drivers/iio/common/scmi_sensors/scmi_iio.c

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

File Facts

System
Linux kernel
Corpus path
drivers/iio/common/scmi_sensors/scmi_iio.c
Extension
.c
Size
19974 bytes
Lines
722
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 scmi_iio_priv {
	const struct scmi_sensor_proto_ops *sensor_ops;
	struct scmi_protocol_handle *ph;
	const struct scmi_sensor_info *sensor_info;
	struct iio_dev *indio_dev;
	/* lock to protect against multiple access to the device */
	struct mutex lock;
	/* adding one additional channel for timestamp */
	s64 iio_buf[SCMI_IIO_NUM_OF_AXIS + 1];
	struct notifier_block sensor_update_nb;
	u32 *freq_avail;
};

static int scmi_iio_sensor_update_cb(struct notifier_block *nb,
				     unsigned long event, void *data)
{
	struct scmi_sensor_update_report *sensor_update = data;
	struct iio_dev *scmi_iio_dev;
	struct scmi_iio_priv *sensor;
	s8 tstamp_scale;
	u64 time, time_ns;
	int i;

	if (sensor_update->readings_count == 0)
		return NOTIFY_DONE;

	sensor = container_of(nb, struct scmi_iio_priv, sensor_update_nb);

	for (i = 0; i < sensor_update->readings_count; i++)
		sensor->iio_buf[i] = sensor_update->readings[i].value;

	if (!sensor->sensor_info->timestamped) {
		time_ns = ktime_to_ns(sensor_update->timestamp);
	} else {
		/*
		 *  All the axes are supposed to have the same value for timestamp.
		 *  We are just using the values from the Axis 0 here.
		 */
		time = sensor_update->readings[0].timestamp;

		/*
		 *  Timestamp returned by SCMI is in seconds and is equal to
		 *  time * power-of-10 multiplier(tstamp_scale) seconds.
		 *  Converting the timestamp to nanoseconds (10⁹) below.
		 */
		tstamp_scale = sensor->sensor_info->tstamp_scale + 9;
		if (tstamp_scale < 0) {
			do_div(time, int_pow(10, abs(tstamp_scale)));
			time_ns = time;
		} else {
			time_ns = time * int_pow(10, tstamp_scale);
		}
	}

	scmi_iio_dev = sensor->indio_dev;
	iio_push_to_buffers_with_timestamp(scmi_iio_dev, sensor->iio_buf,
					   time_ns);
	return NOTIFY_OK;
}

static int scmi_iio_buffer_preenable(struct iio_dev *iio_dev)
{
	struct scmi_iio_priv *sensor = iio_priv(iio_dev);
	u32 sensor_config = 0;
	int err;

	if (sensor->sensor_info->timestamped)
		sensor_config |= FIELD_PREP(SCMI_SENS_CFG_TSTAMP_ENABLED_MASK,
					    SCMI_SENS_CFG_TSTAMP_ENABLE);

	sensor_config |= FIELD_PREP(SCMI_SENS_CFG_SENSOR_ENABLED_MASK,
				    SCMI_SENS_CFG_SENSOR_ENABLE);
	err = sensor->sensor_ops->config_set(sensor->ph,
					     sensor->sensor_info->id,
					     sensor_config);
	if (err)
		dev_err(&iio_dev->dev, "Error in enabling sensor %s err %d",
			sensor->sensor_info->name, err);

	return err;
}

static int scmi_iio_buffer_postdisable(struct iio_dev *iio_dev)
{
	struct scmi_iio_priv *sensor = iio_priv(iio_dev);
	u32 sensor_config = 0;
	int err;

	sensor_config |= FIELD_PREP(SCMI_SENS_CFG_SENSOR_ENABLED_MASK,
				    SCMI_SENS_CFG_SENSOR_DISABLE);

Annotation

Implementation Notes