The of_xlate callback is used to tanslate a device-tree GPIO specifier
into a chip relative GPIO number and flags. This callback needs to be
implemented by GPIO controller driver which doesn't uses the "classic"
device-tree description, which is:
gpio = <&gpio-phandle gpio_num gpio_flags>;
But uses something else, like this (but not limited to):
gpio = <&gpio-phandle gpio_bank gpio_num gpio_flags>;
Currently no GPIO driver require this of_xlate callback, but this will
be used for sunxi's GPIO support.
Signed-off-by: Jules Maselbas <jmaselbas@xxxxxxxxx>
---
drivers/gpio/gpiolib.c | 60 ++++++++++++++++++++++--------------------
drivers/of/of_gpio.c | 5 ++--
include/gpio.h | 3 ++-
3 files changed, 37 insertions(+), 31 deletions(-)
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index f845a57394..97a99b84e3 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -444,44 +444,27 @@ static int of_hog_gpio(struct device_node *np, struct gpio_chip *chip,
unsigned int idx)
{
struct device_node *chip_np = chip->dev->device_node;
+ struct of_phandle_args gpiospec;
unsigned long flags = 0;
- u32 gpio_cells, gpio_num, gpio_flags;
+ u32 gpio_flags;
int ret, gpio;
const char *name = NULL;
- ret = of_property_read_u32(chip_np, "#gpio-cells", &gpio_cells);
+ ret = of_parse_phandle_with_args(chip_np, "gpios", "#gpio-cells", idx,
+ &gpiospec);
if (ret)
return ret;
- /*
- * Support for GPIOs that don't have #gpio-cells set to 2 is
- * not implemented
- */
- if (WARN_ON(gpio_cells != 2))
- return -ENOTSUPP;
-
- ret = of_property_read_u32_index(np, "gpios", idx * gpio_cells,
- &gpio_num);
- if (ret)
- return ret;
-
- ret = of_property_read_u32_index(np, "gpios", idx * gpio_cells + 1,
- &gpio_flags);
- if (ret)
- return ret;
-
- if (gpio_flags & OF_GPIO_ACTIVE_LOW)
- flags |= GPIOF_ACTIVE_LOW;
-
- gpio = gpio_get_num(chip->dev, gpio_num);
+ gpio = gpio_of_xlate(chip->dev, &gpiospec, &gpio_flags);
if (gpio == -EPROBE_DEFER)
return gpio;
-
if (gpio < 0) {
- dev_err(chip->dev, "unable to get gpio %u\n", gpio_num);
+ dev_err(chip->dev, "unable to get gpio: %d\n", gpio);
return gpio;
}
+ if (gpio_flags & OF_GPIO_ACTIVE_LOW)
+ flags |= GPIOF_ACTIVE_LOW;
/*
* Note that, in order to be compatible with Linux, the code
@@ -636,7 +619,24 @@ void gpiochip_remove(struct gpio_chip *chip)
list_del(&chip->list);
}
-int gpio_get_num(struct device_d *dev, int gpio)
+static int of_gpio_simple_xlate(struct gpio_chip *chip,
+ const struct of_phandle_args *gpiospec,
+ u32 *flags)
+{
+ /*
+ * Support for GPIOs that don't have #gpio-cells set to 2 is
+ * not implemented
+ */
+ if (WARN_ON(gpiospec->args_count != 2))
+ return -ENOTSUPP;
+
+ if (flags)
+ *flags = gpiospec->args[1];
+
+ return chip->base + gpiospec->args[0];
+}
+
+int gpio_of_xlate(struct device_d *dev, struct of_phandle_args *gpiospec, int *flags)
{
struct gpio_chip *chip;
@@ -644,8 +644,12 @@ int gpio_get_num(struct device_d *dev, int gpio)
return -ENODEV;
list_for_each_entry(chip, &chip_list, list) {
- if (chip->dev == dev)
- return chip->base + gpio;
+ if (chip->dev != dev)
+ continue;
+ if (chip->ops->of_xlate)
+ return chip->ops->of_xlate(chip, gpiospec, flags);
+ else
+ return of_gpio_simple_xlate(chip, gpiospec, flags);
}
return -EPROBE_DEFER;
diff --git a/drivers/of/of_gpio.c b/drivers/of/of_gpio.c
index 42e0347529..c23923b425 100644
--- a/drivers/of/of_gpio.c
+++ b/drivers/of/of_gpio.c
@@ -62,6 +62,7 @@ int of_get_named_gpio_flags(struct device_node *np, const char *propname,
{
struct of_phandle_args out_args;
struct device_d *dev;
+ int of_flags;
int ret;
ret = of_parse_phandle_with_args(np, propname, "#gpio-cells",
@@ -79,7 +80,7 @@ int of_get_named_gpio_flags(struct device_node *np, const char *propname,
return -EPROBE_DEFER;
}
- ret = gpio_get_num(dev, out_args.args[0]);
+ ret = gpio_of_xlate(dev, &out_args, &of_flags);
if (ret == -EPROBE_DEFER)
return ret;
if (ret < 0) {
@@ -89,7 +90,7 @@ int of_get_named_gpio_flags(struct device_node *np, const char *propname,
}
if (flags) {
- *flags = out_args.args[1];
+ *flags = of_flags;
of_gpio_flags_quirks(np, propname, flags, index);
}
diff --git a/include/gpio.h b/include/gpio.h
index 6134190138..8218722dcb 100644
--- a/include/gpio.h
+++ b/include/gpio.h
@@ -171,6 +171,7 @@ struct gpio_ops {
int (*get_direction)(struct gpio_chip *chip, unsigned offset);
int (*get)(struct gpio_chip *chip, unsigned offset);
void (*set)(struct gpio_chip *chip, unsigned offset, int value);
+ int (*of_xlate)(struct gpio_chip *chip, const struct of_phandle_args *gpiospec, u32 *flags);
};
struct gpio_chip {
@@ -187,7 +188,7 @@ struct gpio_chip {
int gpiochip_add(struct gpio_chip *chip);
void gpiochip_remove(struct gpio_chip *chip);
-int gpio_get_num(struct device_d *dev, int gpio);
+int gpio_of_xlate(struct device_d *dev, struct of_phandle_args *gpiospec, int *flags);
struct gpio_chip *gpio_get_chip(int gpio);
#endif /* __GPIO_H */
--
2.17.1
