MIPS: AR7: Implement gpiolib

[safe/jmp/linux-2.6] / arch / mips / ar7 / gpio.c

diff --git a/arch/mips/ar7/gpio.c b/arch/mips/ar7/gpio.c
index 74e14a3..0e9f4e1 100644 (file)
--- a/arch/mips/ar7/gpio.c
+++ b/arch/mips/ar7/gpio.c
@@ -1,6 +1,7 @@
 /*
  * Copyright (C) 2007 Felix Fietkau <nbd@openwrt.org>
  * Copyright (C) 2007 Eugene Konev <ejka@openwrt.org>
+ * Copyright (C) 2009 Florian Fainelli <florian@openwrt.org>
  *
  * 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
@@ -18,31 +19,113 @@
  */
 
 #include <linux/module.h>
+#include <linux/gpio.h>
 
 #include <asm/mach-ar7/gpio.h>
 
-static const char *ar7_gpio_list[AR7_GPIO_MAX];
+struct ar7_gpio_chip {
+       void __iomem    *regs;
+       struct gpio_chip chip;
+};
 
-int gpio_request(unsigned gpio, const char *label)
+static int ar7_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
 {
-       if (gpio >= AR7_GPIO_MAX)
-               return -EINVAL;
+       struct ar7_gpio_chip *gpch =
+                               container_of(chip, struct ar7_gpio_chip, chip);
+       void __iomem *gpio_in = gpch->regs + AR7_GPIO_INPUT;
 
-       if (ar7_gpio_list[gpio])
-               return -EBUSY;
+       return readl(gpio_in) & (1 << gpio);
+}
+
+static void ar7_gpio_set_value(struct gpio_chip *chip,
+                               unsigned gpio, int value)
+{
+       struct ar7_gpio_chip *gpch =
+                               container_of(chip, struct ar7_gpio_chip, chip);
+       void __iomem *gpio_out = gpch->regs + AR7_GPIO_OUTPUT;
+       unsigned tmp;
+
+       tmp = readl(gpio_out) & ~(1 << gpio);
+       if (value)
+               tmp |= 1 << gpio;
+       writel(tmp, gpio_out);
+}
+
+static int ar7_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
+{
+       struct ar7_gpio_chip *gpch =
+                               container_of(chip, struct ar7_gpio_chip, chip);
+       void __iomem *gpio_dir = gpch->regs + AR7_GPIO_DIR;
 
-       if (label)
-               ar7_gpio_list[gpio] = label;
-       else
-               ar7_gpio_list[gpio] = "busy";
+       writel(readl(gpio_dir) | (1 << gpio), gpio_dir);
 
        return 0;
 }
-EXPORT_SYMBOL(gpio_request);
 
-void gpio_free(unsigned gpio)
+static int ar7_gpio_direction_output(struct gpio_chip *chip,
+                                       unsigned gpio, int value)
 {
-       BUG_ON(!ar7_gpio_list[gpio]);
-       ar7_gpio_list[gpio] = NULL;
+       struct ar7_gpio_chip *gpch =
+                               container_of(chip, struct ar7_gpio_chip, chip);
+       void __iomem *gpio_dir = gpch->regs + AR7_GPIO_DIR;
+
+       ar7_gpio_set_value(chip, gpio, value);
+       writel(readl(gpio_dir) & ~(1 << gpio), gpio_dir);
+
+       return 0;
+}
+
+static struct ar7_gpio_chip ar7_gpio_chip = {
+       .chip = {
+               .label          = "ar7-gpio",
+               .direction_input        = ar7_gpio_direction_input,
+               .direction_output       = ar7_gpio_direction_output,
+               .set                    = ar7_gpio_set_value,
+               .get                    = ar7_gpio_get_value,
+               .base                   = 0,
+               .ngpio                  = AR7_GPIO_MAX,
+       }
+};
+
+int ar7_gpio_enable(unsigned gpio)
+{
+       void __iomem *gpio_en = ar7_gpio_chip.regs + AR7_GPIO_ENABLE;
+
+       writel(readl(gpio_en) | (1 << gpio), gpio_en);
+
+       return 0;
+}
+EXPORT_SYMBOL(ar7_gpio_enable);
+
+int ar7_gpio_disable(unsigned gpio)
+{
+       void __iomem *gpio_en = ar7_gpio_chip.regs + AR7_GPIO_ENABLE;
+
+       writel(readl(gpio_en) & ~(1 << gpio), gpio_en);
+
+       return 0;
+}
+EXPORT_SYMBOL(ar7_gpio_disable);
+
+static int __init ar7_gpio_init(void)
+{
+       int ret;
+
+       ar7_gpio_chip.regs = ioremap_nocache(AR7_REGS_GPIO,
+                                       AR7_REGS_GPIO + 0x10);
+
+       if (!ar7_gpio_chip.regs) {
+               printk(KERN_ERR "ar7-gpio: failed to ioremap regs\n");
+               return -ENOMEM;
+       }
+
+       ret = gpiochip_add(&ar7_gpio_chip.chip);
+       if (ret) {
+               printk(KERN_ERR "ar7-gpio: failed to add gpiochip\n");
+               return ret;
+       }
+       printk(KERN_INFO "ar7-gpio: registered %d GPIOs\n",
+                               ar7_gpio_chip.chip.ngpio);
+       return ret;
 }
-EXPORT_SYMBOL(gpio_free);
+arch_initcall(ar7_gpio_init);