linux-imx

/*

 * GPIO Driver for Loongson 1 SoC

 *

 * Copyright (C) 2015-2016 Zhang, Keguang <keguang.zhang@gmail.com>

 *

 * This file is licensed under the terms of the GNU General Public

 * License version 2. This program is licensed "as is" without any

 * warranty of any kind, whether express or implied.

 */

​

#include <linux/module.h>

#include <linux/gpio/driver.h>

#include <linux/platform_device.h>

#include <linux/bitops.h>

​

/* Loongson 1 GPIO Register Definitions */

#define GPIO_CFG        0x0

#define GPIO_DIR        0x10

#define GPIO_DATA       0x20

#define GPIO_OUTPUT     0x30

​

static void __iomem *gpio_reg_base;

​

static int ls1x_gpio_request(struct gpio_chip *gc, unsigned int offset)

{

    unsigned long flags;

​

    spin_lock_irqsave(&gc->bgpio_lock, flags);

    __raw_writel(__raw_readl(gpio_reg_base + GPIO_CFG) | BIT(offset),

             gpio_reg_base + GPIO_CFG);

    spin_unlock_irqrestore(&gc->bgpio_lock, flags);

​

    return 0;

}

​

static void ls1x_gpio_free(struct gpio_chip *gc, unsigned int offset)

{

    unsigned long flags;

​

    spin_lock_irqsave(&gc->bgpio_lock, flags);

    __raw_writel(__raw_readl(gpio_reg_base + GPIO_CFG) & ~BIT(offset),

             gpio_reg_base + GPIO_CFG);

    spin_unlock_irqrestore(&gc->bgpio_lock, flags);

}

​

static int ls1x_gpio_probe(struct platform_device *pdev)

{

    struct device *dev = &pdev->dev;

    struct gpio_chip *gc;

    struct resource *res;

    int ret;

​

    gc = devm_kzalloc(dev, sizeof(*gc), GFP_KERNEL);

    if (!gc)

        return -ENOMEM;

​

    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

    gpio_reg_base = devm_ioremap_resource(dev, res);

    if (IS_ERR(gpio_reg_base))

        return PTR_ERR(gpio_reg_base);

​

    ret = bgpio_init(gc, dev, 4, gpio_reg_base + GPIO_DATA,

             gpio_reg_base + GPIO_OUTPUT, NULL,