// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2023 Axis Communications AB
*
* Datasheet: https://www.ti.com/lit/gpn/opt4001
*
* Device driver for the Texas Instruments OPT4001.
*/
#include <linux/bitfield.h>
#include <linux/i2c.h>
#include <linux/iio/iio.h>
#include <linux/math64.h>
#include <linux/module.h>
#include <linux/property.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>
/* OPT4001 register set */
#define OPT4001_LIGHT1_MSB 0x00
#define OPT4001_LIGHT1_LSB 0x01
#define OPT4001_CTRL 0x0A
#define OPT4001_DEVICE_ID 0x11
/* OPT4001 register mask */
#define OPT4001_EXPONENT_MASK GENMASK(15, 12)
#define OPT4001_MSB_MASK GENMASK(11, 0)
#define OPT4001_LSB_MASK GENMASK(15, 8)
#define OPT4001_COUNTER_MASK GENMASK(7, 4)
#define OPT4001_CRC_MASK GENMASK(3, 0)
/* OPT4001 device id mask */
#define OPT4001_DEVICE_ID_MASK GENMASK(11, 0)
/* OPT4001 control registers mask */
#define OPT4001_CTRL_QWAKE_MASK GENMASK(15, 15)
#define OPT4001_CTRL_RANGE_MASK GENMASK(13, 10)
#define OPT4001_CTRL_CONV_TIME_MASK GENMASK(9, 6)
#define OPT4001_CTRL_OPER_MODE_MASK GENMASK(5, 4)
#define OPT4001_CTRL_LATCH_MASK GENMASK(3, 3)
#define OPT4001_CTRL_INT_POL_MASK GENMASK(2, 2)
#define OPT4001_CTRL_FAULT_COUNT GENMASK(0, 1)
/* OPT4001 constants */
#define OPT4001_DEVICE_ID_VAL 0x121
/* OPT4001 operating modes */
#define OPT4001_CTRL_OPER_MODE_OFF 0x0
#define OPT4001_CTRL_OPER_MODE_FORCED 0x1
#define OPT4001_CTRL_OPER_MODE_ONE_SHOT 0x2
#define OPT4001_CTRL_OPER_MODE_CONTINUOUS 0x3
/* OPT4001 conversion control register definitions */
#define OPT4001_CTRL_CONVERSION_0_6MS 0x0
#define OPT4001_CTRL_CONVERSION_1MS 0x1
#define OPT4001_CTRL_CONVERSION_1_8MS 0x2
#define OPT4001_CTRL_CONVERSION_3_4MS 0x3
#define OPT4001_CTRL_CONVERSION_6_5MS 0x4
#define OPT4001_CTRL_CONVERSION_12_7MS 0x5
#define OPT4001_CTRL_CONVERSION_25MS 0x6
#define OPT4001_CTRL_CONVERSION_50MS 0x7
#define OPT4001_CTRL_CONVERSION_100MS 0x8
#define OPT4001_CTRL_CONVERSION_200MS 0x9
#define OPT4001_CTRL_CONVERSION_400MS 0xa
#define OPT4001_CTRL_CONVERSION_800MS 0xb
/* OPT4001 scale light level range definitions */
#define OPT4001_CTRL_LIGHT_SCALE_AUTO 12
/* OPT4001 default values */
#define OPT4001_DEFAULT_CONVERSION_TIME OPT4001_CTRL_CONVERSION_800MS
/*
* The different packaging of OPT4001 has different constants used when calculating
* lux values.
