diff options
Diffstat (limited to 'drivers/spi')
| -rw-r--r-- | drivers/spi/spi-fsl-dspi.c | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c index f37090ad7ad1..158cb48c0f4a 100644 --- a/drivers/spi/spi-fsl-dspi.c +++ b/drivers/spi/spi-fsl-dspi.c @@ -1084,6 +1084,22 @@ static int dspi_slave_abort(struct spi_master *master) return 0; } +/* + * EOQ mode will inevitably deassert its PCS signal on last word in a queue + * (hardware limitation), so we need to inform the spi_device that larger + * buffers than the FIFO size are going to have the chip select randomly + * toggling, so it has a chance to adapt its message sizes. + */ +static size_t dspi_max_message_size(struct spi_device *spi) +{ + struct fsl_dspi *dspi = spi_controller_get_devdata(spi->controller); + + if (dspi->devtype_data->trans_mode == DSPI_EOQ_MODE) + return dspi->devtype_data->fifo_size; + + return SIZE_MAX; +} + static int dspi_probe(struct platform_device *pdev) { struct device_node *np = pdev->dev.of_node; @@ -1105,6 +1121,7 @@ static int dspi_probe(struct platform_device *pdev) ctlr->setup = dspi_setup; ctlr->transfer_one_message = dspi_transfer_one_message; + ctlr->max_message_size = dspi_max_message_size; ctlr->dev.of_node = pdev->dev.of_node; ctlr->cleanup = dspi_cleanup; |