diff options
Diffstat (limited to 'target/linux/bcm27xx/patches-5.4/950-0646-spi-Force-CS_HIGH-if-GPIO-descriptors-are-used.patch')
| -rw-r--r-- | target/linux/bcm27xx/patches-5.4/950-0646-spi-Force-CS_HIGH-if-GPIO-descriptors-are-used.patch | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/target/linux/bcm27xx/patches-5.4/950-0646-spi-Force-CS_HIGH-if-GPIO-descriptors-are-used.patch b/target/linux/bcm27xx/patches-5.4/950-0646-spi-Force-CS_HIGH-if-GPIO-descriptors-are-used.patch new file mode 100644 index 0000000000..42d22c3003 --- /dev/null +++ b/target/linux/bcm27xx/patches-5.4/950-0646-spi-Force-CS_HIGH-if-GPIO-descriptors-are-used.patch @@ -0,0 +1,48 @@ +From 5f2eface651ba5da9caaa84ccca14b9202ba6202 Mon Sep 17 00:00:00 2001 +From: Phil Elwell <phil@raspberrypi.com> +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 <phil@raspberrypi.com> +--- + drivers/spi/spi.c | 9 +++++++++ + 1 file changed, 9 insertions(+) + +--- a/drivers/spi/spi.c ++++ b/drivers/spi/spi.c +@@ -3115,6 +3115,7 @@ 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; + +@@ -3132,6 +3133,14 @@ 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_warn(&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, |