*/
struct opt4001_chip_info {
int mul;
int div;
const char *name;
};
struct opt4001_chip {
struct regmap *regmap;
struct i2c_client *client;
u8 int_time;
const struct opt4001_chip_info *chip_info;
};
static const struct opt4001_chip_info opt4001_sot_5x3_info = {
.mul = 4375,
.div = 10000000,
.name = "opt4001-sot-5x3"
};
static const struct opt4001_chip_info opt4001_picostar_info = {
.mul = 3125,
.div = 10000000,
.name = "opt4001-picostar"
};
static const int opt4001_int_time_available[][2] = {
{ 0, 600 },
{ 0, 1000 },
{ 0, 1800 },
{ 0, 3400 },
{ 0, 6500 },
{ 0, 12700 },
{ 0, 25000 },
{ 0, 50000 },
{ 0, 100000 },
{ 0, 200000 },
{ 0, 400000 },
{ 0, 800000 },
};
/*
* Conversion time is integration time + time to set register
* this is used as integration time.
*/
static const int opt4001_int_time_reg[][2] = {
{ 600, OPT4001_CTRL_CONVERSION_0_6MS },
{ 1000, OPT4001_CTRL_CONVERSION_1MS },
{ 1800, OPT4001_CTRL_CONVERSION_1_8MS },
{ 3400, OPT4001_CTRL_CONVERSION_3_4MS },
{ 6500, OPT4001_CTRL_CONVERSION_6_5MS },
{ 12700, OPT4001_CTRL_CONVERSION_12_7MS },
{ 25000, OPT4001_CTRL_CONVERSION_25MS },
{ 50000, OPT4001_CTRL_CONVERSION_50MS },
{ 100000, OPT4001_CTRL_CONVERSION_100MS },
{ 200000, OPT4001_CTRL_CONVERSION_200MS },
{ 400000, OPT4001_CTRL_CONVERSION_400MS },
{ 800000, OPT4001_CTRL_CONVERSION_800MS },
};
static int opt4001_als_time_to_index(const u32 als_integration_time)
{
int i;
for (i = 0; i < ARRAY_SIZE(opt4001_int_time_available); i++) {
if (als_integration_time == opt4001_int_time_available[i][1])
return i;
}
return -EINVAL;
}
static u8 opt4001_calculate_crc(u8 exp, u32 mantissa, u8 count)
{
u8 crc;
crc = (hweight32(mantissa) + hweight32(exp) + hweight32(count)) % 2;
crc |= ((hweight32(mantissa & 0xAAAAA) + hweight32(exp & 0xA)
+ hweight32(count & 0xA)) % 2) << 1;
crc |= ((hweight32(mantissa & 0x88888) + hweight32(exp & 0x8)
+ hweight32(count & 0x8)) % 2) << 2;
crc |= (hweight32(mantissa & 0x80808) % 2) << 3;
return crc;
}
static int opt4001_read_lux_value(struct iio_dev *indio_dev,
int *val, int *val2)
{
struct opt4001_chip *chip = iio_priv(indio_dev);
struct device *dev = &chip->client->dev;
unsigned int light1;
unsigned int light2;
u16 msb;
u16 lsb;
u8 exp;
u8 count;
u8 crc;
u8 calc_crc;
u64 lux_raw;
int ret;
ret = regmap_read(chip->regmap, OPT4001_LIGHT1_MSB, &light1);
if (ret < 0) {
dev_err(dev, "Failed to read data bytes");
return ret;
}
ret = regmap_read(chip->regmap, OPT4001_LIGHT1_LSB, &light2);
if (ret < 0) {
dev_err(dev, "Failed to read data bytes");
return ret;
}
count = FIELD_GET(OPT4001_COUNTER_MASK, light2);
exp = FIELD_GET(OPT4001_EXPONENT_MASK, light1);
crc = FIELD_GET(OPT4001_CRC_MASK, light2);
msb = FIELD_GET(OPT4001_MSB_MASK, light1);
lsb = FIELD_GET(OPT4001_LSB_MASK, light2);
lux_raw = (msb << 8) + lsb;
calc_crc = opt4001_calculate_crc(exp, lux_raw, count);
if (calc_crc != crc)
return -EIO;
lux_raw = lux_raw << exp;
lux_raw = lux_raw * chip->chip_info->mul;
*val = div_u64_rem(lux_raw, chip->chip_info->div, val2);
*val2 = *val2 * 100;
return IIO_VAL_INT_PLUS_NANO;
}
