From mboxrd@z Thu Jan 1 00:00:00 1970 From: Esben Haabendal Subject: [PATCH 07/12] spi: spi-fsl-dspi: Fix MCR register handling Date: Wed, 20 Jun 2018 09:34:37 +0200 Message-ID: <20180620073442.20913-8-esben.haabendal@gmail.com> References: <20180620073442.20913-1-esben.haabendal@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Cc: Kurt Kanzenbach , Angelo Dureghello , Nikita Yushchenko , Sanchayan Maity , Yuan Yao , linux-kernel@vger.kernel.org, Esben Haabendal , =?UTF-8?q?Martin=20Hundeb=C3=B8ll?= To: Mark Brown , linux-spi@vger.kernel.org Return-path: In-Reply-To: <20180620073442.20913-1-esben.haabendal@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-spi.vger.kernel.org From: Esben Haabendal The MCR register is not changed, so initialize it in dspi_init(). The exception is the CLR_TXF and CLR_RXF bits, which should be written to before each transfer to make sure we start with empty FIFOs. With MCR register now configured as volatile, the regmap_update_bits will do a real read-modify-write cycle. Signed-off-by: Esben Haabendal Cc: Martin Hundebøll --- drivers/spi/spi-fsl-dspi.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c index 5c5905b6509f..d83d3496d538 100644 --- a/drivers/spi/spi-fsl-dspi.c +++ b/drivers/spi/spi-fsl-dspi.c @@ -120,7 +120,6 @@ #define DMA_COMPLETION_TIMEOUT msecs_to_jiffies(3000) struct chip_data { - u32 mcr_val; u32 ctar_val; u16 void_write_data; }; @@ -644,10 +643,9 @@ static int dspi_transfer_one_message(struct spi_master *master, else dspi->bytes_per_word = 2; - regmap_write(dspi->regmap, SPI_MCR, dspi->cur_chip->mcr_val); regmap_update_bits(dspi->regmap, SPI_MCR, - SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF, - SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF); + SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF, + SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF); regmap_write(dspi->regmap, SPI_CTAR(0), dspi->cur_chip->ctar_val | SPI_FRAME_BITS(transfer->bits_per_word)); @@ -725,9 +723,6 @@ static int dspi_setup(struct spi_device *spi) sck_cs_delay = pdata->sck_cs_delay; } - chip->mcr_val = SPI_MCR_MASTER | SPI_MCR_PCSIS | - SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF; - chip->void_write_data = 0; clkrate = clk_get_rate(dspi->clk); @@ -883,6 +878,7 @@ static const struct regmap_config dspi_regmap_config = { static void dspi_init(struct fsl_dspi *dspi) { + regmap_write(dspi->regmap, SPI_MCR, SPI_MCR_MASTER | SPI_MCR_PCSIS); regmap_write(dspi->regmap, SPI_SR, SPI_SR_CLEAR); } -- 2.17.1