linux-imx

/*

 * watchdog driver for ZTE's zx2967 family

 *

 * Copyright (C) 2017 ZTE Ltd.

 *

 * Author: Baoyou Xie <baoyou.xie@linaro.org>

 *

 * License terms: GNU General Public License (GPL) version 2

 */

​

#include <linux/clk.h>

#include <linux/io.h>

#include <linux/mfd/syscon.h>

#include <linux/module.h>

#include <linux/of_address.h>

#include <linux/platform_device.h>

#include <linux/regmap.h>

#include <linux/reset.h>

#include <linux/watchdog.h>

​

#define ZX2967_WDT_CFG_REG          0x4

#define ZX2967_WDT_LOAD_REG         0x8

#define ZX2967_WDT_REFRESH_REG          0x18

#define ZX2967_WDT_START_REG            0x1c

​

#define ZX2967_WDT_REFRESH_MASK         GENMASK(5, 0)

​

#define ZX2967_WDT_CFG_DIV(n)           ((((n) & 0xff) - 1) << 8)

#define ZX2967_WDT_START_EN         0x1

​

/*

 * Hardware magic number.

 * When watchdog reg is written, the lowest 16 bits are valid, but

 * the highest 16 bits should be always this number.

 */

#define ZX2967_WDT_WRITEKEY         (0x1234 << 16)

#define ZX2967_WDT_VAL_MASK         GENMASK(15, 0)

​

#define ZX2967_WDT_DIV_DEFAULT          16

#define ZX2967_WDT_DEFAULT_TIMEOUT      32

#define ZX2967_WDT_MIN_TIMEOUT          1

#define ZX2967_WDT_MAX_TIMEOUT          524

#define ZX2967_WDT_MAX_COUNT            0xffff

​

#define ZX2967_WDT_CLK_FREQ         0x8000

​

#define ZX2967_WDT_FLAG_REBOOT_MON      BIT(0)

​

struct zx2967_wdt {

    struct watchdog_device  wdt_device;

    void __iomem        *reg_base;

    struct clk      *clock;

};

​

static inline u32 zx2967_wdt_readl(struct zx2967_wdt *wdt, u16 reg)

{

    return readl_relaxed(wdt->reg_base + reg);

}

​

static inline void zx2967_wdt_writel(struct zx2967_wdt *wdt, u16 reg, u32 val)

{

    writel_relaxed(val | ZX2967_WDT_WRITEKEY, wdt->reg_base + reg);

}