Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754708AbcKQS2X (ORCPT ); Thu, 17 Nov 2016 13:28:23 -0500 Received: from mail-pg0-f65.google.com ([74.125.83.65]:32840 "EHLO mail-pg0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752247AbcKQS2V (ORCPT ); Thu, 17 Nov 2016 13:28:21 -0500 From: Sanchayan Maity To: broonie@kernel.org Cc: stefan@agner.ch, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-spi@vger.kernel.org, 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: X-Mailer: git-send-email 2.10.2 In-Reply-To: References: <20161111122036.fubv7b4jc5vkdxhc@sirena.org.uk> In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1302 Lines: 37 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