Commit 9d2f715d authored by Akinobu Mita's avatar Akinobu Mita Committed by Jonathan Cameron
Browse files

iio: light: tcs3472: support out-of-threshold events 



The TCS3472 device provides interrupt signal for out-of-threshold events
with persistence filter.

This change adds interrupt support for the threshold events and enables
to configure the period of time by persistence filter.

Cc: Peter Meerwald <pmeerw@pmeerw.net>
Cc: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: default avatarAkinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent 1405ddfb

drivers/iio/light/tcs3472.c

+254 −8
Original line number Diff line number Diff line
@@ -13,7 +13,7 @@ 
 *

 * Datasheet: http://ams.com/eng/content/download/319364/1117183/file/TCS3472_Datasheet_EN_v2.pdf

 *

 * TODO: interrupt support, thresholds, wait time

 * TODO: wait time

 */



#include <linux/module.h>
@@ -23,6 +23,7 @@ 


#include <linux/iio/iio.h>

#include <linux/iio/sysfs.h>

#include <linux/iio/events.h>

#include <linux/iio/trigger_consumer.h>

#include <linux/iio/buffer.h>

#include <linux/iio/triggered_buffer.h>
@@ -31,12 +32,15 @@ 


#define TCS3472_COMMAND BIT(7)

#define TCS3472_AUTO_INCR BIT(5)

#define TCS3472_SPECIAL_FUNC (BIT(5) | BIT(6))



#define TCS3472_INTR_CLEAR (TCS3472_COMMAND | TCS3472_SPECIAL_FUNC | 0x06)



#define TCS3472_ENABLE (TCS3472_COMMAND | 0x00)

#define TCS3472_ATIME (TCS3472_COMMAND | 0x01)

#define TCS3472_WTIME (TCS3472_COMMAND | 0x03)

#define TCS3472_AILT (TCS3472_COMMAND | 0x04)

#define TCS3472_AIHT (TCS3472_COMMAND | 0x06)

#define TCS3472_AILT (TCS3472_COMMAND | TCS3472_AUTO_INCR | 0x04)

#define TCS3472_AIHT (TCS3472_COMMAND | TCS3472_AUTO_INCR | 0x06)

#define TCS3472_PERS (TCS3472_COMMAND | 0x0c)

#define TCS3472_CONFIG (TCS3472_COMMAND | 0x0d)

#define TCS3472_CONTROL (TCS3472_COMMAND | 0x0f)
@@ -47,19 +51,42 @@ 
#define TCS3472_GDATA (TCS3472_COMMAND | TCS3472_AUTO_INCR | 0x18)

#define TCS3472_BDATA (TCS3472_COMMAND | TCS3472_AUTO_INCR | 0x1a)



#define TCS3472_STATUS_AINT BIT(4)

#define TCS3472_STATUS_AVALID BIT(0)

#define TCS3472_ENABLE_AIEN BIT(4)

#define TCS3472_ENABLE_AEN BIT(1)

#define TCS3472_ENABLE_PON BIT(0)

#define TCS3472_CONTROL_AGAIN_MASK (BIT(0) | BIT(1))



struct tcs3472_data {

	struct i2c_client *client;

	struct mutex lock;

	u16 low_thresh;

	u16 high_thresh;

	u8 enable;

	u8 control;

	u8 atime;

	u8 apers;

	u16 buffer[8]; /* 4 16-bit channels + 64-bit timestamp */

};



static const struct iio_event_spec tcs3472_events[] = {

	{

		.type = IIO_EV_TYPE_THRESH,

		.dir = IIO_EV_DIR_RISING,

		.mask_separate = BIT(IIO_EV_INFO_VALUE),

	}, {

		.type = IIO_EV_TYPE_THRESH,

		.dir = IIO_EV_DIR_FALLING,

		.mask_separate = BIT(IIO_EV_INFO_VALUE),

	}, {

		.type = IIO_EV_TYPE_THRESH,

		.dir = IIO_EV_DIR_EITHER,

		.mask_separate = BIT(IIO_EV_INFO_ENABLE) |

				 BIT(IIO_EV_INFO_PERIOD),

	},

};



#define TCS3472_CHANNEL(_color, _si, _addr) { \

	.type = IIO_INTENSITY, \

	.modified = 1, \
@@ -75,6 +102,8 @@ struct tcs3472_data { 
		.storagebits = 16, \

		.endianness = IIO_CPU, \

	}, \

	.event_spec = _si ? NULL : tcs3472_events, \

	.num_event_specs = _si ? 0 : ARRAY_SIZE(tcs3472_events), \

}



static const int tcs3472_agains[] = { 1, 4, 16, 60 };
@@ -182,6 +211,166 @@ static int tcs3472_write_raw(struct iio_dev *indio_dev, 
	return -EINVAL;

