#include <linux/kernel.h>
  #include <linux/mm.h>
  #include <linux/fs.h>
  #include <linux/errno.h>
  #include <linux/string.h>
  #include <linux/blkdev.h>
  #include <linux/module.h>
  #include <linux/blkpg.h>
  #include <linux/cdrom.h>
  #include <linux/delay.h>
  #include <linux/slab.h>
  #include <asm/io.h>
  #include <asm/uaccess.h>
  
  #include <scsi/scsi.h>
  #include <scsi/scsi_dbg.h>
  #include <scsi/scsi_device.h>
  #include <scsi/scsi_eh.h>
  #include <scsi/scsi_host.h>
  #include <scsi/scsi_ioctl.h>
  #include <scsi/scsi_cmnd.h>
  
  #include "sr.h"
  
  #if 0
  #define DEBUG
  #endif
  
  /* The sr_is_xa() seems to trigger firmware bugs with some drives :-(
   * It is off by default and can be turned on with this module parameter */
  static int xa_test = 0;
  
  module_param(xa_test, int, S_IRUGO | S_IWUSR);
  
  /* primitive to determine whether we need to have GFP_DMA set based on
   * the status of the unchecked_isa_dma flag in the host structure */
  #define SR_GFP_DMA(cd) (((cd)->device->host->unchecked_isa_dma) ? GFP_DMA : 0)
  
  
  static int sr_read_tochdr(struct cdrom_device_info *cdi,
  		struct cdrom_tochdr *tochdr)
  {
  	struct scsi_cd *cd = cdi->handle;
  	struct packet_command cgc;
  	int result;
  	unsigned char *buffer;
  
  	buffer = kmalloc(32, GFP_KERNEL | SR_GFP_DMA(cd));
  	if (!buffer)
  		return -ENOMEM;
  
  	memset(&cgc, 0, sizeof(struct packet_command));
  	cgc.timeout = IOCTL_TIMEOUT;
  	cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
  	cgc.cmd[8] = 12;		/* LSB of length */
  	cgc.buffer = buffer;
  	cgc.buflen = 12;
  	cgc.quiet = 1;
  	cgc.data_direction = DMA_FROM_DEVICE;
  
  	result = sr_do_ioctl(cd, &cgc);
  
  	tochdr->cdth_trk0 = buffer[2];
  	tochdr->cdth_trk1 = buffer[3];
  
  	kfree(buffer);
  	return result;
  }
  
  static int sr_read_tocentry(struct cdrom_device_info *cdi,
  		struct cdrom_tocentry *tocentry)
  {
  	struct scsi_cd *cd = cdi->handle;
  	struct packet_command cgc;
  	int result;
  	unsigned char *buffer;
  
  	buffer = kmalloc(32, GFP_KERNEL | SR_GFP_DMA(cd));
  	if (!buffer)
  		return -ENOMEM;
  
  	memset(&cgc, 0, sizeof(struct packet_command));
  	cgc.timeout = IOCTL_TIMEOUT;
  	cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
  	cgc.cmd[1] |= (tocentry->cdte_format == CDROM_MSF) ? 0x02 : 0;
  	cgc.cmd[6] = tocentry->cdte_track;
  	cgc.cmd[8] = 12;		/* LSB of length */
  	cgc.buffer = buffer;
  	cgc.buflen = 12;
  	cgc.data_direction = DMA_FROM_DEVICE;
  
  	result = sr_do_ioctl(cd, &cgc);
  
  	tocentry->cdte_ctrl = buffer[5] & 0xf;
  	tocentry->cdte_adr = buffer[5] >> 4;
  	tocentry->cdte_datamode = (tocentry->cdte_ctrl & 0x04) ? 1 : 0;
  	if (tocentry->cdte_format == CDROM_MSF) {
  		tocentry->cdte_addr.msf.minute = buffer[9];
  		tocentry->cdte_addr.msf.second = buffer[10];
  		tocentry->cdte_addr.msf.frame = buffer[11];
  	} else
  		tocentry->cdte_addr.lba = (((((buffer[8] << 8) + buffer[9]) << 8)
  			+ buffer[10]) << 8) + buffer[11];
  
