/**

 * $Id$

 *

 * 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;

    }

}