/**

  * $Id$

  *

  * Linux cd-rom device driver. 

  *

  * Copyright (c) 2005 Nathan Keynes.

  *

  * This program is free software; you can redistribute it and/or modify

  * it under the terms of the GNU General Public License as published by

  * the Free Software Foundation; either version 2 of the License, or

  * (at your option) any later version.

  *

  * This program 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 General Public License for more details.

  */

 #include <unistd.h>

 #include <stdlib.h>

 #include <stdio.h>

 #include <string.h>

 #include <errno.h>

 #include <linux/cdrom.h>

 #include <sys/stat.h>

 #include <sys/ioctl.h>

 #include <fstab.h>

 #include <fcntl.h>

 #include "gdrom/gddriver.h"

 #include "gdrom/packet.h"

 #include "dream.h"

 #define MAXTOCENTRIES 600  /* This is a fairly generous overestimate really */

 #define MAXTOCSIZE 4 + (MAXTOCENTRIES*11)

 #define MAX_SECTORS_PER_CALL 1

 static uint32_t inline lbatomsf( uint32_t lba ) {

     union cdrom_addr addr;

     lba = lba + CD_MSF_OFFSET;

     addr.msf.frame = lba % CD_FRAMES;

     int seconds = lba / CD_FRAMES;

     addr.msf.second = seconds % CD_SECS;

     addr.msf.minute = seconds / CD_SECS;

     return addr.lba;

 }

 #define LBATOMSF( lba ) lbatomsf(lba)

 static gboolean linux_image_is_valid( FILE *f );

 static gdrom_disc_t linux_open_device( const gchar *filename, FILE *f );

 static gdrom_error_t linux_read_disc_toc( gdrom_image_t disc );

 static gdrom_error_t linux_read_sector( gdrom_disc_t disc, uint32_t sector,

                                         int mode, unsigned char *buf, uint32_t *length );

 static gdrom_error_t linux_send_command( int fd, char *cmd, unsigned char *buffer, size_t *buflen,

                                          int direction );

 static int linux_drive_status( gdrom_disc_t disc );

 struct gdrom_image_class cdrom_device_class = { "Linux", NULL,

         linux_image_is_valid, linux_open_device };

 GList *cdrom_get_native_devices(void)

 {

     GList *list = NULL;

     struct fstab *ent;

     struct stat st;

     setfsent();

     while( (ent = getfsent()) != NULL ) {

         if( (stat(ent->fs_spec, &st) != -1) && 

                 S_ISBLK(st.st_mode) ) {

             /* Got a valid block device - is it a CDROM? */

             int fd = open(ent->fs_spec, O_RDONLY|O_NONBLOCK);

             if( fd == -1 )

                 continue;

             int caps = ioctl(fd, CDROM_GET_CAPABILITY);

             if( caps != -1 ) {

                 /* Appears to support CDROM functions */

                 list = g_list_append( list, gdrom_device_new(ent->fs_spec, ent->fs_spec));

             }

             close(fd);

         }

     }

     return list;

 }

 gdrom_disc_t cdrom_open_device( const gchar *method, const gchar *path )

 {

     return NULL;

 }

 static gboolean linux_image_is_valid( FILE *f )

 {

     struct stat st;

     struct cdrom_tochdr tochdr;

     if( fstat(fileno(f), &st) == -1 ) {

         return FALSE; /* can't stat device? */

     }

     if( !S_ISBLK(st.st_mode) ) {

         return FALSE; /* Not a block device */

     }

     if( ioctl(fileno(f), CDROMREADTOCHDR, &tochdr) == -1 ) {

         /* Quick check that this is really a CD */

         return FALSE;

     }

     return TRUE;

 }

 static gdrom_disc_t linux_open_device( const gchar *filename, FILE *f ) 

 {

     gdrom_disc_t disc;

     disc = gdrom_image_new(filename, f);

     if( disc == NULL ) {

         ERROR("Unable to allocate memory!");

         return NULL;

     }

     gdrom_error_t status = linux_read_disc_toc( (gdrom_image_t)disc );

     if( status != 0 ) {

         gdrom_image_destroy_no_close(disc);

         if( status == 0xFFFF ) {

             ERROR("Unable to load disc table of contents (%s)", strerror(errno));

         } else {

             ERROR("Unable to load disc table of contents (sense %d,%d)",

                     status &0xFF, status >> 8 );

         }

         return NULL;

     }

     disc->read_sector = linux_read_sector;

     disc->drive_status = linux_drive_status;

     return disc;

 }

 static int linux_drive_status( gdrom_disc_t disc )

 {

     int fd = fileno(((gdrom_image_t)disc)->file);

     int status = ioctl(fd, CDROM_DRIVE_STATUS, CDSL_CURRENT);

     if( status == CDS_DISC_OK ) {

         status = ioctl(fd, CDROM_MEDIA_CHANGED, CDSL_CURRENT);

         if( status != 0 ) {

             linux_read_disc_toc( (gdrom_image_t)disc);

         }

         return ((gdrom_image_t)disc)->disc_type | IDE_DISC_READY;

     } else {

         return IDE_DISC_NONE;

     }

 }

 /**

  * Read the full table of contents into the disc from the device.

