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Commit b84894c7 authored by Kevin Tsai's avatar Kevin Tsai Committed by Jonathan Cameron
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iio: Added Capella cm3232 ambient light sensor driver. 



CM3232 is an advanced ambient light sensor with I2C protocol interface.
The I2C slave address is internally hardwired as 0x10 (7-bit).  Writing
to configure register is byte mode, but reading ALS register requests to
use word mode for 16-bit resolution.

Signed-off-by: default avatarKevin Tsai <ktsai@capellamicro.com>
Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
parent a77945fd

Documentation/devicetree/bindings/i2c/trivial-devices.txt

+1 −0
Original line number Diff line number Diff line
@@ -34,6 +34,7 @@ atmel,24c512 i2c serial eeprom (24cxx) 
atmel,24c1024		i2c serial eeprom  (24cxx)

atmel,at97sc3204t	i2c trusted platform module (TPM)

capella,cm32181		CM32181: Ambient Light Sensor

capella,cm3232		CM3232: Ambient Light Sensor

catalyst,24c32		i2c serial eeprom

cirrus,cs42l51		Cirrus Logic CS42L51 audio codec

dallas,ds1307		64 x 8, Serial, I2C Real-Time Clock

MAINTAINERS

+6 −0
Original line number Diff line number Diff line
@@ -2379,6 +2379,12 @@ F: security/capability.c 
F:	security/commoncap.c

F:	kernel/capability.c



CAPELLA MICROSYSTEMS LIGHT SENSOR DRIVER

M:	Kevin Tsai <ktsai@capellamicro.com>

S:	Maintained

F:	drivers/iio/light/cm*

F:	Documentation/devicetree/bindings/i2c/trivial-devices.txt



CC2520 IEEE-802.15.4 RADIO DRIVER

M:	Varka Bhadram <varkabhadram@gmail.com>

L:	linux-wpan@vger.kernel.org

drivers/iio/light/Kconfig

+11 −0
Original line number Diff line number Diff line
@@ -48,6 +48,17 @@ config CM32181 
	 To compile this driver as a module, choose M here:

	 the module will be called cm32181.



config CM3232

	depends on I2C

	tristate "CM3232 ambient light sensor"

	help

	 Say Y here if you use cm3232.

	 This option enables ambient light sensor using

	 Capella Microsystems cm3232 device driver.



	 To compile this driver as a module, choose M here:

	 the module will be called cm3232.



config CM36651

	depends on I2C

	tristate "CM36651 driver"

drivers/iio/light/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@ obj-$(CONFIG_ADJD_S311) += adjd_s311.o 
obj-$(CONFIG_AL3320A)		+= al3320a.o

obj-$(CONFIG_APDS9300)		+= apds9300.o

obj-$(CONFIG_CM32181)		+= cm32181.o

obj-$(CONFIG_CM3232)		+= cm3232.o

obj-$(CONFIG_CM36651)		+= cm36651.o

obj-$(CONFIG_GP2AP020A00F)	+= gp2ap020a00f.o

obj-$(CONFIG_HID_SENSOR_ALS)	+= hid-sensor-als.o

drivers/iio/light/cm3232.c

0 → 100644
+403 −0
Original line number Diff line number Diff line 
/*

 * CM3232 Ambient Light Sensor

 *

 * Copyright (C) 2014-2015 Capella Microsystems Inc.

 * Author: Kevin Tsai <ktsai@capellamicro.com>

 *

 * This program is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2, as published

 * by the Free Software Foundation.

 *

 * IIO driver for CM3232 (7-bit I2C slave address 0x10).

