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Commit e3023bf8 authored by Linus Walleij's avatar Linus Walleij
Browse files

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: default avatarLinus Walleij <linus.walleij@linaro.org>
parent 910f38be

drivers/gpio/gpiolib-of.c

+37 −0
Original line number Diff line number Diff line
@@ -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)