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path: root/drivers/iio/light/ltr390.c
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Diffstat (limited to 'drivers/iio/light/ltr390.c')
-rw-r--r--drivers/iio/light/ltr390.c916
1 files changed, 916 insertions, 0 deletions
diff --git a/drivers/iio/light/ltr390.c b/drivers/iio/light/ltr390.c
new file mode 100644
index 000000000000..fc387426fa87
--- /dev/null
+++ b/drivers/iio/light/ltr390.c
@@ -0,0 +1,916 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * IIO driver for Lite-On LTR390 ALS and UV sensor
+ * (7-bit I2C slave address 0x53)
+ *
+ * Based on the work of:
+ * Shreeya Patel and Shi Zhigang (LTRF216 Driver)
+ *
+ * Copyright (C) 2023 Anshul Dalal <anshulusr@gmail.com>
+ *
+ * Datasheet:
+ * https://optoelectronics.liteon.com/upload/download/DS86-2015-0004/LTR-390UV_Final_%20DS_V1%201.pdf
+ *
+ * TODO:
+ * - Support for configurable gain and resolution
+ * - Sensor suspend/resume support
+ * - Add support for reading the ALS
+ * - Interrupt support
+ */
+
+#include <linux/bitfield.h>
+#include <linux/device.h>
+#include <linux/i2c.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/math.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/events.h>
+
+#include <linux/unaligned.h>
+
+#define LTR390_MAIN_CTRL 0x00
+#define LTR390_ALS_UVS_MEAS_RATE 0x04
+#define LTR390_ALS_UVS_GAIN 0x05
+#define LTR390_PART_ID 0x06
+#define LTR390_MAIN_STATUS 0x07
+
+#define LTR390_ALS_DATA 0x0D
+#define LTR390_ALS_DATA_BYTE(n) (LTR390_ALS_DATA + (n))
+
+#define LTR390_UVS_DATA 0x10
+#define LTR390_UVS_DATA_BYTE(n) (LTR390_UVS_DATA + (n))
+
+#define LTR390_INT_CFG 0x19
+#define LTR390_INT_PST 0x1A
+
+#define LTR390_THRESH_UP 0x21
+#define LTR390_THRESH_UP_BYTE(n) (LTR390_THRESH_UP + (n))
+
+#define LTR390_THRESH_LOW 0x24
+#define LTR390_THRESH_LOW_BYTE(n) (LTR390_THRESH_LOW + (n))
+
+#define LTR390_PART_NUMBER_ID 0xb
+#define LTR390_ALS_UVS_GAIN_MASK GENMASK(2, 0)
+#define LTR390_ALS_UVS_MEAS_RATE_MASK GENMASK(2, 0)
+#define LTR390_ALS_UVS_INT_TIME_MASK GENMASK(6, 4)
+#define LTR390_ALS_UVS_INT_TIME(x) FIELD_PREP(LTR390_ALS_UVS_INT_TIME_MASK, (x))
+#define LTR390_INT_PST_MASK GENMASK(7, 4)
+#define LTR390_INT_PST_VAL(x) FIELD_PREP(LTR390_INT_PST_MASK, (x))
+
+#define LTR390_SW_RESET BIT(4)
+#define LTR390_UVS_MODE BIT(3)
+#define LTR390_SENSOR_ENABLE BIT(1)
+#define LTR390_LS_INT_EN BIT(2)
+#define LTR390_LS_INT_SEL_UVS BIT(5)
+
+#define LTR390_FRACTIONAL_PRECISION 100
+
+/*
+ * At 20-bit resolution (integration time: 400ms) and 18x gain, 2300 counts of
+ * the sensor are equal to 1 UV Index [Datasheet Page#8].
