// SPDX-License-Identifier: GPL-2.0
/*
* ROHM BH1710/BH1715/BH1721/BH1750/BH1751 ambient light sensor driver
*
* Copyright (c) Tomasz Duszynski <[email protected]>
*
* Data sheets:
* http://rohmfs.rohm.com/en/products/databook/datasheet/ic/sensor/light/bh1710fvc-e.pdf
* http://rohmfs.rohm.com/en/products/databook/datasheet/ic/sensor/light/bh1715fvc-e.pdf
* http://rohmfs.rohm.com/en/products/databook/datasheet/ic/sensor/light/bh1721fvc-e.pdf
* http://rohmfs.rohm.com/en/products/databook/datasheet/ic/sensor/light/bh1750fvi-e.pdf
* http://rohmfs.rohm.com/en/products/databook/datasheet/ic/sensor/light/bh1751fvi-e.pdf
*
* 7-bit I2C slave addresses:
* 0x23 (ADDR pin low)
* 0x5C (ADDR pin high)
*
*/
#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/module.h>
#define BH1750_POWER_DOWN 0x00
#define BH1750_ONE_TIME_H_RES_MODE 0x20 /* auto-mode for BH1721 */
#define BH1750_CHANGE_INT_TIME_H_BIT 0x40
#define BH1750_CHANGE_INT_TIME_L_BIT 0x60
enum {
BH1710,
BH1721,
BH1750,
};
struct bh1750_chip_info;
struct bh1750_data {
struct i2c_client *client;
struct mutex lock;
const struct bh1750_chip_info *chip_info;
u16 mtreg;
};
struct bh1750_chip_info {
u16 mtreg_min;
u16 mtreg_max;
u16 mtreg_default;
int mtreg_to_usec;
int mtreg_to_scale;
/*
* For BH1710/BH1721 all possible integration time values won't fit
* into one page so displaying is limited to every second one.
* Note, that user can still write proper values which were not
* listed.
*/
int inc;
u16 int_time_low_mask;
u16 int_time_high_mask;
};
static const struct bh1750_chip_info bh1750_chip_info_tbl[] = {
[BH1710] = { 140, 1022, 300, 400, 250000000, 2, 0x001F, 0x03E0 },
[BH1721] = { 140, 1020, 300, 400, 250000000, 2, 0x0010, 0x03E0 },
[BH1750] = { 31, 254, 69, 1740, 57500000, 1, 0x001F, 0x00E0 },
};
static int bh1750_change_int_time(struct bh1750_data *data, int usec)
{
int ret;
u16 val;
u8 regval;
const struct bh1750_chip_info *chip_info = data->chip_info;
if ((usec % chip_info->mtreg_to_usec) != 0)
return -EINVAL;
val = usec / chip_info->mtreg_to_usec;
if (val < chip_info->mtreg_min || val > chip_info->mtreg_max)
return -EINVAL;
ret = i2c_smbus_write_byte(data->client, BH1750_POWER_DOWN);
if (ret < 0)
return ret;
regval = (val & chip_info->int_time_high_mask) >> 5;
ret = i2c_smbus_write_byte(data->client,
BH1750_CHANGE_INT_TIME_H_BIT | regval);
if (ret < 0)
return ret;
regval = val & chip_info->int_time_low_mask;
ret = i2c_smbus_write_byte(data->client,
BH1750_CHANGE_INT_TIME_L_BIT | regval);
if (ret < 0)
return ret;
data->mtreg = val;
return 0;
}
static int bh1750_read(struct bh1750_data *data, int *val)
{
int ret;
__be16 result;
const struct bh1750_chip_info *chip_info = data->chip_info;
unsigned long delay = chip_info->mtreg_to_usec * data->mtreg;
/*
* BH1721 will enter continuous mode on receiving this command.
* Note, that this eliminates need for bh1750_resume().
