[ARM] tegra: add GPIO support

v2: fixes from Mike Rapoport:
	- move gpio-names.h to arch/arm/mach-tegra
    fixes from Russell King
	- include linux/io.h and linux/gpio.h instead of asm/io.h
	  and asm/gpio.h
    additional changes:
    	- add macros to convert between irq and gpio numbers for platform data
	- change for_each_bit to for_each_set_bit in gpio.c
v3:
	- minor bugfixes

Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Erik Gilling <konkers@android.com>

1 files changed, 348 insertions, 0 deletions

diff --git a/arch/arm/mach-tegra/gpio.c b/arch/arm/mach-tegra/gpio.c
new file mode 100644
index 00000000000..fe78fba25f3
--- /dev/null
+++ b/arch/arm/mach-tegra/gpio.c
@@ -0,0 +1,348 @@
+/*
+ * arch/arm/mach-tegra/gpio.c
+ *
+ * Copyright (c) 2010 Google, Inc
+ *
+ * Author:
+ *	Erik Gilling <konkers@google.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/irq.h>
+
+#include <linux/io.h>
+#include <linux/gpio.h>
+
+#include <mach/iomap.h>
+
+#define GPIO_BANK(x)		((x) >> 5)
+#define GPIO_PORT(x)		(((x) >> 3) & 0x3)
+#define GPIO_BIT(x)		((x) & 0x7)
+
+#define GPIO_REG(x)		(IO_TO_VIRT(TEGRA_GPIO_BASE) +	\
+				 GPIO_BANK(x) * 0x80 +		\
+				 GPIO_PORT(x) * 4)
+
+#define GPIO_CNF(x)		(GPIO_REG(x) + 0x00)
+#define GPIO_OE(x)		(GPIO_REG(x) + 0x10)
+#define GPIO_OUT(x)		(GPIO_REG(x) + 0X20)
+#define GPIO_IN(x)		(GPIO_REG(x) + 0x30)
+#define GPIO_INT_STA(x)		(GPIO_REG(x) + 0x40)
+#define GPIO_INT_ENB(x)		(GPIO_REG(x) + 0x50)
+#define GPIO_INT_LVL(x)		(GPIO_REG(x) + 0x60)
+#define GPIO_INT_CLR(x)		(GPIO_REG(x) + 0x70)
+
+#define GPIO_MSK_CNF(x)		(GPIO_REG(x) + 0x800)
+#define GPIO_MSK_OE(x)		(GPIO_REG(x) + 0x810)
+#define GPIO_MSK_OUT(x)		(GPIO_REG(x) + 0X820)
+#define GPIO_MSK_INT_STA(x)	(GPIO_REG(x) + 0x840)
+#define GPIO_MSK_INT_ENB(x)	(GPIO_REG(x) + 0x850)
+#define GPIO_MSK_INT_LVL(x)	(GPIO_REG(x) + 0x860)
+
+#define GPIO_INT_LVL_MASK		0x010101
+#define GPIO_INT_LVL_EDGE_RISING	0x000101
+#define GPIO_INT_LVL_EDGE_FALLING	0x000100
+#define GPIO_INT_LVL_EDGE_BOTH		0x010100
+#define GPIO_INT_LVL_LEVEL_HIGH		0x000001
+#define GPIO_INT_LVL_LEVEL_LOW		0x000000
+
+struct tegra_gpio_bank {
+	int bank;
+	int irq;
+	spinlock_t lvl_lock[4];
+};
+
+
+static struct tegra_gpio_bank tegra_gpio_banks[] = {
+	{.bank = 0, .irq = INT_GPIO1},
+	{.bank = 1, .irq = INT_GPIO2},
+	{.bank = 2, .irq = INT_GPIO3},
+	{.bank = 3, .irq = INT_GPIO4},
+	{.bank = 4, .irq = INT_GPIO5},
+	{.bank = 5, .irq = INT_GPIO6},
+	{.bank = 6, .irq = INT_GPIO7},
+};
+
+static int tegra_gpio_compose(int bank, int port, int bit)
+{
+	return (bank << 5) | ((port & 0x3) << 3) | (bit & 0x7);
+}
+
+static void tegra_gpio_mask_write(u32 reg, int gpio, int value)
+{
+	u32 val;
+
+	val = 0x100 << GPIO_BIT(gpio);
+	if (value)
+		val |= 1 << GPIO_BIT(gpio);
+	__raw_writel(val, reg);
+}
+
+void tegra_gpio_enable(int gpio)
+{
+	tegra_gpio_mask_write(GPIO_MSK_CNF(gpio), gpio, 1);
+}
+
+void tegra_gpio_disable(int gpio)
+{
+	tegra_gpio_mask_write(GPIO_MSK_CNF(gpio), gpio, 0);
+}
