/*

   * IDE ATAPI floppy driver.
   *

   * Copyright (C) 1996-1999  Gadi Oxman <gadio@netvision.net.il>
   * Copyright (C) 2000-2002  Paul Bristow <paul@paulbristow.net>
   * Copyright (C) 2005       Bartlomiej Zolnierkiewicz

   *

   * This driver supports the following IDE floppy drives:
   *
   * LS-120/240 SuperDisk
   * Iomega Zip 100/250
   * Iomega PC Card Clik!/PocketZip
   *

   * For a historical changelog see
   * Documentation/ide/ChangeLog.ide-floppy.1996-2002

   */

  #include <linux/types.h>
  #include <linux/string.h>
  #include <linux/kernel.h>
  #include <linux/delay.h>
  #include <linux/timer.h>
  #include <linux/mm.h>
  #include <linux/interrupt.h>
  #include <linux/major.h>
  #include <linux/errno.h>
  #include <linux/genhd.h>
  #include <linux/slab.h>
  #include <linux/cdrom.h>
  #include <linux/ide.h>

  #include <linux/hdreg.h>

  #include <linux/bitops.h>

  #include <linux/mutex.h>

  #include <linux/scatterlist.h>

  #include <scsi/scsi_ioctl.h>

  #include <asm/byteorder.h>

  #include <linux/irq.h>
  #include <linux/uaccess.h>
  #include <linux/io.h>

  #include <asm/unaligned.h>

  #include "ide-floppy.h"

  /*

   * After each failed packet command we issue a request sense command and retry
   * the packet command IDEFLOPPY_MAX_PC_RETRIES times.

   */
  #define IDEFLOPPY_MAX_PC_RETRIES	3

  /* format capacities descriptor codes */

  #define CAPACITY_INVALID	0x00
  #define CAPACITY_UNFORMATTED	0x01
  #define CAPACITY_CURRENT	0x02
  #define CAPACITY_NO_CARTRIDGE	0x03

  /*
   * The following delay solves a problem with ATAPI Zip 100 drive where BSY bit
   * was apparently being deasserted before the unit was ready to receive data.
   */
  #define IDEFLOPPY_PC_DELAY	(HZ/20)	/* default delay for ZIP 100 (50ms) */

  /* Error code returned in rq->errors to the higher part of the driver. */

  #define	IDEFLOPPY_ERROR_GENERAL		101

  /*

   * Used to finish servicing a request. For read/write requests, we will call
   * ide_end_request to pass to the next buffer.

   */

  static int ide_floppy_end_request(ide_drive_t *drive, int uptodate, int nsecs)

  {

  	struct ide_disk_obj *floppy = drive->driver_data;

  	struct request *rq = drive->hwif->rq;

  	int error;

  	ide_debug_log(IDE_DBG_FUNC, "Call %s
  ", __func__);

  
  	switch (uptodate) {

  	case 0:
  		error = IDEFLOPPY_ERROR_GENERAL;
  		break;
  
  	case 1:
  		error = 0;
  		break;
  
  	default:
  		error = uptodate;

  	}

  	if (error)
  		floppy->failed_pc = NULL;
  	/* Why does this happen? */
  	if (!rq)
  		return 0;

  	if (!blk_special_request(rq)) {

  		/* our real local end request function */
  		ide_end_request(drive, uptodate, nsecs);
  		return 0;
  	}
  	rq->errors = error;
  	/* fixme: need to move this local also */
  	ide_end_drive_cmd(drive, 0, 0);
  	return 0;
  }

  static void idefloppy_update_buffers(ide_drive_t *drive,
  				struct ide_atapi_pc *pc)

  {
  	struct request *rq = pc->rq;
  	struct bio *bio = rq->bio;
  
  	while ((bio = rq->bio) != NULL)

  		ide_floppy_end_request(drive, 1, 0);

  }

  static void ide_floppy_callback(ide_drive_t *drive, int dsc)

  {

  	struct ide_disk_obj *floppy = drive->driver_data;

  	struct ide_atapi_pc *pc = drive->pc;

  	int uptodate = pc->error ? 0 : 1;

  	ide_debug_log(IDE_DBG_FUNC, "Call %s
  ", __func__);

  	if (floppy->failed_pc == pc)
  		floppy->failed_pc = NULL;

  	if (pc->c[0] == GPCMD_READ_10 || pc->c[0] == GPCMD_WRITE_10 ||
  	    (pc->rq && blk_pc_request(pc->rq)))
  		uptodate = 1; /* FIXME */
  	else if (pc->c[0] == GPCMD_REQUEST_SENSE) {

  		u8 *buf = pc->buf;

  		if (!pc->error) {
  			floppy->sense_key = buf[2] & 0x0F;
  			floppy->asc = buf[12];
  			floppy->ascq = buf[13];
  			floppy->progress_indication = buf[15] & 0x80 ?
  				(u16)get_unaligned((u16 *)&buf[16]) : 0x10000;

  			if (floppy->failed_pc)

  				ide_debug_log(IDE_DBG_PC, "pc = %x, ",
  					      floppy->failed_pc->c[0]);

  			ide_debug_log(IDE_DBG_SENSE, "sense key = %x, asc = %x,"
  				      "ascq = %x
  ", floppy->sense_key,
  				      floppy->asc, floppy->ascq);