  */

 static gdrom_error_t linux_read_disc_toc( gdrom_image_t disc )

 {

     int fd = fileno(disc->file);

     unsigned char buf[MAXTOCSIZE];

     size_t buflen = sizeof(buf);

     char cmd[12] = { 0x43, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

     cmd[7] = (sizeof(buf))>>8;

     cmd[8] = (sizeof(buf))&0xFF;

     memset( buf, 0, sizeof(buf) );

     gdrom_error_t status = linux_send_command( fd, cmd, buf, &buflen, CGC_DATA_READ );

     if( status != 0 ) {

         return status;

     }

     mmc_parse_toc2( disc, buf );

     return 0;

 }

 gdrom_error_t linux_play_audio( gdrom_disc_t disc, uint32_t lba, uint32_t endlba )

 {

     int fd = fileno( ((gdrom_image_t)disc)->file );

     uint32_t real_sector = lba - CD_MSF_OFFSET;

     uint32_t length = endlba - lba;

     uint32_t buflen = 0;

     char cmd[12] = { 0xA5, 0,0,0, 0,0,0,0, 0,0,0,0 };

     cmd[2] = (real_sector >> 24) & 0xFF;

     cmd[3] = (real_sector >> 16) & 0xFF;

     cmd[4] = (real_sector >> 8) & 0xFF;

     cmd[5] = real_sector & 0xFF;

     cmd[6] = (length >> 24) & 0xFF;

     cmd[7] = (length >> 16) & 0xFF;

     cmd[8] = (length >> 8) & 0xFF;

     cmd[9] = length & 0xFF;

     return linux_send_command( fd, cmd, NULL, &buflen, CGC_DATA_NONE );

 }

 gdrom_error_t linux_stop_audio( gdrom_disc_t disc )

 {

     int fd = fileno( ((gdrom_image_t)disc)->file );

     uint32_t buflen = 0;

     char cmd[12] = {0x4E,0,0,0, 0,0,0,0, 0,0,0,0};

     return linux_send_command( fd, cmd, NULL, &buflen, CGC_DATA_NONE );

 }

 static gdrom_error_t linux_read_sector( gdrom_disc_t disc, uint32_t sector,

                                         int mode, unsigned char *buf, uint32_t *length )

 {

     gdrom_image_t image = (gdrom_image_t)disc;

     int fd = fileno(image->file);

     uint32_t real_sector = sector - CD_MSF_OFFSET;

     uint32_t sector_size = MAX_SECTOR_SIZE;

     char cmd[12];

     mmc_make_read_cd_cmd( cmd, real_sector, mode );

     gdrom_error_t status = linux_send_command( fd, cmd, buf, &sector_size, CGC_DATA_READ );

     if( status != 0 ) {

         return status;

     }

     *length = 2048;

     return 0;

 }

 /**

  * Send a packet command to the device and wait for a response. 

  * @return 0 on success, -1 on an operating system error, or a sense error

  * code on a device error.

  */

 static gdrom_error_t linux_send_command( int fd, char *cmd, unsigned char *buffer, size_t *buflen,

                                          int direction )

 {

     struct request_sense sense;

     struct cdrom_generic_command cgc;

     memset( &cgc, 0, sizeof(cgc) );

     memset( &sense, 0, sizeof(sense) );

     memcpy( cgc.cmd, cmd, 12 );

     cgc.buffer = buffer;

     cgc.buflen = *buflen;

     cgc.sense = &sense;

     cgc.data_direction = direction;

     if( ioctl(fd, CDROM_SEND_PACKET, &cgc) < 0 ) {

         if( sense.sense_key == 0 ) {

             return -1; 

         } else {

             /* TODO: Map newer codes back to the ones used by the gd-rom. */

             return sense.sense_key | (sense.asc<<8);

         }

     } else {

         *buflen = cgc.buflen;

         return 0;

     }

 }