+ *
+ * For the default resolution of 18-bit (integration time: 100ms) and default
+ * gain of 3x, the counts/uvi are calculated as follows:
+ * 2300 / ((3/18) * (100/400)) = 95.83
+ */
+#define LTR390_COUNTS_PER_UVI 96
+
+/*
+ * 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 LTR390_WINDOW_FACTOR 1
+
+enum ltr390_mode {
+ LTR390_SET_ALS_MODE,
+ LTR390_SET_UVS_MODE,
+};
+
+enum ltr390_meas_rate {
+ LTR390_GET_FREQ,
+ LTR390_GET_PERIOD,
+};
+
+struct ltr390_data {
+ struct regmap *regmap;
+ struct i2c_client *client;
+ /* Protects device from simulataneous reads */
+ struct mutex lock;
+ enum ltr390_mode mode;
+ int gain;
+ int int_time_us;
+ bool irq_enabled;
+};
+
+static const struct regmap_range ltr390_readable_reg_ranges[] = {
+ regmap_reg_range(LTR390_MAIN_CTRL, LTR390_MAIN_CTRL),
+ regmap_reg_range(LTR390_ALS_UVS_MEAS_RATE, LTR390_MAIN_STATUS),
+ regmap_reg_range(LTR390_ALS_DATA_BYTE(0), LTR390_UVS_DATA_BYTE(2)),
+ regmap_reg_range(LTR390_INT_CFG, LTR390_INT_PST),
+ regmap_reg_range(LTR390_THRESH_UP_BYTE(0), LTR390_THRESH_LOW_BYTE(2)),
+};
+
+static const struct regmap_access_table ltr390_readable_reg_table = {
+ .yes_ranges = ltr390_readable_reg_ranges,
+ .n_yes_ranges = ARRAY_SIZE(ltr390_readable_reg_ranges),
+};
+
+static const struct regmap_range ltr390_writeable_reg_ranges[] = {
+ regmap_reg_range(LTR390_MAIN_CTRL, LTR390_MAIN_CTRL),
+ regmap_reg_range(LTR390_ALS_UVS_MEAS_RATE, LTR390_ALS_UVS_GAIN),
+ regmap_reg_range(LTR390_INT_CFG, LTR390_INT_PST),
+ regmap_reg_range(LTR390_THRESH_UP_BYTE(0), LTR390_THRESH_LOW_BYTE(2)),
+};
+
+static const struct regmap_access_table ltr390_writeable_reg_table = {
+ .yes_ranges = ltr390_writeable_reg_ranges,
+ .n_yes_ranges = ARRAY_SIZE(ltr390_writeable_reg_ranges),
+};
+
+static const struct regmap_config ltr390_regmap_config = {
+ .name = "ltr390",
+ .reg_bits = 8,
+ .reg_stride = 1,
+ .val_bits = 8,
+ .max_register = LTR390_THRESH_LOW_BYTE(2),
+ .rd_table = &ltr390_readable_reg_table,
+ .wr_table = &ltr390_writeable_reg_table,
+};
+
+/* Sampling frequency is in mili Hz and mili Seconds */
+static const int ltr390_samp_freq_table[][2] = {
+ [0] = { 40000, 25 },
+ [1] = { 20000, 50 },
+ [2] = { 10000, 100 },
+ [3] = { 5000, 200 },
+ [4] = { 2000, 500 },
+ [5] = { 1000, 1000 },
+ [6] = { 500, 2000 },
+ [7] = { 500, 2000 },
+};
+
+static int ltr390_register_read(struct ltr390_data *data, u8 register_address)
+{
+ struct device *dev = &data->client->dev;
+ int ret;
+ u8 receive_buffer[3];
+
+ ret = regmap_bulk_read(data->regmap, register_address, receive_buffer,
+ sizeof(receive_buffer));
+ if (ret) {
+ dev_err(dev, "failed to read measurement data");
+ return ret;
+ }
+
+ return get_unaligned_le24(receive_buffer);
+}
+
+static int ltr390_set_mode(struct ltr390_data *data, enum ltr390_mode mode)
+{
+ int ret;
+
+ if (data->mode == mode)
+ return 0;
+
+ switch (mode) {
+ case LTR390_SET_ALS_MODE:
+ ret = regmap_clear_bits(data->regmap, LTR390_MAIN_CTRL, LTR390_UVS_MODE);
+ break;
+
+ case LTR390_SET_UVS_MODE:
