[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 000000000000..fe78fba25f3c
--- /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