  	kfree(buffer);
  	return result;
  }
  
  #define IOCTL_RETRIES 3
  
  /* ATAPI drives don't have a SCMD_PLAYAUDIO_TI command.  When these drives
     are emulating a SCSI device via the idescsi module, they need to have
     CDROMPLAYTRKIND commands translated into CDROMPLAYMSF commands for them */
  
  static int sr_fake_playtrkind(struct cdrom_device_info *cdi, struct cdrom_ti *ti)
  {
  	struct cdrom_tocentry trk0_te, trk1_te;
  	struct cdrom_tochdr tochdr;
  	struct packet_command cgc;
  	int ntracks, ret;
  
  	ret = sr_read_tochdr(cdi, &tochdr);
  	if (ret)
  		return ret;
  
  	ntracks = tochdr.cdth_trk1 - tochdr.cdth_trk0 + 1;
  	
  	if (ti->cdti_trk1 == ntracks) 
  		ti->cdti_trk1 = CDROM_LEADOUT;
  	else if (ti->cdti_trk1 != CDROM_LEADOUT)
  		ti->cdti_trk1 ++;
  
  	trk0_te.cdte_track = ti->cdti_trk0;
  	trk0_te.cdte_format = CDROM_MSF;
  	trk1_te.cdte_track = ti->cdti_trk1;
  	trk1_te.cdte_format = CDROM_MSF;
  	
  	ret = sr_read_tocentry(cdi, &trk0_te);
  	if (ret)
  		return ret;
  	ret = sr_read_tocentry(cdi, &trk1_te);
  	if (ret)
  		return ret;
  
  	memset(&cgc, 0, sizeof(struct packet_command));
  	cgc.cmd[0] = GPCMD_PLAY_AUDIO_MSF;
  	cgc.cmd[3] = trk0_te.cdte_addr.msf.minute;
  	cgc.cmd[4] = trk0_te.cdte_addr.msf.second;
  	cgc.cmd[5] = trk0_te.cdte_addr.msf.frame;
  	cgc.cmd[6] = trk1_te.cdte_addr.msf.minute;
  	cgc.cmd[7] = trk1_te.cdte_addr.msf.second;
  	cgc.cmd[8] = trk1_te.cdte_addr.msf.frame;
  	cgc.data_direction = DMA_NONE;
  	cgc.timeout = IOCTL_TIMEOUT;
  	return sr_do_ioctl(cdi->handle, &cgc);
  }
  
  static int sr_play_trkind(struct cdrom_device_info *cdi,
  		struct cdrom_ti *ti)
  
  {
  	struct scsi_cd *cd = cdi->handle;
  	struct packet_command cgc;
  	int result;
  
  	memset(&cgc, 0, sizeof(struct packet_command));
  	cgc.timeout = IOCTL_TIMEOUT;
  	cgc.cmd[0] = GPCMD_PLAYAUDIO_TI;
  	cgc.cmd[4] = ti->cdti_trk0;
  	cgc.cmd[5] = ti->cdti_ind0;
  	cgc.cmd[7] = ti->cdti_trk1;
  	cgc.cmd[8] = ti->cdti_ind1;
  	cgc.data_direction = DMA_NONE;
  
  	result = sr_do_ioctl(cd, &cgc);
  	if (result == -EDRIVE_CANT_DO_THIS)
  		result = sr_fake_playtrkind(cdi, ti);
  
  	return result;
  }
  
  /* We do our own retries because we want to know what the specific
     error code is.  Normally the UNIT_ATTENTION code will automatically
     clear after one error */
  
  int sr_do_ioctl(Scsi_CD *cd, struct packet_command *cgc)
  {
  	struct scsi_device *SDev;
  	struct scsi_sense_hdr sshdr;
  	int result, err = 0, retries = 0;
  	struct request_sense *sense = cgc->sense;
  
