From 43840b26213fb0522ab464e9a31f148122acaa80 Mon Sep 17 00:00:00 2001 From: Phil Elwell Date: Fri, 17 Apr 2020 10:46:19 +0100 Subject: [PATCH] spi: Force CS_HIGH if GPIO descriptors are used Commit f3186dd87669 ("spi: Optionally use GPIO descriptors for CS GPIOs") amended of_spi_parse_dt() to always set SPI_CS_HIGH for SPI slaves whose Chip Select is defined by a "cs-gpios" devicetree property. This change breaks drivers whose probe functions set the mode field of the spi_device because in doing so they clear the SPI_CS_HIGH flag. Fix by setting SPI_CS_HIGH in spi_setup (under the same conditions as in of_spi_parse_dt()). See also: 83b2a8fe43bd ("spi: spidev: Fix CS polarity if GPIO descriptors are used") Fixes: f3186dd87669 ("spi: Optionally use GPIO descriptors for CS GPIOs") Signed-off-by: Phil Elwell SQUASH: spi: Demote SPI_CS_HIGH warning to KERN_DEBUG This warning is unavoidable from a client's perspective and doesn't indicate anything wrong (just surprising). SQUASH with "spi: use_gpio_descriptor fixup moved to spi_setup" Signed-off-by: Phil Elwell --- drivers/spi/spi.c | 9 +++++++++ 1 file changed, 9 insertions(+) --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -3469,6 +3469,7 @@ static int __spi_validate_bits_per_word( */ int spi_setup(struct spi_device *spi) { + struct spi_controller *ctlr = spi->controller; unsigned bad_bits, ugly_bits; int status; @@ -3490,6 +3491,14 @@ int spi_setup(struct spi_device *spi) (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL | SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL))) return -EINVAL; + + if (ctlr->use_gpio_descriptors && ctlr->cs_gpiods && + ctlr->cs_gpiods[spi->chip_select] && !(spi->mode & SPI_CS_HIGH)) { + dev_dbg(&spi->dev, + "setup: forcing CS_HIGH (use_gpio_descriptors)\n"); + spi->mode |= SPI_CS_HIGH; + } + /* help drivers fail *cleanly* when they need options * that aren't supported with their current controller * SPI_CS_WORD has a fallback software implementation,