From d7aa9d52b7f9b2d600f9b2479767c24d438a2c68 Mon Sep 17 00:00:00 2001 From: Phil Elwell Date: Tue, 3 Jul 2018 14:23:47 +0100 Subject: [PATCH] spi: Make GPIO CSs honour the SPI_NO_CS flag The SPI configuration state includes an SPI_NO_CS flag that disables all CS line manipulation, for applications that want to manage their own chip selects. However, this flag is ignored by the GPIO CS code in the SPI framework. Correct this omission with a trivial patch. See: https://github.com/raspberrypi/linux/issues/2169 Signed-off-by: Phil Elwell --- drivers/spi/spi.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -733,7 +733,9 @@ static void spi_set_cs(struct spi_device enable = !enable; if (gpio_is_valid(spi->cs_gpio)) { - gpio_set_value_cansleep(spi->cs_gpio, !enable); + /* Honour the SPI_NO_CS flag */ + if (!(spi->mode & SPI_NO_CS)) + gpio_set_value_cansleep(spi->cs_gpio, !enable); /* Some SPI masters need both GPIO CS & slave_select */ if ((spi->controller->flags & SPI_MASTER_GPIO_SS) && spi->controller->set_cs)