[PATCH v2 2/3] iio: hid-sensor-als: Add light color temperature support

[Srinivas Pandruvada]

From: Basavaraj Natikar <Basavaraj.Natikar@xxxxxxx>

In most cases, ambient color sensors also support light color temperature.
As a result, add support of light color temperature.

Signed-off-by: Basavaraj Natikar <Basavaraj.Natikar@xxxxxxx>
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>
---
v2:
Original patch from Basavaraj Natikar <Basavaraj.Natikar@xxxxxxx> is
modified to prevent failure when the new usage id is not found in the
descriptor.

 drivers/iio/light/hid-sensor-als.c | 41 ++++++++++++++++++++++++++++--
 include/linux/hid-sensor-ids.h     |  1 +
 2 files changed, 40 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/light/hid-sensor-als.c b/drivers/iio/light/hid-sensor-als.c
index e57ad1946b56..8d6beacc338a 100644
--- a/drivers/iio/light/hid-sensor-als.c
+++ b/drivers/iio/light/hid-sensor-als.c
@@ -14,8 +14,9 @@
 #include "../common/hid-sensors/hid-sensor-trigger.h"
 
 enum {
-	CHANNEL_SCAN_INDEX_INTENSITY = 0,
-	CHANNEL_SCAN_INDEX_ILLUM = 1,
+	CHANNEL_SCAN_INDEX_INTENSITY,
+	CHANNEL_SCAN_INDEX_ILLUM,
+	CHANNEL_SCAN_INDEX_COLOR_TEMP,
 	CHANNEL_SCAN_INDEX_MAX
 };
 
@@ -65,6 +66,16 @@ 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)
 };
 
@@ -103,6 +114,11 @@ 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;
@@ -223,6 +239,10 @@ 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);
@@ -267,10 +287,27 @@ static int als_parse_report(struct platform_device *pdev,
 			st->als[i].report_id);
 	}
 
+	ret = sensor_hub_input_get_attribute_info(hsdev, HID_INPUT_REPORT,
+				usage_id,
+				HID_USAGE_SENSOR_LIGHT_COLOR_TEMPERATURE,
+				&st->als[CHANNEL_SCAN_INDEX_COLOR_TEMP]);
+	if (ret < 0)
+		goto skip_temp_channel;
+
+	channels[index++] = als_channels[CHANNEL_SCAN_INDEX_COLOR_TEMP];
+
+	als_adjust_channel_bit_mask(channels, CHANNEL_SCAN_INDEX_COLOR_TEMP,
+				st->als[CHANNEL_SCAN_INDEX_COLOR_TEMP].size);
+
+	dev_dbg(&pdev->dev, "als %x:%x\n",
+		st->als[CHANNEL_SCAN_INDEX_COLOR_TEMP].index,
+		st->als[CHANNEL_SCAN_INDEX_COLOR_TEMP].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);
 
+skip_temp_channel:
 	*channels_out = channels;
 	*size_channels_out = index;
 
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