drivers/misc/isl29003.c: driver for the ISL29003 ambient light sensor (3cdbbeeb) · Commits · e / devices / android_kernel_samsung_universal8895

Documentation/misc-devices/isl29003

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		Kernel driver isl29003
		=====================

		Supported chips:
		* Intersil ISL29003
		Prefix: 'isl29003'
		Addresses scanned: none
		Datasheet:
		http://www.intersil.com/data/fn/fn7464.pdf

		Author: Daniel Mack <daniel@caiaq.de>


		Description
		-----------
		The ISL29003 is an integrated light sensor with a 16-bit integrating type
		ADC, I2C user programmable lux range select for optimized counts/lux, and
		I2C multi-function control and monitoring capabilities. The internal ADC
		provides 16-bit resolution while rejecting 50Hz and 60Hz flicker caused by
		artificial light sources.

		The driver allows to set the lux range, the bit resolution, the operational
		mode (see below) and the power state of device and can read the current lux
		value, of course.


		Detection
		---------

		The ISL29003 does not have an ID register which could be used to identify
		it, so the detection routine will just try to read from the configured I2C
		addess and consider the device to be present as soon as it ACKs the
		transfer.


		Sysfs entries
		-------------

		range:
		0: 0 lux to 1000 lux (default)
		1: 0 lux to 4000 lux
		2: 0 lux to 16,000 lux
		3: 0 lux to 64,000 lux

		resolution:
		0: 2^16 cycles (default)
		1: 2^12 cycles
		2: 2^8 cycles
		3: 2^4 cycles

		mode:
		0: diode1's current (unsigned 16bit) (default)
		1: diode1's current (unsigned 16bit)
		2: difference between diodes (l1 - l2, signed 15bit)

		power_state:
		0: device is disabled (default)
		1: device is enabled

		lux (read only):
		returns the value from the last sensor reading

drivers/misc/Kconfig

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		@@ -223,6 +223,16 @@ config DELL_LAPTOP
		This driver adds support for rfkill and backlight control to Dell
		laptops.

		config ISL29003
		tristate "Intersil ISL29003 ambient light sensor"
		depends on I2C && SYSFS
		help
		If you say yes here you get support for the Intersil ISL29003
		ambient light sensor.

		This driver can also be built as a module. If so, the module
		will be called isl29003.

		source "drivers/misc/c2port/Kconfig"
		source "drivers/misc/eeprom/Kconfig"

drivers/misc/Makefile

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		@@ -18,5 +18,6 @@ obj-$(CONFIG_KGDB_TESTS) += kgdbts.o
		obj-$(CONFIG_SGI_XP) += sgi-xp/
		obj-$(CONFIG_SGI_GRU) += sgi-gru/
		obj-$(CONFIG_HP_ILO) += hpilo.o
		obj-$(CONFIG_ISL29003) += isl29003.o
		obj-$(CONFIG_C2PORT) += c2port/
		obj-y += eeprom/

drivers/misc/isl29003.c

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		/*
		* isl29003.c - Linux kernel module for
		* Intersil ISL29003 ambient light sensor
		*
		* See file:Documentation/misc-devices/isl29003
		*
		* Copyright (c) 2009 Daniel Mack <daniel@caiaq.de>
		*
		* Based on code written by
		* Rodolfo Giometti <giometti@linux.it>
		* Eurotech S.p.A. <info@eurotech.it>
		*
		* This program is free software; you can redistribute it and/or modify
		* it under the terms of the GNU General Public License as published by
		* the Free Software Foundation; either version 2 of the License, or
		* (at your option) any later version.
		*
		* This program is distributed in the hope that it will be useful,
		* but WITHOUT ANY WARRANTY; without even the implied warranty of
		* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
		* GNU General Public License for more details.
		*
		* You should have received a copy of the GNU General Public License
		* along with this program; if not, write to the Free Software
		* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
		*/

		#include <linux/module.h>
		#include <linux/init.h>
		#include <linux/slab.h>
		#include <linux/i2c.h>
		#include <linux/mutex.h>
		#include <linux/delay.h>

		#define ISL29003_DRV_NAME "isl29003"
		#define DRIVER_VERSION "1.0"

		#define ISL29003_REG_COMMAND 0x00
		#define ISL29003_ADC_ENABLED (1 << 7)
		#define ISL29003_ADC_PD (1 << 6)
		#define ISL29003_TIMING_INT (1 << 5)
		#define ISL29003_MODE_SHIFT (2)
		#define ISL29003_MODE_MASK (0x3 << ISL29003_MODE_SHIFT)
		#define ISL29003_RES_SHIFT (0)
		#define ISL29003_RES_MASK (0x3 << ISL29003_RES_SHIFT)

