Watchdog.h

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/*
 * Copyright (c) 2015-2016, Texas Instruments Incorporated
 * All rights reserved.
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/*!*****************************************************************************
 *  @file       Watchdog.h
 *
 *  @brief      Watchdog driver interface
 *
 *  The Watchdog header file should be included in an application as follows:
 *  @code
 *  #include <ti/drivers/Watchdog.h>
 *  @endcode
 *
 *  # Overview #
 *
 *  A watchdog timer can be used to generate a reset signal if a system has
 *  become unresponsive. The Watchdog driver simplifies configuring and
 *  starting the watchdog peripherals. The watchdog peripheral can be
 *  configured with resets either on or off and a user-specified timeout
 *  period.
 *
 *  When the watchdog peripheral is configured not to generate a reset, it
 *  can be used to cause a hardware interrupt at a programmable interval.
 *  The driver provides the ability to specify a user-provided callback
 *  function that is called when the watchdog causes an interrupt.
 *
 *  # Operation #
 *
 *  The Watchdog driver simplifies configuring and starting the Watchdog
 *  peripherals. The Watchdog can be set up to produce a reset signal after a
 *  timeout, or simply cause a hardware interrupt at a programmable interval.
 *  The driver provides the ability to specify a callback function that is
 *  called when the Watchdog causes an interrupt.
 *
 *  When resets are turned on, it is the user application's responsibility to
 *  call Watchdog_clear() in order to clear the Watchdog and prevent a reset.
 *  Watchdog_clear() can be called at any time.
 *
 *  # Usage #
 *
 *  The Watchdog driver must be initialized by calling Watchdog_init(),
 *  before any other Watchdog APIs can be called.
 *  Once the watchdog is initialized, a Watchdog object can be created
 *  through the following steps:
 *  -   Create and initialize the Watchdog_Params structure.
 *  -   Assign desired values to parameters.
 *  -   Call Watchdog_open().
 *  -   Save the Watchdog_Handle returned by Watchdog_open(). This will be
 *  used to interact with the Watchdog object just created.
 *
 *  To have a user-defined function run at the hardware interrupt caused by
 *  a watchdog timer timeout, define a function of the following type:
 *  @code
 *    typedef void (*Watchdog_Callback)(uintptr_t);
 *  @endcode
 *  Then pass the function to Watchdog_open() through the Watchdog_Params
 *  structure.
 *
 *  An example of the Watchdog creation process that uses a callback
 *  function:
 *  @code
 *    Watchdog_Params params;
 *    Watchdog_Handle watchdog;
 *
 *    Watchdog_init();
 *
 *    Watchdog_Params_init(&params);
 *    params.resetMode = Watchdog_RESET_ON;
 *    params.callbackFxn = UserCallbackFxn;
 *
 *    watchdog = Watchdog_open(Board_WATCHDOG, &params);
 *    if (watchdog == NULL) {
 *        `Error opening watchdog`
 *    }
 *  @endcode
 *
 *  If no Watchdog_Params structure is passed to Watchdog_open(), the
 *  default values are used. By default, the Watchdog driver has resets
 *  turned on, no callback function specified, and stalls the timer at
 *  breakpoints during debugging.
 *
 *  Options for the resetMode parameter are Watchdog_RESET_ON and
 *  Watchdog_RESET_OFF. The latter allows the watchdog to be used like
 *  another timer interrupt. When resetMode is Watchdog_RESET_ON, it is up
 *  to the application to call Watchdog_clear() to clear the Watchdog
 *  interrupt flag to prevent a reset. Watchdog_clear() can be called at
 *  any time.
 *
 *  # Implementation #
 *
 *  This module serves as the main interface for TI-RTOS applications. Its
 *  purpose is to redirect the module's APIs to specific peripheral
 *  implementations which are specified using a pointer to a
 *  Watchdog_FxnTable.
 *
 *  The Watchdog driver interface module is joined (at link time)
 *  to a NULL-terminated array of Watchdog_Config data structures named
 *  *Watchdog_config*. *Watchdog_config* is implemented in the application with
 *  each entry being an instance of a Watchdog peripheral. Each entry in
 *  *Watchdog_config* contains a:
 *  - (Watchdog_FxnTable *) to a set of functions that implement a Watchdog
 *    peripheral
 *  - (void *) data object that is associated with the Watchdog_FxnTable
 *  - (void *) hardware attributes that are associated to the Watchdog_FxnTable
 *
 *******************************************************************************
 */