+ ret = regmap_set_bits(data->regmap, LTR390_MAIN_CTRL, LTR390_UVS_MODE);
+ break;
+ }
+
+ if (ret)
+ return ret;
+
+ data->mode = mode;
+ return 0;
+}
+
+static int ltr390_counts_per_uvi(struct ltr390_data *data)
+{
+ const int orig_gain = 18;
+ const int orig_int_time = 400;
+
+ return DIV_ROUND_CLOSEST(23 * data->gain * data->int_time_us, 10 * orig_gain * orig_int_time);
+}
+
+static int ltr390_get_samp_freq_or_period(struct ltr390_data *data,
+ enum ltr390_meas_rate option)
+{
+ int ret, value;
+
+ ret = regmap_read(data->regmap, LTR390_ALS_UVS_MEAS_RATE, &value);
+ if (ret < 0)
+ return ret;
+ value = FIELD_GET(LTR390_ALS_UVS_MEAS_RATE_MASK, value);
+
+ return ltr390_samp_freq_table[value][option];
+}
+
+
+static int ltr390_do_read_raw(struct iio_dev *iio_device,
+ struct iio_chan_spec const *chan, int *val,
+ int *val2, long mask)
+{
+ int ret;
+ struct ltr390_data *data = iio_priv(iio_device);
+
+ guard(mutex)(&data->lock);
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ switch (chan->type) {
+ case IIO_UVINDEX:
+ ret = ltr390_set_mode(data, LTR390_SET_UVS_MODE);
+ if (ret < 0)
+ return ret;
+
+ ret = ltr390_register_read(data, LTR390_UVS_DATA);
+ if (ret < 0)
+ return ret;
+ break;
+
+ case IIO_LIGHT:
+ ret = ltr390_set_mode(data, LTR390_SET_ALS_MODE);
+ if (ret < 0)
+ return ret;
+
+ ret = ltr390_register_read(data, LTR390_ALS_DATA);
+ if (ret < 0)
+ return ret;
+ break;
+
+ default:
+ return -EINVAL;
+ }
+ *val = ret;
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_SCALE:
+ switch (chan->type) {
+ case IIO_UVINDEX:
+ *val = LTR390_WINDOW_FACTOR * LTR390_FRACTIONAL_PRECISION;
+ *val2 = ltr390_counts_per_uvi(data);
+ return IIO_VAL_FRACTIONAL;
+
+ case IIO_LIGHT:
+ *val = LTR390_WINDOW_FACTOR * 6 * 100;
+ *val2 = data->gain * data->int_time_us;
+ return IIO_VAL_FRACTIONAL;
+
+ default:
+ return -EINVAL;
+ }
+
+ case IIO_CHAN_INFO_INT_TIME:
+ *val = data->int_time_us;
+ return IIO_VAL_INT;
+
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ *val = ltr390_get_samp_freq_or_period(data, LTR390_GET_FREQ);
+ return IIO_VAL_INT;
+
+ default:
+ return -EINVAL;
+ }
+}
+
+static int ltr390_read_raw(struct iio_dev *iio_device,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ int ret;
+ struct ltr390_data *data = iio_priv(iio_device);
+ struct device *dev = &data->client->dev;
+
+ ret = pm_runtime_resume_and_get(dev);
+ if (ret < 0) {
+ dev_err(dev, "runtime PM failed to resume: %d\n", ret);
+ return ret;
+ }
+
+ ret = ltr390_do_read_raw(iio_device, chan, val, val2, mask);
+
+ pm_runtime_put_autosuspend(dev);
+
+ return ret;
+}
+
+/* integration time in us */
+static const int ltr390_int_time_map_us[] = { 400000, 200000, 100000, 50000, 25000, 12500 };
+static const int ltr390_gain_map[] = { 1, 3, 6, 9, 18 };
+static const int ltr390_freq_map[] = { 40000, 20000, 10000, 5000, 2000, 1000, 500, 500 };
+
+static const struct iio_event_spec ltr390_event_spec[] = {
+ {
+ .type = IIO_EV_TYPE_THRESH,
+ .dir = IIO_EV_DIR_RISING,
+ .mask_separate = BIT(IIO_EV_INFO_VALUE),
+ }, {
