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

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

File Facts

System
Linux kernel
Corpus path
drivers/iio/temperature/hid-sensor-temperature.c
Extension
.c
Size
8371 bytes
Lines
295
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 temperature_state {
	struct hid_sensor_common common_attributes;
	struct hid_sensor_hub_attribute_info temperature_attr;
	struct {
		s32 temperature_data;
		aligned_s64 timestamp;
	} scan;
	int scale_pre_decml;
	int scale_post_decml;
	int scale_precision;
	int value_offset;
};

static const u32 temperature_sensitivity_addresses[] = {
	HID_USAGE_SENSOR_DATA_ENVIRONMENTAL_TEMPERATURE,
};

/* Channel definitions */
static const struct iio_chan_spec temperature_channels[] = {
	{
		.type = IIO_TEMP,
		.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 temperature_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 temperature_read_raw(struct iio_dev *indio_dev,
				struct iio_chan_spec const *chan,
				int *val, int *val2, long mask)
{
	struct temperature_state *temp_st = iio_priv(indio_dev);

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		if (chan->type != IIO_TEMP)
			return -EINVAL;
		hid_sensor_power_state(
			&temp_st->common_attributes, true);
		*val = sensor_hub_input_attr_get_raw_value(
			temp_st->common_attributes.hsdev,
			HID_USAGE_SENSOR_TEMPERATURE,
			HID_USAGE_SENSOR_DATA_ENVIRONMENTAL_TEMPERATURE,
			temp_st->temperature_attr.report_id,
			SENSOR_HUB_SYNC,
			temp_st->temperature_attr.logical_minimum < 0);
		hid_sensor_power_state(
				&temp_st->common_attributes,
				false);

		return IIO_VAL_INT;

	case IIO_CHAN_INFO_SCALE:
		*val = temp_st->scale_pre_decml;
		*val2 = temp_st->scale_post_decml;
		return temp_st->scale_precision;

	case IIO_CHAN_INFO_OFFSET:
		*val = temp_st->value_offset;
		return IIO_VAL_INT;

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

	case IIO_CHAN_INFO_HYSTERESIS:
		return hid_sensor_read_raw_hyst_value(
				&temp_st->common_attributes, val, val2);
	default:
		return -EINVAL;
	}
}

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

Annotation

Implementation Notes