  		} else

  			printk(KERN_ERR PFX "Error in REQUEST SENSE itself - "
  			       "Aborting request!
  ");

  	}

  	ide_floppy_end_request(drive, uptodate, 0);

  }

  static void ide_floppy_report_error(struct ide_disk_obj *floppy,

  				    struct ide_atapi_pc *pc)

  {

  	/* supress error messages resulting from Medium not present */

  	if (floppy->sense_key == 0x02 &&
  	    floppy->asc       == 0x3a &&
  	    floppy->ascq      == 0x00)

  		return;

  	printk(KERN_ERR PFX "%s: I/O error, pc = %2x, key = %2x, "

  			"asc = %2x, ascq = %2x
  ",
  			floppy->drive->name, pc->c[0], floppy->sense_key,
  			floppy->asc, floppy->ascq);

  }

  static ide_startstop_t idefloppy_issue_pc(ide_drive_t *drive,

  		struct ide_atapi_pc *pc)

  {

  	struct ide_disk_obj *floppy = drive->driver_data;

  	if (floppy->failed_pc == NULL &&

  	    pc->c[0] != GPCMD_REQUEST_SENSE)

  		floppy->failed_pc = pc;

  	/* Set the current packet command */

  	drive->pc = pc;

  	if (pc->retries > IDEFLOPPY_MAX_PC_RETRIES) {

  		if (!(pc->flags & PC_FLAG_SUPPRESS_ERROR))

  			ide_floppy_report_error(floppy, pc);
  		/* Giving up */
  		pc->error = IDEFLOPPY_ERROR_GENERAL;

  		floppy->failed_pc = NULL;

  		drive->pc_callback(drive, 0);

  		return ide_stopped;
  	}

  	ide_debug_log(IDE_DBG_FUNC, "%s: Retry #%d
  ", __func__, pc->retries);

  
  	pc->retries++;

  	return ide_issue_pc(drive);

  }

  void ide_floppy_create_read_capacity_cmd(struct ide_atapi_pc *pc)

  {

  	ide_init_pc(pc);

  	pc->c[0] = GPCMD_READ_FORMAT_CAPACITIES;

  	pc->c[7] = 255;
  	pc->c[8] = 255;

  	pc->req_xfer = 255;

  }

  /* A mode sense command is used to "sense" floppy parameters. */

  void ide_floppy_create_mode_sense_cmd(struct ide_atapi_pc *pc, u8 page_code)

  {

  	u16 length = 8; /* sizeof(Mode Parameter Header) = 8 Bytes */

  	ide_init_pc(pc);

  	pc->c[0] = GPCMD_MODE_SENSE_10;

  	pc->c[1] = 0;

  	pc->c[2] = page_code;

  
  	switch (page_code) {

  	case IDEFLOPPY_CAPABILITIES_PAGE:
  		length += 12;
  		break;
  	case IDEFLOPPY_FLEXIBLE_DISK_PAGE:
  		length += 32;
  		break;
  	default:

  		printk(KERN_ERR PFX "unsupported page code in %s
  ", __func__);

  	}

  	put_unaligned(cpu_to_be16(length), (u16 *) &pc->c[7]);

  	pc->req_xfer = length;

  }

  static void idefloppy_create_rw_cmd(ide_drive_t *drive,

  				    struct ide_atapi_pc *pc, struct request *rq,

  				    unsigned long sector)

  {

  	struct ide_disk_obj *floppy = drive->driver_data;

  	int block = sector / floppy->bs_factor;
  	int blocks = rq->nr_sectors / floppy->bs_factor;
  	int cmd = rq_data_dir(rq);

  	ide_debug_log(IDE_DBG_FUNC, "%s: block: %d, blocks: %d
  ", __func__,
  		      block, blocks);

  	ide_init_pc(pc);

  	pc->c[0] = cmd == READ ? GPCMD_READ_10 : GPCMD_WRITE_10;
  	put_unaligned(cpu_to_be16(blocks), (unsigned short *)&pc->c[7]);

  	put_unaligned(cpu_to_be32(block), (unsigned int *) &pc->c[2]);

  	memcpy(rq->cmd, pc->c, 12);

  	pc->rq = rq;

  	pc->b_count = 0;

  	if (rq->cmd_flags & REQ_RW)

  		pc->flags |= PC_FLAG_WRITING;

  	pc->buf = NULL;
  	pc->req_xfer = pc->buf_size = blocks * floppy->block_size;

  	pc->flags |= PC_FLAG_DMA_OK;

