driver.h

/*
 driver.h
 Header file for driver model example
 Paul Lever

 */

#ifndef __DRIVER_H__
#define __DRIVER_H__

#include "mem.h"

// define a handle for users
typedef void * PVOID;
typedef PVOID HANDLE;

// define a handle for internal use
// (normally we would hide this from users)
typedef struct
{
    INT8U DrvIndex;         // index of driver list for this device
    INT8U DevIndex;         // index of device within driver
    OS_EVENT *Event;        // Handle's semaphore
    INT8U RefCount;         // reference count for Handle
} OSDRV_HANDLE_INTERNAL, *POSDRV_HANDLE_INTERNAL;

// device name link list
struct _OSDRV_NAME;
typedef struct _OSDRV_NAME
{
    char *pName;                            // name of device
    struct _OSDRV_NAME *pNext;      // link to next name
} OSDRV_NAME, *POSDRV_NAME;

// Configuration table for driver initialization
//   exclusive means that the driver model will only give the driver one request at a time
//   per handle. A driver that only wants to handle one request per device at a ti8me should
//   set Exclusive when it registers and only allow one Open per device
typedef struct
{
    INT8U Exclusive;        // TRUE, device accepts only one request at a time
    OSDRV_NAME Name;        // device name, linked list
} OSDRV_CONFIG, *POSDRV_CONFIG;

// forward reference
struct _OSDRV_DISPATCH;
// Driver initialization function prototype
typedef INT8U(*POSDRV_INIT)(struct _OSDRV_DISPATCH* pDispatch,
            PVOID *ppContext, POSDRV_CONFIG pConfig);
// Driver Open function prototype
typedef INT8U(*POSDRV_OPEN)(INT8U DeviceIndex, PVOID pContext, INT8U Flags);
// Driver Close function prototype
typedef INT8U(*POSDRV_CLOSE)(INT8U DeviceIndex, PVOID pContext);
// Driver Read function prototype
typedef INT8U(*POSDRV_READ)(INT8U DeviceIndex, PVOID pContext, PVOID pBuffer,
            INT32U* pCount);
// Driver Write function prototype
typedef INT8U(*POSDRV_WRITE)(INT8U DeviceIndex, PVOID pContext, PVOID pBuffer,
            INT32U* pCount);
// Driver Ioctl function prototype
typedef INT8U(*POSDRV_IOCTL)(INT8U DeviceIndex, PVOID pContext, INT8U Control,
            PVOID pBuffer, INT32U* pCount);

// Dispatch function entry points for a driver
typedef struct _OSDRV_DISPATCH
{
    POSDRV_INIT pInit; // Initialization function
    POSDRV_OPEN pOpen; // Open function
    POSDRV_CLOSE pClose; // Close function
    POSDRV_READ pRead; // Read function
    POSDRV_WRITE pWrite; // Write function
    POSDRV_IOCTL pIoctl; // Ioctl function
} OSDRV_DISPATCH, *POSDRV_DISPATCH;

// the table of drivers to be supported in this build
// create this table, initializing only the Dispatch.pInit item
// and pass to OSDRV_Init() on startup
typedef struct
{
    OSDRV_DISPATCH Dispatch;        // dispatch table for driver
    OSDRV_CONFIG Config;            // configuration of device
    PVOID pContext;                         // context for driver, by Handle
    INT8U Initialized;                      // is device initialized
    INT8U RefCount;                         // reference count for driver
} OSDRV_DRIVER_ENTRY, *POSDRV_DRIVER_ENTRY;

// define driver specific errors status
//
// returned when hanlde was not created
#define OS_DRV_INVALID_HANDLE  ((HANDLE)0xFFFF)
// returned when device not found or not available
// (should be unique with ucos_ii.h OS_ errors)
#define OS_DRV_NO_ERR           OS_NO_ERR
#define OS_DRV_NO_DEVICE    200
// driver subsystem not initialized.
#define OS_DRV_NOT_INIT             201
// request not supported on this device
#define OS_DRV_UNSUPPORTED  202
// insufficient buffer size
#define OS_DRV_BUFFER_SIZE  203
// error, device is busy
#define OS_DRV_BUSY                 204
// error, bad data
#define OS_DRV_DATA                 205
// error, device error
#define OS_DRV_DEVICE               206

// Open Flags
// open for read
#define OSDRV_READ          0x01
// open for write
#define OSDRV_WRITE         0x02
// open for exclsuive
#define OSDRV_EXCLUSIVE     0x04

//driver model memory allocation routines
// only usable after OS starts
#define DRV_MEMALLOC(x) tmemalloc(x)
#define DRV_MEMFREE(x)  tmemfree(x)

// function prototypes
// driver subsystem initialization function
INT8U OSDRV_SubsysInit(POSDRV_DRIVER_ENTRY pDriverTable, INT8U Count);
// driver utility function prototypes
INT8U OSDRV_AddName(POSDRV_CONFIG pConfig, char * pName);

// prototypes for applications to use
// Open device
HANDLE Open(char *pName, INT8U Flags);
INT8U Close(HANDLE H);
INT8U Read(HANDLE H, PVOID pBuffer, INT32U* pLength);
INT8U Write(HANDLE H, PVOID pBuffer, INT32U* pLength);
INT8U Ioctl(HANDLE H, INT8U Control, PVOID pBuffer, INT32U* pLength);

#endif //__DRIVER__