+ .type = IIO_EV_TYPE_THRESH,
+ .dir = IIO_EV_DIR_FALLING,
+ .mask_separate = BIT(IIO_EV_INFO_VALUE),
+ }, {
+ .type = IIO_EV_TYPE_THRESH,
+ .dir = IIO_EV_DIR_EITHER,
+ .mask_separate = BIT(IIO_EV_INFO_ENABLE) |
+ BIT(IIO_EV_INFO_PERIOD),
+ }
+};
+
+static const struct iio_chan_spec ltr390_channels[] = {
+ /* UV sensor */
+ {
+ .type = IIO_UVINDEX,
+ .scan_index = 0,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
+ .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME) | BIT(IIO_CHAN_INFO_SAMP_FREQ),
+ .info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_INT_TIME) |
+ BIT(IIO_CHAN_INFO_SCALE) |
+ BIT(IIO_CHAN_INFO_SAMP_FREQ),
+ .event_spec = ltr390_event_spec,
+ .num_event_specs = ARRAY_SIZE(ltr390_event_spec),
+ },
+ /* ALS sensor */
+ {
+ .type = IIO_LIGHT,
+ .scan_index = 1,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
+ .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME) | BIT(IIO_CHAN_INFO_SAMP_FREQ),
+ .info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_INT_TIME) |
+ BIT(IIO_CHAN_INFO_SCALE) |
+ BIT(IIO_CHAN_INFO_SAMP_FREQ),
+ .event_spec = ltr390_event_spec,
+ .num_event_specs = ARRAY_SIZE(ltr390_event_spec),
+ },
+};
+
+static int ltr390_set_gain(struct ltr390_data *data, int val)
+{
+ int ret, idx;
+
+ for (idx = 0; idx < ARRAY_SIZE(ltr390_gain_map); idx++) {
+ if (ltr390_gain_map[idx] != val)
+ continue;
+
+ guard(mutex)(&data->lock);
+ ret = regmap_update_bits(data->regmap,
+ LTR390_ALS_UVS_GAIN,
+ LTR390_ALS_UVS_GAIN_MASK, idx);
+ if (ret)
+ return ret;
+
+ data->gain = ltr390_gain_map[idx];
+ return 0;
+ }
+
+ return -EINVAL;
+}
+
+static int ltr390_set_int_time(struct ltr390_data *data, int val)
+{
+ int ret, idx;
+
+ for (idx = 0; idx < ARRAY_SIZE(ltr390_int_time_map_us); idx++) {
+ if (ltr390_int_time_map_us[idx] != val)
+ continue;
+
+ guard(mutex)(&data->lock);
+ ret = regmap_update_bits(data->regmap,
+ LTR390_ALS_UVS_MEAS_RATE,
+ LTR390_ALS_UVS_INT_TIME_MASK,
+ LTR390_ALS_UVS_INT_TIME(idx));
+ if (ret)
+ return ret;
+
+ data->int_time_us = ltr390_int_time_map_us[idx];
+ return 0;
+ }
+
+ return -EINVAL;
+}
+
+static int ltr390_set_samp_freq(struct ltr390_data *data, int val)
+{
+ int idx;
+
+ for (idx = 0; idx < ARRAY_SIZE(ltr390_samp_freq_table); idx++) {
+ if (ltr390_samp_freq_table[idx][0] != val)
+ continue;
+
+ guard(mutex)(&data->lock);
+ return regmap_update_bits(data->regmap,
+ LTR390_ALS_UVS_MEAS_RATE,
+ LTR390_ALS_UVS_MEAS_RATE_MASK, idx);
+ }
+
+ return -EINVAL;
+}
+
+static int ltr390_read_avail(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_SCALE:
+ *length = ARRAY_SIZE(ltr390_gain_map);
+ *type = IIO_VAL_INT;
+ *vals = ltr390_gain_map;
+ return IIO_AVAIL_LIST;
+ case IIO_CHAN_INFO_INT_TIME:
+ *length = ARRAY_SIZE(ltr390_int_time_map_us);
+ *type = IIO_VAL_INT;
+ *vals = ltr390_int_time_map_us;
+ return IIO_AVAIL_LIST;
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ *length = ARRAY_SIZE(ltr390_freq_map);
+ *type = IIO_VAL_INT;
+ *vals = ltr390_freq_map;
