[PATCH v4 3/4] iio: hid-sensor-als: Add light color temperature support

[Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>]

From: Basavaraj Natikar <Basavaraj.Natikar@amd.com>

On some platforms, ambient color sensors also support light color
temperature. Add support of light color temperature.

Signed-off-by: Basavaraj Natikar <Basavaraj.Natikar@amd.com>
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
---
v4:
  - Index is fixed for each channel instead of packing for absent channels
v3:
Simplilified as no special processing is required in als_parse_report()
v2:
Original patch from Basavaraj Natikar <Basavaraj.Natikar@amd.com> is
modified to prevent failure when the new usage id is not found in the
descriptor.

 drivers/iio/light/hid-sensor-als.c | 21 +++++++++++++++++++++
 include/linux/hid-sensor-ids.h     |  1 +
 2 files changed, 22 insertions(+)

diff --git a/drivers/iio/light/hid-sensor-als.c b/drivers/iio/light/hid-sensor-als.c
index 521af52b3f3b..0e9a25c51676 100644
--- a/drivers/iio/light/hid-sensor-als.c
+++ b/drivers/iio/light/hid-sensor-als.c
@@ -16,6 +16,7 @@
 enum {
 	CHANNEL_SCAN_INDEX_INTENSITY,
 	CHANNEL_SCAN_INDEX_ILLUM,
+	CHANNEL_SCAN_INDEX_COLOR_TEMP,
 	CHANNEL_SCAN_INDEX_MAX
 };
 
@@ -42,6 +43,7 @@ struct als_state {
 static const u32 als_usage_ids[] = {
 	HID_USAGE_SENSOR_LIGHT_ILLUM,
 	HID_USAGE_SENSOR_LIGHT_ILLUM,
+	HID_USAGE_SENSOR_LIGHT_COLOR_TEMPERATURE,
 };
 
 static const u32 als_sensitivity_addresses[] = {
@@ -73,6 +75,16 @@ static const struct iio_chan_spec als_channels[] = {
 		BIT(IIO_CHAN_INFO_HYSTERESIS_RELATIVE),
 		.scan_index = CHANNEL_SCAN_INDEX_ILLUM,
 	},
+	{
+		.type = IIO_COLORTEMP,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
+		BIT(IIO_CHAN_INFO_SCALE) |
+		BIT(IIO_CHAN_INFO_SAMP_FREQ) |
+		BIT(IIO_CHAN_INFO_HYSTERESIS) |
+		BIT(IIO_CHAN_INFO_HYSTERESIS_RELATIVE),
+		.scan_index = CHANNEL_SCAN_INDEX_COLOR_TEMP,
+	},
 	IIO_CHAN_SOFT_TIMESTAMP(CHANNEL_SCAN_INDEX_TIMESTAMP)
 };
 
@@ -113,6 +125,11 @@ static int als_read_raw(struct iio_dev *indio_dev,
 			min = als_state->als[chan->scan_index].logical_minimum;
 			address = HID_USAGE_SENSOR_LIGHT_ILLUM;
 			break;
+		case  CHANNEL_SCAN_INDEX_COLOR_TEMP:
+			report_id = als_state->als[chan->scan_index].report_id;
+			min = als_state->als[chan->scan_index].logical_minimum;
+			address = HID_USAGE_SENSOR_LIGHT_COLOR_TEMPERATURE;
+			break;
 		default:
 			report_id = -1;
 			break;
@@ -233,6 +250,10 @@ static int als_capture_sample(struct hid_sensor_hub_device *hsdev,
 		als_state->scan.illum[CHANNEL_SCAN_INDEX_ILLUM] = sample_data;
 		ret = 0;
 		break;
+	case HID_USAGE_SENSOR_LIGHT_COLOR_TEMPERATURE:
+		als_state->scan.illum[CHANNEL_SCAN_INDEX_COLOR_TEMP] = sample_data;
+		ret = 0;
+		break;
 	case HID_USAGE_SENSOR_TIME_TIMESTAMP:
 		als_state->timestamp = hid_sensor_convert_timestamp(&als_state->common_attributes,
 								    *(s64 *)raw_data);
diff --git a/include/linux/hid-sensor-ids.h b/include/linux/hid-sensor-ids.h
index 13b1e65fbdcc..8af4fb3e0254 100644
--- a/include/linux/hid-sensor-ids.h
+++ b/include/linux/hid-sensor-ids.h
@@ -21,6 +21,7 @@
 #define HID_USAGE_SENSOR_ALS					0x200041
 #define HID_USAGE_SENSOR_DATA_LIGHT				0x2004d0
 #define HID_USAGE_SENSOR_LIGHT_ILLUM				0x2004d1
+#define HID_USAGE_SENSOR_LIGHT_COLOR_TEMPERATURE		0x2004d2
 
 /* PROX (200011) */
 #define HID_USAGE_SENSOR_PROX                                   0x200011
-- 
2.43.0