linux-imx

// SPDX-License-Identifier: GPL-2.0

/*

 * Intel Management Engine Interface (Intel MEI) Linux driver

 * Copyright (c) 2015, Intel Corporation.

 */

​

#include <linux/module.h>

#include <linux/slab.h>

#include <linux/interrupt.h>

#include <linux/debugfs.h>

#include <linux/completion.h>

#include <linux/watchdog.h>

​

#include <linux/uuid.h>

#include <linux/mei_cl_bus.h>

​

/*

 * iAMT Watchdog Device

 */

#define INTEL_AMT_WATCHDOG_ID "iamt_wdt"

​

#define MEI_WDT_DEFAULT_TIMEOUT   120  /* seconds */

#define MEI_WDT_MIN_TIMEOUT       120  /* seconds */

#define MEI_WDT_MAX_TIMEOUT     65535  /* seconds */

​

/* Commands */

#define MEI_MANAGEMENT_CONTROL 0x02

​

/* MEI Management Control version number */

#define MEI_MC_VERSION_NUMBER  0x10

​

/* Sub Commands */

#define MEI_MC_START_WD_TIMER_REQ  0x13

#define MEI_MC_START_WD_TIMER_RES  0x83

#define   MEI_WDT_STATUS_SUCCESS 0

#define   MEI_WDT_WDSTATE_NOT_REQUIRED 0x1

#define MEI_MC_STOP_WD_TIMER_REQ   0x14

​

/**

 * enum mei_wdt_state - internal watchdog state

 *

 * @MEI_WDT_PROBE: wd in probing stage

 * @MEI_WDT_IDLE: wd is idle and not opened

 * @MEI_WDT_START: wd was opened, start was called

 * @MEI_WDT_RUNNING: wd is expecting keep alive pings

 * @MEI_WDT_STOPPING: wd is stopping and will move to IDLE

 * @MEI_WDT_NOT_REQUIRED: wd device is not required

 */

enum mei_wdt_state {

    MEI_WDT_PROBE,

    MEI_WDT_IDLE,

    MEI_WDT_START,

    MEI_WDT_RUNNING,

    MEI_WDT_STOPPING,

    MEI_WDT_NOT_REQUIRED,

};

​

static const char *mei_wdt_state_str(enum mei_wdt_state state)

{

    switch (state) {

    case MEI_WDT_PROBE:

        return "PROBE";

    case MEI_WDT_IDLE: