From: Linus Walleij linus.walleij@linaro.org
[ Upstream commit 71b8f600b034c7f5780f6fb311dabfe331c64feb ]
We have a special quirk to handle the Freescale nonstandard SPI chipselect GPIOs in the gpiolib-of.c file, but it currently only handles the case where the GPIOs are actually requested (gpiod_*get()).
We also need to handle that the SPI core attempts to count the GPIOs before use, and that needs a similar quirk in the OF part of the library.
Cc: Christophe Leroy christophe.leroy@c-s.fr Reported-by: Christophe Leroy christophe.leroy@c-s.fr Fixes: 0f0581b24bd0 ("spi: fsl: Convert to use CS GPIO descriptors") Signed-off-by: Linus Walleij linus.walleij@linaro.org Tested-by: Christophe Leroy christophe.leroy@c-s.fr Link: https://lore.kernel.org/r/20191128083718.39177-2-linus.walleij@linaro.org Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpio/gpiolib-of.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+)
diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c index 80ea49f570f4..43ffec3a6fbb 100644 --- a/drivers/gpio/gpiolib-of.c +++ b/drivers/gpio/gpiolib-of.c @@ -23,6 +23,29 @@ #include "gpiolib.h" #include "gpiolib-of.h"
+/** + * of_gpio_spi_cs_get_count() - special GPIO counting for SPI + * Some elder GPIO controllers need special quirks. Currently we handle + * the Freescale GPIO controller with bindings that doesn't use the + * established "cs-gpios" for chip selects but instead rely on + * "gpios" for the chip select lines. If we detect this, we redirect + * the counting of "cs-gpios" to count "gpios" transparent to the + * driver. + */ +int of_gpio_spi_cs_get_count(struct device *dev, const char *con_id) +{ + struct device_node *np = dev->of_node; + + if (!IS_ENABLED(CONFIG_SPI_MASTER)) + return 0; + if (!con_id || strcmp(con_id, "cs")) + return 0; + if (!of_device_is_compatible(np, "fsl,spi") && + !of_device_is_compatible(np, "aeroflexgaisler,spictrl")) + return 0; + return of_gpio_named_count(np, "gpios"); +} + /* * This is used by external users of of_gpio_count() from <linux/of_gpio.h> * @@ -35,6 +58,10 @@ int of_gpio_get_count(struct device *dev, const char *con_id) char propname[32]; unsigned int i;
+ ret = of_gpio_spi_cs_get_count(dev, con_id); + if (ret > 0) + return ret; + for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) { if (con_id) snprintf(propname, sizeof(propname), "%s-%s",