ead53f22dc
None of the files touched here are modules, and they are not exporting any symbols either -- so there is no need to be including the module.h. Builds of all the files remains successful. Even kernel/module.c does not need to include it, since it includes linux/moduleloader.h instead. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
152 lines
3.2 KiB
C
152 lines
3.2 KiB
C
/*
|
|
* 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.
|
|
*/
|
|
|
|
#include <linux/init.h>
|
|
#include <linux/kernel.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 <linux/slab.h>
|
|
#include <asm/prom.h>
|
|
#include "simple_gpio.h"
|
|
|
|
struct u8_gpio_chip {
|
|
struct of_mm_gpio_chip mm_gc;
|
|
spinlock_t lock;
|
|
|
|
/* shadowed data register to clear/set bits safely */
|
|
u8 data;
|
|
};
|
|
|
|
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);
|
|
}
|
|
|
|
static u8 u8_pin2mask(unsigned int pin)
|
|
{
|
|
return 1 << (8 - 1 - pin);
|
|
}
|
|
|
|
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);
|
|
|
|
return in_8(mm_gc->regs) & u8_pin2mask(gpio);
|
|
}
|
|
|
|
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;
|
|
|
|
spin_lock_irqsave(&u8_gc->lock, flags);
|
|
|
|
if (val)
|
|
u8_gc->data |= u8_pin2mask(gpio);
|
|
else
|
|
u8_gc->data &= ~u8_pin2mask(gpio);
|
|
|
|
out_8(mm_gc->regs, u8_gc->data);
|
|
|
|
spin_unlock_irqrestore(&u8_gc->lock, flags);
|
|
}
|
|
|
|
static int u8_gpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static int u8_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
|
|
{
|
|
u8_gpio_set(gc, gpio, val);
|
|
return 0;
|
|
}
|
|
|
|
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);
|
|
|
|
u8_gc->data = in_8(mm_gc->regs);
|
|
}
|
|
|
|
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 gpio_chip *gc;
|
|
|
|
u8_gc = kzalloc(sizeof(*u8_gc), GFP_KERNEL);
|
|
if (!u8_gc)
|
|
return -ENOMEM;
|
|
|
|
spin_lock_init(&u8_gc->lock);
|
|
|
|
mm_gc = &u8_gc->mm_gc;
|
|
gc = &mm_gc->gc;
|
|
|
|
mm_gc->save_regs = u8_gpio_save_regs;
|
|
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;
|
|
|
|
ret = of_mm_gpiochip_add(np, mm_gc);
|
|
if (ret)
|
|
goto err;
|
|
return 0;
|
|
err:
|
|
kfree(u8_gc);
|
|
return ret;
|
|
}
|
|
|
|
void __init simple_gpiochip_init(const char *compatible)
|
|
{
|
|
struct device_node *np;
|
|
|
|
for_each_compatible_node(np, NULL, compatible) {
|
|
int ret;
|
|
struct resource r;
|
|
|
|
ret = of_address_to_resource(np, 0, &r);
|
|
if (ret)
|
|
goto err;
|
|
|
|
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);
|
|
}
|
|
}
|