This patch implements GPIO API as described in Documentation/gpio.txt.
Two calls unimplemented though: irq_to_gpio and gpio_to_irq.
This patch also provides OF helpers.
Signed-off-by: Anton Vorontsov <[EMAIL PROTECTED]>
---
arch/powerpc/Kconfig | 3 ++
arch/powerpc/kernel/prom_parse.c | 64 ++++++++++++++++++++++++++++++++++++++
include/asm-powerpc/gpio.h | 47 ++++++++++++++++++++++++++++
include/asm-powerpc/prom.h | 23 +++++++++++++
4 files changed, 137 insertions(+), 0 deletions(-)
create mode 100644 include/asm-powerpc/gpio.h
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 232c298..a4fa173 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -73,6 +73,9 @@ config GENERIC_FIND_NEXT_BIT
bool
default y
+config GENERIC_GPIO
+ bool
+
config ARCH_NO_VIRT_TO_BUS
def_bool PPC64
diff --git a/arch/powerpc/kernel/prom_parse.c b/arch/powerpc/kernel/prom_parse.c
index 90eb3a3..9875598 100644
--- a/arch/powerpc/kernel/prom_parse.c
+++ b/arch/powerpc/kernel/prom_parse.c
@@ -7,6 +7,7 @@
#include <linux/ioport.h>
#include <linux/etherdevice.h>
#include <asm/prom.h>
+#include <asm/gpio.h>
#include <asm/pci-bridge.h>
#ifdef DEBUG
@@ -1079,3 +1080,66 @@ void __iomem *of_iomap(struct device_node *np, int index)
return ioremap(res.start, 1 + res.end - res.start);
}
EXPORT_SYMBOL(of_iomap);
+
+int __of_parse_gpio_bank_pin(struct device_node *np, int index,
+ int bank_width, int max_bank)
+{
+ int bank;
+ int pin;
+ const u32 *gpios;
+
+ /*
+ * We can get there only if of_get_gpio() succeeded, thus
+ * no need checking for "gpios" existence.
+ */
+ gpios = of_get_property(np, "gpios", NULL);
+ bank = gpios[index * 2];
+ pin = gpios[index * 2 + 1];
+
+ if (bank >= max_bank || pin >= bank_width)
+ return -EINVAL;
+
+ return bank * bank_width + pin;
+}
+EXPORT_SYMBOL_GPL(__of_parse_gpio_bank_pin);
+
+int of_get_gpio(struct device_node *np, int index)
+{
+ int ret = -EINVAL;
+ const phandle *gc_ph;
+ struct device_node *gc;
+ struct of_gpio_chip *of_gpio_chip;
+ int size;
+ const u32 *gpio_cells;
+ const u32 *gpios;
+ u32 nr_cells;
+
+ gc_ph = of_get_property(np, "gpio-parent", NULL);
+ if (!gc_ph)
+ return ret;
+
+ gc = of_find_node_by_phandle(*gc_ph);
+ if (!gc || !gc->data)
+ return ret;
+
+ gpio_cells = of_get_property(gc, "#gpio-cells", &size);
+ if (!gpio_cells || size != sizeof(*gpio_cells) || *gpio_cells == 0)
+ goto err;
+
+ gpios = of_get_property(np, "gpios", &size);
+ if (!gpios)
+ goto err;
+ nr_cells = size / sizeof(u32);
+
+ if (nr_cells < *gpio_cells || nr_cells % *gpio_cells ||
+ index > nr_cells / *gpio_cells - 1)
+ goto err;
+
+ of_gpio_chip = gc->data;
+
+ ret = of_gpio_chip->xlate(np, index);
+err:
+ of_node_put(gc);
+ return ret;
+}
+EXPORT_SYMBOL(of_get_gpio);
diff --git a/include/asm-powerpc/gpio.h b/include/asm-powerpc/gpio.h
new file mode 100644
index 0000000..e0a4f85
--- /dev/null
+++ b/include/asm-powerpc/gpio.h
@@ -0,0 +1,47 @@
+/*
+ * Generic GPIO API implementation for PowerPC.
+ *
+ * Copyright (c) 2007 MontaVista Software, Inc.
+ * Copyright (c) 2007 Anton Vorontsov <[EMAIL PROTECTED]>
+ *
+ * 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 __ASM_POWERPC_GPIO_H
+#define __ASM_POWERPC_GPIO_H
+
+extern int gpio_request(unsigned int gpio, const char *label);
+static inline void gpio_free(unsigned int gpio) {}
+
+extern int gpio_direction_input(unsigned int gpio);
+extern int gpio_direction_output(unsigned int gpio, int value);
+
+extern int gpio_get_value(unsigned int gpio);
+extern int gpio_set_value(unsigned int gpio, int value);
+
+/*
+ * Not implemented, yet.
+ */
+static inline int gpio_to_irq(unsigned int gpio)
+{
+ return -ENOSYS;
+}
+
+static inline int irq_to_gpio(unsigned int irq)
+{
+ return -ENOSYS;
+}
+
+/*
+ * OF specific gpio_chip handler.
+ */
+struct of_gpio_chip {
+ int (*xlate)(struct device_node *np, int index);
+};
+
+#include <asm-generic/gpio.h>
+
+#endif /* __ASM_POWERPC_GPIO_H */
diff --git a/include/asm-powerpc/prom.h b/include/asm-powerpc/prom.h
index 78b7b0d..f882efc 100644
--- a/include/asm-powerpc/prom.h
+++ b/include/asm-powerpc/prom.h
@@ -330,6 +330,29 @@ extern int of_irq_to_resource(struct device_node *dev, int
index,
*/
extern void __iomem *of_iomap(struct device_node *device, int index);
+/**
+ * __of_parse_gpio_bank_pin - Helper function to translate "bank pin" GPIOs
+ * @np: device node to get GPIO from
+ * @index: index of the GPIO
+ * @bank_width: pins per bank
+ * @max_bank: maximum value to represent a bank
+ *
+ * Returns GPIO number to use with Linux generic GPIO api, or
+ * one of the errno value on the error condition.
+ */
+extern int __of_parse_gpio_bank_pin(struct device_node *np, int index,
+ int bank_width, int max_bank);
+
+/**
+ * of_get_gpio - Translate GPIO number given in the device tree
+ * @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.
+ */
+extern int of_get_gpio(struct device_node *np, int index);
+
/*
* NB: This is here while we transition from using asm/prom.h
* to linux/of.h
--
1.5.2.2
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