Commit 2690be90 authored by Peter Meerwald's avatar Peter Meerwald Committed by Jonathan Cameron
Browse files

iio: Add Lite-On ltr501 ambient light / proximity sensor driver 

combined ambient light (two channels) and proximity sensor with I2C
interface; the ALS channels are visible+IR and IR

datasheet is here
http://optoelectronics.liteon.com/upload/download/DS86-2012-0006/P_100_LTR-501ALS-01_PrelimDS_ver1.1.pdf



v3:
* fix use of sizeof in _read_als()
v2: (thanks to Lars-Peter Clausen)
* cannot use devm_iio_device_register() due to cleanup order in _remove()
* mutex around data wait/read
* turn info message in _probe() into check for part number
* change copyright year to 2014

Signed-off-by: default avatarPeter Meerwald <pmeerw@pmeerw.net>
Reviewed-by: default avatarLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
parent 1a5b7d41

drivers/iio/light/Kconfig

+12 −0
Original line number Diff line number Diff line
@@ -90,6 +90,18 @@ config SENSORS_LM3533 
	  changes. The ALS-control output values can be set per zone for the

	  three current output channels.



config LTR501

	tristate "LTR-501ALS-01 light sensor"

	depends on I2C

	select IIO_BUFFER

	select IIO_TRIGGERED_BUFFER

	help

	 If you say yes here you get support for the Lite-On LTR-501ALS-01

	 ambient light and proximity sensor.



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

         will be called ltr501.



config TCS3472

	tristate "TAOS TCS3472 color light-to-digital converter"

	depends on I2C

drivers/iio/light/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -10,6 +10,7 @@ obj-$(CONFIG_CM36651) += cm36651.o 
obj-$(CONFIG_GP2AP020A00F)	+= gp2ap020a00f.o

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

obj-$(CONFIG_SENSORS_LM3533)	+= lm3533-als.o

obj-$(CONFIG_LTR501)		+= ltr501.o

obj-$(CONFIG_SENSORS_TSL2563)	+= tsl2563.o

obj-$(CONFIG_TCS3472)		+= tcs3472.o

obj-$(CONFIG_TSL4531)		+= tsl4531.o

drivers/iio/light/ltr501.c

0 → 100644
+445 −0
Original line number Diff line number Diff line 
/*

 * ltr501.c - Support for Lite-On LTR501 ambient light and proximity sensor

 *

 * Copyright 2014 Peter Meerwald <pmeerw@pmeerw.net>

 *

 * 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.

 *

 * 7-bit I2C slave address 0x23

 *

 * TODO: interrupt, threshold, measurement rate, IR LED characteristics

 */



#include <linux/module.h>

#include <linux/i2c.h>

#include <linux/err.h>

#include <linux/delay.h>



#include <linux/iio/iio.h>

#include <linux/iio/sysfs.h>

#include <linux/iio/trigger_consumer.h>

#include <linux/iio/buffer.h>

#include <linux/iio/triggered_buffer.h>



#define LTR501_DRV_NAME "ltr501"



#define LTR501_ALS_CONTR 0x80 /* ALS operation mode, SW reset */

#define LTR501_PS_CONTR 0x81 /* PS operation mode */

#define LTR501_PART_ID 0x86

#define LTR501_MANUFAC_ID 0x87

#define LTR501_ALS_DATA1 0x88 /* 16-bit, little endian */

#define LTR501_ALS_DATA0 0x8a /* 16-bit, little endian */

#define LTR501_ALS_PS_STATUS 0x8c

#define LTR501_PS_DATA 0x8d /* 16-bit, little endian */



#define LTR501_ALS_CONTR_SW_RESET BIT(2)

#define LTR501_CONTR_PS_GAIN_MASK (BIT(3) | BIT(2))

#define LTR501_CONTR_PS_GAIN_SHIFT 2

#define LTR501_CONTR_ALS_GAIN_MASK BIT(3)

#define LTR501_CONTR_ACTIVE BIT(1)



#define LTR501_STATUS_ALS_RDY BIT(2)

#define LTR501_STATUS_PS_RDY BIT(0)



#define LTR501_PS_DATA_MASK 0x7ff



struct ltr501_data {

	struct i2c_client *client;

	struct mutex lock_als, lock_ps;

	u8 als_contr, ps_contr;

