SDL_syscdrom.c
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/*
SDL - Simple DirectMedia Layer
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Copyright (C) 1997-2006 Sam Lantinga
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This library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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Sam Lantinga
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slouken@libsdl.org
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*/
/* Functions for system-level CD-ROM audio control */
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <unistd.h>
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#include <sys/ioctl.h>
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#include <sys/cdio.h>
#include "SDL_cdrom.h"
#include "SDL_syscdrom.h"
/* The maximum number of CD-ROM drives we'll detect */
#define MAX_DRIVES 16
/* A list of available CD-ROM drives */
static char *SDL_cdlist[MAX_DRIVES];
static dev_t SDL_cdmode[MAX_DRIVES];
/* The system-dependent CD control functions */
static const char *SDL_SYS_CDName(int drive);
static int SDL_SYS_CDOpen(int drive);
static int SDL_SYS_CDGetTOC(SDL_CD *cdrom);
static CDstatus SDL_SYS_CDStatus(SDL_CD *cdrom, int *position);
static int SDL_SYS_CDPlay(SDL_CD *cdrom, int start, int length);
static int SDL_SYS_CDPause(SDL_CD *cdrom);
static int SDL_SYS_CDResume(SDL_CD *cdrom);
static int SDL_SYS_CDStop(SDL_CD *cdrom);
static int SDL_SYS_CDEject(SDL_CD *cdrom);
static void SDL_SYS_CDClose(SDL_CD *cdrom);
/* Some ioctl() errno values which occur when the tray is empty */
#define ERRNO_TRAYEMPTY(errno) \
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((errno == EIO) || (errno == ENOENT) || (errno == EINVAL) || \
(errno == ENODEV))
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/* Check a drive to see if it is a CD-ROM */
static int CheckDrive(char *drive, struct stat *stbuf)
{
int is_cd, cdfd;
struct ioc_read_subchannel info;
/* If it doesn't exist, return -1 */
if ( stat(drive, stbuf) < 0 ) {
return(-1);
}
/* If it does exist, verify that it's an available CD-ROM */
is_cd = 0;
if ( S_ISCHR(stbuf->st_mode) || S_ISBLK(stbuf->st_mode) ) {
cdfd = open(drive, (O_RDONLY|O_EXCL|O_NONBLOCK), 0);
if ( cdfd >= 0 ) {
info.address_format = CD_MSF_FORMAT;
info.data_format = CD_CURRENT_POSITION;
info.data_len = 0;
info.data = NULL;
/* Under Linux, EIO occurs when a disk is not present.
This isn't 100% reliable, so we use the USE_MNTENT
code above instead.
*/
if ( (ioctl(cdfd, CDIOCREADSUBCHANNEL, &info) == 0) ||
ERRNO_TRAYEMPTY(errno) ) {
is_cd = 1;
}
close(cdfd);
}
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else if (ERRNO_TRAYEMPTY(errno))
is_cd = 1;
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}
return(is_cd);
}
/* Add a CD-ROM drive to our list of valid drives */
static void AddDrive(char *drive, struct stat *stbuf)
{
int i;
if ( SDL_numcds < MAX_DRIVES ) {
/* Check to make sure it's not already in our list.
This can happen when we see a drive via symbolic link.
