iio: hid-sensor-als: Add light chromaticity support

In most cases, ambient color sensors also support the x and y light
colors, which represent the coordinates on the CIE 1931 chromaticity
diagram. Thus, add light chromaticity x and y.
Signed-off-by: Basavaraj Natikar <Basavaraj.Natikar@amd.com>
Acked-by: Srinivas Pandruvada<srinivas.pandruvada@linux.intel.com>
Link: https://lore.kernel.org/r/20230919081054.2050714-8-Basavaraj.Natikar@amd.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/light/hid-sensor-als.c

@@ -17,6 +17,8 @@ enum {
 	CHANNEL_SCAN_INDEX_INTENSITY,
 	CHANNEL_SCAN_INDEX_ILLUM,
 	CHANNEL_SCAN_INDEX_COLOR_TEMP,
+	CHANNEL_SCAN_INDEX_CHROMATICITY_X,
+	CHANNEL_SCAN_INDEX_CHROMATICITY_Y,
 	CHANNEL_SCAN_INDEX_MAX
 };
 
@@ -76,6 +78,30 @@ static const struct iio_chan_spec als_channels[] = {
 		BIT(IIO_CHAN_INFO_HYSTERESIS_RELATIVE),
 		.scan_index = CHANNEL_SCAN_INDEX_COLOR_TEMP,
 	},
+	{
+		.type = IIO_CHROMATICITY,
+		.modified = 1,
+		.channel2 = IIO_MOD_X,
+		.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_CHROMATICITY_X,
+	},
+	{
+		.type = IIO_CHROMATICITY,
+		.modified = 1,
+		.channel2 = IIO_MOD_Y,
+		.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_CHROMATICITY_Y,
+	},
 	IIO_CHAN_SOFT_TIMESTAMP(CHANNEL_SCAN_INDEX_TIMESTAMP)
 };
 
@@ -119,6 +145,16 @@ static int als_read_raw(struct iio_dev *indio_dev,
 			min = als_state->als[chan->scan_index].logical_minimum;
 			address = HID_USAGE_SENSOR_LIGHT_COLOR_TEMPERATURE;
 			break;
+		case  CHANNEL_SCAN_INDEX_CHROMATICITY_X:
+			report_id = als_state->als[chan->scan_index].report_id;
+			min = als_state->als[chan->scan_index].logical_minimum;
+			address = HID_USAGE_SENSOR_LIGHT_CHROMATICITY_X;
+			break;
+		case  CHANNEL_SCAN_INDEX_CHROMATICITY_Y:
+			report_id = als_state->als[chan->scan_index].report_id;
+			min = als_state->als[chan->scan_index].logical_minimum;
+			address = HID_USAGE_SENSOR_LIGHT_CHROMATICITY_Y;
+			break;
 		default:
 			report_id = -1;
 			break;
@@ -243,6 +279,14 @@ static int als_capture_sample(struct hid_sensor_hub_device *hsdev,
 		als_state->scan.illum[CHANNEL_SCAN_INDEX_COLOR_TEMP] = sample_data;
 		ret = 0;
 		break;
+	case HID_USAGE_SENSOR_LIGHT_CHROMATICITY_X:
+		als_state->scan.illum[CHANNEL_SCAN_INDEX_CHROMATICITY_X] = sample_data;
+		ret = 0;
+		break;
+	case HID_USAGE_SENSOR_LIGHT_CHROMATICITY_Y:
+		als_state->scan.illum[CHANNEL_SCAN_INDEX_CHROMATICITY_Y] = 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);
@@ -291,6 +335,25 @@ static int als_parse_report(struct platform_device *pdev,
 		st->als[CHANNEL_SCAN_INDEX_COLOR_TEMP].index,
 		st->als[CHANNEL_SCAN_INDEX_COLOR_TEMP].report_id);
 
+	for (i = 0; i < 2; i++) {
+		int next_scan_index = CHANNEL_SCAN_INDEX_CHROMATICITY_X + i;
+
+		ret = sensor_hub_input_get_attribute_info(hsdev,
+				HID_INPUT_REPORT, usage_id,
+				HID_USAGE_SENSOR_LIGHT_CHROMATICITY_X + i,
+				&st->als[next_scan_index]);
+		if (ret < 0)
+			return ret;
+
+		als_adjust_channel_bit_mask(channels,
+					CHANNEL_SCAN_INDEX_CHROMATICITY_X + i,
+					st->als[next_scan_index].size);
+
+		dev_dbg(&pdev->dev, "als %x:%x\n",
+			st->als[next_scan_index].index,
+			st->als[next_scan_index].report_id);
+	}
+
 	st->scale_precision = hid_sensor_format_scale(usage_id,
 				&st->als[CHANNEL_SCAN_INDEX_INTENSITY],
 				&st->scale_pre_decml, &st->scale_post_decml);

include/linux/hid-sensor-ids.h

@@ -22,6 +22,9 @@
 #define HID_USAGE_SENSOR_DATA_LIGHT				0x2004d0
 #define HID_USAGE_SENSOR_LIGHT_ILLUM				0x2004d1
 #define HID_USAGE_SENSOR_LIGHT_COLOR_TEMPERATURE		0x2004d2
+#define HID_USAGE_SENSOR_LIGHT_CHROMATICITY			0x2004d3
+#define HID_USAGE_SENSOR_LIGHT_CHROMATICITY_X			0x2004d4
+#define HID_USAGE_SENSOR_LIGHT_CHROMATICITY_Y			0x2004d5
 
 /* PROX (200011) */
 #define HID_USAGE_SENSOR_PROX                                   0x200011