Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
iio: light: ltr390: Add configurable gain and resolution
Add support for configuring and reading the gain and resolution
(integration time). Also provide the available values for gain and
resoltion respectively via `read_avail` callback.
Signed-off-by: Abhash Jha <abhashkumarjha123@gmail.com>
Link: https://patch.msgid.link/20240731063706.25412-2-abhashkumarjha123@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
authored by
Abhash Jha
and committed by
Jonathan Cameron
13fad260
d6b133a6
+126
-12
+126
-12
drivers/iio/light/ltr390.c
+126
-12
drivers/iio/light/ltr390.c
···
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#include <linux/module.h>
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#include <linux/mutex.h>
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#include <linux/regmap.h>
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#include <linux/bitfield.h>
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#include <linux/iio/iio.h>
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#include <asm/unaligned.h>
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#define LTR390_MAIN_CTRL 0x00
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#define LTR390_PART_ID 0x06
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#define LTR390_UVS_DATA 0x10
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#define LTR390_MAIN_CTRL 0x00
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#define LTR390_ALS_UVS_MEAS_RATE 0x04
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#define LTR390_ALS_UVS_GAIN 0x05
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#define LTR390_PART_ID 0x06
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#define LTR390_ALS_DATA 0x0D
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#define LTR390_UVS_DATA 0x10
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#define LTR390_INT_CFG 0x19
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#define LTR390_PART_NUMBER_ID 0xb
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#define LTR390_ALS_UVS_GAIN_MASK 0x07
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#define LTR390_ALS_UVS_INT_TIME_MASK 0x70
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#define LTR390_ALS_UVS_INT_TIME(x) FIELD_PREP(LTR390_ALS_UVS_INT_TIME_MASK, (x))
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#define LTR390_SW_RESET BIT(4)
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#define LTR390_UVS_MODE BIT(3)
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#define LTR390_SENSOR_ENABLE BIT(1)
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#define LTR390_PART_NUMBER_ID 0xb
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/*
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* At 20-bit resolution (integration time: 400ms) and 18x gain, 2300 counts of
···
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struct i2c_client *client;
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/* Protects device from simulataneous reads */
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struct mutex lock;
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int gain;
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int int_time_us;
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};
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static const struct regmap_config ltr390_regmap_config = {
···
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struct device *dev = &data->client->dev;
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int ret;
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u8 recieve_buffer[3];
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guard(mutex)(&data->lock);
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ret = regmap_bulk_read(data->regmap, register_address, recieve_buffer,
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sizeof(recieve_buffer));
···
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int ret;
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struct ltr390_data *data = iio_priv(iio_device);
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guard(mutex)(&data->lock);
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switch (mask) {
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case IIO_CHAN_INFO_RAW:
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ret = ltr390_register_read(data, LTR390_UVS_DATA);
···
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*val = LTR390_WINDOW_FACTOR;
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*val2 = LTR390_COUNTS_PER_UVI;
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return IIO_VAL_FRACTIONAL;
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case IIO_CHAN_INFO_INT_TIME:
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*val = data->int_time_us;
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return IIO_VAL_INT;
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default:
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return -EINVAL;
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}
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}
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/* integration time in us */
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static const int ltr390_int_time_map_us[] = { 400000, 200000, 100000, 50000, 25000, 12500 };
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static const int ltr390_gain_map[] = { 1, 3, 6, 9, 18 };
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static const struct iio_chan_spec ltr390_channel = {
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.type = IIO_UVINDEX,
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
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.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME),
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.info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_INT_TIME) | BIT(IIO_CHAN_INFO_SCALE)
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};
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static int ltr390_set_gain(struct ltr390_data *data, int val)
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{
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int ret, idx;
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for (idx = 0; idx < ARRAY_SIZE(ltr390_gain_map); idx++) {
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if (ltr390_gain_map[idx] != val)
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continue;
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guard(mutex)(&data->lock);
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ret = regmap_update_bits(data->regmap,
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LTR390_ALS_UVS_GAIN,
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LTR390_ALS_UVS_GAIN_MASK, idx);
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if (ret)
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return ret;
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data->gain = ltr390_gain_map[idx];
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return 0;
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}
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return -EINVAL;
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}
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static int ltr390_set_int_time(struct ltr390_data *data, int val)
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{
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int ret, idx;
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for (idx = 0; idx < ARRAY_SIZE(ltr390_int_time_map_us); idx++) {
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if (ltr390_int_time_map_us[idx] != val)
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continue;
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guard(mutex)(&data->lock);
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ret = regmap_update_bits(data->regmap,
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LTR390_ALS_UVS_MEAS_RATE,
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LTR390_ALS_UVS_INT_TIME_MASK,
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LTR390_ALS_UVS_INT_TIME(idx));
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if (ret)
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return ret;
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data->int_time_us = ltr390_int_time_map_us[idx];
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return 0;
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}
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return -EINVAL;
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}
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static int ltr390_read_avail(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
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const int **vals, int *type, int *length, long mask)
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{
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switch (mask) {
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case IIO_CHAN_INFO_SCALE:
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*length = ARRAY_SIZE(ltr390_gain_map);
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*type = IIO_VAL_INT;
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*vals = ltr390_gain_map;
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return IIO_AVAIL_LIST;
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case IIO_CHAN_INFO_INT_TIME:
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*length = ARRAY_SIZE(ltr390_int_time_map_us);
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*type = IIO_VAL_INT;
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*vals = ltr390_int_time_map_us;
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return IIO_AVAIL_LIST;
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default:
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return -EINVAL;
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}
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}
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static int ltr390_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
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int val, int val2, long mask)
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{
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struct ltr390_data *data = iio_priv(indio_dev);
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switch (mask) {
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case IIO_CHAN_INFO_SCALE:
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if (val2 != 0)
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return -EINVAL;
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return ltr390_set_gain(data, val);
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case IIO_CHAN_INFO_INT_TIME:
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if (val2 != 0)
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return -EINVAL;
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return ltr390_set_int_time(data, val);
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default:
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return -EINVAL;
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}
···
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static const struct iio_info ltr390_info = {
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.read_raw = ltr390_read_raw,
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};
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static const struct iio_chan_spec ltr390_channel = {
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.type = IIO_UVINDEX,
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE)
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.write_raw = ltr390_write_raw,
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.read_avail = ltr390_read_avail,
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};
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static int ltr390_probe(struct i2c_client *client)
···
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"regmap initialization failed\n");
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data->client = client;
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/* default value of integration time from pg: 15 of the datasheet */
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data->int_time_us = 100000;
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/* default value of gain from pg: 16 of the datasheet */
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data->gain = 3;
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mutex_init(&data->lock);
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indio_dev->info = <r390_info;