  }

  static void idefloppy_blockpc_cmd(struct ide_disk_obj *floppy,

  		struct ide_atapi_pc *pc, struct request *rq)

  {

  	ide_init_pc(pc);

  	memcpy(pc->c, rq->cmd, sizeof(pc->c));

  	pc->rq = rq;

  	pc->b_count = 0;

  	if (rq->data_len && rq_data_dir(rq) == WRITE)

  		pc->flags |= PC_FLAG_WRITING;

  	pc->buf = rq->data;

  	if (rq->bio)

  		pc->flags |= PC_FLAG_DMA_OK;

  	/*
  	 * possibly problematic, doesn't look like ide-floppy correctly
  	 * handled scattered requests if dma fails...
  	 */

  	pc->req_xfer = pc->buf_size = rq->data_len;

  }

  static ide_startstop_t ide_floppy_do_request(ide_drive_t *drive,
  					     struct request *rq, sector_t block)

  {

  	struct ide_disk_obj *floppy = drive->driver_data;

  	ide_hwif_t *hwif = drive->hwif;

  	struct ide_atapi_pc *pc;

  	ide_debug_log(IDE_DBG_FUNC, "%s: dev: %s, cmd: 0x%x, cmd_type: %x, "
  		      "errors: %d
  ",
  		      __func__, rq->rq_disk ? rq->rq_disk->disk_name : "?",
  		      rq->cmd[0], rq->cmd_type, rq->errors);

  	ide_debug_log(IDE_DBG_FUNC, "%s: sector: %ld, nr_sectors: %ld, "
  		      "current_nr_sectors: %d
  ",
  		      __func__, (long)rq->sector, rq->nr_sectors,
  		      rq->current_nr_sectors);

  
  	if (rq->errors >= ERROR_MAX) {

  		if (floppy->failed_pc)
  			ide_floppy_report_error(floppy, floppy->failed_pc);

  		else

  			printk(KERN_ERR PFX "%s: I/O error
  ", drive->name);

  		ide_floppy_end_request(drive, 0, 0);

  		return ide_stopped;
  	}

  	if (blk_fs_request(rq)) {

  		if (((long)rq->sector % floppy->bs_factor) ||
  		    (rq->nr_sectors % floppy->bs_factor)) {

  			printk(KERN_ERR PFX "%s: unsupported r/w rq size
  ",
  				drive->name);

  			ide_floppy_end_request(drive, 0, 0);

  			return ide_stopped;
  		}

  		pc = &floppy->queued_pc;

  		idefloppy_create_rw_cmd(drive, pc, rq, (unsigned long)block);

  	} else if (blk_special_request(rq)) {

  		pc = (struct ide_atapi_pc *) rq->buffer;

  	} else if (blk_pc_request(rq)) {

  		pc = &floppy->queued_pc;

  		idefloppy_blockpc_cmd(floppy, pc, rq);

  	} else {

  		blk_dump_rq_flags(rq, PFX "unsupported command in queue");

  		ide_floppy_end_request(drive, 0, 0);

  		return ide_stopped;
  	}

  	if (blk_fs_request(rq) || pc->req_xfer) {
  		ide_init_sg_cmd(drive, rq);
  		ide_map_sg(drive, rq);
  	}

  
  	pc->sg = hwif->sg_table;
  	pc->sg_cnt = hwif->sg_nents;

  	pc->rq = rq;

  	return idefloppy_issue_pc(drive, pc);
  }
  
  /*

   * Look at the flexible disk page parameters. We ignore the CHS capacity
   * parameters and use the LBA parameters instead.

