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yaml --- r: 127650 b: refs/heads/master c: 3d64de9 h: refs/heads/master v: v3
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Anton Vorontsov
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Kumar Gala
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Dec 30, 2008
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--- | ||
refs/heads/master: 94409d6e1088517b6d6c8e669c604cc86d08ac1b | ||
refs/heads/master: 3d64de9c50619d32eb71d993d23a50b98d12d3c0 |
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/* | ||
* Simple Memory-Mapped GPIOs | ||
* | ||
* Copyright (c) MontaVista Software, Inc. 2008. | ||
* | ||
* 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. | ||
*/ | ||
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#include <linux/init.h> | ||
#include <linux/kernel.h> | ||
#include <linux/module.h> | ||
#include <linux/spinlock.h> | ||
#include <linux/types.h> | ||
#include <linux/ioport.h> | ||
#include <linux/io.h> | ||
#include <linux/of.h> | ||
#include <linux/of_gpio.h> | ||
#include <linux/gpio.h> | ||
#include <asm/prom.h> | ||
#include "simple_gpio.h" | ||
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struct u8_gpio_chip { | ||
struct of_mm_gpio_chip mm_gc; | ||
spinlock_t lock; | ||
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/* shadowed data register to clear/set bits safely */ | ||
u8 data; | ||
}; | ||
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static struct u8_gpio_chip *to_u8_gpio_chip(struct of_mm_gpio_chip *mm_gc) | ||
{ | ||
return container_of(mm_gc, struct u8_gpio_chip, mm_gc); | ||
} | ||
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static u8 u8_pin2mask(unsigned int pin) | ||
{ | ||
return 1 << (8 - 1 - pin); | ||
} | ||
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static int u8_gpio_get(struct gpio_chip *gc, unsigned int gpio) | ||
{ | ||
struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc); | ||
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return in_8(mm_gc->regs) & u8_pin2mask(gpio); | ||
} | ||
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static void u8_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val) | ||
{ | ||
struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc); | ||
struct u8_gpio_chip *u8_gc = to_u8_gpio_chip(mm_gc); | ||
unsigned long flags; | ||
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spin_lock_irqsave(&u8_gc->lock, flags); | ||
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if (val) | ||
u8_gc->data |= u8_pin2mask(gpio); | ||
else | ||
u8_gc->data &= ~u8_pin2mask(gpio); | ||
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out_8(mm_gc->regs, u8_gc->data); | ||
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spin_unlock_irqrestore(&u8_gc->lock, flags); | ||
} | ||
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static int u8_gpio_dir_in(struct gpio_chip *gc, unsigned int gpio) | ||
{ | ||
return 0; | ||
} | ||
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static int u8_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val) | ||
{ | ||
u8_gpio_set(gc, gpio, val); | ||
return 0; | ||
} | ||
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static void u8_gpio_save_regs(struct of_mm_gpio_chip *mm_gc) | ||
{ | ||
struct u8_gpio_chip *u8_gc = to_u8_gpio_chip(mm_gc); | ||
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u8_gc->data = in_8(mm_gc->regs); | ||
} | ||
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static int __init u8_simple_gpiochip_add(struct device_node *np) | ||
{ | ||
int ret; | ||
struct u8_gpio_chip *u8_gc; | ||
struct of_mm_gpio_chip *mm_gc; | ||
struct of_gpio_chip *of_gc; | ||
struct gpio_chip *gc; | ||
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u8_gc = kzalloc(sizeof(*u8_gc), GFP_KERNEL); | ||
if (!u8_gc) | ||
return -ENOMEM; | ||
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spin_lock_init(&u8_gc->lock); | ||
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mm_gc = &u8_gc->mm_gc; | ||
of_gc = &mm_gc->of_gc; | ||
gc = &of_gc->gc; | ||
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mm_gc->save_regs = u8_gpio_save_regs; | ||
of_gc->gpio_cells = 2; | ||
gc->ngpio = 8; | ||
gc->direction_input = u8_gpio_dir_in; | ||
gc->direction_output = u8_gpio_dir_out; | ||
gc->get = u8_gpio_get; | ||
gc->set = u8_gpio_set; | ||
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ret = of_mm_gpiochip_add(np, mm_gc); | ||
if (ret) | ||
goto err; | ||
return 0; | ||
err: | ||
kfree(u8_gc); | ||
return ret; | ||
} | ||
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void __init simple_gpiochip_init(const char *compatible) | ||
{ | ||
struct device_node *np; | ||
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for_each_compatible_node(np, NULL, compatible) { | ||
int ret; | ||
struct resource r; | ||
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ret = of_address_to_resource(np, 0, &r); | ||
if (ret) | ||
goto err; | ||
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switch (resource_size(&r)) { | ||
case 1: | ||
ret = u8_simple_gpiochip_add(np); | ||
if (ret) | ||
goto err; | ||
break; | ||
default: | ||
/* | ||
* Whenever you need support for GPIO bank width > 1, | ||
* please just turn u8_ code into huge macros, and | ||
* construct needed uX_ code with it. | ||
*/ | ||
ret = -ENOSYS; | ||
goto err; | ||
} | ||
continue; | ||
err: | ||
pr_err("%s: registration failed, status %d\n", | ||
np->full_name, ret); | ||
} | ||
} |
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#ifndef __SYSDEV_SIMPLE_GPIO_H | ||
#define __SYSDEV_SIMPLE_GPIO_H | ||
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#include <linux/errno.h> | ||
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#ifdef CONFIG_SIMPLE_GPIO | ||
extern void simple_gpiochip_init(const char *compatible); | ||
#else | ||
static inline void simple_gpiochip_init(const char *compatible) {} | ||
#endif /* CONFIG_SIMPLE_GPIO */ | ||
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#endif /* __SYSDEV_SIMPLE_GPIO_H */ |