Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / cdrom / gdrom.c
diff --git a/kernel/drivers/cdrom/gdrom.c b/kernel/drivers/cdrom/gdrom.c
new file mode 100644 (file)
index 0000000..584bc31
--- /dev/null
@@ -0,0 +1,888 @@
+/* GD ROM driver for the SEGA Dreamcast
+ * copyright Adrian McMenamin, 2007
+ * With thanks to Marcus Comstedt and Nathan Keynes
+ * for work in reversing PIO and DMA
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/dma-mapping.h>
+#include <linux/cdrom.h>
+#include <linux/genhd.h>
+#include <linux/bio.h>
+#include <linux/blkdev.h>
+#include <linux/interrupt.h>
+#include <linux/device.h>
+#include <linux/mutex.h>
+#include <linux/wait.h>
+#include <linux/workqueue.h>
+#include <linux/platform_device.h>
+#include <scsi/scsi.h>
+#include <asm/io.h>
+#include <asm/dma.h>
+#include <asm/delay.h>
+#include <mach/dma.h>
+#include <mach/sysasic.h>
+
+#define GDROM_DEV_NAME "gdrom"
+#define GD_SESSION_OFFSET 150
+
+/* GD Rom commands */
+#define GDROM_COM_SOFTRESET 0x08
+#define GDROM_COM_EXECDIAG 0x90
+#define GDROM_COM_PACKET 0xA0
+#define GDROM_COM_IDDEV 0xA1
+
+/* GD Rom registers */
+#define GDROM_BASE_REG                 0xA05F7000
+#define GDROM_ALTSTATUS_REG            (GDROM_BASE_REG + 0x18)
+#define GDROM_DATA_REG                 (GDROM_BASE_REG + 0x80)
+#define GDROM_ERROR_REG                (GDROM_BASE_REG + 0x84)
+#define GDROM_INTSEC_REG               (GDROM_BASE_REG + 0x88)
+#define GDROM_SECNUM_REG               (GDROM_BASE_REG + 0x8C)
+#define GDROM_BCL_REG                  (GDROM_BASE_REG + 0x90)
+#define GDROM_BCH_REG                  (GDROM_BASE_REG + 0x94)
+#define GDROM_DSEL_REG                 (GDROM_BASE_REG + 0x98)
+#define GDROM_STATUSCOMMAND_REG        (GDROM_BASE_REG + 0x9C)
+#define GDROM_RESET_REG                (GDROM_BASE_REG + 0x4E4)
+
+#define GDROM_DMA_STARTADDR_REG        (GDROM_BASE_REG + 0x404)
+#define GDROM_DMA_LENGTH_REG           (GDROM_BASE_REG + 0x408)
+#define GDROM_DMA_DIRECTION_REG        (GDROM_BASE_REG + 0x40C)
+#define GDROM_DMA_ENABLE_REG           (GDROM_BASE_REG + 0x414)
+#define GDROM_DMA_STATUS_REG           (GDROM_BASE_REG + 0x418)
+#define GDROM_DMA_WAIT_REG             (GDROM_BASE_REG + 0x4A0)
+#define GDROM_DMA_ACCESS_CTRL_REG      (GDROM_BASE_REG + 0x4B8)
+
+#define GDROM_HARD_SECTOR      2048
+#define BLOCK_LAYER_SECTOR     512
+#define GD_TO_BLK              4
+
+#define GDROM_DEFAULT_TIMEOUT  (HZ * 7)
+
+static DEFINE_MUTEX(gdrom_mutex);
+static const struct {
+       int sense_key;
+       const char * const text;
+} sense_texts[] = {
+       {NO_SENSE, "OK"},
+       {RECOVERED_ERROR, "Recovered from error"},
+       {NOT_READY, "Device not ready"},
+       {MEDIUM_ERROR, "Disk not ready"},
+       {HARDWARE_ERROR, "Hardware error"},
+       {ILLEGAL_REQUEST, "Command has failed"},
+       {UNIT_ATTENTION, "Device needs attention - disk may have been changed"},
+       {DATA_PROTECT, "Data protection error"},
+       {ABORTED_COMMAND, "Command aborted"},
+};
+
+static struct platform_device *pd;
+static int gdrom_major;
+static DECLARE_WAIT_QUEUE_HEAD(command_queue);
