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-rw-r--r--include/asm-generic/gpio.h33
1 files changed, 31 insertions, 2 deletions
diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
index 6be061d09da..1beff5166e5 100644
--- a/include/asm-generic/gpio.h
+++ b/include/asm-generic/gpio.h
@@ -32,6 +32,8 @@ struct module;
/**
* struct gpio_chip - abstract a GPIO controller
* @label: for diagnostics
+ * @dev: optional device providing the GPIOs
+ * @owner: helps prevent removal of modules exporting active GPIOs
* @direction_input: configures signal "offset" as input, or returns error
* @get: returns value for signal "offset"; for output signals this
* returns either the value actually sensed, or zero
@@ -59,6 +61,7 @@ struct module;
*/
struct gpio_chip {
char *label;
+ struct device *dev;
struct module *owner;
int (*direction_input)(struct gpio_chip *chip,
@@ -74,6 +77,7 @@ struct gpio_chip {
int base;
u16 ngpio;
unsigned can_sleep:1;
+ unsigned exported:1;
};
extern const char *gpiochip_is_requested(struct gpio_chip *chip,
@@ -108,7 +112,18 @@ extern void __gpio_set_value(unsigned gpio, int value);
extern int __gpio_cansleep(unsigned gpio);
-#else
+#ifdef CONFIG_GPIO_SYSFS
+
+/*
+ * A sysfs interface can be exported by individual drivers if they want,
+ * but more typically is configured entirely from userspace.
+ */
+extern int gpio_export(unsigned gpio, bool direction_may_change);
+extern void gpio_unexport(unsigned gpio);
+
+#endif /* CONFIG_GPIO_SYSFS */
+
+#else /* !CONFIG_HAVE_GPIO_LIB */
static inline int gpio_is_valid(int number)
{
@@ -137,6 +152,20 @@ static inline void gpio_set_value_cansleep(unsigned gpio, int value)
gpio_set_value(gpio, value);
}
-#endif
+#endif /* !CONFIG_HAVE_GPIO_LIB */
+
+#ifndef CONFIG_GPIO_SYSFS
+
+/* sysfs support is only available with gpiolib, where it's optional */
+
+static inline int gpio_export(unsigned gpio, bool direction_may_change)
+{
+ return -ENOSYS;
+}
+
+static inline void gpio_unexport(unsigned gpio)
+{
+}
+#endif /* CONFIG_GPIO_SYSFS */
#endif /* _ASM_GENERIC_GPIO_H */