linux-imx

/*

 *      sunxi Watchdog Driver

 *

 *      Copyright (c) 2013 Carlo Caione

 *                    2012 Henrik Nordstrom

 *

 *      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.

 *

 *      Based on xen_wdt.c

 *      (c) Copyright 2010 Novell, Inc.

 */

​

#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 WDT_MAX_TIMEOUT         16

#define WDT_MIN_TIMEOUT         1

#define WDT_TIMEOUT_MASK        0x0F

​

#define WDT_CTRL_RELOAD         ((1 << 0) | (0x0a57 << 1))

​

#define WDT_MODE_EN             (1 << 0)

​

#define DRV_NAME        "sunxi-wdt"

#define DRV_VERSION     "1.0"

​

static bool nowayout = WATCHDOG_NOWAYOUT;

static unsigned int timeout;

​

/*

 * This structure stores the register offsets for different variants

 * of Allwinner's watchdog hardware.

 */

struct sunxi_wdt_reg {

    u8 wdt_ctrl;

    u8 wdt_cfg;

    u8 wdt_mode;

    u8 wdt_timeout_shift;

    u8 wdt_reset_mask;

    u8 wdt_reset_val;

};

​

struct sunxi_wdt_dev {

    struct watchdog_device wdt_dev;

    void __iomem *wdt_base;

    const struct sunxi_wdt_reg *wdt_regs;

};

​

/*

 * wdt_timeout_map maps the watchdog timer interval value in seconds to

 * the value of the register WDT_MODE at bits .wdt_timeout_shift ~ +3

 *

 * [timeout seconds] = register value

 *

 */

​

static const int wdt_timeout_map[] = {

    [1] = 0x1,  /* 1s  */

    [2] = 0x2,  /* 2s  */

    [3] = 0x3,  /* 3s  */

    [4] = 0x4,  /* 4s  */

    [5] = 0x5,  /* 5s  */

    [6] = 0x6,  /* 6s  */

    [8] = 0x7,  /* 8s  */

    [10] = 0x8, /* 10s */

    [12] = 0x9, /* 12s */

    [14] = 0xA, /* 14s */

    [16] = 0xB, /* 16s */

};

​

​

static int sunxi_wdt_restart(struct watchdog_device *wdt_dev,

                 unsigned long action, void *data)

{

    struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);

    void __iomem *wdt_base = sunxi_wdt->wdt_base;

    const struct sunxi_wdt_reg *regs = sunxi_wdt->wdt_regs;

    u32 val;