+
+static void tegra_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+	tegra_gpio_mask_write(GPIO_MSK_OUT(offset), offset, value);
+}
+
+static int tegra_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+	return (__raw_readl(GPIO_IN(offset)) >> GPIO_BIT(offset)) & 0x1;
+}
+
+static int tegra_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
+{
+	tegra_gpio_mask_write(GPIO_MSK_OE(offset), offset, 0);
+	return 0;
+}
+
+static int tegra_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
+					int value)
+{
+	tegra_gpio_set(chip, offset, value);
+	tegra_gpio_mask_write(GPIO_MSK_OE(offset), offset, 1);
+	return 0;
+}
+
+
+
+static struct gpio_chip tegra_gpio_chip = {
+	.label			= "tegra-gpio",
+	.direction_input	= tegra_gpio_direction_input,
+	.get			= tegra_gpio_get,
+	.direction_output	= tegra_gpio_direction_output,
+	.set			= tegra_gpio_set,
+	.base			= 0,
+	.ngpio			= ARCH_NR_GPIOS,
+};
+
+static void tegra_gpio_irq_ack(unsigned int irq)
+{
+	int gpio = irq - INT_GPIO_BASE;
+
+	__raw_writel(1 << GPIO_BIT(gpio), GPIO_INT_CLR(gpio));
+}
+
+static void tegra_gpio_irq_mask(unsigned int irq)
+{
+	int gpio = irq - INT_GPIO_BASE;
+
+	tegra_gpio_mask_write(GPIO_MSK_INT_ENB(gpio), gpio, 0);
+}
+
+static void tegra_gpio_irq_unmask(unsigned int irq)
+{
+	int gpio = irq - INT_GPIO_BASE;
+
+	tegra_gpio_mask_write(GPIO_MSK_INT_ENB(gpio), gpio, 1);
+}
+
+static int tegra_gpio_irq_set_type(unsigned int irq, unsigned int type)
+{
+	int gpio = irq - INT_GPIO_BASE;
+	struct tegra_gpio_bank *bank = get_irq_chip_data(irq);
+	int port = GPIO_PORT(gpio);
+	int lvl_type;
+	int val;
+	unsigned long flags;
+
+	switch (type & IRQ_TYPE_SENSE_MASK) {
+	case IRQ_TYPE_EDGE_RISING:
+		lvl_type = GPIO_INT_LVL_EDGE_RISING;
+		break;
+
+	case IRQ_TYPE_EDGE_FALLING:
+		lvl_type = GPIO_INT_LVL_EDGE_FALLING;
+		break;
+
+	case IRQ_TYPE_EDGE_BOTH:
+		lvl_type = GPIO_INT_LVL_EDGE_BOTH;
+		break;
+
+	case IRQ_TYPE_LEVEL_HIGH:
+		lvl_type = GPIO_INT_LVL_LEVEL_HIGH;
+		break;
+
+	case IRQ_TYPE_LEVEL_LOW:
+		lvl_type = GPIO_INT_LVL_LEVEL_LOW;
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	spin_lock_irqsave(&bank->lvl_lock[port], flags);
+
+	val = __raw_readl(GPIO_INT_LVL(gpio));
+	val &= ~(GPIO_INT_LVL_MASK << GPIO_BIT(gpio));
+	val |= lvl_type << GPIO_BIT(gpio);
+	__raw_writel(val, GPIO_INT_LVL(gpio));
+
+	spin_unlock_irqrestore(&bank->lvl_lock[port], flags);
+
+	if (type & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_LEVEL_HIGH))
+		__set_irq_handler_unlocked(irq, handle_level_irq);
+	else if (type & (IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
+		__set_irq_handler_unlocked(irq, handle_edge_irq);
+
+	return 0;
+}
+
+static void tegra_gpio_irq_handler(unsigned int irq, struct irq_desc *desc)
+{
+	struct tegra_gpio_bank *bank;
+	int port;
+	int pin;
+	int unmasked = 0;
+
+	desc->chip->ack(irq);
+
+	bank = get_irq_data(irq);
+
+	for (port = 0; port < 4; port++) {
+		int gpio = tegra_gpio_compose(bank->bank, port, 0);