  	SDev = cd->device;
  
  	if (!sense) {
  		sense = kmalloc(SCSI_SENSE_BUFFERSIZE, GFP_KERNEL);
  		if (!sense) {
  			err = -ENOMEM;
  			goto out;
  		}
  	}
  
        retry:
  	if (!scsi_block_when_processing_errors(SDev)) {
  		err = -ENODEV;
  		goto out;
  	}
  
  	memset(sense, 0, sizeof(*sense));
  	result = scsi_execute(SDev, cgc->cmd, cgc->data_direction,
  			      cgc->buffer, cgc->buflen, (char *)sense,
  			      cgc->timeout, IOCTL_RETRIES, 0, NULL);
  
  	scsi_normalize_sense((char *)sense, sizeof(*sense), &sshdr);
  
  	/* Minimal error checking.  Ignore cases we know about, and report the rest. */
  	if (driver_byte(result) != 0) {
  		switch (sshdr.sense_key) {
  		case UNIT_ATTENTION:
  			SDev->changed = 1;
  			if (!cgc->quiet)
  				printk(KERN_INFO "%s: disc change detected.
  ", cd->cdi.name);
  			if (retries++ < 10)
  				goto retry;
  			err = -ENOMEDIUM;
  			break;
  		case NOT_READY:	/* This happens if there is no disc in drive */
  			if (sshdr.asc == 0x04 &&
  			    sshdr.ascq == 0x01) {
  				/* sense: Logical unit is in process of becoming ready */
  				if (!cgc->quiet)
  					printk(KERN_INFO "%s: CDROM not ready yet.
  ", cd->cdi.name);
  				if (retries++ < 10) {
  					/* sleep 2 sec and try again */
  					ssleep(2);
  					goto retry;
  				} else {
  					/* 20 secs are enough? */
  					err = -ENOMEDIUM;
  					break;
  				}
  			}
  			if (!cgc->quiet)
  				printk(KERN_INFO "%s: CDROM not ready.  Make sure there is a disc in the drive.
  ", cd->cdi.name);
  #ifdef DEBUG
  			scsi_print_sense_hdr("sr", &sshdr);
  #endif
  			err = -ENOMEDIUM;
  			break;
  		case ILLEGAL_REQUEST:
  			err = -EIO;
  			if (sshdr.asc == 0x20 &&
  			    sshdr.ascq == 0x00)
  				/* sense: Invalid command operation code */
  				err = -EDRIVE_CANT_DO_THIS;
  #ifdef DEBUG
  			__scsi_print_command(cgc->cmd);
  			scsi_print_sense_hdr("sr", &sshdr);
  #endif
  			break;
  		default:
  			printk(KERN_ERR "%s: CDROM (ioctl) error, command: ", cd->cdi.name);
  			__scsi_print_command(cgc->cmd);
  			scsi_print_sense_hdr("sr", &sshdr);
  			err = -EIO;
  		}
  	}
  
  	/* Wake up a process waiting for device */
        out:
  	if (!cgc->sense)
  		kfree(sense);
  	cgc->stat = err;
  	return err;
  }
  
  /* ---------------------------------------------------------------------- */
  /* interface to cdrom.c                                                   */
  
  int sr_tray_move(struct cdrom_device_info *cdi, int pos)
  {
  	Scsi_CD *cd = cdi->handle;
  	struct packet_command cgc;
  
  	memset(&cgc, 0, sizeof(struct packet_command));
  	cgc.cmd[0] = GPCMD_START_STOP_UNIT;
  	cgc.cmd[4] = (pos == 0) ? 0x03 /* close */ : 0x02 /* eject */ ;
  	cgc.data_direction = DMA_NONE;
  	cgc.timeout = IOCTL_TIMEOUT;
  	return sr_do_ioctl(cd, &cgc);
  }
  
  int sr_lock_door(struct cdrom_device_info *cdi, int lock)
  {
  	Scsi_CD *cd = cdi->handle;
  
