From f4b323905d8b3e28b2a9cef9325dbec1b0f7f064 Mon Sep 17 00:00:00 2001 From: Lukasz Majewski Date: Tue, 24 Sep 2019 13:05:47 +0200 Subject: [PATCH] spi: Introduce dspi_slave_abort() function for NXP's dspi SPI driver This change provides the dspi_slave_abort() function, which is a callback for slave_abort() method of SPI controller generic driver. As in the SPI slave mode the transmission is driven by master, any distortion may cause the slave to enter undefined internal state. To avoid this problem the dspi_slave_abort() terminates all pending and ongoing DMA transactions (with sync) and clears internal FIFOs. Signed-off-by: Lukasz Majewski Link: https://lore.kernel.org/r/20190924110547.14770-3-lukma@denx.de Signed-off-by: Mark Brown --- drivers/spi/spi-fsl-dspi.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c index bec758e978fb..2c0f211eed87 100644 --- a/drivers/spi/spi-fsl-dspi.c +++ b/drivers/spi/spi-fsl-dspi.c @@ -1006,6 +1006,25 @@ static void dspi_init(struct fsl_dspi *dspi) SPI_CTARE_FMSZE(0) | SPI_CTARE_DTCP(1)); } +static int dspi_slave_abort(struct spi_master *master) +{ + struct fsl_dspi *dspi = spi_master_get_devdata(master); + + /* + * Terminate all pending DMA transactions for the SPI working + * in SLAVE mode. + */ + dmaengine_terminate_sync(dspi->dma->chan_rx); + dmaengine_terminate_sync(dspi->dma->chan_tx); + + /* Clear the internal DSPI RX and TX FIFO buffers */ + regmap_update_bits(dspi->regmap, SPI_MCR, + SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF, + SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF); + + return 0; +} + static int dspi_probe(struct platform_device *pdev) { struct device_node *np = pdev->dev.of_node; @@ -1030,6 +1049,7 @@ static int dspi_probe(struct platform_device *pdev) ctlr->dev.of_node = pdev->dev.of_node; ctlr->cleanup = dspi_cleanup; + ctlr->slave_abort = dspi_slave_abort; ctlr->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST; pdata = dev_get_platdata(&pdev->dev);