MIPS: ath79: add GPIOLIB support

This patch implements generic GPIO routines for the built-in
GPIO controllers of the Atheros AR71XX/AR724X/AR913X SoCs.

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: Imre Kaloz <kaloz@openwrt.org>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: linux-mips@linux-mips.org
Cc: Luis R. Rodriguez <lrodriguez@atheros.com>
Cc: Cliff Holden <Cliff.Holden@Atheros.com>
Cc: Kathy Giori <Kathy.Giori@Atheros.com>
Patchwork: https://patchwork.linux-mips.org/patch/1948/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 197 insertions, 0 deletions

diff --git a/arch/mips/ath79/gpio.c b/arch/mips/ath79/gpio.c
new file mode 100644
index 000000000000..a0c426b82123
--- /dev/null
+++ b/arch/mips/ath79/gpio.c
@@ -0,0 +1,197 @@
+/*
+ *  Atheros AR71XX/AR724X/AR913X GPIO API support
+ *
+ *  Copyright (C) 2008-2010 Gabor Juhos <juhosg@openwrt.org>
+ *  Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org>
+ *
+ *  This program is free software; you can redistribute it and/or modify it
+ *  under the terms of the GNU General Public License version 2 as published
+ *  by the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/spinlock.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/gpio.h>
+
+#include <asm/mach-ath79/ar71xx_regs.h>
+#include <asm/mach-ath79/ath79.h>
+#include "common.h"
+
+static void __iomem *ath79_gpio_base;
+static unsigned long ath79_gpio_count;
+static DEFINE_SPINLOCK(ath79_gpio_lock);
+
+static void __ath79_gpio_set_value(unsigned gpio, int value)
+{
+        void __iomem *base = ath79_gpio_base;
+
+        if (value)
+                __raw_writel(1 << gpio, base + AR71XX_GPIO_REG_SET);
+        else
+                __raw_writel(1 << gpio, base + AR71XX_GPIO_REG_CLEAR);
+}
+
+static int __ath79_gpio_get_value(unsigned gpio)
+{
+        return (__raw_readl(ath79_gpio_base + AR71XX_GPIO_REG_IN) >> gpio) & 1;
+}
+
+static int ath79_gpio_get_value(struct gpio_chip *chip, unsigned offset)
+{
+        return __ath79_gpio_get_value(offset);
+}
+
+static void ath79_gpio_set_value(struct gpio_chip *chip,
+                                  unsigned offset, int value)
+{
+        __ath79_gpio_set_value(offset, value);
+}
+
+static int ath79_gpio_direction_input(struct gpio_chip *chip,
+                                       unsigned offset)
+{
+        void __iomem *base = ath79_gpio_base;
+        unsigned long flags;
+
+        spin_lock_irqsave(&ath79_gpio_lock, flags);
+
+        __raw_writel(__raw_readl(base + AR71XX_GPIO_REG_OE) & ~(1 << offset),
+                     base + AR71XX_GPIO_REG_OE);
+
+        spin_unlock_irqrestore(&ath79_gpio_lock, flags);
+
+        return 0;
+}
+
+static int ath79_gpio_direction_output(struct gpio_chip *chip,
+                                        unsigned offset, int value)
+{
+        void __iomem *base = ath79_gpio_base;
+        unsigned long flags;
+
+        spin_lock_irqsave(&ath79_gpio_lock, flags);
+
+        if (value)
+                __raw_writel(1 << offset, base + AR71XX_GPIO_REG_SET);
+        else
+                __raw_writel(1 << offset, base + AR71XX_GPIO_REG_CLEAR);
+
+        __raw_writel(__raw_readl(base + AR71XX_GPIO_REG_OE) | (1 << offset),
