diff options
Diffstat (limited to 'drivers/iio/light/al3010.c')
| -rw-r--r-- | drivers/iio/light/al3010.c | 246 |
1 files changed, 246 insertions, 0 deletions
diff --git a/drivers/iio/light/al3010.c b/drivers/iio/light/al3010.c new file mode 100644 index 000000000000..0932fa2b49fa --- /dev/null +++ b/drivers/iio/light/al3010.c @@ -0,0 +1,246 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * AL3010 - Dyna Image Ambient Light Sensor + * + * Copyright (c) 2014, Intel Corporation. + * Copyright (c) 2016, Dyna-Image Corp. + * Copyright (c) 2020, David Heidelberg, Michał Mirosław, Dmitry Osipenko + * + * IIO driver for AL3010 (7-bit I2C slave address 0x1C). + * + * TODO: interrupt support, thresholds + * When the driver will get support for interrupt handling, then interrupt + * will need to be disabled before turning sensor OFF in order to avoid + * potential races with the interrupt handling. + */ + +#include <linux/bitfield.h> +#include <linux/i2c.h> +#include <linux/module.h> +#include <linux/regmap.h> +#include <linux/mod_devicetable.h> + +#include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> + +#define AL3010_REG_SYSTEM 0x00 +#define AL3010_REG_DATA_LOW 0x0c +#define AL3010_REG_CONFIG 0x10 + +#define AL3010_CONFIG_DISABLE 0x00 +#define AL3010_CONFIG_ENABLE 0x01 + +#define AL3010_GAIN_MASK GENMASK(6,4) + +#define AL3010_SCALE_AVAILABLE "1.1872 0.2968 0.0742 0.018" + +enum al3xxxx_range { + AL3XXX_RANGE_1, /* 77806 lx */ + AL3XXX_RANGE_2, /* 19542 lx */ + AL3XXX_RANGE_3, /* 4863 lx */ + AL3XXX_RANGE_4 /* 1216 lx */ +}; + +static const int al3010_scales[][2] = { + {0, 1187200}, {0, 296800}, {0, 74200}, {0, 18600} +}; + +static const struct regmap_config al3010_regmap_config = { + .reg_bits = 8, + .val_bits = 8, + .max_register = AL3010_REG_CONFIG, +}; + +struct al3010_data { + struct regmap *regmap; +}; + +static const struct iio_chan_spec al3010_channels[] = { + { + .type = IIO_LIGHT, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE), + } +}; + +static IIO_CONST_ATTR(in_illuminance_scale_available, AL3010_SCALE_AVAILABLE); + +static struct attribute *al3010_attributes[] = { + &iio_const_attr_in_illuminance_scale_available.dev_attr.attr, + NULL, +}; + +static const struct attribute_group al3010_attribute_group = { + .attrs = al3010_attributes, +}; + +static int al3010_set_pwr_on(struct al3010_data *data) +{ + return regmap_write(data->regmap, AL3010_REG_SYSTEM, AL3010_CONFIG_ENABLE); +} + +static void al3010_set_pwr_off(void *_data) +{ + struct al3010_data *data = _data; + struct device *dev = regmap_get_device(data->regmap); + int ret; + + ret = regmap_write(data->regmap, AL3010_REG_SYSTEM, AL3010_CONFIG_DISABLE); + if (ret) + dev_err(dev, "failed to write system register\n"); +} + +static int al3010_init(struct al3010_data *data) +{ + struct device *dev = regmap_get_device(data->regmap); + int ret; + + ret = al3010_set_pwr_on(data); + if (ret) + return ret; + + ret = devm_add_action_or_reset(dev, al3010_set_pwr_off, data); + if (ret) + return ret; + return regmap_write(data->regmap, AL3010_REG_CONFIG, + FIELD_PREP(AL3010_GAIN_MASK, AL3XXX_RANGE_3)); +} + +static int al3010_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, int *val, + int *val2, long mask) +{ + struct al3010_data *data = iio_priv(indio_dev); + int