drivers/iio/humidity/hid-sensor-humidity.c

Source file repositories/reference/linux-study-clean/drivers/iio/humidity/hid-sensor-humidity.c

File Facts

System
Linux kernel
Corpus path
drivers/iio/humidity/hid-sensor-humidity.c
Extension
.c
Size
8217 bytes
Lines
298
Domain
Driver Families
Bucket
drivers/iio
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

struct hid_humidity_state {
	struct hid_sensor_common common_attributes;
	struct hid_sensor_hub_attribute_info humidity_attr;
	struct {
		s32 humidity_data;
		aligned_s64 timestamp;
	} scan;
	int scale_pre_decml;
	int scale_post_decml;
	int scale_precision;
	int value_offset;
};

static const u32 humidity_sensitivity_addresses[] = {
	HID_USAGE_SENSOR_ATMOSPHERIC_HUMIDITY,
};

/* Channel definitions */
static const struct iio_chan_spec humidity_channels[] = {
	{
		.type = IIO_HUMIDITYRELATIVE,
		.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),
	},
	IIO_CHAN_SOFT_TIMESTAMP(1)
};

/* Adjust channel real bits based on report descriptor */
static void humidity_adjust_channel_bit_mask(struct iio_chan_spec *channels,
					int channel, int size)
{
	channels[channel].scan_type.sign = 's';
	/* Real storage bits will change based on the report desc. */
	channels[channel].scan_type.realbits = size * 8;
	/* Maximum size of a sample to capture is s32 */
	channels[channel].scan_type.storagebits = sizeof(s32) * 8;
}

static int humidity_read_raw(struct iio_dev *indio_dev,
				struct iio_chan_spec const *chan,
				int *val, int *val2, long mask)
{
	struct hid_humidity_state *humid_st = iio_priv(indio_dev);

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		if (chan->type != IIO_HUMIDITYRELATIVE)
			return -EINVAL;
		hid_sensor_power_state(&humid_st->common_attributes, true);
		*val = sensor_hub_input_attr_get_raw_value(
				humid_st->common_attributes.hsdev,
				HID_USAGE_SENSOR_HUMIDITY,
				HID_USAGE_SENSOR_ATMOSPHERIC_HUMIDITY,
				humid_st->humidity_attr.report_id,
				SENSOR_HUB_SYNC,
				humid_st->humidity_attr.logical_minimum < 0);
		hid_sensor_power_state(&humid_st->common_attributes, false);

		return IIO_VAL_INT;

	case IIO_CHAN_INFO_SCALE:
		*val = humid_st->scale_pre_decml;
		*val2 = humid_st->scale_post_decml;

		return humid_st->scale_precision;

	case IIO_CHAN_INFO_OFFSET:
		*val = humid_st->value_offset;

		return IIO_VAL_INT;

	case IIO_CHAN_INFO_SAMP_FREQ:
		return hid_sensor_read_samp_freq_value(
				&humid_st->common_attributes, val, val2);

	case IIO_CHAN_INFO_HYSTERESIS:
		return hid_sensor_read_raw_hyst_value(
				&humid_st->common_attributes, val, val2);

	default:
		return -EINVAL;
	}
}

static int humidity_write_raw(struct iio_dev *indio_dev,
				struct iio_chan_spec const *chan,
				int val, int val2, long mask)

Annotation

Implementation Notes