release/src-rt-6.x.4708/linux/linux-2.6.36/arch/mips/bcm63xx/gpio.c

   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
  21 static DEFINE_SPINLOCK(bcm63xx_gpio_lock);
  22 static u32 gpio_out_low, gpio_out_high;
  23
  24 static 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
  54 static 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
  73 static 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 == BCM63XX_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
 104 static int bcm63xx_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
 105 {
 106         return bcm63xx_gpio_set_direction(chip, gpio, BCM63XX_GPIO_DIR_IN);
 107 }
 108
 109 static 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, BCM63XX_GPIO_DIR_OUT);
 114 }
 115
 116
 117 static 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
 126 int __init bcm63xx_gpio_init(void)
 127 {
 128         gpio_out_low = bcm_gpio_readl(GPIO_DATA_LO_REG);
 129         gpio_out_high = bcm_gpio_readl(GPIO_DATA_HI_REG);
 130         bcm63xx_gpio_chip.ngpio = bcm63xx_gpio_count();
 131         pr_info("registering %d GPIOs\n", bcm63xx_gpio_chip.ngpio);
 132
 133         return gpiochip_add(&bcm63xx_gpio_chip);
 134 }