// SPDX-License-Identifier: GPL-2.0-only
/*
* IIO driver for the light sensor ISL76682.
* ISL76682 is Ambient Light Sensor
*
* Copyright (c) 2023 Marek Vasut <[email protected]>
*/
#include <linux/array_size.h>
#include <linux/bits.h>
#include <linux/cleanup.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/regmap.h>
#include <linux/types.h>
#include <linux/iio/iio.h>
#define ISL76682_REG_COMMAND 0x00
#define ISL76682_COMMAND_EN BIT(7)
#define ISL76682_COMMAND_MODE_CONTINUOUS BIT(6)
#define ISL76682_COMMAND_LIGHT_IR BIT(5)
#define ISL76682_COMMAND_RANGE_LUX_1K 0x0
#define ISL76682_COMMAND_RANGE_LUX_4K 0x1
#define ISL76682_COMMAND_RANGE_LUX_16K 0x2
#define ISL76682_COMMAND_RANGE_LUX_64K 0x3
#define ISL76682_COMMAND_RANGE_LUX_MASK GENMASK(1, 0)
#define ISL76682_REG_ALSIR_L 0x01
#define ISL76682_REG_ALSIR_U 0x02
#define ISL76682_NUM_REGS (ISL76682_REG_ALSIR_U + 1)
#define ISL76682_CONV_TIME_MS 100
#define ISL76682_INT_TIME_US 90000
#define ISL76682_ADC_MAX (BIT(16) - 1)
struct isl76682_chip {
/*
* Lock to synchronize access to device command register
* and the content of range variable below.
*/
struct mutex lock;
struct regmap *regmap;
u8 range;
u8 command;
};
struct isl76682_range {
u8 range;
u32 als;
u32 ir;
};
static struct isl76682_range isl76682_range_table[] = {
{ ISL76682_COMMAND_RANGE_LUX_1K, 15000, 10500 },
{ ISL76682_COMMAND_RANGE_LUX_4K, 60000, 42000 },
{ ISL76682_COMMAND_RANGE_LUX_16K, 240000, 168000 },
{ ISL76682_COMMAND_RANGE_LUX_64K, 960000, 673000 }
};
static int isl76682_get(struct isl76682_chip *chip, bool mode_ir, int *data)
{
u8 command;
int ret;
command = ISL76682_COMMAND_EN | ISL76682_COMMAND_MODE_CONTINUOUS |
chip->range;
if (mode_ir)
command |= ISL76682_COMMAND_LIGHT_IR;
if (command != chip->command) {
ret = regmap_write(chip->regmap, ISL76682_REG_COMMAND, command);
if (ret)
return ret;
/* Need to wait for conversion time if ALS/IR mode enabled */
msleep(ISL76682_CONV_TIME_MS);
chip->command = command;
}
ret = regmap_bulk_read(chip->regmap, ISL76682_REG_ALSIR_L, data, 2);
*data &= ISL76682_ADC_MAX;
return ret;
}
static int isl76682_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val, int val2, long mask)
{
struct isl76682_chip *chip = iio_priv(indio_dev);
int i;
if (mask != IIO_CHAN_INFO_SCALE)
return -EINVAL;
if (val != 0)
return -EINVAL;
for (i = 0; i < ARRAY_SIZE(isl76682_range_table); i++) {
if (chan->type == IIO_LIGHT && val2 != isl76682_range_table[i].als)
continue;
if (chan->type == IIO_INTENSITY && val2 != isl76682_range_table[i].ir)
continue;
scoped_guard(mutex, &chip->lock)
chip->range = isl76682_range_table[i].range;
return 0;
}
return -EINVAL;
}
static int isl76682_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct isl76682_chip *chip = iio_priv(indio_dev);
int ret;
int i;
guard(mutex)(&chip->lock);
switch (mask) {
case IIO_CHAN_INFO_RAW:
switch (chan->type) {
case IIO_LIGHT:
ret = isl76682_get(chip, false, val);
return (ret < 0) ? ret : IIO_VAL_INT;
case IIO_INTENSITY:
ret = isl76682_get(chip, true, val);
return (ret < 0) ? ret : IIO_VAL_INT;
default:
return -EINVAL;
}
case IIO_CHAN_INFO_SCALE:
for (i = 0; i < ARRAY_SIZE(isl76682_range_table); i++) {
if (chip->range != isl76682_range_table[i].range)
continue;
*val = 0;
switch (chan->type) {
case IIO_LIGHT:
*val2 = isl76682_range_table[i].als;
return IIO_VAL_INT_PLUS_MICRO;
case IIO_INTENSITY:
*val2 = isl76682_range_table[i].ir;
return IIO_VAL_INT_PLUS_MICRO;
default:
return -EINVAL;
}
}
return -EINVAL;
case IIO_CHAN_INFO_INT_TIME:
*val = 0;
*val2 = ISL76682_INT_TIME_US;
return IIO_VAL_INT_PLUS_MICRO;
default:
return -EINVAL;
}
}
static int illuminance_scale_available[] = {
0, 15000,
0, 60000,
0, 240000,
0, 960000,
};
static int intensity_scale_available[] = {
0, 10500,
0, 42000,
0, 168000,
0, 673000,
};
static int isl76682_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:
switch (chan->type) {
case IIO_LIGHT:
*vals = illuminance_scale_available;
*length = ARRAY_SIZE(illuminance_scale_available);
*type = IIO_VAL_INT_PLUS_MICRO;
return IIO_AVAIL_LIST;
case IIO_INTENSITY:
*vals = intensity_scale_available;
*length = ARRAY_SIZE(intensity_scale_available);
*type = IIO_VAL_INT_PLUS_MICRO;
return IIO_AVAIL_LIST;
default:
return -EINVAL;
}
default:
return -EINVAL;
}
}
static const struct iio_chan_spec isl76682_channels[] = {
{
.type = IIO_LIGHT,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_SCALE),
.info_mask_shared_by_type_available = BIT(IIO_CHAN_INFO_SCALE),
.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME),
}, {
.type = IIO_INTENSITY,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_SCALE),
.info_mask_shared_by_type_available = BIT(IIO_CHAN_INFO_SCALE),
.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME),
}
};
static const struct iio_info isl76682_info = {
.read_avail = isl76682_read_avail,
.read_raw = isl76682_read_raw,
.write_raw = isl76682_write_raw,
};
static int isl76682_clear_configure_reg(struct isl76682_chip *chip)
{
struct device *dev = regmap_get_device(chip->regmap);
int ret;
ret = regmap_write(chip->regmap, ISL76682_REG_COMMAND, 0x0);
if (ret < 0)
dev_err(dev, "Error %d clearing the CONFIGURE register\n", ret);
/*
* In the success case, the command register was zeroed out.
*
* In the error case, we do not know in which state the command
* register is, so we assume it is zeroed out, so that it would
* be reprogrammed at the next data read out, and at that time
* we hope it would be reprogrammed successfully. That is very
* much a best effort approach.
*/
chip->command = 0;
return ret;
}
static void isl76682_reset_action(void *chip)
{
isl76682_clear_configure_reg(chip);
}
static bool isl76682_is_volatile_reg(struct device *dev, unsigned int reg)
{
switch (reg) {
case ISL76682_REG_ALSIR_L:
case ISL76682_REG_ALSIR_U:
return true;
default:
return false;
}
}
static const struct regmap_config isl76682_regmap_config = {
.reg_bits = 8,
.val_bits = 8,
.volatile_reg = isl76682_is_volatile_reg,
.max_register = ISL76682_NUM_REGS - 1,
.num_reg_defaults_raw = ISL76682_NUM_REGS,
.cache_type = REGCACHE_FLAT,
};
static int isl76682_probe(struct i2c_client *client)
{
struct device *dev = &client->dev;
struct isl76682_chip *chip;
struct iio_dev *indio_dev;
int ret;
indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));
if (!indio_dev)
return -ENOMEM;
chip = iio_priv(indio_dev);
mutex_init(&chip->lock);
chip->regmap = devm_regmap_init_i2c(client, &isl76682_regmap_config);
ret = PTR_ERR_OR_ZERO(chip->regmap);
if (ret)
return dev_err_probe(dev, ret, "Error initializing regmap\n");
chip->range = ISL76682_COMMAND_RANGE_LUX_1K;
ret = isl76682_clear_configure_reg(chip);
if (ret < 0)
return ret;
ret = devm_add_action_or_reset(dev, isl76682_reset_action, chip);
if (ret)
return ret;
indio_dev->info = &isl76682_info;
indio_dev->channels = isl76682_channels;
indio_dev->num_channels = ARRAY_SIZE(isl76682_channels);
indio_dev->name = "isl76682";
indio_dev->modes = INDIO_DIRECT_MODE;
return devm_iio_device_register(dev, indio_dev);
}
static const struct i2c_device_id isl76682_id[] = {
{ "isl76682" },
{ }
};
MODULE_DEVICE_TABLE(i2c, isl76682_id);
static const struct of_device_id isl76682_of_match[] = {
{ .compatible = "isil,isl76682" },
{ }
};
MODULE_DEVICE_TABLE(of, isl76682_of_match);
static struct i2c_driver isl76682_driver = {
.driver = {
.name = "isl76682",
.of_match_table = isl76682_of_match,
},
.probe = isl76682_probe,
.id_table = isl76682_id,
};
module_i2c_driver(isl76682_driver);
MODULE_DESCRIPTION("ISL76682 Ambient Light Sensor driver");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Marek Vasut <[email protected]>");
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