  	return scsi_set_medium_removal(cd->device, lock ?
  		       SCSI_REMOVAL_PREVENT : SCSI_REMOVAL_ALLOW);
  }
  
  int sr_drive_status(struct cdrom_device_info *cdi, int slot)
  {
  	struct scsi_cd *cd = cdi->handle;
  	struct scsi_sense_hdr sshdr;
  	struct media_event_desc med;
  
  	if (CDSL_CURRENT != slot) {
  		/* we have no changer support */
  		return -EINVAL;
  	}
  	if (!scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr))
  		return CDS_DISC_OK;
  
  	/* SK/ASC/ASCQ of 2/4/1 means "unit is becoming ready" */
  	if (scsi_sense_valid(&sshdr) && sshdr.sense_key == NOT_READY
  			&& sshdr.asc == 0x04 && sshdr.ascq == 0x01)
  		return CDS_DRIVE_NOT_READY;
  
  	if (!cdrom_get_media_event(cdi, &med)) {
  		if (med.media_present)
  			return CDS_DISC_OK;
  		else if (med.door_open)
  			return CDS_TRAY_OPEN;
  		else
  			return CDS_NO_DISC;
  	}
  
  	/*
  	 * SK/ASC/ASCQ of 2/4/2 means "initialization required"
  	 * Using CD_TRAY_OPEN results in an START_STOP_UNIT to close
  	 * the tray, which resolves the initialization requirement.
  	 */
  	if (scsi_sense_valid(&sshdr) && sshdr.sense_key == NOT_READY
  			&& sshdr.asc == 0x04 && sshdr.ascq == 0x02)
  		return CDS_TRAY_OPEN;
  
  	/*
  	 * 0x04 is format in progress .. but there must be a disc present!
  	 */
  	if (sshdr.sense_key == NOT_READY && sshdr.asc == 0x04)
  		return CDS_DISC_OK;
  
  	/*
  	 * If not using Mt Fuji extended media tray reports,
  	 * just return TRAY_OPEN since ATAPI doesn't provide
  	 * any other way to detect this...
  	 */
  	if (scsi_sense_valid(&sshdr) &&
  	    /* 0x3a is medium not present */
  	    sshdr.asc == 0x3a)
  		return CDS_NO_DISC;
  	else
  		return CDS_TRAY_OPEN;
  
  	return CDS_DRIVE_NOT_READY;
  }
  
  int sr_disk_status(struct cdrom_device_info *cdi)
  {
  	Scsi_CD *cd = cdi->handle;
  	struct cdrom_tochdr toc_h;
  	struct cdrom_tocentry toc_e;
  	int i, rc, have_datatracks = 0;
  
  	/* look for data tracks */
  	rc = sr_read_tochdr(cdi, &toc_h);
  	if (rc)
  		return (rc == -ENOMEDIUM) ? CDS_NO_DISC : CDS_NO_INFO;
  
  	for (i = toc_h.cdth_trk0; i <= toc_h.cdth_trk1; i++) {
  		toc_e.cdte_track = i;
  		toc_e.cdte_format = CDROM_LBA;
  		if (sr_read_tocentry(cdi, &toc_e))
  			return CDS_NO_INFO;
  		if (toc_e.cdte_ctrl & CDROM_DATA_TRACK) {
  			have_datatracks = 1;
  			break;
  		}
  	}
  	if (!have_datatracks)
  		return CDS_AUDIO;
  
  	if (cd->xa_flag)
  		return CDS_XA_2_1;
  	else
  		return CDS_DATA_1;
  }
  
  int sr_get_last_session(struct cdrom_device_info *cdi,
  			struct cdrom_multisession *ms_info)
  {
  	Scsi_CD *cd = cdi->handle;
  
  	ms_info->addr.lba = cd->ms_offset;
  	ms_info->xa_flag = cd->xa_flag || cd->ms_offset > 0;
  
