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authorLinus Walleij <linus.walleij@linaro.org>2018-12-13 15:22:47 +0100
committerLinus Walleij <linus.walleij@linaro.org>2019-05-31 12:27:11 +0200
commite3023bf80639afc6603f9633eb301845421b8917 (patch)
treeb1c9b4cbdf1a369eef30970d10749d0e9c538cf3 /drivers/gpio/gpiolib-of.c
parent910f38bed9439e765f7e240edfe32b5f04ad92f5 (diff)
gpio: of: Handle the Freescale SPI CS
The Freescale SPI chipselects are special: while everyone else is using "cs-gpios" the Freescale platforms just use "gpios". Fix this by responding with "gpios" when asking for "cs-gpios" in a freescale device node, so we hide this pecularity from the SPI core. Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/gpio/gpiolib-of.c')
-rw-r--r--drivers/gpio/gpiolib-of.c37
1 files changed, 37 insertions, 0 deletions
diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index aec7bd86ae7e..00deb885409c 100644
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -255,6 +255,37 @@ static struct gpio_desc *of_find_spi_gpio(struct device *dev, const char *con_id
}
/*
+ * The old Freescale bindings use simply "gpios" as name for the chip select
+ * lines rather than "cs-gpios" like all other SPI hardware. Account for this
+ * with a special quirk.
+ */
+static struct gpio_desc *of_find_spi_cs_gpio(struct device *dev,
+ const char *con_id,
+ unsigned int idx,
+ unsigned long *flags)
+{
+ struct device_node *np = dev->of_node;
+
+ if (!IS_ENABLED(CONFIG_SPI_MASTER))
+ return ERR_PTR(-ENOENT);
+
+ /* Allow this specifically for Freescale devices */
+ if (!of_device_is_compatible(np, "fsl,spi") &&
+ !of_device_is_compatible(np, "aeroflexgaisler,spictrl"))
+ return ERR_PTR(-ENOENT);
+ /* Allow only if asking for "cs-gpios" */
+ if (!con_id || strcmp(con_id, "cs"))
+ return ERR_PTR(-ENOENT);
+
+ /*
+ * While all other SPI controllers use "cs-gpios" the Freescale
+ * uses just "gpios" so translate to that when "cs-gpios" is
+ * requested.
+ */
+ return of_find_gpio(dev, NULL, idx, flags);
+}
+
+/*
* Some regulator bindings happened before we managed to establish that GPIO
* properties should be named "foo-gpios" so we have this special kludge for
* them.
@@ -325,6 +356,12 @@ struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
/* Special handling for SPI GPIOs if used */
if (IS_ERR(desc))
desc = of_find_spi_gpio(dev, con_id, &of_flags);
+ if (IS_ERR(desc)) {
+ /* This quirk looks up flags and all */
+ desc = of_find_spi_cs_gpio(dev, con_id, idx, flags);
+ if (!IS_ERR(desc))
+ return desc;
+ }
/* Special handling for regulator GPIOs if used */
if (IS_ERR(desc) && PTR_ERR(desc) != -EPROBE_DEFER)