linux-imx

/*

 * MOXA ART SoCs watchdog driver.

 *

 * Copyright (C) 2013 Jonas Jensen

 *

 * Jonas Jensen <jonas.jensen@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/clk.h>

#include <linux/io.h>

#include <linux/module.h>

#include <linux/mod_devicetable.h>

#include <linux/err.h>

#include <linux/kernel.h>

#include <linux/platform_device.h>

#include <linux/watchdog.h>

#include <linux/moduleparam.h>

​

#define REG_COUNT           0x4

#define REG_MODE            0x8

#define REG_ENABLE          0xC

​

struct moxart_wdt_dev {

    struct watchdog_device dev;

    void __iomem *base;

    unsigned int clock_frequency;

};

​

static int heartbeat;

​

static int moxart_wdt_restart(struct watchdog_device *wdt_dev,

                  unsigned long action, void *data)

{

    struct moxart_wdt_dev *moxart_wdt = watchdog_get_drvdata(wdt_dev);

​

    writel(1, moxart_wdt->base + REG_COUNT);

    writel(0x5ab9, moxart_wdt->base + REG_MODE);

    writel(0x03, moxart_wdt->base + REG_ENABLE);

​

    return 0;

}

​

static int moxart_wdt_stop(struct watchdog_device *wdt_dev)

{

    struct moxart_wdt_dev *moxart_wdt = watchdog_get_drvdata(wdt_dev);

​

    writel(0, moxart_wdt->base + REG_ENABLE);

​

    return 0;

}

​

static int moxart_wdt_start(struct watchdog_device *wdt_dev)

{

    struct moxart_wdt_dev *moxart_wdt = watchdog_get_drvdata(wdt_dev);

​

    writel(moxart_wdt->clock_frequency * wdt_dev->timeout,

           moxart_wdt->base + REG_COUNT);

    writel(0x5ab9, moxart_wdt->base + REG_MODE);

    writel(0x03, moxart_wdt->base + REG_ENABLE);

​

    return 0;

}

​

static int moxart_wdt_set_timeout(struct watchdog_device *wdt_dev,

                  unsigned int timeout)

{

    wdt_dev->timeout = timeout;

​

    return 0;

}

​

static const struct watchdog_info moxart_wdt_info = {

    .identity       = "moxart-wdt",

    .options        = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |

              WDIOF_MAGICCLOSE,

};

​

static const struct watchdog_ops moxart_wdt_ops = {

    .owner          = THIS_MODULE,

    .start          = moxart_wdt_start,

    .stop           = moxart_wdt_stop,

    .set_timeout    = moxart_wdt_set_timeout,

    .restart        = moxart_wdt_restart,

};

​

static int moxart_wdt_probe(struct platform_device *pdev)

{

    struct moxart_wdt_dev *moxart_wdt;