From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sanchayan Maity Subject: [PATCH 3/4] spi: spi-fsl-dspi: Fix continuous selection format Date: Thu, 17 Nov 2016 17:46:50 +0530 Message-ID: References: <20161111122036.fubv7b4jc5vkdxhc@sirena.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Sanchayan Maity , linux-spi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, stefan@agner.ch, linux-kernel@vger.kernel.org To: broonie@kernel.org Return-path: In-Reply-To: In-Reply-To: References: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org List-Id: linux-spi.vger.kernel.org Current DMA implementation was not handling the continuous selection format viz. SPI chip select would be deasserted even between sequential serial transfers. Use the cs_change variable and correctly set or reset the CONT bit accordingly for case where peripherals require the chip select to be asserted between sequential transfers. Signed-off-by: Sanchayan Maity --- drivers/spi/spi-fsl-dspi.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c index aee8c88..164e2e1 100644 --- a/drivers/spi/spi-fsl-dspi.c +++ b/drivers/spi/spi-fsl-dspi.c @@ -258,9 +258,16 @@ static int dspi_next_xfer_dma_submit(struct fsl_dspi *dspi) } val = tx_word ? *(u16 *) dspi->tx : *(u8 *) dspi->tx; - dspi->dma->tx_dma_buf[i] = SPI_PUSHR_TXDATA(val) | - SPI_PUSHR_PCS(dspi->cs) | - SPI_PUSHR_CTAS(0); + if (dspi->cs_change) { + dspi->dma->tx_dma_buf[i] = SPI_PUSHR_TXDATA(val) | + SPI_PUSHR_PCS(dspi->cs) | + SPI_PUSHR_CTAS(0); + } else { + dspi->dma->tx_dma_buf[i] = SPI_PUSHR_TXDATA(val) | + SPI_PUSHR_PCS(dspi->cs) | + SPI_PUSHR_CTAS(0) | + SPI_PUSHR_CONT; + } dspi->tx += tx_word + 1; dma->tx_desc = dmaengine_prep_slave_single(dma->chan_tx, -- 2.10.2