 */



#include <linux/i2c.h>

#include <linux/module.h>

#include <linux/iio/iio.h>

#include <linux/iio/sysfs.h>

#include <linux/init.h>



/* Registers Address */

#define CM3232_REG_ADDR_CMD		0x00

#define CM3232_REG_ADDR_ALS		0x50

#define CM3232_REG_ADDR_ID		0x53



#define CM3232_CMD_ALS_DISABLE		BIT(0)



#define CM3232_CMD_ALS_IT_SHIFT		2

#define CM3232_CMD_ALS_IT_MASK		(BIT(2) | BIT(3) | BIT(4))

#define CM3232_CMD_ALS_IT_DEFAULT	(0x01 << CM3232_CMD_ALS_IT_SHIFT)



#define CM3232_CMD_ALS_RESET		BIT(6)



#define CM3232_CMD_DEFAULT		CM3232_CMD_ALS_IT_DEFAULT



#define CM3232_HW_ID			0x32

#define CM3232_CALIBSCALE_DEFAULT	100000

#define CM3232_CALIBSCALE_RESOLUTION	100000

#define CM3232_MLUX_PER_LUX		1000



#define CM3232_MLUX_PER_BIT_DEFAULT	64

#define CM3232_MLUX_PER_BIT_BASE_IT	100000



static const struct {

	int val;

	int val2;

	u8 it;

} cm3232_als_it_scales[] = {

	{0, 100000, 0},	/* 0.100000 */

	{0, 200000, 1},	/* 0.200000 */

	{0, 400000, 2},	/* 0.400000 */

	{0, 800000, 3},	/* 0.800000 */

	{1, 600000, 4},	/* 1.600000 */

	{3, 200000, 5},	/* 3.200000 */

};



struct cm3232_als_info {

	u8 regs_cmd_default;

	u8 hw_id;

	int calibscale;

	int mlux_per_bit;

	int mlux_per_bit_base_it;

};



static struct cm3232_als_info cm3232_als_info_default = {

	.regs_cmd_default = CM3232_CMD_DEFAULT,

	.hw_id = CM3232_HW_ID,

	.calibscale = CM3232_CALIBSCALE_DEFAULT,

	.mlux_per_bit = CM3232_MLUX_PER_BIT_DEFAULT,

	.mlux_per_bit_base_it = CM3232_MLUX_PER_BIT_BASE_IT,

};



struct cm3232_chip {

	struct i2c_client *client;

	struct cm3232_als_info *als_info;

	u8 regs_cmd;

	u16 regs_als;

};



/**

 * cm3232_reg_init() - Initialize CM3232

 * @chip:	pointer of struct cm3232_chip.

 *

 * Check and initialize CM3232 ambient light sensor.

 *

 * Return: 0 for success; otherwise for error code.

 */

static int cm3232_reg_init(struct cm3232_chip *chip)

{

	struct i2c_client *client = chip->client;

	s32 ret;



	chip->als_info = &cm3232_als_info_default;



	/* Identify device */

	ret = i2c_smbus_read_word_data(client, CM3232_REG_ADDR_ID);

	if (ret < 0) {

		dev_err(&chip->client->dev, "Error reading addr_id\n");

		return ret;

	}



	if ((ret & 0xFF) != chip->als_info->hw_id)

		return -ENODEV;



	/* Disable and reset device */

	chip->regs_cmd = CM3232_CMD_ALS_DISABLE | CM3232_CMD_ALS_RESET;

	ret = i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,

					chip->regs_cmd);

	if (ret < 0) {

		dev_err(&chip->client->dev, "Error writing reg_cmd\n");

		return ret;

	}



	/* Register default value */

	chip->regs_cmd = chip->als_info->regs_cmd_default;



	/* Configure register */

	ret = i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,

					chip->regs_cmd);

	if (ret < 0)

		dev_err(&chip->client->dev, "Error writing reg_cmd\n");



	return 0;

}



/**

 *  cm3232_read_als_it() - Get sensor integration time

 *  @chip:	pointer of struct cm3232_chip

 *  @val:	pointer of int to load the integration (sec).

 *  @val2:	pointer of int to load the integration time (microsecond).

 *

 *  Report the current integration time.

 *

 *  Return: IIO_VAL_INT_PLUS_MICRO for success, otherwise -EINVAL.

