[POWERPC] OF helpers for the GPIO API

This implements various helpers to support OF bindings for the GPIO
LIB API.

Previously this was PowerPC specific, but it seems this code isn't
arch-dependent anyhow, so let's place it into of/.

SPARC will not see this addition yet, real hardware seem to not use
GPIOs at all. But this might change:

   http://www.leox.org/docs/faq_MLleon.html

"16-bit I/O port" sounds promising. :-)

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 69 insertions, 0 deletions

diff --git a/include/linux/of_gpio.h b/include/linux/of_gpio.h
new file mode 100644
index 000000000000..2ee97e9877a7
--- /dev/null
+++ b/include/linux/of_gpio.h
@@ -0,0 +1,69 @@
+/*
+ * 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/errno.h>
+#include <asm/gpio.h>
+
+#ifdef CONFIG_OF_GPIO
+
+/*
+ * Generic OF GPIO chip
+ */
+struct of_gpio_chip {
+        struct gpio_chip gc;
+        int gpio_cells;
+        int (*xlate)(struct of_gpio_chip *of_gc, struct device_node *np,
+                     const void *gpio_spec);
+};
+
+static inline struct of_gpio_chip *to_of_gpio_chip(struct gpio_chip *gc)
+{
+        return container_of(gc, struct of_gpio_chip, gc);
+}
+
+/*
+ * OF GPIO chip for memory mapped banks
+ */
+struct of_mm_gpio_chip {
+        struct of_gpio_chip of_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)
+{
+        struct of_gpio_chip *of_gc = to_of_gpio_chip(gc);
+
+        return container_of(of_gc, struct of_mm_gpio_chip, of_gc);
+}
+
+extern int of_get_gpio(struct device_node *np, int index);
+extern int of_mm_gpiochip_add(struct device_node *np,
+                              struct of_mm_gpio_chip *mm_gc);
+extern int of_gpio_simple_xlate(struct of_gpio_chip *of_gc,
+                                struct device_node *np,
+                                const void *gpio_spec);
+#else
+
+/* Drivers may not strictly depend on the GPIO support, so let them link. */
+static inline int of_get_gpio(struct device_node *np, int index)
+{
+        return -ENOSYS;
+}
+
+#endif /* CONFIG_OF_GPIO */
+
+#endif /* __LINUX_OF_GPIO_H */