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-rw-r--r--kernel/include/linux/of_gpio.h154
1 files changed, 154 insertions, 0 deletions
diff --git a/kernel/include/linux/of_gpio.h b/kernel/include/linux/of_gpio.h
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+++ b/kernel/include/linux/of_gpio.h
@@ -0,0 +1,154 @@
+/*
+ * OF helpers for the GPIO API
+ *
+ * Copyright (c) 2007-2008 MontaVista Software, Inc.
+ *
+ * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#ifndef __LINUX_OF_GPIO_H
+#define __LINUX_OF_GPIO_H
+
+#include <linux/compiler.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/gpio.h>
+#include <linux/of.h>
+
+struct device_node;
+
+/*
+ * This is Linux-specific flags. By default controllers' and Linux' mapping
+ * match, but GPIO controllers are free to translate their own flags to
+ * Linux-specific in their .xlate callback. Though, 1:1 mapping is recommended.
+ */
+enum of_gpio_flags {
+ OF_GPIO_ACTIVE_LOW = 0x1,
+};
+
+#ifdef CONFIG_OF_GPIO
+
+/*
+ * OF GPIO chip for memory mapped banks
+ */
+struct of_mm_gpio_chip {
+ struct gpio_chip gc;
+ void (*save_regs)(struct of_mm_gpio_chip *mm_gc);
+ void __iomem *regs;
+};
+
+static inline struct of_mm_gpio_chip *to_of_mm_gpio_chip(struct gpio_chip *gc)
+{
+ return container_of(gc, struct of_mm_gpio_chip, gc);
+}
+
+extern int of_get_named_gpio_flags(struct device_node *np,
+ const char *list_name, int index, enum of_gpio_flags *flags);
+
+extern int of_mm_gpiochip_add(struct device_node *np,
+ struct of_mm_gpio_chip *mm_gc);
+extern void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_gc);
+
+extern void of_gpiochip_add(struct gpio_chip *gc);
+extern void of_gpiochip_remove(struct gpio_chip *gc);
+extern int of_gpio_simple_xlate(struct gpio_chip *gc,
+ const struct of_phandle_args *gpiospec,
+ u32 *flags);
+
+#else /* CONFIG_OF_GPIO */
+
+/* Drivers may not strictly depend on the GPIO support, so let them link. */
+static inline int of_get_named_gpio_flags(struct device_node *np,
+ const char *list_name, int index, enum of_gpio_flags *flags)
+{
+ return -ENOSYS;
+}
+
+static inline int of_gpio_simple_xlate(struct gpio_chip *gc,
+ const struct of_phandle_args *gpiospec,
+ u32 *flags)
+{
+ return -ENOSYS;
+}
+
+static inline void of_gpiochip_add(struct gpio_chip *gc) { }
+static inline void of_gpiochip_remove(struct gpio_chip *gc) { }
+
+#endif /* CONFIG_OF_GPIO */
+
+/**
+ * of_gpio_named_count() - Count GPIOs for a device
+ * @np: device node to count GPIOs for
+ * @propname: property name containing gpio specifier(s)
+ *
+ * The function returns the count of GPIOs specified for a node.
+ * Note that the empty GPIO specifiers count too. Returns either
+ * Number of gpios defined in property,
+ * -EINVAL for an incorrectly formed gpios property, or
+ * -ENOENT for a missing gpios property
+ *
+ * Example:
+ * gpios = <0
+ * &gpio1 1 2
+ * 0
+ * &gpio2 3 4>;
+ *
+ * The above example defines four GPIOs, two of which are not specified.
+ * This function will return '4'
+ */
+static inline int of_gpio_named_count(struct device_node *np, const char* propname)
+{
+ return of_count_phandle_with_args(np, propname, "#gpio-cells");
+}
+
+/**
+ * of_gpio_count() - Count GPIOs for a device
+ * @np: device node to count GPIOs for
+ *
+ * Same as of_gpio_named_count, but hard coded to use the 'gpios' property
+ */
+static inline int of_gpio_count(struct device_node *np)
+{
+ return of_gpio_named_count(np, "gpios");
+}
+
+static inline int of_get_gpio_flags(struct device_node *np, int index,
+ enum of_gpio_flags *flags)
+{
+ return of_get_named_gpio_flags(np, "gpios", index, flags);
+}
+
+/**
+ * of_get_named_gpio() - Get a GPIO number to use with GPIO API
+ * @np: device node to get GPIO from
+ * @propname: Name of property containing gpio specifier(s)
+ * @index: index of the GPIO
+ *
+ * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
+ * value on the error condition.
+ */
+static inline int of_get_named_gpio(struct device_node *np,
+ const char *propname, int index)
+{
+ return of_get_named_gpio_flags(np, propname, index, NULL);
+}
+
+/**
+ * of_get_gpio() - Get a GPIO number to use with GPIO API
+ * @np: device node to get GPIO from
+ * @index: index of the GPIO
+ *
+ * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
+ * value on the error condition.
+ */
+static inline int of_get_gpio(struct device_node *np, int index)
+{
+ return of_get_gpio_flags(np, index, NULL);
+}
+
+#endif /* __LINUX_OF_GPIO_H */