Minimal implementation. This driver provides raw illuminance readings. This is based on drivers/hwmon/al3320.c (*) driver from msm tree written by Tsechih Lin <Tsechih_Lin@xxxxxxxx> * https://android.googlesource.com/kernel/msm.git Signed-off-by: Daniel Baluta <daniel.baluta@xxxxxxxxx> --- Changes since v5: (reported by Hartmut) * fix comments for al3320a_range * make sure we always use a valid index in al3320a_scales Changes since v4: (reported by Peter) * no need to fix endianess when reading raw value Changes since v3: (reported by Hartmut and Jonathan) * dropped the local store for the range, instead read it when necessary * removed wrapper functions * added in_illuminance_scale_available attribute * fix bug when reading raw value, use i2c_smbus_read_word instead of i2c_smbus_read_word_swapped and fix the endianess after read. * small coding style fixes Changes since v2: (reported by Peter Meerwald) * removed definition of DATA_HIGH and SW_RESET as they are not used * added a comment to al3320a_get_adc_value() function * added thresholds on TODO list * small style fixes Changes since v1: (reported by Peter Meerwald) * used u8 instead of int for passing gain and mean_time * used i2c_smbus_read_word_swapped instead of 2 x i2c_smbus_read_byte_data * used devm_iio_device_register instead of iio_device_register * small style fixes drivers/iio/light/Kconfig | 10 ++ drivers/iio/light/Makefile | 1 + drivers/iio/light/al3320a.c | 232 ++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 243 insertions(+) create mode 100644 drivers/iio/light/al3320a.c diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig index bf05ca5..5bea821 100644 --- a/drivers/iio/light/Kconfig +++ b/drivers/iio/light/Kconfig @@ -17,6 +17,16 @@ config ADJD_S311 This driver can also be built as a module. If so, the module will be called adjd_s311. +config AL3320A + tristate "AL3320A ambient light sensor" + depends on I2C + help + Say Y here if you want to build a driver for the Dyna Image AL3320A + ambient light sensor. + + To compile this driver as a module, choose M here: the + module will be called al3320a. + config APDS9300 tristate "APDS9300 ambient light sensor" depends on I2C diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile index 8b8c09f..47877a3 100644 --- a/drivers/iio/light/Makefile +++ b/drivers/iio/light/Makefile @@ -4,6 +4,7 @@ # When adding new entries keep the list in alphabetical order obj-$(CONFIG_ADJD_S311) += adjd_s311.o +obj-$(CONFIG_AL3320A) += al3320a.o obj-$(CONFIG_APDS9300) += apds9300.o obj-$(CONFIG_CM32181) += cm32181.o obj-$(CONFIG_CM36651) += cm36651.o diff --git a/drivers/iio/light/al3320a.c b/drivers/iio/light/al3320a.c new file mode 100644 index 0000000..bc6d670 --- /dev/null +++ b/drivers/iio/light/al3320a.c @@ -0,0 +1,232 @@ +/* + * AL3320A - Dyna Image Ambient Light Sensor + * + * Copyright (c) 2014, Intel Corporation. + * + * This file is subject to the terms and conditions of version 2 of + * the GNU General Public License. See the file COPYING in the main + * directory of this archive for more details. + * + * IIO driver for AL3320A (7-bit I2C slave address 0x1C). + * + * TODO: interrupt support, thresholds + * + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/i2c.h> + +#include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> + +#define AL3320A_DRV_NAME "al3320a" + +#define AL3320A_REG_CONFIG 0x00 +#define AL3320A_REG_STATUS 0x01 +#define AL3320A_REG_INT 0x02 +#define AL3320A_REG_WAIT 0x06 +#define AL3320A_REG_CONFIG_RANGE 0x07 +#define AL3320A_REG_PERSIST 0x08 +#define AL3320A_REG_MEAN_TIME 0x09 +#define AL3320A_REG_ADUMMY 0x0A +#define AL3320A_REG_DATA_LOW 0x22 + +#define AL3320A_REG_LOW_THRESH_LOW 0x30 +#define AL3320A_REG_LOW_THRESH_HIGH 0x31 +#define AL3320A_REG_HIGH_THRESH_LOW 0x32 +#define AL3320A_REG_HIGH_THRESH_HIGH 0x33 + +#define AL3320A_CONFIG_DISABLE 0x00 +#define AL3320A_CONFIG_ENABLE 0x01 + +#define AL3320A_GAIN_SHIFT 1 +#define AL3320A_GAIN_MASK (BIT(2) | BIT(1)) + +/* chip params default values */ +#define AL3320A_DEFAULT_MEAN_TIME 4 +#define AL3320A_DEFAULT_WAIT_TIME 0 /* no waiting */ + +#define AL3320A_SCALE_AVAILABLE "0.512 0.128 0.032 0.01" + +enum