		#define ISL29003_REG_CONTROL 0x01
		#define ISL29003_INT_FLG (1 << 5)
		#define ISL29003_RANGE_SHIFT (2)
		#define ISL29003_RANGE_MASK (0x3 << ISL29003_RANGE_SHIFT)
		#define ISL29003_INT_PERSISTS_SHIFT (0)
		#define ISL29003_INT_PERSISTS_MASK (0xf << ISL29003_INT_PERSISTS_SHIFT)

		#define ISL29003_REG_IRQ_THRESH_HI 0x02
		#define ISL29003_REG_IRQ_THRESH_LO 0x03
		#define ISL29003_REG_LSB_SENSOR 0x04
		#define ISL29003_REG_MSB_SENSOR 0x05
		#define ISL29003_REG_LSB_TIMER 0x06
		#define ISL29003_REG_MSB_TIMER 0x07

		#define ISL29003_NUM_CACHABLE_REGS 4

		struct isl29003_data {
		struct i2c_client *client;
		struct mutex lock;
		u8 reg_cache[ISL29003_NUM_CACHABLE_REGS];
		};

		static int gain_range[] = {
		1000, 4000, 16000, 64000
		};

		/*
		* register access helpers
		*/

		static int __isl29003_read_reg(struct i2c_client *client,
		u32 reg, u8 mask, u8 shift)
		{
		struct isl29003_data *data = i2c_get_clientdata(client);
		return (data->reg_cache[reg] & mask) >> shift;
		}

		static int __isl29003_write_reg(struct i2c_client *client,
		u32 reg, u8 mask, u8 shift, u8 val)
		{
		struct isl29003_data *data = i2c_get_clientdata(client);
		int ret = 0;
		u8 tmp;

		if (reg >= ISL29003_NUM_CACHABLE_REGS)
		return -EINVAL;

		mutex_lock(&data->lock);

		tmp = data->reg_cache[reg];
		tmp &= ~mask;
		tmp \|= val << shift;

		ret = i2c_smbus_write_byte_data(client, reg, tmp);
		if (!ret)
		data->reg_cache[reg] = tmp;

		mutex_unlock(&data->lock);
		return ret;
		}

		/*
		* internally used functions
		*/

		/* range */
		static int isl29003_get_range(struct i2c_client *client)
		{
		return __isl29003_read_reg(client, ISL29003_REG_CONTROL,
		ISL29003_RANGE_MASK, ISL29003_RANGE_SHIFT);
		}

		static int isl29003_set_range(struct i2c_client *client, int range)
		{
		return __isl29003_write_reg(client, ISL29003_REG_CONTROL,
		ISL29003_RANGE_MASK, ISL29003_RANGE_SHIFT, range);
		}

		/* resolution */
		static int isl29003_get_resolution(struct i2c_client *client)
		{
		return __isl29003_read_reg(client, ISL29003_REG_COMMAND,
		ISL29003_RES_MASK, ISL29003_RES_SHIFT);
		}

		static int isl29003_set_resolution(struct i2c_client *client, int res)
		{
		return __isl29003_write_reg(client, ISL29003_REG_COMMAND,
		ISL29003_RES_MASK, ISL29003_RES_SHIFT, res);
		}

		/* mode */
		static int isl29003_get_mode(struct i2c_client *client)
		{
		return __isl29003_read_reg(client, ISL29003_REG_COMMAND,
		ISL29003_RES_MASK, ISL29003_RES_SHIFT);
		}

		static int isl29003_set_mode(struct i2c_client *client, int mode)
		{
		return __isl29003_write_reg(client, ISL29003_REG_COMMAND,
		ISL29003_RES_MASK, ISL29003_RES_SHIFT, mode);
		}

