diff options
Diffstat (limited to 'drivers/iio/light/ltr501.c')
| -rw-r--r-- | drivers/iio/light/ltr501.c | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/drivers/iio/light/ltr501.c b/drivers/iio/light/ltr501.c index 64e235281cef..1ef7d3773ab9 100644 --- a/drivers/iio/light/ltr501.c +++ b/drivers/iio/light/ltr501.c @@ -66,6 +66,9 @@ #define LTR501_REGMAP_NAME "ltr501_regmap" +#define LTR501_LUX_CONV(vis_coeff, vis_data, ir_coeff, ir_data) \ + ((vis_coeff * vis_data) - (ir_coeff * ir_data)) + static const int int_time_mapping[] = {100000, 50000, 200000, 400000}; static const struct reg_field reg_field_it = @@ -298,6 +301,29 @@ static int ltr501_ps_read_samp_period(struct ltr501_data *data, int *val) return IIO_VAL_INT; } +/* IR and visible spectrum coeff's are given in data sheet */ +static unsigned long ltr501_calculate_lux(u16 vis_data, u16 ir_data) +{ + unsigned long ratio, lux; + + if (vis_data == 0) + return 0; + + /* multiply numerator by 100 to avoid handling ratio < 1 */ + ratio = DIV_ROUND_UP(ir_data * 100, ir_data + vis_data); + + if (ratio < 45) + lux = LTR501_LUX_CONV(1774, vis_data, -1105, ir_data); + else if (ratio >= 45 && ratio < 64) + lux = LTR501_LUX_CONV(3772, vis_data, 1336, ir_data); + else if (ratio >= 64 && ratio < 85) + lux = LTR501_LUX_CONV(1690, vis_data, 169, ir_data); + else + lux = 0; + + return lux / 1000; +} + static int ltr501_drdy(struct ltr501_data *data, u8 drdy_mask) { int tries = 100; @@ -548,7 +574,14 @@ static const struct iio_event_spec ltr501_pxs_event_spec[] = { .num_event_specs = _evsize,\ } +#define LTR501_LIGHT_CHANNEL() { \ + .type = IIO_LIGHT, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), \ + .scan_index = -1, \ +} + static const struct iio_chan_spec ltr501_channels[] = { + LTR501_LIGHT_CHANNEL(), LTR501_INTENSITY_CHANNEL(0, LTR501_ALS_DATA0, IIO_MOD_LIGHT_BOTH, 0, ltr501_als_event_spec, ARRAY_SIZE(ltr501_als_event_spec)), @@ -576,6 +609,7 @@ static const struct iio_chan_spec ltr501_channels[] = { }; static const struct iio_chan_spec ltr301_channels[] = { + LTR501_LIGHT_CHANNEL(), LTR501_INTENSITY_CHANNEL(0, LTR501_ALS_DATA0, IIO_MOD_LIGHT_BOTH, 0, ltr501_als_event_spec, ARRAY_SIZE(ltr501_als_event_spec)), @@ -596,6 +630,23 @@ static int ltr501_read_raw(struct iio_dev *indio_dev, int ret, i; switch (mask) { + case IIO_CHAN_INFO_PROCESSED: + if (iio_buffer_enabled(indio_dev)) + return -EBUSY; + + switch (chan->type) { + case IIO_LIGHT: + mutex_lock(&data->lock_als); + ret = ltr501_read_als(data, buf); + mutex_unlock(&data->lock_als); + if (ret < 0) + return ret; + *val = ltr501_calculate_lux(le16_to_cpu(buf[1]), + le16_to_cpu(buf[0])); + return IIO_VAL_INT; + default: + return -EINVAL; + } case IIO_CHAN_INFO_RAW: if (iio_buffer_enabled(indio_dev)) return -EBUSY; |