drivers/iio/pressure/hid-sensor-press.c

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

File Facts

System
Linux kernel
Corpus path
drivers/iio/pressure/hid-sensor-press.c
Extension
.c
Size
9693 bytes
Lines
362
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 press_state {
	struct hid_sensor_hub_callbacks callbacks;
	struct hid_sensor_common common_attributes;
	struct hid_sensor_hub_attribute_info press_attr;
	struct {
		u32 press_data;
		aligned_s64 timestamp;
	} scan;
	int scale_pre_decml;
	int scale_post_decml;
	int scale_precision;
	int value_offset;
	s64 timestamp;
};

static const u32 press_sensitivity_addresses[] = {
	HID_USAGE_SENSOR_DATA_ATMOSPHERIC_PRESSURE,
	HID_USAGE_SENSOR_ATMOSPHERIC_PRESSURE
};

/* Channel definitions */
static const struct iio_chan_spec press_channels[] = {
	{
		.type = IIO_PRESSURE,
		.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_PRESSURE,
	},
	IIO_CHAN_SOFT_TIMESTAMP(CHANNEL_SCAN_INDEX_TIMESTAMP)

};

/* Adjust channel real bits based on report descriptor */
static void press_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 u32 */
	channels[channel].scan_type.storagebits = sizeof(u32) * 8;
}

/* Channel read_raw handler */
static int press_read_raw(struct iio_dev *indio_dev,
			      struct iio_chan_spec const *chan,
			      int *val, int *val2,
			      long mask)
{
	struct press_state *press_state = iio_priv(indio_dev);
	int report_id = -1;
	u32 address;
	int ret_type;
	s32 min;

	*val = 0;
	*val2 = 0;
	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		switch (chan->scan_index) {
		case  CHANNEL_SCAN_INDEX_PRESSURE:
			report_id = press_state->press_attr.report_id;
			min = press_state->press_attr.logical_minimum;
			address = HID_USAGE_SENSOR_ATMOSPHERIC_PRESSURE;
			break;
		default:
			report_id = -1;
			break;
		}
		if (report_id >= 0) {
			hid_sensor_power_state(&press_state->common_attributes,
						true);
			*val = sensor_hub_input_attr_get_raw_value(
				press_state->common_attributes.hsdev,
				HID_USAGE_SENSOR_PRESSURE, address,
				report_id,
				SENSOR_HUB_SYNC,
				min < 0);
			hid_sensor_power_state(&press_state->common_attributes,
						false);
		} else {
			*val = 0;
			return -EINVAL;
		}
		ret_type = IIO_VAL_INT;
		break;
	case IIO_CHAN_INFO_SCALE:

Annotation

Implementation Notes