Typically, in burst mode, the device cannot operate at it's full spi
speed. Hence, the spi transfers for burst mode have to take this into
account. With this change we avoid a potential race with the spi core as
drivers were 'hacking' the device 'max_speed_hz' directly in the
trigger handler.
Reviewed-by: Alexandru Ardelean <ardeleanalex@xxxxxxxxx>
Signed-off-by: Nuno Sa <nuno.sa@xxxxxxxxxx>
---
drivers/iio/imu/adis_buffer.c | 4 ++++
include/linux/iio/imu/adis.h | 2 ++
2 files changed, 6 insertions(+)
diff --git a/drivers/iio/imu/adis_buffer.c b/drivers/iio/imu/adis_buffer.c
index f6dbfbd17d41..351c303c8a8c 100644
--- a/drivers/iio/imu/adis_buffer.c
+++ b/drivers/iio/imu/adis_buffer.c
@@ -51,9 +51,13 @@ static int adis_update_scan_mode_burst(struct iio_dev *indio_dev,
adis->xfer[0].tx_buf = tx;
adis->xfer[0].bits_per_word = 8;
adis->xfer[0].len = 2;
+ if (adis->data->burst_max_speed_hz)
+ adis->xfer[0].speed_hz = adis->data->burst_max_speed_hz;
adis->xfer[1].rx_buf = adis->buffer;
adis->xfer[1].bits_per_word = 8;
adis->xfer[1].len = burst_length;
+ if (adis->data->burst_max_speed_hz)
+ adis->xfer[1].speed_hz = adis->data->burst_max_speed_hz;
spi_message_init(&adis->msg);
spi_message_add_tail(&adis->xfer[0], &adis->msg);
diff --git a/include/linux/iio/imu/adis.h b/include/linux/iio/imu/adis.h
index f9b728d490b1..cf49997d5903 100644
--- a/include/linux/iio/imu/adis.h
+++ b/include/linux/iio/imu/adis.h
@@ -55,6 +55,7 @@ struct adis_timeout {
* this should be the minimum size supported by the device.
* @burst_max_len: Holds the maximum burst size when the device supports
* more than one burst mode with different sizes
+ * @burst_max_speed_hz: Maximum spi speed that can be used in burst mode
*/
struct adis_data {
unsigned int read_delay;
@@ -83,6 +84,7 @@ struct adis_data {
unsigned int burst_reg_cmd;
unsigned int burst_len;
unsigned int burst_max_len;
+ unsigned int burst_max_speed_hz;
};
/**
--
2.31.1