+		unsigned long sta = __raw_readl(GPIO_INT_STA(gpio)) &
+			__raw_readl(GPIO_INT_ENB(gpio));
+		u32 lvl = __raw_readl(GPIO_INT_LVL(gpio));
+
+		for_each_set_bit(pin, &sta, 8) {
+			__raw_writel(1 << pin, GPIO_INT_CLR(gpio));
+
+			/* if gpio is edge triggered, clear condition
+			 * before executing the hander so that we don't
+			 * miss edges
+			 */
+			if (lvl & (0x100 << pin)) {
+				unmasked = 1;
+				desc->chip->unmask(irq);
+			}
+
+			generic_handle_irq(gpio_to_irq(gpio + pin));
+		}
+	}
+
+	if (!unmasked)
+		desc->chip->unmask(irq);
+
+}
+
+
+static struct irq_chip tegra_gpio_irq_chip = {
+	.name		= "GPIO",
+	.ack		= tegra_gpio_irq_ack,
+	.mask		= tegra_gpio_irq_mask,
+	.unmask		= tegra_gpio_irq_unmask,
+	.set_type	= tegra_gpio_irq_set_type,
+};
+
+
+/* This lock class tells lockdep that GPIO irqs are in a different
+ * category than their parents, so it won't report false recursion.
+ */
+static struct lock_class_key gpio_lock_class;
+
+static int __init tegra_gpio_init(void)
+{
+	struct tegra_gpio_bank *bank;
+	int i;
+	int j;
+
+	for (i = 0; i < 7; i++) {
+		for (j = 0; j < 4; j++) {
+			int gpio = tegra_gpio_compose(i, j, 0);
+			__raw_writel(0x00, GPIO_INT_ENB(gpio));
+		}
+	}
+
+	gpiochip_add(&tegra_gpio_chip);
+
+	for (i = INT_GPIO_BASE; i < (INT_GPIO_BASE + ARCH_NR_GPIOS); i++) {
+		bank = &tegra_gpio_banks[GPIO_BANK(irq_to_gpio(i))];
+
+		lockdep_set_class(&irq_desc[i].lock, &gpio_lock_class);
+		set_irq_chip_data(i, bank);
+		set_irq_chip(i, &tegra_gpio_irq_chip);
+		set_irq_handler(i, handle_simple_irq);
+		set_irq_flags(i, IRQF_VALID);
+	}
+
+	for (i = 0; i < ARRAY_SIZE(tegra_gpio_banks); i++) {
+		bank = &tegra_gpio_banks[i];
+
+		set_irq_chained_handler(bank->irq, tegra_gpio_irq_handler);
+		set_irq_data(bank->irq, bank);
+
+		for (j = 0; j < 4; j++)
+			spin_lock_init(&bank->lvl_lock[j]);
+	}
+
+	return 0;
+}
+
+postcore_initcall(tegra_gpio_init);
+
+#ifdef	CONFIG_DEBUG_FS
+
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+
+static int dbg_gpio_show(struct seq_file *s, void *unused)
+{
+	int i;
+	int j;
+
+	for (i = 0; i < 7; i++) {
+		for (j = 0; j < 4; j++) {
+			int gpio = tegra_gpio_compose(i, j, 0);
+			seq_printf(s, "%d:%d %02x %02x %02x %02x %02x %02x %06x\n",
+			       i, j,
+			       __raw_readl(GPIO_CNF(gpio)),
+			       __raw_readl(GPIO_OE(gpio)),
+			       __raw_readl(GPIO_OUT(gpio)),
+			       __raw_readl(GPIO_IN(gpio)),
+			       __raw_readl(GPIO_INT_STA(gpio)),
+			       __raw_readl(GPIO_INT_ENB(gpio)),
+			       __raw_readl(GPIO_INT_LVL(gpio)));
+		}
+	}
+	return 0;
+}
+
+static int dbg_gpio_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, dbg_gpio_show, &inode->i_private);
+}
+
+static const struct file_operations debug_fops = {
+	.open		= dbg_gpio_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+static int __init tegra_gpio_debuginit(void)
+{
+	(void) debugfs_create_file("tegra_gpio", S_IRUGO,
+					NULL, NULL, &debug_fops);
+	return 0;
+}
+late_initcall(tegra_gpio_debuginit);
+#endif