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Commit f007d7f1 authored by Daniel Baluta's avatar Daniel Baluta Committed by Jonathan Cameron
Browse files

iio: Add Dyna-Image AL3320A ambient light sensor driver 

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@asus.com>

* https://android.googlesource.com/kernel/msm.git



Signed-off-by: default avatarDaniel Baluta <daniel.baluta@intel.com>
Reviewed-by: default avatarHartmut Knaack <knaack.h@gmx.de>
Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
parent af14afd2

drivers/iio/light/Kconfig

+10 −0
Original line number Diff line number Diff line
@@ -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

drivers/iio/light/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -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

drivers/iio/light/al3320a.c

0 → 100644
+232 −0
Original line number Diff line number Diff line 
/*

 * 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;



	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;



		ret = (ret & AL3320A_GAIN_MASK) >> AL3320A_GAIN_SHIFT;

		*val = al3320a_scales[ret][0];

		*val2 = al3320a_scales[ret][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@intel.com>");

MODULE_DESCRIPTION("AL3320A Ambient Light Sensor driver");

MODULE_LICENSE("GPL v2");