/*
 * 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, "enter");

	switch (uptodate) {
	case 0:
		error = IDEFLOPPY_ERROR_GENERAL;
		break;

	case 1:
		error = 0;
		break;

	default:
		error = uptodate;
	}

	if (error)
		floppy->failed_pc = NULL;

	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_complete_rq(drive, 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, "enter");

	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!\n");
	}

	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\n",
			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, "retry #%d", 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\n", __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, "block: %d, blocks: %d", 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;

	if (drive->debug_mask & IDE_DBG_RQ)
		blk_dump_rq_flags(rq, (rq->rq_disk
					? rq->rq_disk->disk_name
					: "dev?"));

	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\n", 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\n",
				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\n");
		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\n",
				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\n",
			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\n");
		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\n",
				       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\n", 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\n",
					       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\n",
			       drive->name);
			break;
		case CAPACITY_INVALID:
			printk(KERN_ERR PFX "%s: Invalid capacity for disk "
				"in drive\n", 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,
};