ret, gain, raw; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + /* + * ALS ADC value is stored in two adjacent registers: + * - low byte of output is stored at AL3010_REG_DATA_LOW + * - high byte of output is stored at AL3010_REG_DATA_LOW + 1 + */ + ret = regmap_read(data->regmap, AL3010_REG_DATA_LOW, &raw); + if (ret) + return ret; + + *val = raw; + + return IIO_VAL_INT; + case IIO_CHAN_INFO_SCALE: + ret = regmap_read(data->regmap, AL3010_REG_CONFIG, &gain); + if (ret) + return ret; + + gain = FIELD_GET(AL3010_GAIN_MASK, gain); + *val = al3010_scales[gain][0]; + *val2 = al3010_scales[gain][1]; + + return IIO_VAL_INT_PLUS_MICRO; + } + return -EINVAL; +} + +static int al3010_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, int val, + int val2, long mask) +{ + struct al3010_data *data = iio_priv(indio_dev); + unsigned int i; + + switch (mask) { + case IIO_CHAN_INFO_SCALE: + for (i = 0; i < ARRAY_SIZE(al3010_scales); i++) { + if (val != al3010_scales[i][0] || + val2 != al3010_scales[i][1]) + continue; + + return regmap_write(data->regmap, AL3010_REG_CONFIG, + FIELD_PREP(AL3010_GAIN_MASK, i)); + } + break; + } + return -EINVAL; +} + +static const struct iio_info al3010_info = { + .read_raw = al3010_read_raw, + .write_raw = al3010_write_raw, + .attrs = &al3010_attribute_group, +}; + +static int al3010_probe(struct i2c_client *client) +{ + struct al3010_data *data; + struct device *dev = &client->dev; + struct iio_dev *indio_dev; + int ret; + + indio_dev = devm_iio_device_alloc(dev, sizeof(*data)); + if (!indio_dev) + return -ENOMEM; + + data = iio_priv(indio_dev); + i2c_set_clientdata(client, indio_dev); + data->regmap = devm_regmap_init_i2c(client, &al3010_regmap_config); + if (IS_ERR(data->regmap)) + return dev_err_probe(dev, PTR_ERR(data->regmap), + "cannot allocate regmap\n"); + + indio_dev->info = &al3010_info; + indio_dev->name = "al3010"; + indio_dev->channels = al3010_channels; + indio_dev->num_channels = ARRAY_SIZE(al3010_channels); + indio_dev->modes = INDIO_DIRECT_MODE; + + ret = al3010_init(data); + if (ret) + return dev_err_probe(dev, ret, "failed to init ALS\n"); + + return devm_iio_device_register(dev, indio_dev); +} + +static int al3010_suspend(struct device *dev) +{ + struct al3010_data *data = iio_priv(dev_get_drvdata(dev)); + + al3010_set_pwr_off(data); + return 0; +} + +static int al3010_resume(struct device *dev) +{ + struct al3010_data *data = iio_priv(dev_get_drvdata(dev)); + + return al3010_set_pwr_on(data); +} + +static DEFINE_SIMPLE_DEV_PM_OPS(al3010_pm_ops, al3010_suspend, al3010_resume); + +static const struct i2c_device_id al3010_id[] = { + {"al3010", }, + { } +}; +MODULE_DEVICE_TABLE(i2c, al3010_id); + +static const struct of_device_id al3010_of_match[] = { + { .compatible = "dynaimage,al3010", }, + { } +}; +MODULE_DEVICE_TABLE(of, al3010_of_match); + +static struct i2c_driver al3010_driver = { + .driver = { + .name = "al3010", + .of_match_table = al3010_of_match, + .pm = pm_sleep_ptr(&al3010_pm_ops), + }, + .probe = al3010_probe, + .id_table = al3010_id, +}; +module_i2c_driver(al3010_driver); + +MODULE_AUTHOR("Daniel Baluta <daniel.baluta@nxp.com>"); +MODULE_AUTHOR("David Heidelberg <david@ixit.cz>"); +MODULE_DESCRIPTION("AL3010 Ambient Light Sensor driver"); +MODULE_LICENSE("GPL v2"); |