iio: hid-sensor-als: Add light color temperature support

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>
Link: https://lore.kernel.org/r/20240205185926.3030521-4-srinivas.pandruvada@linux.intel.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

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
 };
 
@@ -43,6 +44,7 @@ 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[] = {
@@ -74,6 +76,16 @@ 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)
 };
 
@@ -112,6 +124,11 @@ 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;
@@ -232,6 +249,10 @@ 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);

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