		/* power_state */
		static int isl29003_set_power_state(struct i2c_client *client, int state)
		{
		return __isl29003_write_reg(client, ISL29003_REG_COMMAND,
		ISL29003_ADC_ENABLED \| ISL29003_ADC_PD, 0,
		state ? ISL29003_ADC_ENABLED : ISL29003_ADC_PD);
		}

		static int isl29003_get_power_state(struct i2c_client *client)
		{
		struct isl29003_data *data = i2c_get_clientdata(client);
		u8 cmdreg = data->reg_cache[ISL29003_REG_COMMAND];
		return ~cmdreg & ISL29003_ADC_PD;
		}

		static int isl29003_get_adc_value(struct i2c_client *client)
		{
		struct isl29003_data *data = i2c_get_clientdata(client);
		int lsb, msb, range, bitdepth;

		mutex_lock(&data->lock);
		lsb = i2c_smbus_read_byte_data(client, ISL29003_REG_LSB_SENSOR);

		if (lsb < 0) {
		mutex_unlock(&data->lock);
		return lsb;
		}

		msb = i2c_smbus_read_byte_data(client, ISL29003_REG_MSB_SENSOR);
		mutex_unlock(&data->lock);

		if (msb < 0)
		return msb;

		range = isl29003_get_range(client);
		bitdepth = (4 - isl29003_get_resolution(client)) * 4;
		return (((msb << 8) \| lsb) * gain_range[range]) >> bitdepth;
		}

		/*
		* sysfs layer
		*/

		/* range */
		static ssize_t isl29003_show_range(struct device *dev,
		struct device_attribute attr, char buf)
		{
		struct i2c_client *client = to_i2c_client(dev);
		return sprintf(buf, "%i\n", isl29003_get_range(client));
		}

		static ssize_t isl29003_store_range(struct device *dev,
		struct device_attribute *attr,
		const char *buf, size_t count)
		{
		struct i2c_client *client = to_i2c_client(dev);
		unsigned long val;
		int ret;

		if ((strict_strtoul(buf, 10, &val) < 0) \|\| (val > 3))
		return -EINVAL;

		ret = isl29003_set_range(client, val);
		if (ret < 0)
		return ret;

		return count;
		}

		static DEVICE_ATTR(range, S_IWUSR \| S_IRUGO,
		isl29003_show_range, isl29003_store_range);


		/* resolution */
		static ssize_t isl29003_show_resolution(struct device *dev,
		struct device_attribute *attr,
		char *buf)
		{
		struct i2c_client *client = to_i2c_client(dev);
		return sprintf(buf, "%d\n", isl29003_get_resolution(client));
		}

		static ssize_t isl29003_store_resolution(struct device *dev,
		struct device_attribute *attr,
		const char *buf, size_t count)
		{
		struct i2c_client *client = to_i2c_client(dev);
		unsigned long val;
		int ret;

		if ((strict_strtoul(buf, 10, &val) < 0) \|\| (val > 3))
		return -EINVAL;

		ret = isl29003_set_resolution(client, val);
		if (ret < 0)
		return ret;

		return count;
		}

		static DEVICE_ATTR(resolution, S_IWUSR \| S_IRUGO,
		isl29003_show_resolution, isl29003_store_resolution);

		/* mode */
		static ssize_t isl29003_show_mode(struct device *dev,
		struct device_attribute attr, char buf)
		{
		struct i2c_client *client = to_i2c_client(dev);
		return sprintf(buf, "%d\n", isl29003_get_mode(client));
		}

		static ssize_t isl29003_store_mode(struct device *dev,
		struct device_attribute attr, const char buf, size_t count)
		{
		struct i2c_client *client = to_i2c_client(dev);
		unsigned long val;
		int ret;

		if ((strict_strtoul(buf, 10, &val) < 0) \|\| (val > 2))
		return -EINVAL;

		ret = isl29003_set_mode(client, val);
		if (ret < 0)
		return ret;

		return count;
		}

		static DEVICE_ATTR(mode, S_IWUSR \| S_IRUGO,
		isl29003_show_mode, isl29003_store_mode);


		/* power state */
		static ssize_t isl29003_show_power_state(struct device *dev,
		struct device_attribute *attr,
		char *buf)
		{
		struct i2c_client *client = to_i2c_client(dev);
		return sprintf(buf, "%d\n", isl29003_get_power_state(client));
		}

		static ssize_t isl29003_store_power_state(struct device *dev,
		struct device_attribute *attr,
		const char *buf, size_t count)
		{
		struct i2c_client *client = to_i2c_client(dev);
		unsigned long val;
		int ret;

		if ((strict_strtoul(buf, 10, &val) < 0) \|\| (val > 1))
		return -EINVAL;

		ret = isl29003_set_power_state(client, val);
		return ret ? ret : count;
		}

		static DEVICE_ATTR(power_state, S_IWUSR \| S_IRUGO,
		isl29003_show_power_state, isl29003_store_power_state);


