gpio.c

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/*
 * 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 <[email protected]>
 * Copyright (C) 2008-2011 Florian Fainelli <[email protected]>
 */

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

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

#ifndef BCMCPU_RUNTIME_DETECT
#define gpio_out_low_reg    GPIO_DATA_LO_REG
#ifdef CONFIG_BCM63XX_CPU_6345
#ifdef gpio_out_low_reg
#undef gpio_out_low_reg
#define gpio_out_low_reg    GPIO_DATA_LO_REG_6345
#endif /* gpio_out_low_reg */
#endif /* CONFIG_BCM63XX_CPU_6345 */

static inline void bcm63xx_gpio_out_low_reg_init(void)
{
}
#else /* ! BCMCPU_RUNTIME_DETECT */
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;
    }
}
#endif /* ! BCMCPU_RUNTIME_DETECT */

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

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

    if (gpio >= chip->ngpio)
        BUG();

    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);
}

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

    if (gpio >= chip->ngpio)
        BUG();

    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;

    if (gpio >= chip->ngpio)
        BUG();

    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(&bcm63xx_gpio_chip);
}