int ret, greendata;
> +       u64 lux, div;
> +
> +       ret = ltrf216a_set_power_state(data, true);
> +       if (ret)
> +               return ret;
> +
> +       greendata = ltrf216a_read_data(data, LTRF216A_ALS_DATA_0);
> +       if (greendata < 0)
> +               return greendata;
> +
> +       ltrf216a_set_power_state(data, false);
> +
> +       lux = greendata * 45 * LTRF216A_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)
> +{
> +       struct ltrf216a_data *data = iio_priv(indio_dev);
> +       int ret;
> +
> +       switch (mask) {
> +       case IIO_CHAN_INFO_PROCESSED:
> +               mutex_lock(&data->lock);
> +               ret = ltrf216a_get_lux(data);
> +               mutex_unlock(&data->lock);
> +               if (ret < 0)
> +                       return ret;
> +               *val = ret;
> +               return IIO_VAL_INT;
> +       case IIO_CHAN_INFO_INT_TIME:
> +               mutex_lock(&data->lock);
> +               ret = ltrf216a_get_int_time(data, val, val2);
> +               mutex_unlock(&data->lock);
> +               return ret;
> +       default:
> +               return -EINVAL;
> +       }
> +}
> +
> +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->lock);
> +               ret = ltrf216a_set_int_time(data, val2);
> +               mutex_unlock(&data->lock);
> +               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 bool ltrf216a_readable_reg(struct device *dev, unsigned int reg)
> +{
> +       switch (reg) {
> +       case LTRF216A_MAIN_CTRL:
> +       case LTRF216A_ALS_MEAS_RES:
> +       case LTRF216A_ALS_GAIN:
> +       case LTRF216A_PART_ID:
> +       case LTRF216A_MAIN_STATUS:
> +       case LTRF216A_ALS_CLEAR_DATA_0:
> +       case LTRF216A_ALS_CLEAR_DATA_1:
> +       case LTRF216A_ALS_CLEAR_DATA_2:
> +       case LTRF216A_ALS_DATA_0:
> +       case LTRF216A_ALS_DATA_1:
> +       case LTRF216A_ALS_DATA_2:
> +       case LTRF216A_INT_CFG:
> +       case LTRF216A_INT_PST:
> +       case LTRF216A_ALS_THRES_UP_0:
> +       case LTRF216A_ALS_THRES_UP_1:
> +       case LTRF216A_ALS_THRES_UP_2:
> +       case LTRF216A_ALS_THRES_LOW_0:
> +       case LTRF216A_ALS_THRES_LOW_1:
> +       case LTRF216A_ALS_THRES_LOW_2:
> +               return true;
> +       default:
> +               return false;
> +       }
> +}
> +
> +static bool ltrf216a_writable_reg(struct device *dev, unsigned int reg)
> +{
> +       switch (reg) {
> +       case LTRF216A_MAIN_CTRL:
> +       case LTRF216A_ALS_MEAS_RES:
> +       case LTRF216A_ALS_GAIN:
> +       case LTRF216A_INT_CFG:
> +       case LTRF216A_INT_PST:
> +       case LTRF216A_ALS_THRES_UP_0:
> +       case LTRF216A_ALS_THRES_UP_1:
> +       case LTRF216A_ALS_THRES_UP_2:
> +       case LTRF216A_ALS_THRES_LOW_0:
> +       case LTRF216A_ALS_THRES_LOW_1:
> +       case LTRF216A_ALS_THRES_LOW_2:
> +               return true;
> +       default:
> +               return false;
> +       }
> +}
> +
> +static bool ltrf216a_volatile_reg(struct device *dev, unsigned int reg)
> +{
> +       switch (reg) {
> +       case LTRF216A_ALS_CLEAR_DATA_0:
> +       case LTRF216A_ALS_CLEAR_DATA_1:
> +       case LTRF216A_ALS_CLEAR_DATA_2:
> +       case LTRF216A_ALS_DATA_0:
> +       case LTRF216A_ALS_DATA_1:
> +       case LTRF216A_ALS_DATA_2:
> +               return true;
> +       default:
> +               return false;
> +       }
> +}
> +
> +static bool ltrf216a_precious_reg(struct device *dev, unsigned int reg)
> +{
> +       return reg == LTRF216A_MAIN_STATUS;
> +}
> +
> +static const struct regmap_config ltrf216a_regmap_config = {
> +       .name = "ltrf216a",
> +       .reg_bits = 8,
> +       .val_bits = 8,
> +       .cache_type = REGCACHE_RBTREE,
> +       .max_register = LTRF216A_ALS_THRES_LOW_2,
> +       .readable_reg = ltrf216a_readable_reg,