};



static int ltr501_drdy(struct ltr501_data *data, u8 drdy_mask)

{

	int tries = 100;

	int ret;



	while (tries--) {

		ret = i2c_smbus_read_byte_data(data->client,

			LTR501_ALS_PS_STATUS);

		if (ret < 0)

			return ret;

		if ((ret & drdy_mask) == drdy_mask)

			return 0;

		msleep(25);

	}



	dev_err(&data->client->dev, "ltr501_drdy() failed, data not ready\n");

	return -EIO;

}



static int ltr501_read_als(struct ltr501_data *data, __le16 buf[2])

{

	int ret = ltr501_drdy(data, LTR501_STATUS_ALS_RDY);

	if (ret < 0)

		return ret;

	/* always read both ALS channels in given order */

	return i2c_smbus_read_i2c_block_data(data->client,

		LTR501_ALS_DATA1, 2 * sizeof(__le16), (u8 *) buf);

}



static int ltr501_read_ps(struct ltr501_data *data)

{

	int ret = ltr501_drdy(data, LTR501_STATUS_PS_RDY);

	if (ret < 0)

		return ret;

	return i2c_smbus_read_word_data(data->client, LTR501_PS_DATA);

}



#define LTR501_INTENSITY_CHANNEL(_idx, _addr, _mod, _shared) { \

	.type = IIO_INTENSITY, \

	.modified = 1, \

	.address = (_addr), \

	.channel2 = (_mod), \

	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \

	.info_mask_shared_by_type = (_shared), \

	.scan_index = (_idx), \

	.scan_type = { \

		.sign = 'u', \

		.realbits = 16, \

		.storagebits = 16, \

		.endianness = IIO_CPU, \

	} \

}



static const struct iio_chan_spec ltr501_channels[] = {

	LTR501_INTENSITY_CHANNEL(0, LTR501_ALS_DATA0, IIO_MOD_LIGHT_BOTH, 0),

	LTR501_INTENSITY_CHANNEL(1, LTR501_ALS_DATA1, IIO_MOD_LIGHT_IR,

		BIT(IIO_CHAN_INFO_SCALE)),

	{

		.type = IIO_PROXIMITY,

		.address = LTR501_PS_DATA,

		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |

			BIT(IIO_CHAN_INFO_SCALE),

		.scan_index = 2,

		.scan_type = {

			.sign = 'u',

			.realbits = 11,

			.storagebits = 16,

			.endianness = IIO_CPU,

		},

	},

	IIO_CHAN_SOFT_TIMESTAMP(3),

};



static const int ltr501_ps_gain[4][2] = {

	{1, 0}, {0, 250000}, {0, 125000}, {0, 62500}

};



static int ltr501_read_raw(struct iio_dev *indio_dev,

				struct iio_chan_spec const *chan,

				int *val, int *val2, long mask)

{

	struct ltr501_data *data = iio_priv(indio_dev);

	__le16 buf[2];

	int ret, i;



	switch (mask) {

	case IIO_CHAN_INFO_RAW:

		if (iio_buffer_enabled(indio_dev))

			return -EBUSY;



		switch (chan->type) {

		case IIO_INTENSITY:

			mutex_lock(&data->lock_als);

			ret = ltr501_read_als(data, buf);

			mutex_unlock(&data->lock_als);

			if (ret < 0)

				return ret;

			*val = le16_to_cpu(chan->address == LTR501_ALS_DATA1 ?

				buf[0] : buf[1]);

			return IIO_VAL_INT;

		case IIO_PROXIMITY:

			mutex_lock(&data->lock_ps);

			ret = ltr501_read_ps(data);

			mutex_unlock(&data->lock_ps);

			if (ret < 0)

				return ret;

			*val = ret & LTR501_PS_DATA_MASK;

			return IIO_VAL_INT;

		default:

			return -EINVAL;

		}

	case IIO_CHAN_INFO_SCALE:

		switch (chan->type) {

		case IIO_INTENSITY:

			if (data->als_contr & LTR501_CONTR_ALS_GAIN_MASK) {

				*val = 0;

				*val2 = 5000;

				return IIO_VAL_INT_PLUS_MICRO;

			} else {

				*val = 1;

				*val2 = 0;

				return IIO_VAL_INT;

