linux-imx

/*

 *  i6300esb:   Watchdog timer driver for Intel 6300ESB chipset

 *

 *  (c) Copyright 2004 Google Inc.

 *  (c) Copyright 2005 David Härdeman <david@2gen.com>

 *

 *  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 i810-tco.c which is in turn based on softdog.c

 *

 *  The timer is implemented in the following I/O controller hubs:

 *  (See the intel documentation on http://developer.intel.com.)

 *  6300ESB chip : document number 300641-004

 *

 *  2004YYZZ Ross Biro

 *  Initial version 0.01

 *  2004YYZZ Ross Biro

 *  Version 0.02

 *  20050210 David Härdeman <david@2gen.com>

 *  Ported driver to kernel 2.6

 *  20171016 Radu Rendec <rrendec@arista.com>

 *  Change driver to use the watchdog subsystem

 *  Add support for multiple 6300ESB devices

 */

​

/*

 *      Includes, defines, variables, module parameters, ...

 */

​

#include <linux/module.h>

#include <linux/types.h>

#include <linux/kernel.h>

#include <linux/fs.h>

#include <linux/mm.h>

#include <linux/miscdevice.h>

#include <linux/watchdog.h>

#include <linux/pci.h>

#include <linux/ioport.h>

#include <linux/uaccess.h>

#include <linux/io.h>

​

/* Module and version information */

#define ESB_MODULE_NAME "i6300ESB timer"

​

/* PCI configuration registers */

#define ESB_CONFIG_REG  0x60            /* Config register                   */

#define ESB_LOCK_REG    0x68            /* WDT lock register                 */

​

/* Memory mapped registers */

#define ESB_TIMER1_REG(w) ((w)->base + 0x00)/* Timer1 value after each reset */

#define ESB_TIMER2_REG(w) ((w)->base + 0x04)/* Timer2 value after each reset */

#define ESB_GINTSR_REG(w) ((w)->base + 0x08)/* General Interrupt Status Reg  */

#define ESB_RELOAD_REG(w) ((w)->base + 0x0c)/* Reload register               */

​

/* Lock register bits */

#define ESB_WDT_FUNC    (0x01 << 2)   /* Watchdog functionality            */

#define ESB_WDT_ENABLE  (0x01 << 1)   /* Enable WDT                        */

#define ESB_WDT_LOCK    (0x01 << 0)   /* Lock (nowayout)                   */

​

/* Config register bits */

#define ESB_WDT_REBOOT  (0x01 << 5)   /* Enable reboot on timeout          */

#define ESB_WDT_FREQ    (0x01 << 2)   /* Decrement frequency               */

#define ESB_WDT_INTTYPE (0x03 << 0)   /* Interrupt type on timer1 timeout  */

​

/* Reload register bits */

#define ESB_WDT_TIMEOUT (0x01 << 9)    /* Watchdog timed out                */

#define ESB_WDT_RELOAD  (0x01 << 8)    /* prevent timeout                   */

​

/* Magic constants */

#define ESB_UNLOCK1     0x80            /* Step 1 to unlock reset registers  */

#define ESB_UNLOCK2     0x86            /* Step 2 to unlock reset registers  */

​

/* module parameters */

/* 30 sec default heartbeat (1 < heartbeat < 2*1023) */

#define ESB_HEARTBEAT_MIN   1

#define ESB_HEARTBEAT_MAX   2046

#define ESB_HEARTBEAT_DEFAULT   30

#define ESB_HEARTBEAT_RANGE __MODULE_STRING(ESB_HEARTBEAT_MIN) \

    "<heartbeat<" __MODULE_STRING(ESB_HEARTBEAT_MAX)

static int heartbeat; /* in seconds */

module_param(heartbeat, int, 0);

MODULE_PARM_DESC(heartbeat,

    "Watchdog heartbeat in seconds. (" ESB_HEARTBEAT_RANGE

    ", default=" __MODULE_STRING(ESB_HEARTBEAT_DEFAULT) ")");

​

static bool nowayout = WATCHDOG_NOWAYOUT;

module_param(nowayout, bool, 0);

MODULE_PARM_DESC(nowayout,

        "Watchdog cannot be stopped once started (default="