al3320a_range { + AL3320A_RANGE_1, /* 33.28 Klx */ + AL3320A_RANGE_2, /* 8.32 Klx */ + AL3320A_RANGE_3, /* 2.08 Klx */ + AL3320A_RANGE_4 /* 0.65 Klx */ +}; + +static const int al3320a_scales[][2] = { + {0, 512000}, {0, 128000}, {0, 32000}, {0, 10000} +}; + +struct al3320a_data { + struct i2c_client *client; +}; + +static const struct iio_chan_spec al3320a_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, AL3320A_SCALE_AVAILABLE); + +static struct attribute *al3320a_attributes[] = { + &iio_const_attr_in_illuminance_scale_available.dev_attr.attr, + NULL, +}; + +static const struct attribute_group al3320a_attribute_group = { + .attrs = al3320a_attributes, +}; + +static int al3320a_init(struct al3320a_data *data) +{ + int ret; + + /* power on */ + ret = i2c_smbus_write_byte_data(data->client, AL3320A_REG_CONFIG, + AL3320A_CONFIG_ENABLE); + if (ret < 0) + return ret; + + ret = i2c_smbus_write_byte_data(data->client, AL3320A_REG_CONFIG_RANGE, + AL3320A_RANGE_3 << AL3320A_GAIN_SHIFT); + if (ret < 0) + return ret; + + ret = i2c_smbus_write_byte_data(data->client, AL3320A_REG_MEAN_TIME, + AL3320A_DEFAULT_MEAN_TIME); + if (ret < 0) + return ret; + + ret = i2c_smbus_write_byte_data(data->client, AL3320A_REG_WAIT, + AL3320A_DEFAULT_WAIT_TIME); + if (ret < 0) + return ret; + + return 0; +} + +static int al3320a_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, int *val, + int *val2, long mask) +{ + struct al3320a_data *data = iio_priv(indio_dev); + int ret, i; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + /* + * ALS ADC value is stored in two adjacent registers: + * - low byte of output is stored at AL3320A_REG_DATA_LOW + * - high byte of output is stored at AL3320A_REG_DATA_LOW + 1 + */ + ret = i2c_smbus_read_word_data(data->client, + AL3320A_REG_DATA_LOW); + if (ret < 0) + return ret; + *val = ret; + return IIO_VAL_INT; + case IIO_CHAN_INFO_SCALE: + ret = i2c_smbus_read_byte_data(data->client, + AL3320A_REG_CONFIG_RANGE); + if (ret < 0) + return ret; + + i = (ret & AL3320A_GAIN_MASK) >> AL3320A_GAIN_SHIFT; + *val = al3320a_scales[i][0]; + *val2 = al3320a_scales[i][1]; + + return IIO_VAL_INT_PLUS_MICRO; + } + return -EINVAL; +} + +static int al3320a_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, int val, + int val2, long mask) +{ + struct al3320a_data *data = iio_priv(indio_dev); + int i; + + switch (mask) { + case IIO_CHAN_INFO_SCALE: + for (i = 0; i < ARRAY_SIZE(al3320a_scales); i++) { + if (val == al3320a_scales[i][0] && + val2 == al3320a_scales[i][1]) + return i2c_smbus_write_byte_data(data->client, + AL3320A_REG_CONFIG_RANGE, + i << AL3320A_GAIN_SHIFT); + } + break; + } + return -EINVAL; +} + +static const struct iio_info al3320a_info = { + .driver_module = THIS_MODULE, + .read_raw = al3320a_read_raw, + .write_raw = al3320a_write_raw, + .attrs = &al3320a_attribute_group, +}; + +static int al3320a_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct al3320a_data *data; + struct iio_dev *indio_dev; + int ret; + + 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; + + indio_dev->dev.parent = &client->dev; + indio_dev->info = &al3320a_info; + indio_dev->name = AL3320A_DRV_NAME; + indio_dev->channels = al3320a_channels; + indio_dev->num_channels = ARRAY_SIZE(al3320a_channels); + indio_dev->modes = INDIO_DIRECT_MODE; + + ret = al3320a_init(data); + if (ret < 0) { + dev_err(&client->dev, "al3320a chip init failed\n"); + return ret; + } + return devm_iio_device_register(&client->dev, indio_dev); +} + +static int al3320a_remove(struct i2c_client *client) +{ + return i2c_smbus_write_byte_data(client, AL3320A_REG_CONFIG, + AL3320A_CONFIG_DISABLE); +} + +static const struct i2c_device_id al3320a_id[] = { + {"al3320a", 0}, + {} +}; +MODULE_DEVICE_TABLE(i2c, al3320a_id); + +static struct i2c_driver al3320a_driver = { + .driver = { + .name = AL3320A_DRV_NAME, + }, + .probe = al3320a_probe, + .remove = al3320a_remove, + .id_table = al3320a_id, +}; + +module_i2c_driver(al3320a_driver); + +MODULE_AUTHOR("Daniel Baluta <daniel.baluta@xxxxxxxxx>"); +MODULE_DESCRIPTION("AL3320A Ambient Light Sensor driver"); +MODULE_LICENSE("GPL v2"); -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
