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

On some platforms, ambient color sensors also support the x and y light
colors, which represent the coordinates on the CIE 1931 chromaticity
diagram. Add light chromaticity x and y.

Signed-off-by: Basavaraj Natikar <[e-mail]>
Signed-off-by: Srinivas Pandruvada <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Jonathan Cameron <[e-mail]>

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

···
 	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
 };
 
···
 	HID_USAGE_SENSOR_LIGHT_ILLUM,
 	HID_USAGE_SENSOR_LIGHT_ILLUM,
 	HID_USAGE_SENSOR_LIGHT_COLOR_TEMPERATURE,
+	HID_USAGE_SENSOR_LIGHT_CHROMATICITY_X,
+	HID_USAGE_SENSOR_LIGHT_CHROMATICITY_Y,
 };
 
 static const u32 als_sensitivity_addresses[] = {
···
 		BIT(IIO_CHAN_INFO_HYSTERESIS) |
 		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)
 };
···
 			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;
+		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;
 	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_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:

include/linux/hid-sensor-ids.h

···
 #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