/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 2008 Maxime Bizon <mbizon@freebox.fr>
 * Copyright (C) 2008-2011 Florian Fainelli <florian@openwrt.org>
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/platform_device.h>
#include <linux/gpio/driver.h>

#include <bcm63xx_cpu.h>
#include <bcm63xx_gpio.h>
#include <bcm63xx_io.h>
#include <bcm63xx_regs.h>

static u32 gpio_out_low_reg;

static void bcm63xx_gpio_out_low_reg_init(void)
{
        switch (bcm63xx_get_cpu_id()) {
        case BCM6345_CPU_ID:
                gpio_out_low_reg = GPIO_DATA_LO_REG_6345;
                break;
        default:
                gpio_out_low_reg = GPIO_DATA_LO_REG;
                break;
        }
}

static DEFINE_SPINLOCK(bcm63xx_gpio_lock);
static u32 gpio_out_low, gpio_out_high;

static int bcm63xx_gpio_set(struct gpio_chip *chip, unsigned int gpio, int val)
{
        u32 reg;
        u32 mask;
        u32 *v;
        unsigned long flags;

        BUG_ON(gpio >= chip->ngpio);

        if (gpio < 32) {
                reg = gpio_out_low_reg;
                mask = 1 << gpio;
                v = &gpio_out_low;
        } else {
                reg = GPIO_DATA_HI_REG;
                mask = 1 << (gpio - 32);
                v = &gpio_out_high;
        }

        spin_lock_irqsave(&bcm63xx_gpio_lock, flags);
        if (val)
                *v |= mask;
        else
                *v &= ~mask;
        bcm_gpio_writel(*v, reg);
        spin_unlock_irqrestore(&bcm63xx_gpio_lock, flags);

        return 0;
}

static int bcm63xx_gpio_get(struct gpio_chip *chip, unsigned gpio)
{
        u32 reg;
        u32 mask;

        BUG_ON(gpio >= chip->ngpio);

        if (gpio < 32) {
                reg = gpio_out_low_reg;
                mask = 1 << gpio;
        } else {
                reg = GPIO_DATA_HI_REG;
                mask = 1 << (gpio - 32);
        }

        return !!(bcm_gpio_readl(reg) & mask);
}

static int bcm63xx_gpio_set_direction(struct gpio_chip *chip,
                                      unsigned gpio, int dir)
{
        u32 reg;
        u32 mask;
        u32 tmp;
        unsigned long flags;

        BUG_ON(gpio >= chip->ngpio);

        if (gpio < 32) {
                reg = GPIO_CTL_LO_REG;
                mask = 1 << gpio;
        } else {
                reg = GPIO_CTL_HI_REG;
                mask = 1 << (gpio - 32);
        }

        spin_lock_irqsave(&bcm63xx_gpio_lock, flags);
        tmp = bcm_gpio_readl(reg);
        if (dir == BCM63XX_GPIO_DIR_IN)
                tmp &= ~mask;
        else
                tmp |= mask;
        bcm_gpio_writel(tmp, reg);
        spin_unlock_irqrestore(&bcm63xx_gpio_lock, flags);

        return 0;
}

static int bcm63xx_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
{
        return bcm63xx_gpio_set_direction(chip, gpio, BCM63XX_GPIO_DIR_IN);
}

static int bcm63xx_gpio_direction_output(struct gpio_chip *chip,
                                         unsigned gpio, int value)
{
        bcm63xx_gpio_set(chip, gpio, value);
        return bcm63xx_gpio_set_direction(chip, gpio, BCM63XX_GPIO_DIR_OUT);
}


static struct gpio_chip bcm63xx_gpio_chip = {
        .label                  = "bcm63xx-gpio",
        .direction_input        = bcm63xx_gpio_direction_input,
        .direction_output       = bcm63xx_gpio_direction_output,
        .get                    = bcm63xx_gpio_get,
        .set                    = bcm63xx_gpio_set,
        .base                   = 0,
};

int __init bcm63xx_gpio_init(void)
{
        bcm63xx_gpio_out_low_reg_init();

        gpio_out_low = bcm_gpio_readl(gpio_out_low_reg);
        if (!BCMCPU_IS_6345())
                gpio_out_high = bcm_gpio_readl(GPIO_DATA_HI_REG);
        bcm63xx_gpio_chip.ngpio = bcm63xx_gpio_count();
        pr_info("registering %d GPIOs\n", bcm63xx_gpio_chip.ngpio);

        return gpiochip_add_data(&bcm63xx_gpio_chip, NULL);
}