/* -*-linux-c-*-
 *
 * vendor-specific code for SCSI CD-ROM's goes here.
 *
 * This is needed becauce most of the new features (multisession and
 * the like) are too new to be included into the SCSI-II standard (to
 * be exact: there is'nt anything in my draft copy).
 *
 * Aug 1997: Ha! Got a SCSI-3 cdrom spec across my fingers. SCSI-3 does
 *           multisession using the READ TOC command (like SONY).
 *
 *           Rearranged stuff here: SCSI-3 is included allways, support
 *           for NEC/TOSHIBA/HP commands is optional.
 *
 *   Gerd Knorr <kraxel@cs.tu-berlin.de> 
 *
 * --------------------------------------------------------------------------
 *
 * support for XA/multisession-CD's
 * 
 *   - NEC:     Detection and support of multisession CD's.
 *     
 *   - TOSHIBA: Detection and support of multisession CD's.
 *              Some XA-Sector tweaking, required for older drives.
 *
 *   - SONY:	Detection and support of multisession CD's.
 *              added by Thomas Quinot <thomas@cuivre.freenix.fr>
 *
 *   - PIONEER, HITACHI, PLEXTOR, MATSHITA, TEAC, PHILIPS: known to
 *              work with SONY (SCSI3 now)  code.
 *
 *   - HP:	Much like SONY, but a little different... (Thomas)
 *              HP-Writers only ??? Maybe other CD-Writers work with this too ?
 *		HP 6020 writers now supported.
 */

#include <linux/config.h>
#include <linux/errno.h>
#include <linux/string.h>

#include <linux/blk.h>
#include "scsi.h"
#include "hosts.h"
#include <scsi/scsi_ioctl.h>

#include <linux/cdrom.h>
#include "sr.h"

#if 0
# define DEBUG
#endif

/* here are some constants to sort the vendors into groups */

#define VENDOR_SCSI3           1   /* default: scsi-3 mmc */

#define VENDOR_NEC             2
#define VENDOR_TOSHIBA         3
#define VENDOR_WRITER          4   /* pre-scsi3 writers */

#define VENDOR_ID (scsi_CDs[minor].vendor)

void
sr_vendor_init(int minor)
{
#ifndef CONFIG_BLK_DEV_SR_VENDOR
	VENDOR_ID = VENDOR_SCSI3;
#else
	char *vendor = scsi_CDs[minor].device->vendor;
	char *model  = scsi_CDs[minor].device->model;

	/* default */
	VENDOR_ID = VENDOR_SCSI3;
	if (scsi_CDs[minor].readcd_known)
		/* this is true for scsi3/mmc drives - no more checks */
		return;

	if (scsi_CDs[minor].device->type == TYPE_WORM) {
		VENDOR_ID = VENDOR_WRITER;

	} else if (!strncmp (vendor, "NEC", 3)) {
		VENDOR_ID = VENDOR_NEC;
		if (!strncmp (model,"CD-ROM DRIVE:25", 15)  ||
		    !strncmp (model,"CD-ROM DRIVE:36", 15)  ||
		    !strncmp (model,"CD-ROM DRIVE:83", 15)  ||
		    !strncmp (model,"CD-ROM DRIVE:84 ",16)
#if 0
		        /* my NEC 3x returns the read-raw data if a read-raw
		           is followed by a read for the same sector - aeb */
		    || !strncmp (model,"CD-ROM DRIVE:500",16)
#endif
		   )
			/* these can't handle multisession, may hang */
			scsi_CDs[minor].cdi.mask |= CDC_MULTI_SESSION;

	} else if (!strncmp (vendor, "TOSHIBA", 7)) {
		VENDOR_ID = VENDOR_TOSHIBA;
		
	}
#endif
}


/* small handy function for switching block length using MODE SELECT,
 * used by sr_read_sector() */

int
sr_set_blocklength(int minor, int blocklength)
{
	unsigned char           *buffer;    /* the buffer for the ioctl */
	unsigned char		cmd[12];    /* the scsi-command */
	struct ccs_modesel_head	*modesel;
	int			rc,density = 0;

#ifdef CONFIG_BLK_DEV_SR_VENDOR
	if (VENDOR_ID == VENDOR_TOSHIBA)
		density = (blocklength > 2048) ? 0x81 : 0x83;
#endif

	buffer = (unsigned char *) scsi_malloc(512);
	if (!buffer) return -ENOMEM;

#ifdef DEBUG
	printk("sr%d: MODE SELECT 0x%x/%d\n",minor,density,blocklength);
#endif
	memset(cmd,0,12);
	cmd[0] = MODE_SELECT;
	cmd[1] = (scsi_CDs[minor].device->lun << 5) | (1 << 4);
	cmd[4] = 12;
	modesel = (struct ccs_modesel_head*)buffer;
	memset(modesel,0,sizeof(*modesel));
	modesel->block_desc_length = 0x08;
	modesel->density           = density;
	modesel->block_length_med  = (blocklength >> 8 ) & 0xff;
	modesel->block_length_lo   =  blocklength        & 0xff;
	if (0 == (rc = sr_do_ioctl(minor, cmd, buffer, sizeof(*modesel), 0)))
		scsi_CDs[minor].sector_size = blocklength;
#ifdef DEBUG
	else
		printk("sr%d: switching blocklength to %d bytes failed\n",
		       minor,blocklength);
#endif
	scsi_free(buffer, 512);
	return rc;
}

/* This function gets called after a media change. Checks if the CD is
   multisession, asks for offset etc. */