		/* lux */
		static ssize_t isl29003_show_lux(struct device *dev,
		struct device_attribute attr, char buf)
		{
		struct i2c_client *client = to_i2c_client(dev);

		/* No LUX data if not operational */
		if (!isl29003_get_power_state(client))
		return -EBUSY;

		return sprintf(buf, "%d\n", isl29003_get_adc_value(client));
		}

		static DEVICE_ATTR(lux, S_IRUGO, isl29003_show_lux, NULL);

		static struct attribute *isl29003_attributes[] = {
		&dev_attr_range.attr,
		&dev_attr_resolution.attr,
		&dev_attr_mode.attr,
		&dev_attr_power_state.attr,
		&dev_attr_lux.attr,
		NULL
		};

		static const struct attribute_group isl29003_attr_group = {
		.attrs = isl29003_attributes,
		};

		static int isl29003_init_client(struct i2c_client *client)
		{
		struct isl29003_data *data = i2c_get_clientdata(client);
		int i;

		/* read all the registers once to fill the cache.
		* if one of the reads fails, we consider the init failed */
		for (i = 0; i < ARRAY_SIZE(data->reg_cache); i++) {
		int v = i2c_smbus_read_byte_data(client, i);
		if (v < 0)
		return -ENODEV;

		data->reg_cache[i] = v;
		}

		/* set defaults */
		isl29003_set_range(client, 0);
		isl29003_set_resolution(client, 0);
		isl29003_set_mode(client, 0);
		isl29003_set_power_state(client, 0);

		return 0;
		}

		/*
		* I2C layer
		*/

		static int __devinit isl29003_probe(struct i2c_client *client,
		const struct i2c_device_id *id)
		{
		struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
		struct isl29003_data *data;
		int err = 0;

		if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
		return -EIO;

		data = kzalloc(sizeof(struct isl29003_data), GFP_KERNEL);
		if (!data)
		return -ENOMEM;

		data->client = client;
		i2c_set_clientdata(client, data);
		mutex_init(&data->lock);

		/* initialize the ISL29003 chip */
		err = isl29003_init_client(client);
		if (err)
		goto exit_kfree;

		/* register sysfs hooks */
		err = sysfs_create_group(&client->dev.kobj, &isl29003_attr_group);
		if (err)
		goto exit_kfree;

		dev_info(&client->dev, "driver version %s enabled\n", DRIVER_VERSION);
		return 0;

		exit_kfree:
		kfree(data);
		return err;
		}

		static int __devexit isl29003_remove(struct i2c_client *client)
		{
		sysfs_remove_group(&client->dev.kobj, &isl29003_attr_group);
		isl29003_set_power_state(client, 0);
		kfree(i2c_get_clientdata(client));
		return 0;
		}

		#ifdef CONFIG_PM
		static int isl29003_suspend(struct i2c_client *client, pm_message_t mesg)
		{
		return isl29003_set_power_state(client, 0);
		}

		static int isl29003_resume(struct i2c_client *client)
		{
		int i;
		struct isl29003_data *data = i2c_get_clientdata(client);

		/* restore registers from cache */
		for (i = 0; i < ARRAY_SIZE(data->reg_cache); i++)
		if (!i2c_smbus_write_byte_data(client, i, data->reg_cache[i]))
		return -EIO;

		return 0;
		}

		#else
		#define isl29003_suspend NULL
		#define isl29003_resume NULL
		#endif /* CONFIG_PM */

		static const struct i2c_device_id isl29003_id[] = {
		{ "isl29003", 0 },
		{}
		};
		MODULE_DEVICE_TABLE(i2c, isl29003_id);

		static struct i2c_driver isl29003_driver = {
		.driver = {
		.name = ISL29003_DRV_NAME,
		.owner = THIS_MODULE,
		},
		.suspend = isl29003_suspend,
		.resume = isl29003_resume,
		.probe = isl29003_probe,
		.remove = __devexit_p(isl29003_remove),
		.id_table = isl29003_id,
		};

		static int __init isl29003_init(void)
		{
		return i2c_add_driver(&isl29003_driver);
		}

		static void __exit isl29003_exit(void)
		{
		i2c_del_driver(&isl29003_driver);
		}

		MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>");
		MODULE_DESCRIPTION("ISL29003 ambient light sensor driver");
		MODULE_LICENSE("GPL v2");
		MODULE_VERSION(DRIVER_VERSION);

		module_init(isl29003_init);
		module_exit(isl29003_exit);