MIPS: AR7: Implement gpiolib

This patch implements gpiolib for the AR7 SoC.

Signed-off-by: Florian Fainelli <florian@openwrt.org>
To: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/816/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 98 insertions, 15 deletions

diff --git a/arch/mips/ar7/gpio.c b/arch/mips/ar7/gpio.c
index 74e14a3dbf4a..0e9f4e13f427 100644
--- 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);