*/
ret = i2c_smbus_write_byte(data->client, BH1750_ONE_TIME_H_RES_MODE);
if (ret < 0)
return ret;
usleep_range(delay + 15000, delay + 40000);
ret = i2c_master_recv(data->client, (char *)&result, 2);
if (ret < 0)
return ret;
*val = be16_to_cpu(result);
return 0;
}
static int bh1750_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
int ret, tmp;
struct bh1750_data *data = iio_priv(indio_dev);
const struct bh1750_chip_info *chip_info = data->chip_info;
switch (mask) {
case IIO_CHAN_INFO_RAW:
switch (chan->type) {
case IIO_LIGHT:
mutex_lock(&data->lock);
ret = bh1750_read(data, val);
mutex_unlock(&data->lock);
if (ret < 0)
return ret;
return IIO_VAL_INT;
default:
return -EINVAL;
}
case IIO_CHAN_INFO_SCALE:
tmp = chip_info->mtreg_to_scale / data->mtreg;
*val = tmp / 1000000;
*val2 = tmp % 1000000;
return IIO_VAL_INT_PLUS_MICRO;
case IIO_CHAN_INFO_INT_TIME:
*val = 0;
*val2 = chip_info->mtreg_to_usec * data->mtreg;
return IIO_VAL_INT_PLUS_MICRO;
default:
return -EINVAL;
}
}
static int bh1750_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val, int val2, long mask)
{
int ret;
struct bh1750_data *data = iio_priv(indio_dev);
switch (mask) {
case IIO_CHAN_INFO_INT_TIME:
if (val != 0)
return -EINVAL;
mutex_lock(&data->lock);
ret = bh1750_change_int_time(data, val2);
mutex_unlock(&data->lock);
return ret;
default:
return -EINVAL;
}
}
static ssize_t bh1750_show_int_time_available(struct device *dev,
struct device_attribute *attr, char *buf)
{
int i;
size_t len = 0;
struct bh1750_data *data = iio_priv(dev_to_iio_dev(dev));
const struct bh1750_chip_info *chip_info = data->chip_info;
for (i = chip_info->mtreg_min; i <= chip_info->mtreg_max; i += chip_info->inc)
len += scnprintf(buf + len, PAGE_SIZE - len, "0.%06d ",
chip_info->mtreg_to_usec * i);
buf[len - 1] = '\n';
return len;
}
static IIO_DEV_ATTR_INT_TIME_AVAIL(bh1750_show_int_time_available);
static struct attribute *bh1750_attributes[] = {
&iio_dev_attr_integration_time_available.dev_attr.attr,
NULL,
};
static const struct attribute_group bh1750_attribute_group = {
.attrs = bh1750_attributes,
};
static const struct iio_info bh1750_info = {
.attrs = &bh1750_attribute_group,
.read_raw = bh1750_read_raw,
.write_raw = bh1750_write_raw,
};
static const struct iio_chan_spec bh1750_channels[] = {
{
.type = IIO_LIGHT,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_SCALE) |
BIT(IIO_CHAN_INFO_INT_TIME)
}
};
static int bh1750_probe(struct i2c_client *client)
{
const struct i2c_device_id *id = i2c_client_get_device_id(client);
int ret, usec;
struct bh1750_data *data;
struct iio_dev *indio_dev;
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
I2C_FUNC_SMBUS_WRITE_BYTE))
return -EOPNOTSUPP;
indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
if (!indio_dev)
return -ENOMEM;
data = iio_priv(indio_dev);
i2c_set_clientdata(client, indio_dev);
data->client = client;
data->chip_info = &bh1750_chip_info_tbl[id->driver_data];
usec = data->chip_info->mtreg_to_usec * data->chip_info->mtreg_default;
ret = bh1750_change_int_time(data, usec);
if (ret < 0)
return ret;
mutex_init(&data->lock);
indio_dev->info = &bh1750_info;
indio_dev->name = id->name;
indio_dev->channels = bh1750_channels;
indio_dev->num_channels = ARRAY_SIZE(bh1750_channels);
indio_dev->modes = INDIO_DIRECT_MODE;
return iio_device_register(indio_dev);
}
static void bh1750_remove(struct i2c_client *client)
{
struct iio_dev *indio_dev = i2c_get_clientdata(client);
struct bh1750_data *data = iio_priv(indio_dev);
iio_device_unregister(indio_dev);
mutex_lock(&data->lock);
i2c_smbus_write_byte(client, BH1750_POWER_DOWN);
mutex_unlock(&data->lock);
}
static int bh1750_suspend(struct device *dev)
{
int ret;
struct bh1750_data *data =
iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
/*
* This is mainly for BH1721 which doesn't enter power down
* mode automatically.
*/
mutex_lock(&data->lock);
ret = i2c_smbus_write_byte(data->client, BH1750_POWER_DOWN);
mutex_unlock(&data->lock);
return ret;
}
static DEFINE_SIMPLE_DEV_PM_OPS(bh1750_pm_ops, bh1750_suspend, NULL);
static const struct i2c_device_id bh1750_id[] = {
{ "bh1710", BH1710 },
{ "bh1715", BH1750 },
{ "bh1721", BH1721 },
{ "bh1750", BH1750 },
{ "bh1751", BH1750 },
{ }
};
MODULE_DEVICE_TABLE(i2c, bh1750_id);
static const struct of_device_id bh1750_of_match[] = {
{ .compatible = "rohm,bh1710", },
{ .compatible = "rohm,bh1715", },
{ .compatible = "rohm,bh1721", },
{ .compatible = "rohm,bh1750", },
{ .compatible = "rohm,bh1751", },
{ }
};
MODULE_DEVICE_TABLE(of, bh1750_of_match);
static struct i2c_driver bh1750_driver = {
.driver = {
.name = "bh1750",
.of_match_table = bh1750_of_match,
.pm = pm_sleep_ptr(&bh1750_pm_ops),
},
.probe = bh1750_probe,
.remove = bh1750_remove,
.id_table = bh1750_id,
};
module_i2c_driver(bh1750_driver);
MODULE_AUTHOR("Tomasz Duszynski <[email protected]>");
MODULE_DESCRIPTION("ROHM BH1710/BH1715/BH1721/BH1750/BH1751 als driver");
MODULE_LICENSE("GPL v2");
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