#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.\n", 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.\n", 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.\n", 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\n",
               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\n");
                /* 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\n", 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\n", cd->cdi.name, is_xa);
#endif
        return is_xa;
}