> +       .writeable_reg = ltrf216a_writable_reg,
> +       .volatile_reg = ltrf216a_volatile_reg,
> +       .precious_reg = ltrf216a_precious_reg,
> +       .disable_locking = true,
> +};
> +
> +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);
> +
> +       data->regmap = devm_regmap_init_i2c(client, &ltrf216a_regmap_config);
> +       if (IS_ERR(data->regmap))
> +               return dev_err_probe(&client->dev, PTR_ERR(data->regmap),
> +                                    "regmap initialization failed\n");
> +
> +       i2c_set_clientdata(client, indio_dev);
> +       data->client = client;
> +
> +       mutex_init(&data->lock);
> +
> +       indio_dev->info = &ltrf216a_info;
> +       indio_dev->name = "ltrf216a";
> +       indio_dev->channels = ltrf216a_channels;
> +       indio_dev->num_channels = ARRAY_SIZE(ltrf216a_channels);
> +       indio_dev->modes = INDIO_DIRECT_MODE;
> +
> +       /* reset sensor, chip fails to respond to this, so ignore any errors */
> +       ltrf216a_reset(indio_dev);
> +
> +       ret = regmap_reinit_cache(data->regmap, &ltrf216a_regmap_config);
> +       if (ret)
> +               return dev_err_probe(&client->dev, ret,
> +                                    "failed to reinit regmap cache\n");
> +
> +       ret = devm_pm_runtime_enable(&client->dev);
> +       if (ret)
> +               return dev_err_probe(&client->dev, ret,
> +                                    "failed to enable runtime PM\n");
> +
> +       pm_runtime_set_autosuspend_delay(&client->dev, 1000);
> +       pm_runtime_use_autosuspend(&client->dev);
> +
> +       if (!IS_ENABLED(CONFIG_PM)) {
> +               ret = ltrf216a_enable(indio_dev);
> +               if (ret)
> +                       return ret;
> +       }
> +
> +       data->int_time = 100000;
> +       data->int_time_fac = 100;
> +       data->als_gain_fac = 3;
> +
> +       return devm_iio_device_register(&client->dev, indio_dev);
> +}
> +
> +static int ltrf216a_runtime_suspend(struct device *dev)
> +{
> +       struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
> +       struct ltrf216a_data *data = iio_priv(indio_dev);
> +       int ret;
> +
> +       ret = ltrf216a_disable(indio_dev);
> +       if (ret)
> +               return ret;
> +
> +       regcache_cache_only(data->regmap, true);
> +
> +       return 0;
> +}
> +
> +static int ltrf216a_runtime_resume(struct device *dev)
> +{
> +       struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
> +       struct ltrf216a_data *data = iio_priv(indio_dev);
> +       int ret;
> +
> +       regcache_cache_only(data->regmap, false);
> +       regcache_mark_dirty(data->regmap);
> +       ret = regcache_sync(data->regmap);
> +       if (ret)
> +               goto cache_only;
> +
> +       ret = ltrf216a_enable(indio_dev);
> +       if (ret)
> +               goto cache_only;
> +
> +       return 0;
> +
> +cache_only:
> +       regcache_cache_only(data->regmap, true);
> +
> +       return ret;
> +}
> +
> +static DEFINE_RUNTIME_DEV_PM_OPS(ltrf216a_pm_ops, ltrf216a_runtime_suspend,
> +                                ltrf216a_runtime_resume, NULL);
> +
> +static const struct i2c_device_id ltrf216a_id[] = {
> +       { "ltrf216a" },
> +       {}
> +};
> +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",
> +               .pm = pm_ptr(&ltrf216a_pm_ops),
> +               .of_match_table = ltrf216a_of_match,
> +       },
> +       .probe_new = ltrf216a_probe,
> +       .id_table = ltrf216a_id,
> +};
> +module_i2c_driver(ltrf216a_driver);
> +
> +MODULE_AUTHOR("Shreeya Patel <shreeya.patel@collabora.com>");
> +MODULE_AUTHOR("Shi Zhigang <Zhigang.Shi@liteon.com>");
> +MODULE_DESCRIPTION("LTRF216A ambient light sensor driver");
> +MODULE_LICENSE("GPL");
> --
> 2.30.2
>


-- 
With Best Regards,
Andy Shevchenko