iio: light: hid-sensor-als: Add duplicate IIO_LIGHT channel

There is one light sensor type defined in the sensor hub specification,
which has one Illuminance field. It doesn't distinguish between ambient
light sensor or color sensor. Currently it is presented as IIO_INTENSITY
channel. There are some user spaces specifically looking for IIO_LIGHT
channel.
To satisfy such user spaces this change also add a duplicate IIO_LIGHT
channel. The units of measurement of Illuminance field is Lux, so it is
still compatible to IIO ABI.

Signed-off-by: Kweh, Hock Leong <hock.leong.kweh@intel.com>
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

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

@@ -31,13 +31,17 @@
 #include <linux/iio/triggered_buffer.h>
 #include "../common/hid-sensors/hid-sensor-trigger.h"
 
-#define CHANNEL_SCAN_INDEX_ILLUM 0
+enum {
+	CHANNEL_SCAN_INDEX_INTENSITY = 0,
+	CHANNEL_SCAN_INDEX_ILLUM = 1,
+	CHANNEL_SCAN_INDEX_MAX
+};
 
 struct als_state {
 	struct hid_sensor_hub_callbacks callbacks;
 	struct hid_sensor_common common_attributes;
 	struct hid_sensor_hub_attribute_info als_illum;
-	u32 illum;
+	u32 illum[CHANNEL_SCAN_INDEX_MAX];
 	int scale_pre_decml;
 	int scale_post_decml;
 	int scale_precision;
@@ -55,6 +59,15 @@ static const struct iio_chan_spec als_channels[] = {
 		BIT(IIO_CHAN_INFO_SCALE) |
 		BIT(IIO_CHAN_INFO_SAMP_FREQ) |
 		BIT(IIO_CHAN_INFO_HYSTERESIS),
+		.scan_index = CHANNEL_SCAN_INDEX_INTENSITY,
+	},
+	{
+		.type = IIO_LIGHT,
+		.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),
 		.scan_index = CHANNEL_SCAN_INDEX_ILLUM,
 	}
 };
@@ -86,6 +99,7 @@ static int als_read_raw(struct iio_dev *indio_dev,
 	switch (mask) {
 	case 0:
 		switch (chan->scan_index) {
+		case  CHANNEL_SCAN_INDEX_INTENSITY:
 		case  CHANNEL_SCAN_INDEX_ILLUM:
 			report_id = als_state->als_illum.report_id;
 			address =
@@ -202,10 +216,12 @@ static int als_capture_sample(struct hid_sensor_hub_device *hsdev,
 	struct iio_dev *indio_dev = platform_get_drvdata(priv);
 	struct als_state *als_state = iio_priv(indio_dev);
 	int ret = -EINVAL;
+	u32 sample_data = *(u32 *)raw_data;
 
 	switch (usage_id) {
 	case HID_USAGE_SENSOR_LIGHT_ILLUM:
-		als_state->illum = *(u32 *)raw_data;
+		als_state->illum[CHANNEL_SCAN_INDEX_INTENSITY] = sample_data;
+		als_state->illum[CHANNEL_SCAN_INDEX_ILLUM] = sample_data;
 		ret = 0;
 		break;
 	default:
@@ -230,6 +246,8 @@ static int als_parse_report(struct platform_device *pdev,
 			&st->als_illum);
 	if (ret < 0)
 		return ret;
+	als_adjust_channel_bit_mask(channels, CHANNEL_SCAN_INDEX_INTENSITY,
+				    st->als_illum.size);
 	als_adjust_channel_bit_mask(channels, CHANNEL_SCAN_INDEX_ILLUM,
 					st->als_illum.size);