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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>
This commit is contained in:
Linus Walleij 2018-12-13 15:22:47 +01:00
parent 910f38bed9
commit e3023bf806
1 changed files with 37 additions and 0 deletions
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37
drivers/gpio/gpiolib-of.c
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@ -254,6 +254,37 @@ static struct gpio_desc *of_find_spi_gpio(struct device *dev, const char *con_id
return desc;
}
/*
* 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
@ -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)