+ return IIO_AVAIL_LIST;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int ltr390_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
+ int val, int val2, long mask)
+{
+ struct ltr390_data *data = iio_priv(indio_dev);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_SCALE:
+ if (val2 != 0)
+ return -EINVAL;
+
+ return ltr390_set_gain(data, val);
+
+ case IIO_CHAN_INFO_INT_TIME:
+ if (val2 != 0)
+ return -EINVAL;
+
+ return ltr390_set_int_time(data, val);
+
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ if (val2 != 0)
+ return -EINVAL;
+
+ return ltr390_set_samp_freq(data, val);
+
+ default:
+ return -EINVAL;
+ }
+}
+
+static int ltr390_read_intr_prst(struct ltr390_data *data, int *val)
+{
+ int ret, prst, samp_period;
+
+ samp_period = ltr390_get_samp_freq_or_period(data, LTR390_GET_PERIOD);
+ ret = regmap_read(data->regmap, LTR390_INT_PST, &prst);
+ if (ret < 0)
+ return ret;
+ *val = prst * samp_period;
+
+ return IIO_VAL_INT;
+}
+
+static int ltr390_write_intr_prst(struct ltr390_data *data, int val)
+{
+ int ret, samp_period, new_val;
+
+ samp_period = ltr390_get_samp_freq_or_period(data, LTR390_GET_PERIOD);
+
+ /* persist period should be greater than or equal to samp period */
+ if (val < samp_period)
+ return -EINVAL;
+
+ new_val = DIV_ROUND_UP(val, samp_period);
+ if (new_val < 0 || new_val > 0x0f)
+ return -EINVAL;
+
+ guard(mutex)(&data->lock);
+ ret = regmap_update_bits(data->regmap,
+ LTR390_INT_PST,
+ LTR390_INT_PST_MASK,
+ LTR390_INT_PST_VAL(new_val));
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static int ltr390_read_threshold(struct iio_dev *indio_dev,
+ enum iio_event_direction dir,
+ int *val, int *val2)
+{
+ struct ltr390_data *data = iio_priv(indio_dev);
+ int ret;
+
+ switch (dir) {
+ case IIO_EV_DIR_RISING:
+ ret = ltr390_register_read(data, LTR390_THRESH_UP);
+ if (ret < 0)
+ return ret;
+ *val = ret;
+ return IIO_VAL_INT;
+
+ case IIO_EV_DIR_FALLING:
+ ret = ltr390_register_read(data, LTR390_THRESH_LOW);
+ if (ret < 0)
+ return ret;
+ *val = ret;
+ return IIO_VAL_INT;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int ltr390_write_threshold(struct iio_dev *indio_dev,
+ enum iio_event_direction dir,
+ int val, int val2)
+{
+ struct ltr390_data *data = iio_priv(indio_dev);
+
+ guard(mutex)(&data->lock);
+ switch (dir) {
+ case IIO_EV_DIR_RISING:
+ return regmap_bulk_write(data->regmap, LTR390_THRESH_UP, &val, 3);
+
+ case IIO_EV_DIR_FALLING:
+ return regmap_bulk_write(data->regmap, LTR390_THRESH_LOW, &val, 3);
+
+ default:
+ return -EINVAL;
+ }
+}
+
+static int ltr390_read_event_value(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan,
+ enum iio_event_type type,
+ enum iio_event_direction dir,
+ enum iio_event_info info,
+ int *val, int *val2)
+{
+ switch (info) {
+ case IIO_EV_INFO_VALUE:
+ return ltr390_read_threshold(indio_dev, dir, val, val2);
+
+ case IIO_EV_INFO_PERIOD:
+ return ltr390_read_intr_prst(iio_priv(indio_dev), val);
+
+ default:
+ return -EINVAL;
+ }
+}
+
+static int ltr390_write_event_value(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan,
