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gpio: Adjust of_xlate API to support multiple GPIO chips

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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: Roland Stigge <stigge@antcom.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
This commit is contained in:
Grant Likely 2012-05-17 13:54:40 -06:00
parent 09d71ff194
commit 3d0f7cf0f3
5 changed files with 43 additions and 49 deletions
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3
arch/arm/mach-imx/mach-mx35_3ds.c
View file

@ -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);
}

84
drivers/gpio/gpiolib-of.c
View file

@ -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;
ret = of_parse_phandle_with_args(np, propname, "#gpio-cells", index,
&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;
}
/* .xlate might decide to not fill in the flags, so clear it. */
/* .of_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;
ret = of_parse_phandle_with_args(np, propname, "#gpio-cells", index,
&gg_data.gpiospec);
if (ret) {
pr_debug("%s: can't parse gpios property\n", __func__);
return -EINVAL;
}
ret += gc->base;
err1:
of_node_put(gpiospec.np);
err0:
gpiochip_find(&gg_data, of_gpiochip_find_and_xlate);
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);
}

2
drivers/gpio/gpiolib.c
View file

@ -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;

2
include/asm-generic/gpio.h
View file

@ -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,

1
include/linux/of_gpio.h
View file

@ -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);