#define BCD_TO_BIN(x)    ((((int)x & 0xf0) >> 4)*10 + ((int)x & 0x0f))

int sr_cd_check(struct cdrom_device_info *cdi)
{
	unsigned long   sector;
	unsigned char   *buffer;     /* the buffer for the ioctl */
	unsigned char   cmd[12];     /* the scsi-command */
	int             rc,no_multi,minor;

	minor = MINOR(cdi->dev);
	if (scsi_CDs[minor].cdi.mask & CDC_MULTI_SESSION)
		return 0;
	
	buffer = (unsigned char *) scsi_malloc(512);
	if(!buffer) return -ENOMEM;
	
	sector   = 0;         /* the multisession sector offset goes here  */
	no_multi = 0;         /* flag: the drive can't handle multisession */
	rc       = 0;
    
	switch(VENDOR_ID) {
	
	case VENDOR_SCSI3:
		memset(cmd,0,12);
		cmd[0] = READ_TOC;
		cmd[1] = (scsi_CDs[minor].device->lun << 5);
		cmd[8] = 12;
		cmd[9] = 0x40;
		rc = sr_do_ioctl(minor, cmd, buffer, 12, 1);
		if (rc != 0)
			break;
		if ((buffer[0] << 8) + buffer[1] < 0x0a) {
			printk(KERN_INFO "sr%d: Hmm, seems the drive "
			       "doesn't support multisession CD's\n",minor);
			no_multi = 1;
			break;
		}
		sector = buffer[11] + (buffer[10] << 8) +
			(buffer[9] << 16) + (buffer[8] << 24);
		if (buffer[6] <= 1) {
			/* ignore sector offsets from first track */
			sector = 0;
		}
		break;
		
#ifdef CONFIG_BLK_DEV_SR_VENDOR
	case VENDOR_NEC: {
		unsigned long min,sec,frame;
		memset(cmd,0,12);
		cmd[0] = 0xde;
		cmd[1] = (scsi_CDs[minor].device->lun << 5) | 0x03;
		cmd[2] = 0xb0;
		rc = sr_do_ioctl(minor, cmd, buffer, 0x16, 1);
		if (rc != 0)
			break;
		if (buffer[14] != 0 && buffer[14] != 0xb0) {
			printk(KERN_INFO "sr%d: Hmm, seems the cdrom "
			       "doesn't support multisession CD's\n",minor);
			no_multi = 1;
			break;
		}
		min    = BCD_TO_BIN(buffer[15]);
		sec    = BCD_TO_BIN(buffer[16]);
		frame  = BCD_TO_BIN(buffer[17]);
		sector = min*CD_SECS*CD_FRAMES + sec*CD_FRAMES + frame;
		break;
	}

	case VENDOR_TOSHIBA: {
		unsigned long min,sec,frame;

		/* we request some disc information (is it a XA-CD ?,
		 * where starts the last session ?) */
		memset(cmd,0,12);
		cmd[0] = 0xc7;
		cmd[1] = (scsi_CDs[minor].device->lun << 5) | 3;
		rc = sr_do_ioctl(minor, cmd, buffer, 4, 1);
		if (rc == -EINVAL) {
			printk(KERN_INFO "sr%d: Hmm, seems the drive "
			       "doesn't support multisession CD's\n",minor);
			no_multi = 1;
			break;
		}
		if (rc != 0)
			break;
		min    = BCD_TO_BIN(buffer[1]);
		sec    = BCD_TO_BIN(buffer[2]);
		frame  = BCD_TO_BIN(buffer[3]);
		sector = min*CD_SECS*CD_FRAMES + sec*CD_FRAMES + frame;
		if (sector)
			sector -= CD_MSF_OFFSET;
		sr_set_blocklength(minor,2048);
		break;
	}

	case VENDOR_WRITER:
		memset(cmd,0,12);
		cmd[0] = READ_TOC;
		cmd[1] = (scsi_CDs[minor].device->lun << 5);
		cmd[8] = 0x04;
		cmd[9] = 0x40;
		rc = sr_do_ioctl(minor, cmd, buffer, 0x04, 1);
		if (rc != 0) {
			break;
		}
		if ((rc = buffer[2]) == 0) {
			printk (KERN_WARNING
				"sr%d: No finished session\n",minor);
			break;
		}

		cmd[0] = READ_TOC; /* Read TOC */
		cmd[1] = (scsi_CDs[minor].device->lun << 5);
		cmd[6] = rc & 0x7f;  /* number of last session */
		cmd[8] = 0x0c;
		cmd[9] = 0x40;
		rc = sr_do_ioctl(minor, cmd, buffer, 12, 1);	
		if (rc != 0) {
			break;
		}

		sector = buffer[11] + (buffer[10] << 8) +
			(buffer[9] << 16) + (buffer[8] << 24);
		break;
#endif /* CONFIG_BLK_DEV_SR_VENDOR */

	default:
		/* should not happen */
		printk(KERN_WARNING
		       "sr%d: unknown vendor code (%i), not initialized ?\n",
		       minor,VENDOR_ID);
		sector = 0;
		no_multi = 1;
		break;
	}
	scsi_CDs[minor].ms_offset = sector;
	scsi_CDs[minor].xa_flag = 0;
	if (CDS_AUDIO != sr_disk_status(cdi) && 1 == sr_is_xa(minor))
		scsi_CDs[minor].xa_flag = 1;
	
	if (2048 != scsi_CDs[minor].sector_size)
		sr_set_blocklength(minor,2048);
	if (no_multi)
		cdi->mask |= CDC_MULTI_SESSION;

#ifdef DEBUG
	if (sector)
		printk(KERN_DEBUG "sr%d: multisession offset=%lu\n",
		       minor,sector);
#endif
	scsi_free(buffer, 512);
	return rc;
}