   */

  static int ide_floppy_get_flexible_disk_page(ide_drive_t *drive,
  					     struct ide_atapi_pc *pc)

  {

  	struct ide_disk_obj *floppy = drive->driver_data;

  	struct gendisk *disk = floppy->disk;

  	u8 *page;

  	int capacity, lba_capacity;

  	u16 transfer_rate, sector_size, cyls, rpm;
  	u8 heads, sectors;

  	ide_floppy_create_mode_sense_cmd(pc, IDEFLOPPY_FLEXIBLE_DISK_PAGE);

  	if (ide_queue_pc_tail(drive, disk, pc)) {

  		printk(KERN_ERR PFX "Can't get flexible disk page params
  ");

  		return 1;
  	}

  	if (pc->buf[3] & 0x80)

  		drive->dev_flags |= IDE_DFLAG_WP;

  	else

  		drive->dev_flags &= ~IDE_DFLAG_WP;

  	set_disk_ro(disk, !!(drive->dev_flags & IDE_DFLAG_WP));

  	page = &pc->buf[8];

  	transfer_rate = be16_to_cpup((__be16 *)&pc->buf[8 + 2]);
  	sector_size   = be16_to_cpup((__be16 *)&pc->buf[8 + 6]);
  	cyls          = be16_to_cpup((__be16 *)&pc->buf[8 + 8]);
  	rpm           = be16_to_cpup((__be16 *)&pc->buf[8 + 28]);
  	heads         = pc->buf[8 + 4];
  	sectors       = pc->buf[8 + 5];

  
  	capacity = cyls * heads * sectors * sector_size;
  
  	if (memcmp(page, &floppy->flexible_disk_page, 32))

  		printk(KERN_INFO PFX "%s: %dkB, %d/%d/%d CHS, %d kBps, "

  				"%d sector size, %d rpm
  ",

  				drive->name, capacity / 1024, cyls, heads,
  				sectors, transfer_rate / 8, sector_size, rpm);
  
  	memcpy(&floppy->flexible_disk_page, page, 32);
  	drive->bios_cyl = cyls;
  	drive->bios_head = heads;
  	drive->bios_sect = sectors;

  	lba_capacity = floppy->blocks * floppy->block_size;

  	if (capacity < lba_capacity) {

  		printk(KERN_NOTICE PFX "%s: The disk reports a capacity of %d "

  			"bytes, but the drive only handles %d
  ",
  			drive->name, lba_capacity, capacity);

  		floppy->blocks = floppy->block_size ?
  			capacity / floppy->block_size : 0;

  		drive->capacity64 = floppy->blocks * floppy->bs_factor;

  	}

  	return 0;
  }

  /*

   * Determine if a media is present in the floppy drive, and if so, its LBA
   * capacity.

   */

  static int ide_floppy_get_capacity(ide_drive_t *drive)

  {

  	struct ide_disk_obj *floppy = drive->driver_data;

  	struct gendisk *disk = floppy->disk;

  	struct ide_atapi_pc pc;

  	u8 *cap_desc;
  	u8 header_len, desc_cnt;
  	int i, rc = 1, blocks, length;

  	drive->bios_cyl = 0;
  	drive->bios_head = drive->bios_sect = 0;

  	floppy->blocks = 0;
  	floppy->bs_factor = 1;

  	drive->capacity64 = 0;

  	ide_floppy_create_read_capacity_cmd(&pc);

  	if (ide_queue_pc_tail(drive, disk, &pc)) {

  		printk(KERN_ERR PFX "Can't get floppy parameters
  ");

  		return 1;
  	}

  	header_len = pc.buf[3];
  	cap_desc = &pc.buf[4];

  	desc_cnt = header_len / 8; /* capacity descriptor of 8 bytes */
  
  	for (i = 0; i < desc_cnt; i++) {
  		unsigned int desc_start = 4 + i*8;

  		blocks = be32_to_cpup((__be32 *)&pc.buf[desc_start]);
  		length = be16_to_cpup((__be16 *)&pc.buf[desc_start + 6]);

  		ide_debug_log(IDE_DBG_PROBE, "Descriptor %d: %dkB, %d blocks, "
  			      "%d sector size
  ",
  			      i, blocks * length / 1024, blocks, length);

  		if (i)
  			continue;
  		/*
  		 * the code below is valid only for the 1st descriptor, ie i=0
  		 */

  		switch (pc.buf[desc_start + 4] & 0x03) {

  		/* Clik! drive returns this instead of CAPACITY_CURRENT */
  		case CAPACITY_UNFORMATTED:

  			if (!(drive->atapi_flags & IDE_AFLAG_CLIK_DRIVE))

  				/*

  				 * If it is not a clik drive, break out
  				 * (maintains previous driver behaviour)
  				 */
  				break;
  		case CAPACITY_CURRENT:
  			/* Normal Zip/LS-120 disks */

  			if (memcmp(cap_desc, &floppy->cap_desc, 8))

  				printk(KERN_INFO PFX "%s: %dkB, %d blocks, %d "
  				       "sector size
  ",
  				       drive->name, blocks * length / 1024,
  				       blocks, length);

  			memcpy(&floppy->cap_desc, cap_desc, 8);

  			if (!length || length % 512) {

  				printk(KERN_NOTICE PFX "%s: %d bytes block size"
  				       " not supported
  ", drive->name, length);