static int opt4001_set_conf(struct opt4001_chip *chip)
{
struct device *dev = &chip->client->dev;
u16 reg;
int ret;
reg = FIELD_PREP(OPT4001_CTRL_RANGE_MASK, OPT4001_CTRL_LIGHT_SCALE_AUTO);
reg |= FIELD_PREP(OPT4001_CTRL_CONV_TIME_MASK, chip->int_time);
reg |= FIELD_PREP(OPT4001_CTRL_OPER_MODE_MASK, OPT4001_CTRL_OPER_MODE_CONTINUOUS);
ret = regmap_write(chip->regmap, OPT4001_CTRL, reg);
if (ret)
dev_err(dev, "Failed to set configuration\n");
return ret;
}
static int opt4001_power_down(struct opt4001_chip *chip)
{
struct device *dev = &chip->client->dev;
int ret;
unsigned int reg;
ret = regmap_read(chip->regmap, OPT4001_DEVICE_ID, ®);
if (ret) {
dev_err(dev, "Failed to read configuration\n");
return ret;
}
/* MODE_OFF is 0x0 so just set bits to 0 */
reg &= ~OPT4001_CTRL_OPER_MODE_MASK;
ret = regmap_write(chip->regmap, OPT4001_CTRL, reg);
if (ret)
dev_err(dev, "Failed to set configuration to power down\n");
return ret;
}
static void opt4001_chip_off_action(void *data)
{
struct opt4001_chip *chip = data;
opt4001_power_down(chip);
}
static const struct iio_chan_spec opt4001_channels[] = {
{
.type = IIO_LIGHT,
.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
.info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_INT_TIME),
.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME)
},
};
static int opt4001_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct opt4001_chip *chip = iio_priv(indio_dev);
switch (mask) {
case IIO_CHAN_INFO_PROCESSED:
return opt4001_read_lux_value(indio_dev, val, val2);
case IIO_CHAN_INFO_INT_TIME:
*val = 0;
*val2 = opt4001_int_time_reg[chip->int_time][0];
return IIO_VAL_INT_PLUS_MICRO;
default:
return -EINVAL;
}
}
static int opt4001_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val, int val2, long mask)
{
struct opt4001_chip *chip = iio_priv(indio_dev);
int int_time;
switch (mask) {
case IIO_CHAN_INFO_INT_TIME:
int_time = opt4001_als_time_to_index(val2);
if (int_time < 0)
return int_time;
chip->int_time = int_time;
return opt4001_set_conf(chip);
default:
return -EINVAL;
}
}
static int opt4001_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(opt4001_int_time_available) * 2;
*vals = (const int *)opt4001_int_time_available;
*type = IIO_VAL_INT_PLUS_MICRO;
return IIO_AVAIL_LIST;
default:
return -EINVAL;
}
}
static const struct iio_info opt4001_info_no_irq = {
.read_raw = opt4001_read_raw,
.write_raw = opt4001_write_raw,
.read_avail = opt4001_read_available,
};
static int opt4001_load_defaults(struct opt4001_chip *chip)
{
chip->int_time = OPT4001_DEFAULT_CONVERSION_TIME;
return opt4001_set_conf(chip);
}
static bool opt4001_readable_reg(struct device *dev, unsigned int reg)
{
switch (reg) {
case OPT4001_LIGHT1_MSB:
case OPT4001_LIGHT1_LSB:
case OPT4001_CTRL:
case OPT4001_DEVICE_ID:
return true;
default:
return false;
}
}
static bool opt4001_writable_reg(struct device *dev, unsigned int reg)
{
switch (reg) {
case OPT4001_CTRL:
return true;
default:
return false;
}
}
static bool opt4001_volatile_reg(struct device *dev, unsigned int reg)
{
switch (reg) {
case OPT4001_LIGHT1_MSB:
case OPT4001_LIGHT1_LSB:
return true;
default:
return false;
}
}
static const struct regmap_config opt4001_regmap_config = {
.name = "opt4001",
.reg_bits = 8,
.val_bits = 16,
.cache_type = REGCACHE_RBTREE,
.max_register = OPT4001_DEVICE_ID,
.readable_reg = opt4001_readable_reg,
.writeable_reg = opt4001_writable_reg,
.volatile_reg = opt4001_volatile_reg,
.val_format_endian = REGMAP_ENDIAN_BIG,
};
static int opt4001_probe(struct i2c_client *client)
{
struct opt4001_chip *chip;
struct iio_dev *indio_dev;
int ret;
uint dev_id;
indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));
if (!indio_dev)
return -ENOMEM;
chip = iio_priv(indio_dev);
ret = devm_regulator_get_enable(&client->dev, "vdd");
if (ret)
return dev_err_probe(&client->dev, ret, "Failed to enable vdd supply\n");
chip->regmap = devm_regmap_init_i2c(client, &opt4001_regmap_config);
if (IS_ERR(chip->regmap))
return dev_err_probe(&client->dev, PTR_ERR(chip->regmap),
"regmap initialization failed\n");
chip->client = client;
indio_dev->info = &opt4001_info_no_irq;
ret = regmap_reinit_cache(chip->regmap, &opt4001_regmap_config);
if (ret)
return dev_err_probe(&client->dev, ret,
"failed to reinit regmap cache\n");
ret = regmap_read(chip->regmap, OPT4001_DEVICE_ID, &dev_id);
if (ret < 0)
return dev_err_probe(&client->dev, ret,
"Failed to read the device ID register\n");
dev_id = FIELD_GET(OPT4001_DEVICE_ID_MASK, dev_id);
if (dev_id != OPT4001_DEVICE_ID_VAL)
dev_warn(&client->dev, "Device ID: %#04x unknown\n", dev_id);
chip->chip_info = i2c_get_match_data(client);
indio_dev->channels = opt4001_channels;
indio_dev->num_channels = ARRAY_SIZE(opt4001_channels);
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->name = chip->chip_info->name;
ret = opt4001_load_defaults(chip);
if (ret < 0)
return dev_err_probe(&client->dev, ret,
"Failed to set sensor defaults\n");
ret = devm_add_action_or_reset(&client->dev,
opt4001_chip_off_action,
chip);
if (ret < 0)
return dev_err_probe(&client->dev, ret,
"Failed to setup power off action\n");
return devm_iio_device_register(&client->dev, indio_dev);
}
/*
* The compatible string determines which constants to use depending on
* opt4001 packaging
*/
static const struct i2c_device_id opt4001_id[] = {
{ "opt4001-sot-5x3", (kernel_ulong_t)&opt4001_sot_5x3_info },
{ "opt4001-picostar", (kernel_ulong_t)&opt4001_picostar_info },
{ }
};
MODULE_DEVICE_TABLE(i2c, opt4001_id);
static const struct of_device_id opt4001_of_match[] = {
{ .compatible = "ti,opt4001-sot-5x3", .data = &opt4001_sot_5x3_info},
{ .compatible = "ti,opt4001-picostar", .data = &opt4001_picostar_info},
{}
};
MODULE_DEVICE_TABLE(of, opt4001_of_match);
static struct i2c_driver opt4001_driver = {
.driver = {
.name = "opt4001",
.of_match_table = opt4001_of_match,
},
.probe = opt4001_probe,
.id_table = opt4001_id,
};
module_i2c_driver(opt4001_driver);
MODULE_AUTHOR("Stefan Windfeldt-Prytz <stefan.windfeldt-prytz@axis.com>");
MODULE_DESCRIPTION("Texas Instruments opt4001 ambient light sensor driver");
MODULE_LICENSE("GPL");
