diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/iio/light/bh1750.c | 332 |
1 files changed, 332 insertions, 0 deletions
diff --git a/drivers/iio/light/bh1750.c b/drivers/iio/light/bh1750.c new file mode 100644 index 000000000..3e92820bc --- /dev/null +++ b/drivers/iio/light/bh1750.c @@ -0,0 +1,332 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * ROHM BH1710/BH1715/BH1721/BH1750/BH1751 ambient light sensor driver + * + * Copyright (c) Tomasz Duszynski <tduszyns@gmail.com> + * + * 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) +{ + 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 <tduszyns@gmail.com>"); +MODULE_DESCRIPTION("ROHM BH1710/BH1715/BH1721/BH1750/BH1751 als driver"); +MODULE_LICENSE("GPL v2"); |