#ifndef ti_drivers_Watchdog__include
#define ti_drivers_Watchdog__include

#ifdef __cplusplus
extern "C" {
#endif


#include <stdint.h>

#define Watchdog_CMD_RESERVED            (32)

#define Watchdog_STATUS_RESERVED        (-32)

#define Watchdog_STATUS_SUCCESS        (0)

#define Watchdog_STATUS_ERROR          (-1)

#define Watchdog_STATUS_UNDEFINEDCMD   (-2)

#define Watchdog_STATUS_UNSUPPORTED   (-3)

/* Add Watchdog_CMD_<commands> here */

typedef struct Watchdog_Config_ *Watchdog_Handle;

typedef enum Watchdog_DebugMode_ {
    Watchdog_DEBUG_STALL_ON, 
    Watchdog_DEBUG_STALL_OFF 
} Watchdog_DebugMode;

typedef enum Watchdog_ResetMode_ {
    Watchdog_RESET_OFF, 
    Watchdog_RESET_ON   
} Watchdog_ResetMode;

typedef void (*Watchdog_Callback)(uintptr_t handle);

typedef struct Watchdog_Params_ {
    Watchdog_Callback   callbackFxn;    
    Watchdog_ResetMode  resetMode;      
    Watchdog_DebugMode  debugStallMode; 
    void               *custom;         
} Watchdog_Params;

typedef void (*Watchdog_ClearFxn)       (Watchdog_Handle handle);

typedef void (*Watchdog_CloseFxn)       (Watchdog_Handle handle);

typedef int_fast16_t (*Watchdog_ControlFxn) (Watchdog_Handle handle,
                                             uint_fast16_t cmd,
                                             void *arg);

typedef void (*Watchdog_InitFxn)        (Watchdog_Handle handle);

typedef Watchdog_Handle (*Watchdog_OpenFxn)  (Watchdog_Handle handle,
                                              Watchdog_Params *params);

typedef int_fast16_t (*Watchdog_SetReloadFxn)(Watchdog_Handle handle,
    uint32_t ticks);

typedef uint32_t (*Watchdog_ConvertMsToTicksFxn)   (uint32_t milliseconds);

typedef struct Watchdog_FxnTable_ {
    Watchdog_ClearFxn             watchdogClear;
    Watchdog_CloseFxn             watchdogClose;
    Watchdog_ControlFxn           watchdogControl;
    Watchdog_InitFxn              watchdogInit;
    Watchdog_OpenFxn              watchdogOpen;
    Watchdog_SetReloadFxn         watchdogSetReload;
    Watchdog_ConvertMsToTicksFxn  watchdogConvertMsToTicks;
} Watchdog_FxnTable;

typedef struct Watchdog_Config_ {
    Watchdog_FxnTable const *fxnTablePtr;

    void                    *object;

    void              const *hwAttrs;
} Watchdog_Config;

extern void Watchdog_clear(Watchdog_Handle handle);

extern void Watchdog_close(Watchdog_Handle handle);

extern int_fast16_t Watchdog_control(Watchdog_Handle handle,
                                     uint_fast16_t cmd,
                                     void *arg);

extern void Watchdog_init(void);

extern Watchdog_Handle Watchdog_open(uint_least8_t index, Watchdog_Params *params);

extern void Watchdog_Params_init(Watchdog_Params *params);

extern int_fast16_t Watchdog_setReload(Watchdog_Handle handle, uint32_t ticks);

extern uint32_t Watchdog_convertMsToTicks(Watchdog_Handle handle, uint32_t milliseconds);

#ifdef __cplusplus
}
#endif

#endif /* ti_drivers_Watchdog__include */