diff options
Diffstat (limited to 'target/linux/bcm27xx/patches-5.15/950-0696-spi-gpio-Add-sck-idle-input-property.patch')
| -rw-r--r-- | target/linux/bcm27xx/patches-5.15/950-0696-spi-gpio-Add-sck-idle-input-property.patch | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/target/linux/bcm27xx/patches-5.15/950-0696-spi-gpio-Add-sck-idle-input-property.patch b/target/linux/bcm27xx/patches-5.15/950-0696-spi-gpio-Add-sck-idle-input-property.patch new file mode 100644 index 0000000000..6b359c4bb8 --- /dev/null +++ b/target/linux/bcm27xx/patches-5.15/950-0696-spi-gpio-Add-sck-idle-input-property.patch @@ -0,0 +1,57 @@ +From c979072887ef70aab2ab6e71544853df71017925 Mon Sep 17 00:00:00 2001 +From: Phil Elwell <phil@raspberrypi.com> +Date: Wed, 12 Jan 2022 08:23:28 +0000 +Subject: [PATCH] spi: gpio: Add sck-idle-input property + +The sck-idle-input property indicates that the spi-gpio driver should +return the SCK line to an input when the chip select signals are +inactive. + +Signed-off-by: Phil Elwell <phil@raspberrypi.com> +--- + drivers/spi/spi-gpio.c | 13 +++++++++++-- + 1 file changed, 11 insertions(+), 2 deletions(-) + +--- a/drivers/spi/spi-gpio.c ++++ b/drivers/spi/spi-gpio.c +@@ -35,6 +35,7 @@ struct spi_gpio { + struct gpio_desc *sck; + struct gpio_desc *miso; + struct gpio_desc *mosi; ++ bool sck_idle_input; + struct gpio_desc **cs_gpios; + }; + +@@ -201,8 +202,12 @@ static void spi_gpio_chipselect(struct s + struct spi_gpio *spi_gpio = spi_to_spi_gpio(spi); + + /* set initial clock line level */ +- if (is_active) +- gpiod_set_value_cansleep(spi_gpio->sck, spi->mode & SPI_CPOL); ++ if (is_active) { ++ if (spi_gpio->sck_idle_input) ++ gpiod_direction_output(spi_gpio->sck, spi->mode & SPI_CPOL); ++ else ++ gpiod_set_value_cansleep(spi_gpio->sck, spi->mode & SPI_CPOL); ++ } + + /* Drive chip select line, if we have one */ + if (spi_gpio->cs_gpios) { +@@ -211,6 +216,9 @@ static void spi_gpio_chipselect(struct s + /* SPI chip selects are normally active-low */ + gpiod_set_value_cansleep(cs, (spi->mode & SPI_CS_HIGH) ? is_active : !is_active); + } ++ ++ if (spi_gpio->sck_idle_input && !is_active) ++ gpiod_direction_input(spi_gpio->sck); + } + + static int spi_gpio_setup(struct spi_device *spi) +@@ -289,6 +297,7 @@ static int spi_gpio_request(struct devic + if (IS_ERR(spi_gpio->miso)) + return PTR_ERR(spi_gpio->miso); + ++ spi_gpio->sck_idle_input = device_property_read_bool(dev, "sck-idle-input"); + spi_gpio->sck = devm_gpiod_get(dev, "sck", GPIOD_OUT_LOW); + return PTR_ERR_OR_ZERO(spi_gpio->sck); + } |