gpio.c

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/*
 * linux/arch/arm/mach-w90x900/gpio.c
 *
 * Generic nuc900 GPIO handling
 *
 *  Wan ZongShun <[email protected]>
 *
 * 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/clk.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/io.h>
#include <linux/gpio.h>

#include <mach/hardware.h>

#define GPIO_BASE       (W90X900_VA_GPIO)
#define GPIO_DIR        (0x04)
#define GPIO_OUT        (0x08)
#define GPIO_IN         (0x0C)
#define GROUPINERV      (0x10)
#define GPIO_GPIO(Nb)       (0x00000001 << (Nb))
#define to_nuc900_gpio_chip(c) container_of(c, struct nuc900_gpio_chip, chip)

#define NUC900_GPIO_CHIP(name, base_gpio, nr_gpio)          \
    {                               \
        .chip = {                       \
            .label        = name,           \
            .direction_input  = nuc900_dir_input,       \
            .direction_output = nuc900_dir_output,      \
            .get          = nuc900_gpio_get,        \
            .set          = nuc900_gpio_set,        \
            .base         = base_gpio,          \
            .ngpio        = nr_gpio,            \
        }                           \
    }

struct nuc900_gpio_chip {
    struct gpio_chip    chip;
    void __iomem        *regbase;   /* Base of group register*/
    spinlock_t      gpio_lock;
};

static int nuc900_gpio_get(struct gpio_chip *chip, unsigned offset)
{
    struct nuc900_gpio_chip *nuc900_gpio = to_nuc900_gpio_chip(chip);
    void __iomem *pio = nuc900_gpio->regbase + GPIO_IN;
    unsigned int regval;

    regval = __raw_readl(pio);
    regval &= GPIO_GPIO(offset);

    return (regval != 0);
}

static void nuc900_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
{
    struct nuc900_gpio_chip *nuc900_gpio = to_nuc900_gpio_chip(chip);
    void __iomem *pio = nuc900_gpio->regbase + GPIO_OUT;
    unsigned int regval;
    unsigned long flags;

    spin_lock_irqsave(&nuc900_gpio->gpio_lock, flags);

    regval = __raw_readl(pio);

    if (val)
        regval |= GPIO_GPIO(offset);
    else
        regval &= ~GPIO_GPIO(offset);

    __raw_writel(regval, pio);

    spin_unlock_irqrestore(&nuc900_gpio->gpio_lock, flags);
}

static int nuc900_dir_input(struct gpio_chip *chip, unsigned offset)
{
    struct nuc900_gpio_chip *nuc900_gpio = to_nuc900_gpio_chip(chip);
    void __iomem *pio = nuc900_gpio->regbase + GPIO_DIR;
    unsigned int regval;
    unsigned long flags;

    spin_lock_irqsave(&nuc900_gpio->gpio_lock, flags);

    regval = __raw_readl(pio);
    regval &= ~GPIO_GPIO(offset);
    __raw_writel(regval, pio);

    spin_unlock_irqrestore(&nuc900_gpio->gpio_lock, flags);

    return 0;
}

static int nuc900_dir_output(struct gpio_chip *chip, unsigned offset, int val)
{
    struct nuc900_gpio_chip *nuc900_gpio = to_nuc900_gpio_chip(chip);
    void __iomem *outreg = nuc900_gpio->regbase + GPIO_OUT;
    void __iomem *pio = nuc900_gpio->regbase + GPIO_DIR;
    unsigned int regval;
    unsigned long flags;

    spin_lock_irqsave(&nuc900_gpio->gpio_lock, flags);

    regval = __raw_readl(pio);
    regval |= GPIO_GPIO(offset);
    __raw_writel(regval, pio);

    regval = __raw_readl(outreg);

    if (val)
        regval |= GPIO_GPIO(offset);
    else
        regval &= ~GPIO_GPIO(offset);

    __raw_writel(regval, outreg);

    spin_unlock_irqrestore(&nuc900_gpio->gpio_lock, flags);

    return 0;
}

static struct nuc900_gpio_chip nuc900_gpio[] = {
    NUC900_GPIO_CHIP("GROUPC", 0, 16),
    NUC900_GPIO_CHIP("GROUPD", 16, 10),
    NUC900_GPIO_CHIP("GROUPE", 26, 14),
    NUC900_GPIO_CHIP("GROUPF", 40, 10),
    NUC900_GPIO_CHIP("GROUPG", 50, 17),
    NUC900_GPIO_CHIP("GROUPH", 67, 8),
    NUC900_GPIO_CHIP("GROUPI", 75, 17),
};

void __init nuc900_init_gpio(int nr_group)
{
    unsigned    i;
    struct nuc900_gpio_chip *gpio_chip;

    for (i = 0; i < nr_group; i++) {
        gpio_chip = &nuc900_gpio[i];
        spin_lock_init(&gpio_chip->gpio_lock);
        gpio_chip->regbase = GPIO_BASE + i * GROUPINERV;
        gpiochip_add(&gpio_chip->chip);
    }
}