From mboxrd@z Thu Jan 1 00:00:00 1970 From: anton.bondarenko.sama@gmail.com (Anton Bondarenko) Date: Tue, 8 Dec 2015 07:43:43 +0100 Subject: [PATCH v6 1/8] spi: imx: fix loopback mode setup after controller reset In-Reply-To: <1449557030-27525-1-git-send-email-anton.bondarenko.sama@gmail.com> References: <1449557030-27525-1-git-send-email-anton.bondarenko.sama@gmail.com> Message-ID: <1449557030-27525-2-git-send-email-anton.bondarenko.sama@gmail.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org If controller hold in reset it's not possible to write any register except CTRL. So all other registers must be updated only after controller bring out from reset. Signed-off-by: Anton Bondarenko --- drivers/spi/spi-imx.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c index 410522f..3aa33c8 100644 --- a/drivers/spi/spi-imx.c +++ b/drivers/spi/spi-imx.c @@ -356,6 +356,9 @@ static int __maybe_unused mx51_ecspi_config(struct spi_imx_data *spi_imx, else cfg &= ~MX51_ECSPI_CONFIG_SSBPOL(config->cs); + /* CTRL register always go first to bring out controller from reset */ + writel(ctrl, spi_imx->base + MX51_ECSPI_CTRL); + reg = readl(spi_imx->base + MX51_ECSPI_TESTREG); if (config->mode & SPI_LOOP) reg |= MX51_ECSPI_TESTREG_LBC; @@ -363,7 +366,6 @@ static int __maybe_unused mx51_ecspi_config(struct spi_imx_data *spi_imx, reg &= ~MX51_ECSPI_TESTREG_LBC; writel(reg, spi_imx->base + MX51_ECSPI_TESTREG); - writel(ctrl, spi_imx->base + MX51_ECSPI_CTRL); writel(cfg, spi_imx->base + MX51_ECSPI_CONFIG); /* -- 2.6.3