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Commit 3d0f7cf0 authored by Grant Likely's avatar Grant Likely
Browse files

gpio: Adjust of_xlate API to support multiple GPIO chips 



This patch changes the of_xlate API to make it possible for multiple
gpio_chips to refer to the same device tree node.  This is useful for
banked GPIO controllers that use multiple gpio_chips for a single
device.  With this change the core code will try calling of_xlate on
each gpio_chip that references the device_node and will return the
gpio number for the first one to return 'true'.

Tested-by: default avatarRoland Stigge <stigge@antcom.de>
Acked-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarGrant Likely <grant.likely@secretlab.ca>
parent 09d71ff1

arch/arm/mach-imx/mach-mx35_3ds.c

+1 −2
Original line number Diff line number Diff line
@@ -96,8 +96,7 @@ static struct i2c_board_info __initdata i2c_devices_3ds[] = { 


static int lcd_power_gpio = -ENXIO;



static int mc9s08dz60_gpiochip_match(struct gpio_chip *chip,

						     const void *data)

static int mc9s08dz60_gpiochip_match(struct gpio_chip *chip, void *data)

{

	return !strcmp(chip->label, data);

}

drivers/gpio/gpiolib-of.c

+38 −42
Original line number Diff line number Diff line
@@ -15,11 +15,39 @@ 
#include <linux/errno.h>

#include <linux/module.h>

#include <linux/io.h>

#include <linux/gpio.h>

#include <linux/of.h>

#include <linux/of_address.h>

#include <linux/of_gpio.h>

#include <linux/slab.h>



/* Private data structure for of_gpiochip_is_match */

struct gg_data {

	enum of_gpio_flags *flags;

	struct of_phandle_args gpiospec;



	int out_gpio;

};



/* Private function for resolving node pointer to gpio_chip */

static int of_gpiochip_find_and_xlate(struct gpio_chip *gc, void *data)

{

	struct gg_data *gg_data = data;

	int ret;



	if ((gc->of_node != gg_data->gpiospec.np) ||

	    (gc->of_gpio_n_cells != gg_data->gpiospec.args_count) ||

	    (!gc->of_xlate))

		return false;



	ret = gc->of_xlate(gc, &gg_data->gpiospec, gg_data->flags);

	if (ret < 0)

		return false;



	gg_data->out_gpio = ret + gc->base;

	return true;

}



/**

 * of_get_named_gpio_flags() - Get a GPIO number and flags to use with GPIO API

 * @np:		device node to get GPIO from
@@ -34,46 +62,25 @@ 
int of_get_named_gpio_flags(struct device_node *np, const char *propname,

                           int index, enum of_gpio_flags *flags)

{

	struct gg_data gg_data = { .flags = flags, .out_gpio = -ENODEV };

	int ret;

	struct gpio_chip *gc;

	struct of_phandle_args gpiospec;



	/* .of_xlate might decide to not fill in the flags, so clear it. */

	if (flags)

		*flags = 0;



	ret = of_parse_phandle_with_args(np, propname, "#gpio-cells", index,

					 &gpiospec);

					 &gg_data.gpiospec);

	if (ret) {

		pr_debug("%s: can't parse gpios property\n", __func__);

		goto err0;

	}



	gc = of_node_to_gpiochip(gpiospec.np);

	if (!gc) {

		pr_debug("%s: gpio controller %s isn't registered\n",

			 np->full_name, gpiospec.np->full_name);

		ret = -ENODEV;

		goto err1;

	}



	if (gpiospec.args_count != gc->of_gpio_n_cells) {

		pr_debug("%s: wrong #gpio-cells for %s\n",

			 np->full_name, gpiospec.np->full_name);

		ret = -EINVAL;

		goto err1;

		return -EINVAL;

	}



	/* .xlate might decide to not fill in the flags, so clear it. */

	if (flags)

		*flags = 0;



	ret = gc->of_xlate(gc, &gpiospec, flags);

	if (ret < 0)

		goto err1;

	gpiochip_find(&gg_data, of_gpiochip_find_and_xlate);



	ret += gc->base;

err1:

	of_node_put(gpiospec.np);

err0:

	of_node_put(gg_data.gpiospec.np);

	pr_debug("%s exited with status %d\n", __func__, ret);

	return ret;

	return gg_data.out_gpio;

}

EXPORT_SYMBOL(of_get_named_gpio_flags);
@@ -227,14 +234,3 @@ void of_gpiochip_remove(struct gpio_chip *chip) 
	if (chip->of_node)

		of_node_put(chip->of_node);

}
 


/* Private function for resolving node pointer to gpio_chip */

static int of_gpiochip_is_match(struct gpio_chip *chip, const void *data)

{

	return chip->of_node == data;

}



struct gpio_chip *of_node_to_gpiochip(struct device_node *np)

{

	return gpiochip_find(np, of_gpiochip_is_match);

}

drivers/gpio/gpiolib.c

+1 −1
Original line number Diff line number Diff line
@@ -1156,7 +1156,7 @@ EXPORT_SYMBOL_GPL(gpiochip_remove); 
 */

struct gpio_chip *gpiochip_find(const void *data,

				int (*match)(struct gpio_chip *chip,

					     const void *data))

					     void *data))

{

	struct gpio_chip *chip = NULL;

	unsigned long flags;

include/asm-generic/gpio.h

+1 −1
Original line number Diff line number Diff line
@@ -144,7 +144,7 @@ extern int gpiochip_add(struct gpio_chip *chip); 
extern int __must_check gpiochip_remove(struct gpio_chip *chip);

extern struct gpio_chip *gpiochip_find(const void *data,

					int (*match)(struct gpio_chip *chip,

						     const void *data));

						     void *data));





/* Always use the library code for GPIO management calls,

include/linux/of_gpio.h

+0 −1
Original line number Diff line number Diff line
@@ -58,7 +58,6 @@ extern int of_mm_gpiochip_add(struct device_node *np, 


extern void of_gpiochip_add(struct gpio_chip *gc);

extern void of_gpiochip_remove(struct gpio_chip *gc);

extern struct gpio_chip *of_node_to_gpiochip(struct device_node *np);

extern int of_gpio_simple_xlate(struct gpio_chip *gc,

				const struct of_phandle_args *gpiospec,

				u32 *flags);