}



/*

 * Translation from APERS field value to the number of consecutive out-of-range

 * clear channel values before an interrupt is generated

 */

static const int tcs3472_intr_pers[] = {

	0, 1, 2, 3, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60

};



static int tcs3472_read_event(struct iio_dev *indio_dev,

	const struct iio_chan_spec *chan, enum iio_event_type type,

	enum iio_event_direction dir, enum iio_event_info info, int *val,

	int *val2)

{

	struct tcs3472_data *data = iio_priv(indio_dev);

	int ret;

	unsigned int period;



	mutex_lock(&data->lock);



	switch (info) {

	case IIO_EV_INFO_VALUE:

		*val = (dir == IIO_EV_DIR_RISING) ?

			data->high_thresh : data->low_thresh;

		ret = IIO_VAL_INT;

		break;

	case IIO_EV_INFO_PERIOD:

		period = (256 - data->atime) * 2400 *

			tcs3472_intr_pers[data->apers];

		*val = period / USEC_PER_SEC;

		*val2 = period % USEC_PER_SEC;

		ret = IIO_VAL_INT_PLUS_MICRO;

		break;

	default:

		ret = -EINVAL;

		break;

	}



	mutex_unlock(&data->lock);



	return ret;

}



static int tcs3472_write_event(struct iio_dev *indio_dev,

	const struct iio_chan_spec *chan, enum iio_event_type type,

	enum iio_event_direction dir, enum iio_event_info info, int val,

	int val2)

{

	struct tcs3472_data *data = iio_priv(indio_dev);

	int ret;

	u8 command;

	int period;

	int i;



	mutex_lock(&data->lock);

	switch (info) {

	case IIO_EV_INFO_VALUE:

		switch (dir) {

		case IIO_EV_DIR_RISING:

			command = TCS3472_AIHT;

			break;

		case IIO_EV_DIR_FALLING:

			command = TCS3472_AILT;

			break;

		default:

			ret = -EINVAL;

			goto error;

		}

		ret = i2c_smbus_write_word_data(data->client, command, val);

		if (ret)

			goto error;



		if (dir == IIO_EV_DIR_RISING)

			data->high_thresh = val;

		else

			data->low_thresh = val;

		break;

	case IIO_EV_INFO_PERIOD:

		period = val * USEC_PER_SEC + val2;

		for (i = 1; i < ARRAY_SIZE(tcs3472_intr_pers) - 1; i++) {

			if (period <= (256 - data->atime) * 2400 *

					tcs3472_intr_pers[i])

				break;

		}

		ret = i2c_smbus_write_byte_data(data->client, TCS3472_PERS, i);

		if (ret)

			goto error;



		data->apers = i;

		break;

	default:

		ret = -EINVAL;

		break;

	}

error:

	mutex_unlock(&data->lock);



	return ret;

}



static int tcs3472_read_event_config(struct iio_dev *indio_dev,

	const struct iio_chan_spec *chan, enum iio_event_type type,

	enum iio_event_direction dir)

{

	struct tcs3472_data *data = iio_priv(indio_dev);

	int ret;



	mutex_lock(&data->lock);

	ret = !!(data->enable & TCS3472_ENABLE_AIEN);

	mutex_unlock(&data->lock);



	return ret;

}



static int tcs3472_write_event_config(struct iio_dev *indio_dev,

	const struct iio_chan_spec *chan, enum iio_event_type type,

	enum iio_event_direction dir, int state)

{

	struct tcs3472_data *data = iio_priv(indio_dev);

	int ret = 0;

	u8 enable_old;



	mutex_lock(&data->lock);



	enable_old = data->enable;



	if (state)

		data->enable |= TCS3472_ENABLE_AIEN;

	else

		data->enable &= ~TCS3472_ENABLE_AIEN;



	if (enable_old != data->enable) {

		ret = i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE,

						data->enable);

		if (ret)

			data->enable = enable_old;

	}

	mutex_unlock(&data->lock);



	return ret;

}



static irqreturn_t tcs3472_event_handler(int irq, void *priv)

{

	struct iio_dev *indio_dev = priv;

	struct tcs3472_data *data = iio_priv(indio_dev);

	int ret;



	ret = i2c_smbus_read_byte_data(data->client, TCS3472_STATUS);

	if (ret >= 0 && (ret & TCS3472_STATUS_AINT)) {

		iio_push_event(indio_dev, IIO_UNMOD_EVENT_CODE(IIO_INTENSITY, 0,

						IIO_EV_TYPE_THRESH,

						IIO_EV_DIR_EITHER),

				iio_get_time_ns(indio_dev));



		i2c_smbus_read_byte_data(data->client, TCS3472_INTR_CLEAR);

