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gpio: Handle counting of Freescale chipselects

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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: 0f0581b24b ("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>
This commit is contained in:
Linus Walleij 2019-11-28 09:37:17 +01:00 committed by Mark Brown
parent f106904968
commit 71b8f600b0
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GPG Key ID: 24D68B725D5487D0
1 changed files with 27 additions and 0 deletions
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27
drivers/gpio/gpiolib-of.c
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@ -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",