/*
 * 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) */

static int ide_floppy_callback(ide_drive_t *drive, int dsc)
{
        struct ide_disk_obj *floppy = drive->driver_data;
        struct ide_atapi_pc *pc = drive->pc;
        struct request *rq = pc->rq;
        int uptodate = pc->error ? 0 : 1;

        ide_debug_log(IDE_DBG_FUNC, "enter");

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

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

                u8 *buf = bio_data(rq->bio);

                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 (drive->failed_pc)
                                ide_debug_log(IDE_DBG_PC, "pc = %x",
                                              drive->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");
        }

        if (blk_special_request(rq))
                rq->errors = uptodate ? 0 : IDE_DRV_ERROR_GENERAL;

        return uptodate;
}

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 ide_floppy_issue_pc(ide_drive_t *drive,
                                           struct ide_cmd *cmd,
                                           struct ide_atapi_pc *pc)
{
        struct ide_disk_obj *floppy = drive->driver_data;

        if (drive->failed_pc == NULL &&
            pc->c[0] != GPCMD_REQUEST_SENSE)
                drive->failed_pc = pc;

        /* Set the current packet command */
        drive->pc = pc;

        if (pc->retries > IDEFLOPPY_MAX_PC_RETRIES) {
                unsigned int done = blk_rq_bytes(drive->hwif->rq);

                if (!(pc->flags & PC_FLAG_SUPPRESS_ERROR))
                        ide_floppy_report_error(floppy, pc);

                /* Giving up */
                pc->error = IDE_DRV_ERROR_GENERAL;

                drive->failed_pc = NULL;
                drive->pc_callback(drive, 0);
                ide_complete_rq(drive, -EIO, done);
                return ide_stopped;
        }

        ide_debug_log(IDE_DBG_FUNC, "retry #%d", pc->retries);

        pc->retries++;

        return ide_issue_pc(drive, cmd);
}

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 = blk_rq_sectors(rq) / 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;
        if (rq->cmd_flags & REQ_RW)
                pc->flags |= PC_FLAG_WRITING;

        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;
        if (blk_rq_bytes(rq)) {
                pc->flags |= PC_FLAG_DMA_OK;
                if (rq_data_dir(rq) == WRITE)
                        pc->flags |= PC_FLAG_WRITING;
        }
}

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;
        struct ide_cmd cmd;
        struct ide_atapi_pc *pc;

        ide_debug_log(IDE_DBG_FUNC, "enter, cmd: 0x%x\n", rq->cmd[0]);

        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 (drive->failed_pc) {
                        ide_floppy_report_error(floppy, drive->failed_pc);
                        drive->failed_pc = NULL;
                } else
                        printk(KERN_ERR PFX "%s: I/O error\n", drive->name);

                if (blk_special_request(rq)) {
                        rq->errors = 0;
                        ide_complete_rq(drive, 0, blk_rq_bytes(rq));
                        return ide_stopped;
                } else
                        goto out_end;
        }
        if (blk_fs_request(rq)) {
                if (((long)blk_rq_pos(rq) % floppy->bs_factor) ||
                    (blk_rq_sectors(rq) % floppy->bs_factor)) {
                        printk(KERN_ERR PFX "%s: unsupported r/w rq size\n",
                                drive->name);
                        goto out_end;
                }
                pc = &floppy->queued_pc;
                idefloppy_create_rw_cmd(drive, pc, rq, (unsigned long)block);
        } else if (blk_special_request(rq) || blk_sense_request(rq)) {
                pc = (struct ide_atapi_pc *)rq->special;
        } else if (blk_pc_request(rq)) {
                pc = &floppy->queued_pc;
                idefloppy_blockpc_cmd(floppy, pc, rq);
        } else
                BUG();

        ide_prep_sense(drive, rq);

        memset(&cmd, 0, sizeof(cmd));

        if (rq_data_dir(rq))
                cmd.tf_flags |= IDE_TFLAG_WRITE;

        cmd.rq = rq;

        if (blk_fs_request(rq) || blk_rq_bytes(rq)) {
                ide_init_sg_cmd(&cmd, blk_rq_bytes(rq));
                ide_map_sg(drive, &cmd);
        }

        pc->rq = rq;

        return ide_floppy_issue_pc(drive, &cmd, pc);
out_end:
        drive->failed_pc = NULL;
        if (blk_fs_request(rq) == 0 && rq->errors == 0)
                rq->errors = -EIO;
        ide_complete_rq(drive, -EIO, blk_rq_bytes(rq));
        return ide_stopped;
}

/*
 * 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, buf[40];
        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, buf, pc->req_xfer)) {
                printk(KERN_ERR PFX "Can't get flexible disk page params\n");
                return 1;
        }

        if (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 = &buf[8];

        transfer_rate = be16_to_cpup((__be16 *)&buf[8 + 2]);
        sector_size   = be16_to_cpup((__be16 *)&buf[8 + 6]);
        cyls          = be16_to_cpup((__be16 *)&buf[8 + 8]);
        rpm           = be16_to_cpup((__be16 *)&buf[8 + 28]);
        heads         = buf[8 + 4];
        sectors       = 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 pc_buf[256], header_len, desc_cnt;
        int i, rc = 1, blocks, length;

        ide_debug_log(IDE_DBG_FUNC, "enter");

        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, pc_buf, pc.req_xfer)) {
                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;

        /*
         * 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,
        .ioctl          = ide_floppy_ioctl,
};