*/
for ( i=0; i<SDL_numcds; ++i ) {
if ( stbuf->st_rdev == SDL_cdmode[i] ) {
#ifdef DEBUG_CDROM
fprintf(stderr, "Duplicate drive detected: %s == %s\n", drive, SDL_cdlist[i]);
#endif
return;
}
}
/* Add this drive to our list */
i = SDL_numcds;
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SDL_cdlist[i] = (char *)SDL_malloc(SDL_strlen(drive)+1);
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if ( SDL_cdlist[i] == NULL ) {
SDL_OutOfMemory();
return;
}
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SDL_strcpy(SDL_cdlist[i], drive);
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SDL_cdmode[i] = stbuf->st_rdev;
++SDL_numcds;
#ifdef DEBUG_CDROM
fprintf(stderr, "Added CD-ROM drive: %s\n", drive);
#endif
}
}
int SDL_SYS_CDInit(void)
{
static char *checklist[] = {
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#ifdef __OpenBSD__
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"?0 cd?c", "cdrom", NULL
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#elif defined(__NetBSD__)
"?0 cd?d", "?0 cd?c", "cdrom", NULL
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#else
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"?0 cd?c", "?0 acd?c", "cdrom", NULL
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#endif
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};
char *SDLcdrom;
int i, j, exists;
char drive[32];
struct stat stbuf;
/* Fill in our driver capabilities */
SDL_CDcaps.Name = SDL_SYS_CDName;
SDL_CDcaps.Open = SDL_SYS_CDOpen;
SDL_CDcaps.GetTOC = SDL_SYS_CDGetTOC;
SDL_CDcaps.Status = SDL_SYS_CDStatus;
SDL_CDcaps.Play = SDL_SYS_CDPlay;
SDL_CDcaps.Pause = SDL_SYS_CDPause;
SDL_CDcaps.Resume = SDL_SYS_CDResume;
SDL_CDcaps.Stop = SDL_SYS_CDStop;
SDL_CDcaps.Eject = SDL_SYS_CDEject;
SDL_CDcaps.Close = SDL_SYS_CDClose;
/* Look in the environment for our CD-ROM drive list */
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SDLcdrom = SDL_getenv("SDL_CDROM"); /* ':' separated list of devices */
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if ( SDLcdrom != NULL ) {
char *cdpath, *delim;
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cdpath = SDL_malloc(SDL_strlen(SDLcdrom)+1);
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if ( cdpath != NULL ) {
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SDL_strcpy(cdpath, SDLcdrom);
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SDLcdrom = cdpath;
do {
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delim = SDL_strchr(SDLcdrom, ':');
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if ( delim ) {
*delim++ = '\0';
}
if ( CheckDrive(SDLcdrom, &stbuf) > 0 ) {
AddDrive(SDLcdrom, &stbuf);
}
if ( delim ) {
SDLcdrom = delim;
} else {
SDLcdrom = NULL;
}
} while ( SDLcdrom );
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SDL_free(cdpath);
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}
/* If we found our drives, there's nothing left to do */
if ( SDL_numcds > 0 ) {
return(0);
}
}
/* Scan the system for CD-ROM drives */
for ( i=0; checklist[i]; ++i ) {
if ( checklist[i][0] == '?' ) {
char *insert;
exists = 1;
for ( j=checklist[i][1]; exists; ++j ) {
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SDL_snprintf(drive, SDL_arraysize(drive), "/dev/%s", &checklist[i][3]);
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insert = SDL_strchr(drive, '?');
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if ( insert != NULL ) {
*insert = j;
}
switch (CheckDrive(drive, &stbuf)) {
/* Drive exists and is a CD-ROM */
case 1:
AddDrive(drive, &stbuf);
break;
/* Drive exists, but isn't a CD-ROM */
case 0:
break;
/* Drive doesn't exist */
case -1:
exists = 0;
break;
}
}
} else {
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SDL_snprintf(drive, SDL_arraysize(drive), "/dev/%s", checklist[i]);
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if ( CheckDrive(drive, &stbuf) > 0 ) {
AddDrive(drive, &stbuf);
}
}
}
return(0);
}
/* General ioctl() CD-ROM command function */
static int SDL_SYS_CDioctl(int id, int command, void *arg)