	}



	return IRQ_HANDLED;

}



static irqreturn_t tcs3472_trigger_handler(int irq, void *p)

{

	struct iio_poll_func *pf = p;
@@ -245,6 +434,10 @@ static const struct attribute_group tcs3472_attribute_group = { 
static const struct iio_info tcs3472_info = {

	.read_raw = tcs3472_read_raw,

	.write_raw = tcs3472_write_raw,

	.read_event_value = tcs3472_read_event,

	.write_event_value = tcs3472_write_event,

	.read_event_config = tcs3472_read_event_config,

	.write_event_config = tcs3472_write_event_config,

	.attrs = &tcs3472_attribute_group,

};
@@ -262,6 +455,7 @@ static int tcs3472_probe(struct i2c_client *client, 
	data = iio_priv(indio_dev);

	i2c_set_clientdata(client, indio_dev);

	data->client = client;

	mutex_init(&data->lock);



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

	indio_dev->info = &tcs3472_info;
@@ -291,12 +485,29 @@ static int tcs3472_probe(struct i2c_client *client, 
		return ret;

	data->atime = ret;



	ret = i2c_smbus_read_word_data(data->client, TCS3472_AILT);

	if (ret < 0)

		return ret;

	data->low_thresh = ret;



	ret = i2c_smbus_read_word_data(data->client, TCS3472_AIHT);

	if (ret < 0)

		return ret;

	data->high_thresh = ret;



	data->apers = 1;

	ret = i2c_smbus_write_byte_data(data->client, TCS3472_PERS,

					data->apers);

	if (ret < 0)

		return ret;



	ret = i2c_smbus_read_byte_data(data->client, TCS3472_ENABLE);

	if (ret < 0)

		return ret;



	/* enable device */

	data->enable = ret | TCS3472_ENABLE_PON | TCS3472_ENABLE_AEN;

	data->enable &= ~TCS3472_ENABLE_AIEN;

	ret = i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE,

		data->enable);

	if (ret < 0)
@@ -307,12 +518,24 @@ static int tcs3472_probe(struct i2c_client *client, 
	if (ret < 0)

		return ret;



	if (client->irq) {

		ret = request_threaded_irq(client->irq, NULL,

					   tcs3472_event_handler,

					   IRQF_TRIGGER_FALLING | IRQF_SHARED |

					   IRQF_ONESHOT,

					   client->name, indio_dev);

		if (ret)

			goto buffer_cleanup;

	}



	ret = iio_device_register(indio_dev);

	if (ret < 0)

		goto buffer_cleanup;

		goto free_irq;



	return 0;



free_irq:

	free_irq(client->irq, indio_dev);

buffer_cleanup:

	iio_triggered_buffer_cleanup(indio_dev);

	return ret;
@@ -320,8 +543,19 @@ buffer_cleanup: 


static int tcs3472_powerdown(struct tcs3472_data *data)

{

	return i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE,

		data->enable & ~(TCS3472_ENABLE_AEN | TCS3472_ENABLE_PON));

	int ret;

	u8 enable_mask = TCS3472_ENABLE_AEN | TCS3472_ENABLE_PON;



	mutex_lock(&data->lock);



	ret = i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE,

		data->enable & ~enable_mask);

	if (!ret)

		data->enable &= ~enable_mask;



	mutex_unlock(&data->lock);



	return ret;

}



static int tcs3472_remove(struct i2c_client *client)
@@ -329,6 +563,7 @@ static int tcs3472_remove(struct i2c_client *client) 
	struct iio_dev *indio_dev = i2c_get_clientdata(client);



	iio_device_unregister(indio_dev);

	free_irq(client->irq, indio_dev);

	iio_triggered_buffer_cleanup(indio_dev);

	tcs3472_powerdown(iio_priv(indio_dev));
@@ -347,8 +582,19 @@ static int tcs3472_resume(struct device *dev) 
{

	struct tcs3472_data *data = iio_priv(i2c_get_clientdata(

		to_i2c_client(dev)));

	return i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE,

		data->enable | (TCS3472_ENABLE_AEN | TCS3472_ENABLE_PON));

	int ret;

	u8 enable_mask = TCS3472_ENABLE_AEN | TCS3472_ENABLE_PON;



	mutex_lock(&data->lock);



	ret = i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE,

		data->enable | enable_mask);

	if (!ret)

		data->enable |= enable_mask;



	mutex_unlock(&data->lock);



	return ret;

}

#endif

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