linux/arch/mips/bcm63xx/gpio.c
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   1/*
   2 * This file is subject to the terms and conditions of the GNU General Public
   3 * License.  See the file "COPYING" in the main directory of this archive
   4 * for more details.
   5 *
   6 * Copyright (C) 2008 Maxime Bizon <mbizon@freebox.fr>
   7 * Copyright (C) 2008 Florian Fainelli <florian@openwrt.org>
   8 */
   9
  10#include <linux/kernel.h>
  11#include <linux/module.h>
  12#include <linux/spinlock.h>
  13#include <linux/platform_device.h>
  14#include <linux/gpio.h>
  15
  16#include <bcm63xx_cpu.h>
  17#include <bcm63xx_gpio.h>
  18#include <bcm63xx_io.h>
  19#include <bcm63xx_regs.h>
  20
  21static DEFINE_SPINLOCK(bcm63xx_gpio_lock);
  22static u32 gpio_out_low, gpio_out_high;
  23
  24static void bcm63xx_gpio_set(struct gpio_chip *chip,
  25                             unsigned gpio, int val)
  26{
  27        u32 reg;
  28        u32 mask;
  29        u32 *v;
  30        unsigned long flags;
  31
  32        if (gpio >= chip->ngpio)
  33                BUG();
  34
  35        if (gpio < 32) {
  36                reg = GPIO_DATA_LO_REG;
  37                mask = 1 << gpio;
  38                v = &gpio_out_low;
  39        } else {
  40                reg = GPIO_DATA_HI_REG;
  41                mask = 1 << (gpio - 32);
  42                v = &gpio_out_high;
  43        }
  44
  45        spin_lock_irqsave(&bcm63xx_gpio_lock, flags);
  46        if (val)
  47                *v |= mask;
  48        else
  49                *v &= ~mask;
  50        bcm_gpio_writel(*v, reg);
  51        spin_unlock_irqrestore(&bcm63xx_gpio_lock, flags);
  52}
  53
  54static int bcm63xx_gpio_get(struct gpio_chip *chip, unsigned gpio)
  55{
  56        u32 reg;
  57        u32 mask;
  58
  59        if (gpio >= chip->ngpio)
  60                BUG();
  61
  62        if (gpio < 32) {
  63                reg = GPIO_DATA_LO_REG;
  64                mask = 1 << gpio;
  65        } else {
  66                reg = GPIO_DATA_HI_REG;
  67                mask = 1 << (gpio - 32);
  68        }
  69
  70        return !!(bcm_gpio_readl(reg) & mask);
  71}
  72
  73static int bcm63xx_gpio_set_direction(struct gpio_chip *chip,
  74                                      unsigned gpio, int dir)
  75{
  76        u32 reg;
  77        u32 mask;
  78        u32 tmp;
  79        unsigned long flags;
  80
  81        if (gpio >= chip->ngpio)
  82                BUG();
  83
  84        if (gpio < 32) {
  85                reg = GPIO_CTL_LO_REG;
  86                mask = 1 << gpio;
  87        } else {
  88                reg = GPIO_CTL_HI_REG;
  89                mask = 1 << (gpio - 32);
  90        }
  91
  92        spin_lock_irqsave(&bcm63xx_gpio_lock, flags);
  93        tmp = bcm_gpio_readl(reg);
  94        if (dir == GPIO_DIR_IN)
  95                tmp &= ~mask;
  96        else
  97                tmp |= mask;
  98        bcm_gpio_writel(tmp, reg);
  99        spin_unlock_irqrestore(&bcm63xx_gpio_lock, flags);
 100
 101        return 0;
 102}
 103
 104static int bcm63xx_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
 105{
 106        return bcm63xx_gpio_set_direction(chip, gpio, GPIO_DIR_IN);
 107}
 108
 109static int bcm63xx_gpio_direction_output(struct gpio_chip *chip,
 110                                         unsigned gpio, int value)
 111{
 112        bcm63xx_gpio_set(chip, gpio, value);
 113        return bcm63xx_gpio_set_direction(chip, gpio, GPIO_DIR_OUT);
 114}
 115
 116
 117static struct gpio_chip bcm63xx_gpio_chip = {
 118        .label                  = "bcm63xx-gpio",
 119        .direction_input        = bcm63xx_gpio_direction_input,
 120        .direction_output       = bcm63xx_gpio_direction_output,
 121        .get                    = bcm63xx_gpio_get,
 122        .set                    = bcm63xx_gpio_set,
 123        .base                   = 0,
 124};
 125
 126int __init bcm63xx_gpio_init(void)
 127{
 128        bcm63xx_gpio_chip.ngpio = bcm63xx_gpio_count();
 129        pr_info("registering %d GPIOs\n", bcm63xx_gpio_chip.ngpio);
 130
 131        return gpiochip_add(&bcm63xx_gpio_chip);
 132}
 133
 134arch_initcall(bcm63xx_gpio_init);
 135