			}

		case IIO_PROXIMITY:

			i = (data->ps_contr & LTR501_CONTR_PS_GAIN_MASK) >>

				LTR501_CONTR_PS_GAIN_SHIFT;

			*val = ltr501_ps_gain[i][0];

			*val2 = ltr501_ps_gain[i][1];

			return IIO_VAL_INT_PLUS_MICRO;

		default:

			return -EINVAL;

		}

	}

	return -EINVAL;

}



static int ltr501_get_ps_gain_index(int val, int val2)

{

	int i;



	for (i = 0; i < ARRAY_SIZE(ltr501_ps_gain); i++)

		if (val == ltr501_ps_gain[i][0] && val2 == ltr501_ps_gain[i][1])

			return i;



	return -1;

}



static int ltr501_write_raw(struct iio_dev *indio_dev,

			       struct iio_chan_spec const *chan,

			       int val, int val2, long mask)

{

	struct ltr501_data *data = iio_priv(indio_dev);

	int i;



	if (iio_buffer_enabled(indio_dev))

		return -EBUSY;



	switch (mask) {

	case IIO_CHAN_INFO_SCALE:

		switch (chan->type) {

		case IIO_INTENSITY:

			if (val == 0 && val2 == 5000)

				data->als_contr |= LTR501_CONTR_ALS_GAIN_MASK;

			else if (val == 1 && val2 == 0)

				data->als_contr &= ~LTR501_CONTR_ALS_GAIN_MASK;

			else

				return -EINVAL;

			return i2c_smbus_write_byte_data(data->client,

				LTR501_ALS_CONTR, data->als_contr);

		case IIO_PROXIMITY:

			i = ltr501_get_ps_gain_index(val, val2);

			if (i < 0)

				return -EINVAL;

			data->ps_contr &= ~LTR501_CONTR_PS_GAIN_MASK;

			data->ps_contr |= i << LTR501_CONTR_PS_GAIN_SHIFT;

			return i2c_smbus_write_byte_data(data->client,

				LTR501_PS_CONTR, data->ps_contr);

		default:

			return -EINVAL;

		}

	}

	return -EINVAL;

}



static IIO_CONST_ATTR(in_proximity_scale_available, "1 0.25 0.125 0.0625");

static IIO_CONST_ATTR(in_intensity_scale_available, "1 0.005");



static struct attribute *ltr501_attributes[] = {

	&iio_const_attr_in_proximity_scale_available.dev_attr.attr,

	&iio_const_attr_in_intensity_scale_available.dev_attr.attr,

	NULL

};



static const struct attribute_group ltr501_attribute_group = {

	.attrs = ltr501_attributes,

};



static const struct iio_info ltr501_info = {

	.read_raw = ltr501_read_raw,

	.write_raw = ltr501_write_raw,

	.attrs = &ltr501_attribute_group,

	.driver_module = THIS_MODULE,

};



static int ltr501_write_contr(struct i2c_client *client, u8 als_val, u8 ps_val)

{

	int ret = i2c_smbus_write_byte_data(client, LTR501_ALS_CONTR, als_val);

	if (ret < 0)

		return ret;



	return i2c_smbus_write_byte_data(client, LTR501_PS_CONTR, ps_val);

}



static irqreturn_t ltr501_trigger_handler(int irq, void *p)

{

	struct iio_poll_func *pf = p;

	struct iio_dev *indio_dev = pf->indio_dev;

	struct ltr501_data *data = iio_priv(indio_dev);

	u16 buf[8];

	__le16 als_buf[2];

	u8 mask = 0;

	int j = 0;

	int ret;



	memset(buf, 0, sizeof(buf));



	/* figure out which data needs to be ready */

	if (test_bit(0, indio_dev->active_scan_mask) ||

		test_bit(1, indio_dev->active_scan_mask))

		mask |= LTR501_STATUS_ALS_RDY;

	if (test_bit(2, indio_dev->active_scan_mask))

		mask |= LTR501_STATUS_PS_RDY;



	ret = ltr501_drdy(data, mask);

	if (ret < 0)

		goto done;



	if (mask & LTR501_STATUS_ALS_RDY) {

		ret = i2c_smbus_read_i2c_block_data(data->client,

			LTR501_ALS_DATA1, sizeof(als_buf), (u8 *) als_buf);

		if (ret < 0)

			return ret;

		if (test_bit(0, indio_dev->active_scan_mask))

			buf[j++] = le16_to_cpu(als_buf[1]);

		if (test_bit(1, indio_dev->active_scan_mask))

			buf[j++] = le16_to_cpu(als_buf[0]);