+ enum iio_event_type type,
+ enum iio_event_direction dir,
+ enum iio_event_info info,
+ int val, int val2)
+{
+ switch (info) {
+ case IIO_EV_INFO_VALUE:
+ if (val2 != 0)
+ return -EINVAL;
+
+ return ltr390_write_threshold(indio_dev, dir, val, val2);
+
+ case IIO_EV_INFO_PERIOD:
+ if (val2 != 0)
+ return -EINVAL;
+
+ return ltr390_write_intr_prst(iio_priv(indio_dev), val);
+
+ default:
+ return -EINVAL;
+ }
+}
+
+static int ltr390_read_event_config(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan,
+ enum iio_event_type type,
+ enum iio_event_direction dir)
+{
+ struct ltr390_data *data = iio_priv(indio_dev);
+ int ret, status;
+
+ ret = regmap_read(data->regmap, LTR390_INT_CFG, &status);
+ if (ret < 0)
+ return ret;
+
+ return FIELD_GET(LTR390_LS_INT_EN, status);
+}
+
+static int ltr390_do_event_config(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan,
+ enum iio_event_type type,
+ enum iio_event_direction dir,
+ bool state)
+{
+ struct ltr390_data *data = iio_priv(indio_dev);
+ int ret;
+
+ if (!state)
+ return regmap_clear_bits(data->regmap, LTR390_INT_CFG, LTR390_LS_INT_EN);
+
+ ret = regmap_set_bits(data->regmap, LTR390_INT_CFG, LTR390_LS_INT_EN);
+ if (ret < 0)
+ return ret;
+
+ switch (chan->type) {
+ case IIO_LIGHT:
+ ret = ltr390_set_mode(data, LTR390_SET_ALS_MODE);
+ if (ret < 0)
+ return ret;
+
+ return regmap_clear_bits(data->regmap, LTR390_INT_CFG, LTR390_LS_INT_SEL_UVS);
+
+ case IIO_UVINDEX:
+ ret = ltr390_set_mode(data, LTR390_SET_UVS_MODE);
+ if (ret < 0)
+ return ret;
+
+ return regmap_set_bits(data->regmap, LTR390_INT_CFG, LTR390_LS_INT_SEL_UVS);
+
+ default:
+ return -EINVAL;
+ }
+}
+
+static int ltr390_write_event_config(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan,
+ enum iio_event_type type,
+ enum iio_event_direction dir,
+ bool state)
+{
+ int ret;
+ struct ltr390_data *data = iio_priv(indio_dev);
+ struct device *dev = &data->client->dev;
+
+ guard(mutex)(&data->lock);
+
+ if (state && !data->irq_enabled) {
+ ret = pm_runtime_resume_and_get(dev);
+ if (ret < 0) {
+ dev_err(dev, "runtime PM failed to resume: %d\n", ret);
+ return ret;
+ }
+ data->irq_enabled = true;
+ }
+
+ ret = ltr390_do_event_config(indio_dev, chan, type, dir, state);
+
+ if (!state && data->irq_enabled) {
+ data->irq_enabled = false;
+ pm_runtime_put_autosuspend(dev);
+ }
+
+ return ret;
+}
+
+static int ltr390_debugfs_reg_access(struct iio_dev *indio_dev,
+ unsigned int reg, unsigned int writeval,
+ unsigned int *readval)
+{
+ struct ltr390_data *data = iio_priv(indio_dev);
+
+ guard(mutex)(&data->lock);
+
+ if (readval)
+ return regmap_read(data->regmap, reg, readval);
+
+ return regmap_write(data->regmap, reg, writeval);
+}
+
+static const struct iio_info ltr390_info = {
+ .read_raw = ltr390_read_raw,
+ .write_raw = ltr390_write_raw,
+ .read_avail = ltr390_read_avail,
+ .read_event_value = ltr390_read_event_value,
+ .read_event_config = ltr390_read_event_config,
+ .write_event_value = ltr390_write_event_value,
+ .write_event_config = ltr390_write_event_config,
