[MIPS] generic txx9 gpio support

This is a board-independent TXx9 gpio API implementation using gpiolib.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

2 files changed, 89 insertions, 0 deletions

diff --git a/arch/mips/kernel/Makefile b/arch/mips/kernel/Makefile
index d0ca4d41bb7..87067e8fee9 100644
--- a/arch/mips/kernel/Makefile
+++ b/arch/mips/kernel/Makefile
@@ -81,6 +81,8 @@ obj-$(CONFIG_64BIT)		+= cpu-bugs64.o
 
 obj-$(CONFIG_I8253)		+= i8253.o
 
+obj-$(CONFIG_GPIO_TXX9)		+= gpio_txx9.o
+
 obj-$(CONFIG_KEXEC)		+= machine_kexec.o relocate_kernel.o
 obj-$(CONFIG_EARLY_PRINTK)	+= early_printk.o
 
diff --git a/arch/mips/kernel/gpio_txx9.c b/arch/mips/kernel/gpio_txx9.c
new file mode 100644
index 00000000000..b1436a85799
--- /dev/null
+++ b/arch/mips/kernel/gpio_txx9.c
@@ -0,0 +1,87 @@
+/*
+ * A gpio chip driver for TXx9 SoCs
+ *
+ * Copyright (C) 2008 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
+ *
+ * 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/init.h>
+#include <linux/spinlock.h>
+#include <linux/gpio.h>
+#include <linux/errno.h>
+#include <linux/io.h>
+#include <asm/txx9pio.h>
+
+static DEFINE_SPINLOCK(txx9_gpio_lock);
+
+static struct txx9_pio_reg __iomem *txx9_pioptr;
+
+static int txx9_gpio_get(struct gpio_chip *chip, unsigned int offset)
+{
+	return __raw_readl(&txx9_pioptr->din) & (1 << offset);
+}
+
+static void txx9_gpio_set_raw(unsigned int offset, int value)
+{
+	u32 val;
+	val = __raw_readl(&txx9_pioptr->dout);
+	if (value)
+		val |= 1 << offset;
+	else
+		val &= ~(1 << offset);
+	__raw_writel(val, &txx9_pioptr->dout);
+}
+
+static void txx9_gpio_set(struct gpio_chip *chip, unsigned int offset,
+			  int value)
+{
+	unsigned long flags;
+	spin_lock_irqsave(&txx9_gpio_lock, flags);
+	txx9_gpio_set_raw(offset, value);
+	mmiowb();
+	spin_unlock_irqrestore(&txx9_gpio_lock, flags);
+}
+
+static int txx9_gpio_dir_in(struct gpio_chip *chip, unsigned int offset)
+{
+	spin_lock_irq(&txx9_gpio_lock);
+	__raw_writel(__raw_readl(&txx9_pioptr->dir) & ~(1 << offset),
+		     &txx9_pioptr->dir);
+	mmiowb();
+	spin_unlock_irq(&txx9_gpio_lock);
+	return 0;
+}
+
+static int txx9_gpio_dir_out(struct gpio_chip *chip, unsigned int offset,
+			     int value)
+{
+	spin_lock_irq(&txx9_gpio_lock);
+	txx9_gpio_set_raw(offset, value);
+	__raw_writel(__raw_readl(&txx9_pioptr->dir) | (1 << offset),
+		     &txx9_pioptr->dir);
+	mmiowb();
+	spin_unlock_irq(&txx9_gpio_lock);
+	return 0;
+}
+
+static struct gpio_chip txx9_gpio_chip = {
+	.get = txx9_gpio_get,
+	.set = txx9_gpio_set,
+	.direction_input = txx9_gpio_dir_in,
+	.direction_output = txx9_gpio_dir_out,
+	.label = "TXx9",
+};
+
+int __init txx9_gpio_init(unsigned long baseaddr,
+			  unsigned int base, unsigned int num)
+{
+	txx9_pioptr = ioremap(baseaddr, sizeof(struct txx9_pio_reg));
+	if (!txx9_pioptr)
+		return -ENODEV;
+	txx9_gpio_chip.base = base;
+	txx9_gpio_chip.ngpio = num;
+	return gpiochip_add(&txx9_gpio_chip);
+}