 */

static int cm3232_read_als_it(struct cm3232_chip *chip, int *val, int *val2)

{

	u16 als_it;

	int i;



	als_it = chip->regs_cmd;

	als_it &= CM3232_CMD_ALS_IT_MASK;

	als_it >>= CM3232_CMD_ALS_IT_SHIFT;

	for (i = 0; i < ARRAY_SIZE(cm3232_als_it_scales); i++) {

		if (als_it == cm3232_als_it_scales[i].it) {

			*val = cm3232_als_it_scales[i].val;

			*val2 = cm3232_als_it_scales[i].val2;

			return IIO_VAL_INT_PLUS_MICRO;

		}

	}



	return -EINVAL;

}



/**

 * cm3232_write_als_it() - Write sensor integration time

 * @chip:	pointer of struct cm3232_chip.

 * @val:	integration time in second.

 * @val2:	integration time in microsecond.

 *

 * Convert integration time to sensor value.

 *

 * Return: i2c_smbus_write_byte_data command return value.

 */

static int cm3232_write_als_it(struct cm3232_chip *chip, int val, int val2)

{

	struct i2c_client *client = chip->client;

	u16 als_it, cmd;

	int i;

	s32 ret;



	for (i = 0; i < ARRAY_SIZE(cm3232_als_it_scales); i++) {

		if (val == cm3232_als_it_scales[i].val &&

			val2 == cm3232_als_it_scales[i].val2) {



			als_it = cm3232_als_it_scales[i].it;

			als_it <<= CM3232_CMD_ALS_IT_SHIFT;



			cmd = chip->regs_cmd & ~CM3232_CMD_ALS_IT_MASK;

			cmd |= als_it;

			ret = i2c_smbus_write_byte_data(client,

							CM3232_REG_ADDR_CMD,

							cmd);

			if (ret < 0)

				return ret;

			chip->regs_cmd = cmd;

			return 0;

		}

	}

	return -EINVAL;

}



/**

 * cm3232_get_lux() - report current lux value

 * @chip:	pointer of struct cm3232_chip.

 *

 * Convert sensor data to lux.  It depends on integration

 * time and calibscale variable.

 *

 * Return: Zero or positive value is lux, otherwise error code.

 */

static int cm3232_get_lux(struct cm3232_chip *chip)

{

	struct i2c_client *client = chip->client;

	struct cm3232_als_info *als_info = chip->als_info;

	int ret;

	int val, val2;

	int als_it;

	u64 lux;



	/* Calculate mlux per bit based on als_it */

	ret = cm3232_read_als_it(chip, &val, &val2);

	if (ret < 0)

		return -EINVAL;

	als_it = val * 1000000 + val2;

	lux = (__force u64)als_info->mlux_per_bit;

	lux *= als_info->mlux_per_bit_base_it;

	lux = div_u64(lux, als_it);



	ret = i2c_smbus_read_word_data(client, CM3232_REG_ADDR_ALS);

	if (ret < 0) {

		dev_err(&client->dev, "Error reading reg_addr_als\n");

		return ret;

	}



	chip->regs_als = (u16)ret;

	lux *= chip->regs_als;

	lux *= als_info->calibscale;

	lux = div_u64(lux, CM3232_CALIBSCALE_RESOLUTION);

	lux = div_u64(lux, CM3232_MLUX_PER_LUX);



	if (lux > 0xFFFF)

		lux = 0xFFFF;



	return (int)lux;

}



static int cm3232_read_raw(struct iio_dev *indio_dev,

			struct iio_chan_spec const *chan,

			int *val, int *val2, long mask)

{

	struct cm3232_chip *chip = iio_priv(indio_dev);

	struct cm3232_als_info *als_info = chip->als_info;

	int ret;



	switch (mask) {

	case IIO_CHAN_INFO_PROCESSED:

		ret = cm3232_get_lux(chip);

		if (ret < 0)

			return ret;

		*val = ret;

		return IIO_VAL_INT;

	case IIO_CHAN_INFO_CALIBSCALE:

		*val = als_info->calibscale;

		return IIO_VAL_INT;

	case IIO_CHAN_INFO_INT_TIME:

		return cm3232_read_als_it(chip, val, val2);

	}



	return -EINVAL;

}



static int cm3232_write_raw(struct iio_dev *indio_dev,

			struct iio_chan_spec const *chan,

			int val, int val2, long mask)

{

	struct cm3232_chip *chip = iio_priv(indio_dev);

	struct cm3232_als_info *als_info = chip->als_info;



	switch (mask) {

	case IIO_CHAN_INFO_CALIBSCALE:

		als_info->calibscale = val;

		return 0;

	case IIO_CHAN_INFO_INT_TIME:

		return cm3232_write_als_it(chip, val, val2);

	}



	return -EINVAL;

}



/**

 * cm3232_get_it_available() - Get available ALS IT value

 * @dev:	pointer of struct device.

