mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson
synced 2025-10-31 03:13:59 +00:00
391c970c0d
Implement generic OF gpio hooks and thus make device-enabled GPIO chips (i.e. the ones that have gpio_chip->dev specified) automatically attach to the OpenFirmware subsystem. Which means that now we can handle I2C and SPI GPIO chips almost* transparently. * "Almost" because some chips still require platform data, and for these chips OF-glue is still needed, though with this change the glue will be much smaller. Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca> Cc: David Brownell <dbrownell@users.sourceforge.net> Cc: Bill Gatliff <bgat@billgatliff.com> Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Jean Delvare <khali@linux-fr.org> Cc: Andrew Morton <akpm@linux-foundation.org> CC: linux-kernel@vger.kernel.org CC: devicetree-discuss@lists.ozlabs.org
93 lines
2.4 KiB
C
93 lines
2.4 KiB
C
/*
|
|
* 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>
|
|
|
|
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_gpio_flags(struct device_node *np, int index,
|
|
enum of_gpio_flags *flags);
|
|
extern unsigned int of_gpio_count(struct device_node *np);
|
|
|
|
extern int of_mm_gpiochip_add(struct device_node *np,
|
|
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 struct gpio_chip *of_node_to_gpiochip(struct device_node *np);
|
|
|
|
#else /* CONFIG_OF_GPIO */
|
|
|
|
/* Drivers may not strictly depend on the GPIO support, so let them link. */
|
|
static inline int of_get_gpio_flags(struct device_node *np, int index,
|
|
enum of_gpio_flags *flags)
|
|
{
|
|
return -ENOSYS;
|
|
}
|
|
|
|
static inline unsigned int of_gpio_count(struct device_node *np)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
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_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 */
|