  	return 0;
  }
  
  int sr_get_mcn(struct cdrom_device_info *cdi, struct cdrom_mcn *mcn)
  {
  	Scsi_CD *cd = cdi->handle;
  	struct packet_command cgc;
  	char *buffer = kmalloc(32, GFP_KERNEL | SR_GFP_DMA(cd));
  	int result;
  
  	if (!buffer)
  		return -ENOMEM;
  
  	memset(&cgc, 0, sizeof(struct packet_command));
  	cgc.cmd[0] = GPCMD_READ_SUBCHANNEL;
  	cgc.cmd[2] = 0x40;	/* I do want the subchannel info */
  	cgc.cmd[3] = 0x02;	/* Give me medium catalog number info */
  	cgc.cmd[8] = 24;
  	cgc.buffer = buffer;
  	cgc.buflen = 24;
  	cgc.data_direction = DMA_FROM_DEVICE;
  	cgc.timeout = IOCTL_TIMEOUT;
  	result = sr_do_ioctl(cd, &cgc);
  
  	memcpy(mcn->medium_catalog_number, buffer + 9, 13);
  	mcn->medium_catalog_number[13] = 0;
  
  	kfree(buffer);
  	return result;
  }
  
  int sr_reset(struct cdrom_device_info *cdi)
  {
  	return 0;
  }
  
  int sr_select_speed(struct cdrom_device_info *cdi, int speed)
  {
  	Scsi_CD *cd = cdi->handle;
  	struct packet_command cgc;
  
  	if (speed == 0)
  		speed = 0xffff;	/* set to max */
  	else
  		speed *= 177;	/* Nx to kbyte/s */
  
  	memset(&cgc, 0, sizeof(struct packet_command));
  	cgc.cmd[0] = GPCMD_SET_SPEED;	/* SET CD SPEED */
  	cgc.cmd[2] = (speed >> 8) & 0xff;	/* MSB for speed (in kbytes/sec) */
  	cgc.cmd[3] = speed & 0xff;	/* LSB */
  	cgc.data_direction = DMA_NONE;
  	cgc.timeout = IOCTL_TIMEOUT;
  
  	if (sr_do_ioctl(cd, &cgc))
  		return -EIO;
  	return 0;
  }
  
  /* ----------------------------------------------------------------------- */
  /* this is called by the generic cdrom driver. arg is a _kernel_ pointer,  */
  /* because the generic cdrom driver does the user access stuff for us.     */
  /* only cdromreadtochdr and cdromreadtocentry are left - for use with the  */
  /* sr_disk_status interface for the generic cdrom driver.                  */
  
  int sr_audio_ioctl(struct cdrom_device_info *cdi, unsigned int cmd, void *arg)
  {
  	switch (cmd) {
  	case CDROMREADTOCHDR:
  		return sr_read_tochdr(cdi, arg);
  	case CDROMREADTOCENTRY:
  		return sr_read_tocentry(cdi, arg);
  	case CDROMPLAYTRKIND:
  		return sr_play_trkind(cdi, arg);
  	default:
  		return -EINVAL;
  	}
  }
  
  /* -----------------------------------------------------------------------
   * a function to read all sorts of funny cdrom sectors using the READ_CD
   * scsi-3 mmc command
   *
   * lba:     linear block address
   * format:  0 = data (anything)
   *          1 = audio
   *          2 = data (mode 1)
   *          3 = data (mode 2)
   *          4 = data (mode 2 form1)
   *          5 = data (mode 2 form2)
   * blksize: 2048 | 2336 | 2340 | 2352
   */
  
  static int sr_read_cd(Scsi_CD *cd, unsigned char *dest, int lba, int format, int blksize)
  {
  	struct packet_command cgc;
  
