NetBSD/gnu/dist/gdb/rdi-share/devsw.h

267 lines
7.9 KiB
C

/*
* Copyright (C) 1995 Advanced RISC Machines Limited. All rights reserved.
*
* This software may be freely used, copied, modified, and distributed
* provided that the above copyright notice is preserved in all copies of the
* software.
*/
/* -*-C-*-
*
*
*/
#ifndef angsd_devsw_h
#define angsd_devsw_h
#include "devclnt.h"
#include "adperr.h"
#include "drivers.h"
#ifndef __cplusplus
typedef struct Packet Packet;
typedef struct DevSWState DevSWState;
#endif
/*
* the basic structure used for passing packets around
*/
struct Packet
{
struct Packet *pk_next; /* XXX first field in struct */
unsigned int pk_length;
unsigned char *pk_buffer;
};
/*
* control structure, used for maintaining device switcher state
*/
struct DevSWState
{
unsigned int ds_opendevchans; /* bitmap of open device channels */
/*
* queue of packets read for the various device channels
*/
Packet *ds_readqueue[DC_NUM_CHANNELS];
/*
* structures for managing active read and write operations
*/
Packet *ds_nextreadpacket;
DriverCall ds_activeread;
DriverCall ds_activewrite;
};
#ifdef __cplusplus
extern "C" {
#endif
/*
* Function: DevSW_AllocatePacket
* Purpose: Claim some memory to hold a struct Packet, and the buffer for
* that packet.
*
* Params:
* Input: length Size of the buffer in struct Packet.
*
* Returns:
* OK: Pointer to the newly malloc()ed Packet.
* Error: NULL
*/
Packet *DevSW_AllocatePacket(const unsigned int length);
/*
* Function: DevSW_FreePacket
* Purpose: Free the memory associated with a struct Packet.
*
* Pre-conditions The structure must have been originally claimed
* via DevSW_AllocatePacket.
*
* Params:
* Input: pk The packet to be freed.
*
* Returns: Nothing
*/
void DevSW_FreePacket(Packet *pk);
/*
* Function: DevSW_Open
* Purpose: Open the specified device driver
*
* Params:
* Input: name Identifies which device to open. This can either be
* a host specific identifier (e.g. "/dev/ttya",
* "COM1:"), or a number which is used to refer to
* `standard' interfaces, so "1" would be the first host
* interface, "2" the second, and so on.
*
* arg Driver specific arguments. For example, some serial
* drivers accept speed and control arguments such as
* "9600" or "19200/NO_BREAK". These arguments are
* completely free-form: it is the individual drivers
* which do the necessary interpretation.
*
* type The type of packet the caller is interested in. Only
* one open is allowed for each type of packet.
*
* In/Out: device The device driver to open
*
* Returns:
* OK: adp_ok
* Error: adp_device_open_failed
* adp_device_already_open
* adp_malloc_failure
*/
AdpErrs DevSW_Open(DeviceDescr *device, const char *name, const char *arg,
const DevChanID type);
/*
* Function: DevSW_Match
* Purpose: Minimal veneer for DeviceMatch
*
* Params:
* Input: device The device driver to match.
*
* name Identifies which device to open. This can either be
* a host specific identifier (e.g. "/dev/ttya",
* "COM1:"), or a number which is used to refer to
* `standard' interfaces, so "1" would be the first host
* interface, "2" the second, and so on.
*
* arg Driver specific arguments. For example, some serial
* drivers accept speed and control arguments such as
* "9600" or "19200/NO_BREAK". These arguments are
* completely free-form: it is the individual drivers
* which do the necessary interpretation.
*
* Returns:
* OK: adp_ok
* Error: adp_failed
*/
AdpErrs DevSW_Match(const DeviceDescr *device, const char *name,
const char *arg);
/*
* Function: DevSW_Close
* Purpose: Close the specified device driver. All packets of the type
* used by the caller held within the switching layer will
* be discarded.
*
* Pre-conditions: Device must have been previously opened.
*
* Params:
* Input: device The device driver to close
*
* type The type of packet the caller was interested in.
*
* Returns:
* OK: adp_ok
* Error: adp_device_not_open
*/
AdpErrs DevSW_Close(const DeviceDescr *device, const DevChanID type);
/*
* Function: DevSW_Read
* Purpose: Read a packet of appropriate type from the device driver
*
* Params:
* Input: device The device driver to read packet from.
*
* type The type of packet the caller is interested in.
*
* Output: packet Pointer to new packet (if one is available)
* NULL (if no complete packet is available)
*
* Input: block If TRUE, read may safely block for a short period
* of time (say up to 20ms), to avoid high CPU load
* whilst waiting for a reply.
* If FALSE, read MUST NOT block.
*
* Returns:
* OK: adp_ok
* Error: adp_bad_packet
*
* Post-conditions: The calling function is responsible for freeing the
* resources used by the packet when it is no longer
* needed.
*/
AdpErrs DevSW_Read(const DeviceDescr *device, const DevChanID type,
Packet **packet, bool block);
/*
* Function: DevSW_Write
* Purpose: Try to write a packet to the device driver. The write will
* be bounced if another write is still in progress.
*
* Params:
* Input: device The device driver to write a packet to.
*
* packet The packet to be written.
*
* type The type to be assigned to the packet.
*
* Returns:
* OK: adp_ok
* Error: adp_illegal_args
* adp_write_busy
*
* Post-conditions: The calling function retains "ownership" of the packet,
* i.e. it is responsible for freeing the resources used
* by the packet when it is no longer needed.
*/
AdpErrs DevSW_Write(const DeviceDescr *device, Packet *packet, DevChanID type);
/*
* Function: DevSW_FlushPendingWrite
* Purpose: If a write is in progress, give it a chance to finish.
*
* Params:
* Input: device The device driver to flush.
*
* Returns:
* adp_ok no pending write, or write flushed completely
* adp_write_busy pending write not flushed completely
*/
AdpErrs DevSW_FlushPendingWrite(const DeviceDescr *device);
/*
* Function: DevSW_Ioctl
* Purpose: Perform miscellaneous control operations. This is a minimal
* veneer to DeviceIoctl.
*
* Params:
* Input: device The device driver to control.
*
* opcode Reason code indicating the operation to perform.
*
* In/Out: args Pointer to opcode-sensitive arguments/result space.
*
* Returns:
* OK: adp_ok
* Error: adp_failed
*/
AdpErrs DevSW_Ioctl(const DeviceDescr *device, const int opcode, void *args);
/*
* Function: DevSW_WriteFinished
* Purpose: Return TRUE if the active device has finished writing
* the last packet to be sent, or FALSE if a packet is still
* being transmitted.
*
* Params:
* Input: device The device driver to check.
*
* Returns:
* TRUE: write finished or inactive
* FALSE: write in progress
*/
bool DevSW_WriteFinished(const DeviceDescr *device);
#ifdef __cplusplus
}
#endif
#endif /* ndef angsd_devsw_h */
/* EOF devsw.h */