+ .debugfs_reg_access = ltr390_debugfs_reg_access,
+};
+
+static irqreturn_t ltr390_interrupt_handler(int irq, void *private)
+{
+ struct iio_dev *indio_dev = private;
+ struct ltr390_data *data = iio_priv(indio_dev);
+ int ret, status;
+
+ /* Reading the status register to clear the interrupt flag, Datasheet pg: 17*/
+ ret = regmap_read(data->regmap, LTR390_MAIN_STATUS, &status);
+ if (ret < 0)
+ return ret;
+
+ switch (data->mode) {
+ case LTR390_SET_ALS_MODE:
+ iio_push_event(indio_dev,
+ IIO_UNMOD_EVENT_CODE(IIO_LIGHT, 0,
+ IIO_EV_TYPE_THRESH,
+ IIO_EV_DIR_EITHER),
+ iio_get_time_ns(indio_dev));
+ break;
+
+ case LTR390_SET_UVS_MODE:
+ iio_push_event(indio_dev,
+ IIO_UNMOD_EVENT_CODE(IIO_UVINDEX, 0,
+ IIO_EV_TYPE_THRESH,
+ IIO_EV_DIR_EITHER),
+ iio_get_time_ns(indio_dev));
+ break;
+ }
+
+ return IRQ_HANDLED;
+}
+
+static void ltr390_powerdown(void *priv)
+{
+ struct ltr390_data *data = priv;
+ struct device *dev = &data->client->dev;
+ int ret;
+
+ guard(mutex)(&data->lock);
+
+ /* Ensure that power off and interrupts are disabled */
+ if (data->irq_enabled) {
+ ret = regmap_clear_bits(data->regmap, LTR390_INT_CFG, LTR390_LS_INT_EN);
+ if (ret < 0)
+ dev_err(dev, "failed to disable interrupts\n");
+
+ data->irq_enabled = false;
+ pm_runtime_put_autosuspend(dev);
+ }
+
+ ret = regmap_clear_bits(data->regmap, LTR390_MAIN_CTRL, LTR390_SENSOR_ENABLE);
+ if (ret < 0)
+ dev_err(dev, "failed to disable sensor\n");
+}
+
+static int ltr390_pm_init(struct ltr390_data *data)
+{
+ int ret;
+ struct device *dev = &data->client->dev;
+
+ ret = devm_pm_runtime_set_active_enabled(dev);
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to enable runtime PM\n");
+
+ pm_runtime_set_autosuspend_delay(dev, 1000);
+ pm_runtime_use_autosuspend(dev);
+ return 0;
+}
+
+static int ltr390_probe(struct i2c_client *client)
+{
+ struct ltr390_data *data;
+ struct iio_dev *indio_dev;
+ struct device *dev;
+ int ret, part_number;
+
+ dev = &client->dev;
+ indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ i2c_set_clientdata(client, indio_dev);
+
+ data = iio_priv(indio_dev);
+ data->regmap = devm_regmap_init_i2c(client, &ltr390_regmap_config);
+ if (IS_ERR(data->regmap))
+ return dev_err_probe(dev, PTR_ERR(data->regmap),
+ "regmap initialization failed\n");
+
+ data->client = client;
+ /* default value of integration time from pg: 15 of the datasheet */
+ data->int_time_us = 100000;
+ /* default value of gain from pg: 16 of the datasheet */
+ data->gain = 3;
+ /* default mode for ltr390 is ALS mode */
+ data->mode = LTR390_SET_ALS_MODE;
+ /* default value of irq_enabled is false */
+ data->irq_enabled = false;
+
+ mutex_init(&data->lock);
+
+ indio_dev->info = &ltr390_info;
+ indio_dev->channels = ltr390_channels;
+ indio_dev->num_channels = ARRAY_SIZE(ltr390_channels);
+ indio_dev->name = "ltr390";
+
+ ret = regmap_read(data->regmap, LTR390_PART_ID, &part_number);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "failed to get sensor's part id\n");
