On Thu, Jul 14, 2022 at 11:14 AM Shreeya Patel <shreeya.patel@xxxxxxxxxxxxx> wrote: > > Add initial support for ltrf216a ambient light sensor. Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx> > Datasheet: https://gitlab.steamos.cloud/shreeya/iio/-/blob/main/LTRF216A.pdf > Co-developed-by: Zhigang Shi <Zhigang.Shi@xxxxxxxxxx> > Signed-off-by: Zhigang Shi <Zhigang.Shi@xxxxxxxxxx> > Co-developed-by: Dmitry Osipenko <dmitry.osipenko@xxxxxxxxxxxxx> > Signed-off-by: Dmitry Osipenko <dmitry.osipenko@xxxxxxxxxxxxx> > Signed-off-by: Shreeya Patel <shreeya.patel@xxxxxxxxxxxxx> > --- > > 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@xxxxxxxxxxxxx/ > > 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@xxxxxxxxxxxxx> > + * > + * Copyright (C) 2021 Lite-On Technology Corp (Singapore) > + * Author: Shi Zhigang <Zhigang.Shi@xxxxxxxxxx> > + * > + * 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, <rf216a_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 = <rf216a_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, <rf216a_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(<rf216a_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@xxxxxxxxxxxxx>"); > +MODULE_AUTHOR("Shi Zhigang <Zhigang.Shi@xxxxxxxxxx>"); > +MODULE_DESCRIPTION("LTRF216A ambient light sensor driver"); > +MODULE_LICENSE("GPL"); > -- > 2.30.2 > -- With Best Regards, Andy Shevchenko
