@@ -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_get_count(dev, "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",
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> --- ChangeLog v1->v2: - Hardcode the quirk to look for "gpios" as this is all we support and else the call would just recurse back and fail again. - Provide a proper NULL check so we don't upset strcmp(). Mark: I change my mind, better to keep the patches together, once Christophe has it working with my patch stack let's just merge all of it. --- drivers/gpio/gpiolib-of.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) -- 2.23.0