+                     base + AR71XX_GPIO_REG_OE);
+
+        spin_unlock_irqrestore(&ath79_gpio_lock, flags);
+
+        return 0;
+}
+
+static struct gpio_chip ath79_gpio_chip = {
+        .label                  = "ath79",
+        .get                    = ath79_gpio_get_value,
+        .set                    = ath79_gpio_set_value,
+        .direction_input        = ath79_gpio_direction_input,
+        .direction_output       = ath79_gpio_direction_output,
+        .base                   = 0,
+};
+
+void ath79_gpio_function_enable(u32 mask)
+{
+        void __iomem *base = ath79_gpio_base;
+        unsigned long flags;
+
+        spin_lock_irqsave(&ath79_gpio_lock, flags);
+
+        __raw_writel(__raw_readl(base + AR71XX_GPIO_REG_FUNC) | mask,
+                     base + AR71XX_GPIO_REG_FUNC);
+        /* flush write */
+        __raw_readl(base + AR71XX_GPIO_REG_FUNC);
+
+        spin_unlock_irqrestore(&ath79_gpio_lock, flags);
+}
+
+void ath79_gpio_function_disable(u32 mask)
+{
+        void __iomem *base = ath79_gpio_base;
+        unsigned long flags;
+
+        spin_lock_irqsave(&ath79_gpio_lock, flags);
+
+        __raw_writel(__raw_readl(base + AR71XX_GPIO_REG_FUNC) & ~mask,
+                     base + AR71XX_GPIO_REG_FUNC);
+        /* flush write */
+        __raw_readl(base + AR71XX_GPIO_REG_FUNC);
+
+        spin_unlock_irqrestore(&ath79_gpio_lock, flags);
+}
+
+void ath79_gpio_function_setup(u32 set, u32 clear)
+{
+        void __iomem *base = ath79_gpio_base;
+        unsigned long flags;
+
+        spin_lock_irqsave(&ath79_gpio_lock, flags);
+
+        __raw_writel((__raw_readl(base + AR71XX_GPIO_REG_FUNC) & ~clear) | set,
+                     base + AR71XX_GPIO_REG_FUNC);
+        /* flush write */
+        __raw_readl(base + AR71XX_GPIO_REG_FUNC);
+
+        spin_unlock_irqrestore(&ath79_gpio_lock, flags);
+}
+
+void __init ath79_gpio_init(void)
+{
+        int err;
+
+        if (soc_is_ar71xx())
+                ath79_gpio_count = AR71XX_GPIO_COUNT;
+        else if (soc_is_ar724x())
+                ath79_gpio_count = AR724X_GPIO_COUNT;
+        else if (soc_is_ar913x())
+                ath79_gpio_count = AR913X_GPIO_COUNT;
+        else
+                BUG();
+
+        ath79_gpio_base = ioremap_nocache(AR71XX_GPIO_BASE, AR71XX_GPIO_SIZE);
+        ath79_gpio_chip.ngpio = ath79_gpio_count;
+
+        err = gpiochip_add(&ath79_gpio_chip);
+        if (err)
+                panic("cannot add AR71xx GPIO chip, error=%d", err);
+}
+
+int gpio_get_value(unsigned gpio)
+{
+        if (gpio < ath79_gpio_count)
+                return __ath79_gpio_get_value(gpio);
+
+        return __gpio_get_value(gpio);
+}
+EXPORT_SYMBOL(gpio_get_value);
+
+void gpio_set_value(unsigned gpio, int value)
+{
+        if (gpio < ath79_gpio_count)
+                __ath79_gpio_set_value(gpio, value);
+        else
+                __gpio_set_value(gpio, value);
+}
+EXPORT_SYMBOL(gpio_set_value);
+
+int gpio_to_irq(unsigned gpio)
+{
+        /* FIXME */
+        return -EINVAL;
+}
+EXPORT_SYMBOL(gpio_to_irq);
+
+int irq_to_gpio(unsigned irq)
+{
+        /* FIXME */
+        return -EINVAL;
+}
+EXPORT_SYMBOL(irq_to_gpio);