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| author |   Linus Walleij <linus.walleij@linaro.org> | 2019-11-28 09:37:17 +0100 |
|---|---|---|
| committer |   Mark Brown <broonie@kernel.org> | 2019-11-28 13:17:17 +0000 |
| commit | 71b8f600b034c7f5780f6fb311dabfe331c64feb (patch) | |
| tree | 5dc1372ad879eeb09097ae2f017587e3cabfd1f6 /drivers/gpio | |
| parent | spi: fsl: Fix GPIO descriptor support (diff) | |
| download | linux-dev-71b8f600b034c7f5780f6fb311dabfe331c64feb.tar.xz linux-dev-71b8f600b034c7f5780f6fb311dabfe331c64feb.zip | |
gpio: Handle counting of Freescale chipselects
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>
Diffstat (limited to 'drivers/gpio')
| -rw-r--r-- | drivers/gpio/gpiolib-of.c | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c index 1eea2c6c2e1d..4b19e7e26b90 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", |