From a15dc3d657fa2df08d1adbed926050314b5f4ba7 Mon Sep 17 00:00:00 2001 From: Clark Wang Date: Mon, 7 Jan 2019 07:47:43 +0000 Subject: [PATCH] spi: lpspi: Fix CLK pin becomes low before one transfer Remove Reset operation in fsl_lpspi_config(). This RST may cause both CLK and CS pins go from high to low level under cs-gpio mode. Add fsl_lpspi_reset() function after one message transfer to clear all flags in use. Signed-off-by: Clark Wang Reviewed-by: Fugang Duan Signed-off-by: Mark Brown --- drivers/spi/spi-fsl-lpspi.c | 24 ++++++++++++++++++++---- 1 file changed, 20 insertions(+), 4 deletions(-) diff --git a/drivers/spi/spi-fsl-lpspi.c b/drivers/spi/spi-fsl-lpspi.c index d0b2d551cc43..391863914043 100644 --- a/drivers/spi/spi-fsl-lpspi.c +++ b/drivers/spi/spi-fsl-lpspi.c @@ -268,10 +268,6 @@ static int fsl_lpspi_config(struct fsl_lpspi_data *fsl_lpspi) u32 temp; int ret; - temp = CR_RST; - writel(temp, fsl_lpspi->base + IMX7ULP_CR); - writel(0, fsl_lpspi->base + IMX7ULP_CR); - if (!fsl_lpspi->is_slave) { ret = fsl_lpspi_set_bitrate(fsl_lpspi); if (ret) @@ -362,6 +358,24 @@ static int fsl_lpspi_wait_for_completion(struct spi_controller *controller) return 0; } +static int fsl_lpspi_reset(struct fsl_lpspi_data *fsl_lpspi) +{ + u32 temp; + + /* Disable all interrupt */ + fsl_lpspi_intctrl(fsl_lpspi, 0); + + /* W1C for all flags in SR */ + temp = 0x3F << 8; + writel(temp, fsl_lpspi->base + IMX7ULP_SR); + + /* Clear FIFO and disable module */ + temp = CR_RRF | CR_RTF; + writel(temp, fsl_lpspi->base + IMX7ULP_CR); + + return 0; +} + static int fsl_lpspi_transfer_one(struct spi_controller *controller, struct spi_device *spi, struct spi_transfer *t) @@ -383,6 +397,8 @@ static int fsl_lpspi_transfer_one(struct spi_controller *controller, if (ret) return ret; + fsl_lpspi_reset(fsl_lpspi); + return 0; } -- 2.11.0