From 9da7e18573c725eaa6123c401df57d6a4f6a0ea2 Mon Sep 17 00:00:00 2001 From: Sascha Hauer Date: Tue, 22 Nov 2016 12:43:01 +0100 Subject: spi: i.MX: reset controller on init In rare cases the controller is does not work right after probe. When this happens the registers show that the TXFIFO contains words, but the transfer is never started. We observed that on some boards which boot from SPI NOR. The xload SPI code leaves the controller enabled, so the SPI controller is enabled during probe(). Disabling it before usage (and thus resetting it) helps. We haven't found out why exactly this happens. Signed-off-by: Sascha Hauer --- drivers/spi/imx_spi.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'drivers') diff --git a/drivers/spi/imx_spi.c b/drivers/spi/imx_spi.c index 806ca67bda..876699a02d 100644 --- a/drivers/spi/imx_spi.c +++ b/drivers/spi/imx_spi.c @@ -348,6 +348,13 @@ static u32 imx_xchg_single(struct spi_device *spi, u32 tx_val) return imx_spi_maybe_reverse_bits(spi, rx_val); } +static void cspi_2_3_init(struct imx_spi *imx) +{ + void __iomem *base = imx->regs; + + writel(0, base + CSPI_2_3_CTRL); +} + static void imx_spi_do_transfer(struct spi_device *spi) { struct imx_spi *imx = container_of(spi->master, struct imx_spi, master); @@ -519,6 +526,7 @@ static __maybe_unused struct spi_imx_devtype_data spi_imx_devtype_data_2_3 = { .chipselect = cspi_2_3_chipselect, .do_transfer = cspi_2_3_do_transfer, .xchg_single = cspi_2_3_xchg_single, + .init = cspi_2_3_init, }; static int imx_spi_dt_probe(struct imx_spi *imx) -- cgit v1.2.3