 * @attr:	pointer of struct device_attribute.

 * @buf:	pointer of return string buffer.

 *

 * Display the available integration time in second.

 *

 * Return: string length.

 */

static ssize_t cm3232_get_it_available(struct device *dev,

			struct device_attribute *attr, char *buf)

{

	int i, len;



	for (i = 0, len = 0; i < ARRAY_SIZE(cm3232_als_it_scales); i++)

		len += scnprintf(buf + len, PAGE_SIZE - len, "%u.%06u ",

			cm3232_als_it_scales[i].val,

			cm3232_als_it_scales[i].val2);

	return len + scnprintf(buf + len, PAGE_SIZE - len, "\n");

}



static const struct iio_chan_spec cm3232_channels[] = {

	{

		.type = IIO_LIGHT,

		.info_mask_separate =

			BIT(IIO_CHAN_INFO_PROCESSED) |

			BIT(IIO_CHAN_INFO_CALIBSCALE) |

			BIT(IIO_CHAN_INFO_INT_TIME),

	}

};



static IIO_DEVICE_ATTR(in_illuminance_integration_time_available,

			S_IRUGO, cm3232_get_it_available, NULL, 0);



static struct attribute *cm3232_attributes[] = {

	&iio_dev_attr_in_illuminance_integration_time_available.dev_attr.attr,

	NULL,

};



static const struct attribute_group cm3232_attribute_group = {

	.attrs = cm3232_attributes

};



static const struct iio_info cm3232_info = {

	.driver_module		= THIS_MODULE,

	.read_raw		= &cm3232_read_raw,

	.write_raw		= &cm3232_write_raw,

	.attrs			= &cm3232_attribute_group,

};



static int cm3232_probe(struct i2c_client *client,

			const struct i2c_device_id *id)

{

	struct cm3232_chip *chip;

	struct iio_dev *indio_dev;

	int ret;



	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));

	if (!indio_dev)

		return -ENOMEM;



	chip = iio_priv(indio_dev);

	i2c_set_clientdata(client, indio_dev);

	chip->client = client;



	indio_dev->dev.parent = &client->dev;

	indio_dev->channels = cm3232_channels;

	indio_dev->num_channels = ARRAY_SIZE(cm3232_channels);

	indio_dev->info = &cm3232_info;

	indio_dev->name = id->name;

	indio_dev->modes = INDIO_DIRECT_MODE;



	ret = cm3232_reg_init(chip);

	if (ret) {

		dev_err(&client->dev,

			"%s: register init failed\n",

			__func__);

		return ret;

	}



	return iio_device_register(indio_dev);

}



static int cm3232_remove(struct i2c_client *client)

{

	struct iio_dev *indio_dev = i2c_get_clientdata(client);



	i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,

		CM3232_CMD_ALS_DISABLE);



	iio_device_unregister(indio_dev);



	return 0;

}



static const struct i2c_device_id cm3232_id[] = {

	{"cm3232", 0},

	{}

};



MODULE_DEVICE_TABLE(i2c, cm3232_id);



static const struct of_device_id cm3232_of_match[] = {

	{.compatible = "capella,cm3232"},

	{}

};



static struct i2c_driver cm3232_driver = {

	.driver = {

		.name	= "cm3232",

		.owner	= THIS_MODULE,

		.of_match_table = of_match_ptr(cm3232_of_match),

	},

	.id_table	= cm3232_id,

	.probe		= cm3232_probe,

	.remove		= cm3232_remove,

};



module_i2c_driver(cm3232_driver);



MODULE_AUTHOR("Kevin Tsai <ktsai@capellamicro.com>");

MODULE_DESCRIPTION("CM3232 ambient light sensor driver");

MODULE_LICENSE("GPL");