linux-imx

/*

 *      Meson Watchdog Driver

 *

 *      Copyright (c) 2014 Carlo Caione

 *

 *      This program is free software; you can redistribute it and/or

 *      modify it under the terms of the GNU General Public License

 *      as published by the Free Software Foundation; either version

 *      2 of the License, or (at your option) any later version.

 */

​

#include <linux/clk.h>

#include <linux/delay.h>

#include <linux/err.h>

#include <linux/init.h>

#include <linux/io.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/moduleparam.h>

#include <linux/of.h>

#include <linux/of_device.h>

#include <linux/platform_device.h>

#include <linux/types.h>

#include <linux/watchdog.h>

​

#define DRV_NAME        "meson_wdt"

​

#define MESON_WDT_TC        0x00

#define MESON_WDT_DC_RESET  (3 << 24)

​

#define MESON_WDT_RESET     0x04

​

#define MESON_WDT_TIMEOUT   30

#define MESON_WDT_MIN_TIMEOUT   1

​

#define MESON_SEC_TO_TC(s, c)   ((s) * (c))

​

static bool nowayout = WATCHDOG_NOWAYOUT;

static unsigned int timeout;

​

struct meson_wdt_data {

    unsigned int enable;

    unsigned int terminal_count_mask;

    unsigned int count_unit;

};

​

static struct meson_wdt_data meson6_wdt_data = {

    .enable         = BIT(22),

    .terminal_count_mask    = 0x3fffff,

    .count_unit     = 100000, /* 10 us */

};

​

static struct meson_wdt_data meson8b_wdt_data = {

    .enable         = BIT(19),

    .terminal_count_mask    = 0xffff,

    .count_unit     = 7812, /* 128 us */

};

​

struct meson_wdt_dev {

    struct watchdog_device wdt_dev;

    void __iomem *wdt_base;

    const struct meson_wdt_data *data;

};

​

static int meson_wdt_restart(struct watchdog_device *wdt_dev,

                 unsigned long action, void *data)

{

    struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev);

    u32 tc_reboot = MESON_WDT_DC_RESET;

​

    tc_reboot |= meson_wdt->data->enable;

​

    while (1) {

        writel(tc_reboot, meson_wdt->wdt_base + MESON_WDT_TC);

        mdelay(5);

    }

​

    return 0;

}

​

static int meson_wdt_ping(struct watchdog_device *wdt_dev)

{

    struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev);

​

    writel(0, meson_wdt->wdt_base + MESON_WDT_RESET);

​

    return 0;

}

​

static void meson_wdt_change_timeout(struct watchdog_device *wdt_dev,

                     unsigned int timeout)

{