From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Lechner Subject: [PATCH 1/3] spi: always use software fallback for SPI_CS_WORD when using cs_gio Date: Tue, 18 Sep 2018 12:08:48 -0500 Message-ID: <20180918170850.2749-2-david@lechnology.com> References: <20180918170850.2749-1-david@lechnology.com> Cc: David Lechner , Jonathan Cameron , Hartmut Knaack , Lars-Peter Clausen , Peter Meerwald-Stadler , Mark Brown , Geert Uytterhoeven , linux-kernel@vger.kernel.org To: linux-spi@vger.kernel.org, linux-iio@vger.kernel.org Return-path: In-Reply-To: <20180918170850.2749-1-david@lechnology.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-spi.vger.kernel.org This modifies the condition for using the software fallback implementation for SPI_CS_WORD when the SPI controller is using a GPIO for the CS line. When using a GPIO for CS, the hardware implementation won't work, so we just enable the software fallback globally in this case. Signed-off-by: David Lechner --- drivers/spi/spi.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index e4fb87b304a0..03833924ca6c 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -2841,11 +2841,13 @@ static int __spi_validate(struct spi_device *spi, struct spi_message *message) return -EINVAL; /* If an SPI controller does not support toggling the CS line on each - * transfer (indicated by the SPI_CS_WORD flag), we can emulate it by + * transfer (indicated by the SPI_CS_WORD flag) or we are using a GPIO + * for the CS line, we can emulate the CS-per-word hardware function by * splitting transfers into one-word transfers and ensuring that * cs_change is set for each transfer. */ - if ((spi->mode & SPI_CS_WORD) && !(ctlr->mode_bits & SPI_CS_WORD)) { + if ((spi->mode & SPI_CS_WORD) && (!(ctlr->mode_bits & SPI_CS_WORD) || + gpio_is_valid(spi->cs_gpio))) { size_t maxsize; int ret; -- 2.17.1