  #ifdef DEBUG
  	printk("%s: sr_read_cd lba=%d format=%d blksize=%d
  ",
  	       cd->cdi.name, lba, format, blksize);
  #endif
  
  	memset(&cgc, 0, sizeof(struct packet_command));
  	cgc.cmd[0] = GPCMD_READ_CD;	/* READ_CD */
  	cgc.cmd[1] = ((format & 7) << 2);
  	cgc.cmd[2] = (unsigned char) (lba >> 24) & 0xff;
  	cgc.cmd[3] = (unsigned char) (lba >> 16) & 0xff;
  	cgc.cmd[4] = (unsigned char) (lba >> 8) & 0xff;
  	cgc.cmd[5] = (unsigned char) lba & 0xff;
  	cgc.cmd[8] = 1;
  	switch (blksize) {
  	case 2336:
  		cgc.cmd[9] = 0x58;
  		break;
  	case 2340:
  		cgc.cmd[9] = 0x78;
  		break;
  	case 2352:
  		cgc.cmd[9] = 0xf8;
  		break;
  	default:
  		cgc.cmd[9] = 0x10;
  		break;
  	}
  	cgc.buffer = dest;
  	cgc.buflen = blksize;
  	cgc.data_direction = DMA_FROM_DEVICE;
  	cgc.timeout = IOCTL_TIMEOUT;
  	return sr_do_ioctl(cd, &cgc);
  }
  
  /*
   * read sectors with blocksizes other than 2048
   */
  
  static int sr_read_sector(Scsi_CD *cd, int lba, int blksize, unsigned char *dest)
  {
  	struct packet_command cgc;
  	int rc;
  
  	/* we try the READ CD command first... */
  	if (cd->readcd_known) {
  		rc = sr_read_cd(cd, dest, lba, 0, blksize);
  		if (-EDRIVE_CANT_DO_THIS != rc)
  			return rc;
  		cd->readcd_known = 0;
  		printk("CDROM does'nt support READ CD (0xbe) command
  ");
  		/* fall & retry the other way */
  	}
  	/* ... if this fails, we switch the blocksize using MODE SELECT */
  	if (blksize != cd->device->sector_size) {
  		if (0 != (rc = sr_set_blocklength(cd, blksize)))
  			return rc;
  	}
  #ifdef DEBUG
  	printk("%s: sr_read_sector lba=%d blksize=%d
  ", cd->cdi.name, lba, blksize);
  #endif
  
  	memset(&cgc, 0, sizeof(struct packet_command));
  	cgc.cmd[0] = GPCMD_READ_10;
  	cgc.cmd[2] = (unsigned char) (lba >> 24) & 0xff;
  	cgc.cmd[3] = (unsigned char) (lba >> 16) & 0xff;
  	cgc.cmd[4] = (unsigned char) (lba >> 8) & 0xff;
  	cgc.cmd[5] = (unsigned char) lba & 0xff;
  	cgc.cmd[8] = 1;
  	cgc.buffer = dest;
  	cgc.buflen = blksize;
  	cgc.data_direction = DMA_FROM_DEVICE;
  	cgc.timeout = IOCTL_TIMEOUT;
  	rc = sr_do_ioctl(cd, &cgc);
  
  	return rc;
  }
  
  /*
   * read a sector in raw mode to check the sector format
   * ret: 1 == mode2 (XA), 0 == mode1, <0 == error 
   */
  
  int sr_is_xa(Scsi_CD *cd)
  {
  	unsigned char *raw_sector;
  	int is_xa;
  
  	if (!xa_test)
  		return 0;
  
  	raw_sector = kmalloc(2048, GFP_KERNEL | SR_GFP_DMA(cd));
  	if (!raw_sector)
  		return -ENOMEM;
  	if (0 == sr_read_sector(cd, cd->ms_offset + 16,
  				CD_FRAMESIZE_RAW1, raw_sector)) {
  		is_xa = (raw_sector[3] == 0x02) ? 1 : 0;
  	} else {
  		/* read a raw sector failed for some reason. */
  		is_xa = -1;
  	}
  	kfree(raw_sector);
  #ifdef DEBUG
  	printk("%s: sr_is_xa: %d
  ", cd->cdi.name, is_xa);
  #endif
  	return is_xa;
  }