  			} else {

  				floppy->blocks = blocks;
  				floppy->block_size = length;
  				floppy->bs_factor = length / 512;
  				if (floppy->bs_factor != 1)

  					printk(KERN_NOTICE PFX "%s: Warning: "
  					       "non 512 bytes block size not "
  					       "fully supported
  ",
  					       drive->name);

  				drive->capacity64 =
  					floppy->blocks * floppy->bs_factor;

  				rc = 0;

  			}
  			break;
  		case CAPACITY_NO_CARTRIDGE:
  			/*
  			 * This is a KERN_ERR so it appears on screen
  			 * for the user to see
  			 */

  			printk(KERN_ERR PFX "%s: No disk in drive
  ",
  			       drive->name);

  			break;
  		case CAPACITY_INVALID:

  			printk(KERN_ERR PFX "%s: Invalid capacity for disk "

  				"in drive
  ", drive->name);
  			break;
  		}

  		ide_debug_log(IDE_DBG_PROBE, "Descriptor 0 Code: %d
  ",
  			      pc.buf[desc_start + 4] & 0x03);

  	}
  
  	/* Clik! disk does not support get_flexible_disk_page */

  	if (!(drive->atapi_flags & IDE_AFLAG_CLIK_DRIVE))

  		(void) ide_floppy_get_flexible_disk_page(drive, &pc);

  	return rc;
  }

  static void ide_floppy_setup(ide_drive_t *drive)

  {

  	struct ide_disk_obj *floppy = drive->driver_data;

  	u16 *id = drive->id;

  	drive->pc_callback	 = ide_floppy_callback;
  	drive->pc_update_buffers = idefloppy_update_buffers;
  	drive->pc_io_buffers	 = ide_io_buffers;

  	/*

  	 * We used to check revisions here. At this point however I'm giving up.
  	 * Just assume they are all broken, its easier.

  	 *

  	 * The actual reason for the workarounds was likely a driver bug after
  	 * all rather than a firmware bug, and the workaround below used to hide
  	 * it. It should be fixed as of version 1.9, but to be on the safe side
  	 * we'll leave the limitation below for the 2.2.x tree.

  	 */

  	if (!strncmp((char *)&id[ATA_ID_PROD], "IOMEGA ZIP 100 ATAPI", 20)) {

  		drive->atapi_flags |= IDE_AFLAG_ZIP_DRIVE;

  		/* This value will be visible in the /proc/ide/hdx/settings */

  		drive->pc_delay = IDEFLOPPY_PC_DELAY;

  		blk_queue_max_sectors(drive->queue, 64);
  	}
  
  	/*

  	 * Guess what? The IOMEGA Clik! drive also needs the above fix. It makes
  	 * nasty clicking noises without it, so please don't remove this.
  	 */

  	if (strncmp((char *)&id[ATA_ID_PROD], "IOMEGA Clik!", 11) == 0) {

  		blk_queue_max_sectors(drive->queue, 64);

  		drive->atapi_flags |= IDE_AFLAG_CLIK_DRIVE;

  		/* IOMEGA Clik! drives do not support lock/unlock commands */

  		drive->dev_flags &= ~IDE_DFLAG_DOORLOCKING;

  	}

  	(void) ide_floppy_get_capacity(drive);

  
  	ide_proc_register_driver(drive, floppy->driver);

  
  	drive->dev_flags |= IDE_DFLAG_ATTACH;

  }

  
  static void ide_floppy_flush(ide_drive_t *drive)
  {
  }
  
  static int ide_floppy_init_media(ide_drive_t *drive, struct gendisk *disk)
  {
  	int ret = 0;
  
  	if (ide_do_test_unit_ready(drive, disk))
  		ide_do_start_stop(drive, disk, 1);
  
  	ret = ide_floppy_get_capacity(drive);
  
  	set_capacity(disk, ide_gd_capacity(drive));
  
  	return ret;
  }
  
  const struct ide_disk_ops ide_atapi_disk_ops = {
  	.check		= ide_check_atapi_device,
  	.get_capacity	= ide_floppy_get_capacity,
  	.setup		= ide_floppy_setup,
  	.flush		= ide_floppy_flush,
  	.init_media	= ide_floppy_init_media,
  	.set_doorlock	= ide_set_media_lock,
  	.do_request	= ide_floppy_do_request,
  	.end_request	= ide_floppy_end_request,
  	.ioctl		= ide_floppy_ioctl,
  };