From dbf20809d6e0072ad189c937761d58bf98a47b43 Mon Sep 17 00:00:00 2001 From: Nuno Sa Date: Tue, 27 Apr 2021 10:54:52 +0200 Subject: [PATCH] iio: adis: add burst_max_speed_hz variable 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 Signed-off-by: Nuno Sa Link: https://lore.kernel.org/r/20210427085454.30616-5-nuno.sa@analog.com Signed-off-by: Jonathan Cameron --- 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; }; /**