From 844b47027da0754e089c224c8c7d371f812320fd Mon Sep 17 00:00:00 2001 From: Kuppuswamy Sathyanarayanan Date: Sun, 19 Apr 2015 02:10:01 -0700 Subject: [PATCH] iio: ltr501: Add integration time support Added support to modify and read ALS integration time. Signed-off-by: Kuppuswamy Sathyanarayanan Signed-off-by: Jonathan Cameron --- drivers/iio/light/ltr501.c | 90 +++++++++++++++++++++++++++++++++++++- 1 file changed, 89 insertions(+), 1 deletion(-) diff --git a/drivers/iio/light/ltr501.c b/drivers/iio/light/ltr501.c index e2f73547fdc5..809260402a53 100644 --- a/drivers/iio/light/ltr501.c +++ b/drivers/iio/light/ltr501.c @@ -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; -- 2.20.1