	}



	if (mask & LTR501_STATUS_PS_RDY) {

		ret = i2c_smbus_read_word_data(data->client, LTR501_PS_DATA);

		if (ret < 0)

			goto done;

		buf[j++] = ret & LTR501_PS_DATA_MASK;

	}



	iio_push_to_buffers_with_timestamp(indio_dev, buf,

		iio_get_time_ns());



done:

	iio_trigger_notify_done(indio_dev->trig);



	return IRQ_HANDLED;

}



static int ltr501_init(struct ltr501_data *data)

{

	int ret;



	ret = i2c_smbus_read_byte_data(data->client, LTR501_ALS_CONTR);

	if (ret < 0)

		return ret;

	data->als_contr = ret | LTR501_CONTR_ACTIVE;



	ret = i2c_smbus_read_byte_data(data->client, LTR501_PS_CONTR);

	if (ret < 0)

		return ret;

	data->ps_contr = ret | LTR501_CONTR_ACTIVE;



	return ltr501_write_contr(data->client, data->als_contr,

		data->ps_contr);

}



static int ltr501_probe(struct i2c_client *client,

			  const struct i2c_device_id *id)

{

	struct ltr501_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;

	mutex_init(&data->lock_als);

	mutex_init(&data->lock_ps);



	ret = i2c_smbus_read_byte_data(data->client, LTR501_PART_ID);

	if (ret < 0)

		return ret;

	if ((ret >> 4) != 0x8)

		return -ENODEV;



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

	indio_dev->info = &ltr501_info;

	indio_dev->channels = ltr501_channels;

	indio_dev->num_channels = ARRAY_SIZE(ltr501_channels);

	indio_dev->name = LTR501_DRV_NAME;

	indio_dev->modes = INDIO_DIRECT_MODE;



	ret = ltr501_init(data);

	if (ret < 0)

		return ret;



	ret = iio_triggered_buffer_setup(indio_dev, NULL,

		ltr501_trigger_handler, NULL);

	if (ret)

		return ret;



	ret = iio_device_register(indio_dev);

	if (ret)

		goto error_unreg_buffer;



	return 0;



error_unreg_buffer:

	iio_triggered_buffer_cleanup(indio_dev);

	return ret;

}



static int ltr501_powerdown(struct ltr501_data *data)

{

	return ltr501_write_contr(data->client,

		data->als_contr & ~LTR501_CONTR_ACTIVE,

		data->ps_contr & ~LTR501_CONTR_ACTIVE);

}



static int ltr501_remove(struct i2c_client *client)

{

	struct iio_dev *indio_dev = i2c_get_clientdata(client);



	iio_device_unregister(indio_dev);

	iio_triggered_buffer_cleanup(indio_dev);

	ltr501_powerdown(iio_priv(indio_dev));



	return 0;

}



#ifdef CONFIG_PM_SLEEP

static int ltr501_suspend(struct device *dev)

{

	struct ltr501_data *data = iio_priv(i2c_get_clientdata(

		to_i2c_client(dev)));

	return ltr501_powerdown(data);

}



static int ltr501_resume(struct device *dev)

{

	struct ltr501_data *data = iio_priv(i2c_get_clientdata(

		to_i2c_client(dev)));



	return ltr501_write_contr(data->client, data->als_contr,

		data->ps_contr);

}

#endif



static SIMPLE_DEV_PM_OPS(ltr501_pm_ops, ltr501_suspend, ltr501_resume);



static const struct i2c_device_id ltr501_id[] = {

	{ "ltr501", 0 },

	{ }

};

MODULE_DEVICE_TABLE(i2c, ltr501_id);



static struct i2c_driver ltr501_driver = {

	.driver = {

		.name   = LTR501_DRV_NAME,

		.pm	= &ltr501_pm_ops,

		.owner  = THIS_MODULE,

	},

	.probe  = ltr501_probe,

	.remove	= ltr501_remove,

	.id_table = ltr501_id,

};



module_i2c_driver(ltr501_driver);



MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");

MODULE_DESCRIPTION("Lite-On LTR501 ambient light and proximity sensor driver");

MODULE_LICENSE("GPL");

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