Commit 844b4702 authored by Kuppuswamy Sathyanarayanan's avatar Kuppuswamy Sathyanarayanan Committed by Jonathan Cameron
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iio: ltr501: Add integration time support 



Added support to modify and read ALS integration time.

Signed-off-by: default avatarKuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
parent 49064b5a

drivers/iio/light/ltr501.c

+89 −1
Original line number Diff line number Diff line
@@ -28,6 +28,7 @@ 


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

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

#define LTR501_ALS_MEAS_RATE 0x85 /* ALS integ time, measurement rate*/

#define LTR501_PART_ID 0x86

#define LTR501_MANUFAC_ID 0x87

#define LTR501_ALS_DATA1 0x88 /* 16-bit, little endian */
@@ -49,11 +50,17 @@ 


#define LTR501_REGMAP_NAME "ltr501_regmap"



static const int int_time_mapping[] = {100000, 50000, 200000, 400000};



static const struct reg_field reg_field_it =

				REG_FIELD(LTR501_ALS_MEAS_RATE, 3, 4);



struct ltr501_data {

	struct i2c_client *client;

	struct mutex lock_als, lock_ps;

	u8 als_contr, ps_contr;

	struct regmap *regmap;

	struct regmap_field *reg_it;

};



static int ltr501_drdy(struct ltr501_data *data, u8 drdy_mask)
@@ -74,6 +81,58 @@ static int ltr501_drdy(struct ltr501_data *data, u8 drdy_mask) 
	return -EIO;

}



static int ltr501_set_it_time(struct ltr501_data *data, int it)

{

	int ret, i, index = -1, status;



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

		if (int_time_mapping[i] == it) {

			index = i;

			break;

		}

	}

	/* Make sure integ time index is valid */

	if (index < 0)

		return -EINVAL;



	ret = regmap_read(data->regmap, LTR501_ALS_CONTR, &status);

	if (ret < 0)

		return ret;



	if (status & LTR501_CONTR_ALS_GAIN_MASK) {

		/*

		 * 200 ms and 400 ms integ time can only be

		 * used in dynamic range 1

		 */

		if (index > 1)

			return -EINVAL;

	} else

		/* 50 ms integ time can only be used in dynamic range 2 */

		if (index == 1)

			return -EINVAL;



	return regmap_field_write(data->reg_it, index);

}



/* read int time in micro seconds */

static int ltr501_read_it_time(struct ltr501_data *data, int *val, int *val2)

{

	int ret, index;



	ret = regmap_field_read(data->reg_it, &index);

	if (ret < 0)

		return ret;



	/* Make sure integ time index is valid */

	if (index < 0 || index >= ARRAY_SIZE(int_time_mapping))

		return -EINVAL;



	*val2 = int_time_mapping[index];

	*val = 0;



	return IIO_VAL_INT_PLUS_MICRO;

}



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

{

	int ret;
@@ -121,7 +180,8 @@ static int ltr501_read_ps(struct ltr501_data *data) 
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)),

				 BIT(IIO_CHAN_INFO_SCALE) |

				 BIT(IIO_CHAN_INFO_INT_TIME)),

	{

		.type = IIO_PROXIMITY,

		.address = LTR501_PS_DATA,
@@ -196,6 +256,13 @@ static int ltr501_read_raw(struct iio_dev *indio_dev, 
		default:

			return -EINVAL;

		}

	case IIO_CHAN_INFO_INT_TIME:

		switch (chan->type) {

		case IIO_INTENSITY:

			return ltr501_read_it_time(data, val, val2);

		default:

			return -EINVAL;

		}

	}

	return -EINVAL;

}
@@ -246,16 +313,30 @@ static int ltr501_write_raw(struct iio_dev *indio_dev, 
		default:

			return -EINVAL;

		}

	case IIO_CHAN_INFO_INT_TIME:

		switch (chan->type) {

		case IIO_INTENSITY:

			if (val != 0)

				return -EINVAL;

			mutex_lock(&data->lock_als);

			i = ltr501_set_it_time(data, val2);

			mutex_unlock(&data->lock_als);

			return i;

		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 IIO_CONST_ATTR_INT_TIME_AVAIL("0.05 0.1 0.2 0.4");



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,

	&iio_const_attr_integration_time_available.dev_attr.attr,

	NULL

};
@@ -404,6 +485,13 @@ static int ltr501_probe(struct i2c_client *client, 
	mutex_init(&data->lock_als);

	mutex_init(&data->lock_ps);



	data->reg_it = devm_regmap_field_alloc(&client->dev, regmap,

					       reg_field_it);

	if (IS_ERR(data->reg_it)) {

		dev_err(&client->dev, "Integ time reg field init failed.\n");

		return PTR_ERR(data->reg_it);

	}



	ret = regmap_read(data->regmap, LTR501_PART_ID, &partid);

	if (ret < 0)

		return ret;