/*
 * arch/arm/mach-ks8695/gpio.c
 *
 * Copyright (C) 2006 Andrew Victor
 *
 * 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.
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/module.h>

#include <asm/io.h>
#include <asm/hardware.h>
#include <asm/mach/irq.h>

#include <asm/arch/regs-gpio.h>
#include <asm/arch/gpio.h>

/*
 * Configure a GPIO line for either GPIO function, or its internal
 * function (Interrupt, Timer, etc).
 */
static void __init_or_module ks8695_gpio_mode(unsigned int pin, short gpio)
{
        unsigned int enable[] = { IOPC_IOEINT0EN, IOPC_IOEINT1EN, IOPC_IOEINT2EN, IOPC_IOEINT3EN, IOPC_IOTIM0EN, IOPC_IOTIM1EN };
        unsigned long x, flags;

        if (pin > KS8695_GPIO_5)        /* only GPIO 0..5 have internal functions */
                return;

        local_irq_save(flags);

        x = __raw_readl(KS8695_GPIO_VA + KS8695_IOPC);
        if (gpio)                       /* GPIO: set bit to 0 */
                x &= ~enable[pin];
        else                            /* Internal function: set bit to 1 */
                x |= enable[pin];
        __raw_writel(x, KS8695_GPIO_VA + KS8695_IOPC);

        local_irq_restore(flags);
}


static unsigned short gpio_irq[] = { KS8695_IRQ_EXTERN0, KS8695_IRQ_EXTERN1, KS8695_IRQ_EXTERN2, KS8695_IRQ_EXTERN3 };

/*
 * Configure GPIO pin as external interrupt source.
 */
int __init_or_module ks8695_gpio_interrupt(unsigned int pin, unsigned int type)
{
        unsigned long x, flags;

        if (pin > KS8695_GPIO_3)        /* only GPIO 0..3 can generate IRQ */
                return -EINVAL;

        local_irq_save(flags);

        /* set pin as input */
        x = __raw_readl(KS8695_GPIO_VA + KS8695_IOPM);
        x &= ~IOPM_(pin);
        __raw_writel(x, KS8695_GPIO_VA + KS8695_IOPM);

        local_irq_restore(flags);

        /* Set IRQ triggering type */
        set_irq_type(gpio_irq[pin], type);

        /* enable interrupt mode */
        ks8695_gpio_mode(pin, 0);

        return 0;
}
EXPORT_SYMBOL(ks8695_gpio_interrupt);



/* .... Generic GPIO interface .............................................. */

/*
 * Configure the GPIO line as an input.
 */
int __init_or_module gpio_direction_input(unsigned int pin)
{
        unsigned long x, flags;

        if (pin > KS8695_GPIO_15)
                return -EINVAL;

        /* set pin to GPIO mode */
        ks8695_gpio_mode(pin, 1);

        local_irq_save(flags);

        /* set pin as input */
        x = __raw_readl(KS8695_GPIO_VA + KS8695_IOPM);
        x &= ~IOPM_(pin);
        __raw_writel(x, KS8695_GPIO_VA + KS8695_IOPM);

        local_irq_restore(flags);

        return 0;
}
EXPORT_SYMBOL(gpio_direction_input);


/*
 * Configure the GPIO line as an output, with default state.
 */
int __init_or_module gpio_direction_output(unsigned int pin, unsigned int state)
{
        unsigned long x, flags;

        if (pin > KS8695_GPIO_15)
                return -EINVAL;

        /* set pin to GPIO mode */
        ks8695_gpio_mode(pin, 1);

        local_irq_save(flags);

        /* set line state */
        x = __raw_readl(KS8695_GPIO_VA + KS8695_IOPD);
        if (state)
                x |= (1 << pin);
        else
                x &= ~(1 << pin);
        __raw_writel(x, KS8695_GPIO_VA + KS8695_IOPD);

        /* set pin as output */
        x = __raw_readl(KS8695_GPIO_VA + KS8695_IOPM);
        x |= IOPM_(pin);
        __raw_writel(x, KS8695_GPIO_VA + KS8695_IOPM);

        local_irq_restore(flags);

        return 0;
}
EXPORT_SYMBOL(gpio_direction_output);


/*
 * Set the state of an output GPIO line.
 */
void gpio_set_value(unsigned int pin, unsigned int state)
{
        unsigned long x, flags;

        if (pin > KS8695_GPIO_15)
                return;

        local_irq_save(flags);

        /* set output line state */
        x = __raw_readl(KS8695_GPIO_VA + KS8695_IOPD);
        if (state)
                x |= (1 << pin);
        else
                x &= ~(1 << pin);
        __raw_writel(x, KS8695_GPIO_VA + KS8695_IOPD);

        local_irq_restore(flags);
}
EXPORT_SYMBOL(gpio_set_value);


/*
 * Read the state of a GPIO line.
 */
int gpio_get_value(unsigned int pin)
{
        unsigned long x;

        if (pin > KS8695_GPIO_15)
                return -EINVAL;

        x = __raw_readl(KS8695_GPIO_VA + KS8695_IOPD);
        return (x & (1 << pin)) != 0;
}
EXPORT_SYMBOL(gpio_get_value);


/*
 * Map GPIO line to IRQ number.
 */
int gpio_to_irq(unsigned int pin)
{
        if (pin > KS8695_GPIO_3)        /* only GPIO 0..3 can generate IRQ */
                return -EINVAL;

        return gpio_irq[pin];
}
EXPORT_SYMBOL(gpio_to_irq);


/*
 * Map IRQ number to GPIO line.
 */
int irq_to_gpio(unsigned int irq)
{
        if ((irq < KS8695_IRQ_EXTERN0) || (irq > KS8695_IRQ_EXTERN3))
                return -EINVAL;

        return (irq - KS8695_IRQ_EXTERN0);
}
EXPORT_SYMBOL(irq_to_gpio);