{
int retval;
retval = ioctl(id, command, arg);
if ( retval < 0 ) {
SDL_SetError("ioctl() error: %s", strerror(errno));
}
return(retval);
}
static const char *SDL_SYS_CDName(int drive)
{
return(SDL_cdlist[drive]);
}
static int SDL_SYS_CDOpen(int drive)
{
return(open(SDL_cdlist[drive], (O_RDONLY|O_EXCL|O_NONBLOCK), 0));
}
static int SDL_SYS_CDGetTOC(SDL_CD *cdrom)
{
struct ioc_toc_header toc;
int i, okay;
struct ioc_read_toc_entry entry;
struct cd_toc_entry data;
okay = 0;
if ( SDL_SYS_CDioctl(cdrom->id, CDIOREADTOCHEADER, &toc) == 0 ) {
cdrom->numtracks = toc.ending_track-toc.starting_track+1;
if ( cdrom->numtracks > SDL_MAX_TRACKS ) {
cdrom->numtracks = SDL_MAX_TRACKS;
}
/* Read all the track TOC entries */
for ( i=0; i<=cdrom->numtracks; ++i ) {
if ( i == cdrom->numtracks ) {
cdrom->track[i].id = 0xAA; /* CDROM_LEADOUT */
} else {
cdrom->track[i].id = toc.starting_track+i;
}
entry.starting_track = cdrom->track[i].id;
entry.address_format = CD_MSF_FORMAT;
entry.data_len = sizeof(data);
entry.data = &data;
if ( SDL_SYS_CDioctl(cdrom->id, CDIOREADTOCENTRYS,
&entry) < 0 ) {
break;
} else {
cdrom->track[i].type = data.control;
cdrom->track[i].offset = MSF_TO_FRAMES(
data.addr.msf.minute,
data.addr.msf.second,
data.addr.msf.frame);
cdrom->track[i].length = 0;
if ( i > 0 ) {
cdrom->track[i-1].length =
cdrom->track[i].offset-
cdrom->track[i-1].offset;
}
}
}
if ( i == (cdrom->numtracks+1) ) {
okay = 1;
}
}
return(okay ? 0 : -1);
}
/* Get CD-ROM status */
static CDstatus SDL_SYS_CDStatus(SDL_CD *cdrom, int *position)
{
CDstatus status;
struct ioc_toc_header toc;
struct ioc_read_subchannel info;
struct cd_sub_channel_info data;
info.address_format = CD_MSF_FORMAT;
info.data_format = CD_CURRENT_POSITION;
info.track = 0;
info.data_len = sizeof(data);
info.data = &data;
if ( ioctl(cdrom->id, CDIOCREADSUBCHANNEL, &info) < 0 ) {
if ( ERRNO_TRAYEMPTY(errno) ) {
status = CD_TRAYEMPTY;
} else {
status = CD_ERROR;
}
} else {
switch (data.header.audio_status) {
case CD_AS_AUDIO_INVALID:
case CD_AS_NO_STATUS:
/* Try to determine if there's a CD available */
if (ioctl(cdrom->id,CDIOREADTOCHEADER,&toc)==0)
status = CD_STOPPED;
else
status = CD_TRAYEMPTY;
break;
case CD_AS_PLAY_COMPLETED:
status = CD_STOPPED;
break;
case CD_AS_PLAY_IN_PROGRESS:
status = CD_PLAYING;
break;
case CD_AS_PLAY_PAUSED:
status = CD_PAUSED;
break;
default:
status = CD_ERROR;
break;
}
}
if ( position ) {
if ( status == CD_PLAYING || (status == CD_PAUSED) ) {
*position = MSF_TO_FRAMES(
data.what.position.absaddr.msf.minute,
data.what.position.absaddr.msf.second,
data.what.position.absaddr.msf.frame);
} else {
*position = 0;
}
}
return(status);
}
/* Start play */
static int SDL_SYS_CDPlay(SDL_CD *cdrom, int start, int length)
{
struct ioc_play_msf playtime;
FRAMES_TO_MSF(start,
&playtime.start_m, &playtime.start_s, &playtime.start_f);
FRAMES_TO_MSF(start+length,
&playtime.end_m, &playtime.end_s, &playtime.end_f);
#ifdef DEBUG_CDROM
fprintf(stderr, "Trying to play from %d:%d:%d to %d:%d:%d\n",
playtime.start_m, playtime.start_s, playtime.start_f,
playtime.end_m, playtime.end_s, playtime.end_f);
#endif
ioctl(cdrom->id, CDIOCSTART, 0);
return(SDL_SYS_CDioctl(cdrom->id, CDIOCPLAYMSF, &playtime));
}
/* Pause play */
static int SDL_SYS_CDPause(SDL_CD *cdrom)
{
return(SDL_SYS_CDioctl(cdrom->id, CDIOCPAUSE, 0));
}
/* Resume play */
static int SDL_SYS_CDResume(SDL_CD *cdrom)
{
return(SDL_SYS_CDioctl(cdrom->id, CDIOCRESUME, 0));
}
/* Stop play */
static int SDL_SYS_CDStop(SDL_CD *cdrom)
{
return(SDL_SYS_CDioctl(cdrom->id, CDIOCSTOP, 0));
}
/* Eject the CD-ROM */
static int SDL_SYS_CDEject(SDL_CD *cdrom)
{
return(SDL_SYS_CDioctl(cdrom->id, CDIOCEJECT, 0));
}
/* Close the CD-ROM handle */
static void SDL_SYS_CDClose(SDL_CD *cdrom)
{
close(cdrom->id);
}
void SDL_SYS_CDQuit(void)
{
int i;
if ( SDL_numcds > 0 ) {
for ( i=0; i<SDL_numcds; ++i ) {
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SDL_free(SDL_cdlist[i]);
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}
SDL_numcds = 0;
}
}