drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c

Source file repositories/reference/linux-study-clean/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c

File Facts

System
Linux kernel
Corpus path
drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c
Extension
.c
Size
8936 bytes
Lines
330
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 cros_ec_sensors_state {
	/* Shared by all sensors */
	struct cros_ec_sensors_core_state core;

	struct iio_chan_spec channels[CROS_EC_SENSORS_MAX_CHANNELS];
};

static int cros_ec_sensors_read(struct iio_dev *indio_dev,
			  struct iio_chan_spec const *chan,
			  int *val, int *val2, long mask)
{
	struct cros_ec_sensors_state *st = iio_priv(indio_dev);
	s16 data = 0;
	s64 val64;
	int i;
	int ret;
	int idx = chan->scan_index;

	mutex_lock(&st->core.cmd_lock);

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		ret = st->core.read_ec_sensors_data(indio_dev, 1 << idx, &data);
		if (ret < 0)
			break;
		ret = IIO_VAL_INT;
		*val = data;
		break;
	case IIO_CHAN_INFO_CALIBBIAS:
		st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_OFFSET;
		st->core.param.sensor_offset.flags = 0;

		ret = cros_ec_motion_send_host_cmd(&st->core, 0);
		if (ret < 0)
			break;

		/* Save values */
		for (i = CROS_EC_SENSOR_X; i < CROS_EC_SENSOR_MAX_AXIS; i++)
			st->core.calib[i].offset =
				st->core.resp->sensor_offset.offset[i];
		ret = IIO_VAL_INT;
		*val = st->core.calib[idx].offset;
		break;
	case IIO_CHAN_INFO_CALIBSCALE:
		st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_SCALE;
		st->core.param.sensor_offset.flags = 0;

		ret = cros_ec_motion_send_host_cmd(&st->core, 0);
		if (ret == -EPROTO || ret == -EOPNOTSUPP) {
			/* Reading calibscale is not supported on older EC. */
			*val = 1;
			*val2 = 0;
			ret = IIO_VAL_INT_PLUS_MICRO;
			break;
		} else if (ret) {
			break;
		}

		/* Save values */
		for (i = CROS_EC_SENSOR_X; i < CROS_EC_SENSOR_MAX_AXIS; i++)
			st->core.calib[i].scale =
				st->core.resp->sensor_scale.scale[i];

		*val = st->core.calib[idx].scale >> 15;
		*val2 = ((st->core.calib[idx].scale & 0x7FFF) * 1000000LL) /
			MOTION_SENSE_DEFAULT_SCALE;
		ret = IIO_VAL_INT_PLUS_MICRO;
		break;
	case IIO_CHAN_INFO_SCALE:
		st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_RANGE;
		st->core.param.sensor_range.data = EC_MOTION_SENSE_NO_VALUE;

		ret = cros_ec_motion_send_host_cmd(&st->core, 0);
		if (ret < 0)
			break;

		val64 = st->core.resp->sensor_range.ret;
		switch (st->core.type) {
		case MOTIONSENSE_TYPE_ACCEL:
			/*
			 * EC returns data in g, IIO expects m/s^2.
			 * Do not use IIO_G_TO_M_S_2 to avoid precision loss.
			 */
			*val = div_s64(val64 * 980665, 10);
			*val2 = 10000 << (CROS_EC_SENSOR_BITS - 1);
			ret = IIO_VAL_FRACTIONAL;
			break;
		case MOTIONSENSE_TYPE_GYRO:
			/*
			 * EC returns data in dps, iio expects rad/s.

Annotation

Implementation Notes