+ /* Lower 4 bits of `part_number` change with hardware revisions */
+ if (part_number >> 4 != LTR390_PART_NUMBER_ID)
+ dev_info(dev, "received invalid product id: 0x%x", part_number);
+ dev_dbg(dev, "LTR390, product id: 0x%x\n", part_number);
+
+ /* reset sensor, chip fails to respond to this, so ignore any errors */
+ regmap_set_bits(data->regmap, LTR390_MAIN_CTRL, LTR390_SW_RESET);
+
+ /* Wait for the registers to reset before proceeding */
+ usleep_range(1000, 2000);
+
+ ret = regmap_set_bits(data->regmap, LTR390_MAIN_CTRL, LTR390_SENSOR_ENABLE);
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to enable the sensor\n");
+
+ ret = devm_add_action_or_reset(dev, ltr390_powerdown, data);
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to add action or reset\n");
+
+ if (client->irq) {
+ ret = devm_request_threaded_irq(dev, client->irq,
+ NULL, ltr390_interrupt_handler,
+ IRQF_ONESHOT,
+ "ltr390_thresh_event",
+ indio_dev);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "request irq (%d) failed\n", client->irq);
+ }
+
+ ret = ltr390_pm_init(data);
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to initialize runtime PM\n");
+
+ return devm_iio_device_register(dev, indio_dev);
+}
+
+static int ltr390_suspend(struct device *dev)
+{
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct ltr390_data *data = iio_priv(indio_dev);
+
+ return regmap_clear_bits(data->regmap, LTR390_MAIN_CTRL,
+ LTR390_SENSOR_ENABLE);
+}
+
+static int ltr390_resume(struct device *dev)
+{
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct ltr390_data *data = iio_priv(indio_dev);
+
+ return regmap_set_bits(data->regmap, LTR390_MAIN_CTRL,
+ LTR390_SENSOR_ENABLE);
+}
+
+static int ltr390_runtime_suspend(struct device *dev)
+{
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct ltr390_data *data = iio_priv(indio_dev);
+
+ return regmap_clear_bits(data->regmap, LTR390_MAIN_CTRL, LTR390_SENSOR_ENABLE);
+}
+
+static int ltr390_runtime_resume(struct device *dev)
+{
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct ltr390_data *data = iio_priv(indio_dev);
+
+ return regmap_set_bits(data->regmap, LTR390_MAIN_CTRL, LTR390_SENSOR_ENABLE);
+}
+
+static const struct dev_pm_ops ltr390_pm_ops = {
+ SYSTEM_SLEEP_PM_OPS(ltr390_suspend, ltr390_resume)
+ RUNTIME_PM_OPS(ltr390_runtime_suspend, ltr390_runtime_resume, NULL)
+};
+
+static const struct i2c_device_id ltr390_id[] = {
+ { "ltr390" },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, ltr390_id);
+
+static const struct of_device_id ltr390_of_table[] = {
+ { .compatible = "liteon,ltr390" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, ltr390_of_table);
+
+static struct i2c_driver ltr390_driver = {
+ .driver = {
+ .name = "ltr390",
+ .of_match_table = ltr390_of_table,
+ .pm = pm_ptr(&ltr390_pm_ops),
+ },
+ .probe = ltr390_probe,
+ .id_table = ltr390_id,
+};
+module_i2c_driver(ltr390_driver);
+
+MODULE_AUTHOR("Anshul Dalal <anshulusr@gmail.com>");
+MODULE_DESCRIPTION("Lite-On LTR390 ALS and UV sensor Driver");
+MODULE_LICENSE("GPL");