+static DECLARE_WAIT_QUEUE_HEAD(request_queue);
+
+static DEFINE_SPINLOCK(gdrom_lock);
+static void gdrom_readdisk_dma(struct work_struct *work);
+static DECLARE_WORK(work, gdrom_readdisk_dma);
+static LIST_HEAD(gdrom_deferred);
+
+struct gdromtoc {
+       unsigned int entry[99];
+       unsigned int first, last;
+       unsigned int leadout;
+};
+
+static struct gdrom_unit {
+       struct gendisk *disk;
+       struct cdrom_device_info *cd_info;
+       int status;
+       int pending;
+       int transfer;
+       char disk_type;
+       struct gdromtoc *toc;
+       struct request_queue *gdrom_rq;
+} gd;
+
+struct gdrom_id {
+       char mid;
+       char modid;
+       char verid;
+       char padA[13];
+       char mname[16];
+       char modname[16];
+       char firmver[16];
+       char padB[16];
+};
+
+static int gdrom_getsense(short *bufstring);
+static int gdrom_packetcommand(struct cdrom_device_info *cd_info,
+       struct packet_command *command);
+static int gdrom_hardreset(struct cdrom_device_info *cd_info);
+
+static bool gdrom_is_busy(void)
+{
+       return (__raw_readb(GDROM_ALTSTATUS_REG) & 0x80) != 0;
+}
+
+static bool gdrom_data_request(void)
+{
+       return (__raw_readb(GDROM_ALTSTATUS_REG) & 0x88) == 8;
+}
+
+static bool gdrom_wait_clrbusy(void)
+{
+       unsigned long timeout = jiffies + GDROM_DEFAULT_TIMEOUT;
+       while ((__raw_readb(GDROM_ALTSTATUS_REG) & 0x80) &&
+               (time_before(jiffies, timeout)))
+               cpu_relax();
+       return time_before(jiffies, timeout + 1);
+}
+
+static bool gdrom_wait_busy_sleeps(void)
+{
+       unsigned long timeout;
+       /* Wait to get busy first */
+       timeout = jiffies + GDROM_DEFAULT_TIMEOUT;
+       while (!gdrom_is_busy() && time_before(jiffies, timeout))
+               cpu_relax();
+       /* Now wait for busy to clear */
+       return gdrom_wait_clrbusy();
+}
+
+static void gdrom_identifydevice(void *buf)
+{
+       int c;
+       short *data = buf;
+       /* If the device won't clear it has probably
+       * been hit by a serious failure - but we'll
+       * try to return a sense key even so */
+       if (!gdrom_wait_clrbusy()) {
+               gdrom_getsense(NULL);
+               return;
+       }
+       __raw_writeb(GDROM_COM_IDDEV, GDROM_STATUSCOMMAND_REG);
+       if (!gdrom_wait_busy_sleeps()) {
+               gdrom_getsense(NULL);
+               return;
+       }
+       /* now read in the data */
+       for (c = 0; c < 40; c++)
+               data[c] = __raw_readw(GDROM_DATA_REG);
+}
+
+static void gdrom_spicommand(void *spi_string, int buflen)
+{
+       short *cmd = spi_string;
+       unsigned long timeout;
+
+       /* ensure IRQ_WAIT is set */
+       __raw_writeb(0x08, GDROM_ALTSTATUS_REG);
+       /* specify how many bytes we expect back */
+       __raw_writeb(buflen & 0xFF, GDROM_BCL_REG);
+       __raw_writeb((buflen >> 8) & 0xFF, GDROM_BCH_REG);
+       /* other parameters */
+       __raw_writeb(0, GDROM_INTSEC_REG);
+       __raw_writeb(0, GDROM_SECNUM_REG);
+       __raw_writeb(0, GDROM_ERROR_REG);
+       /* Wait until we can go */
+       if (!gdrom_wait_clrbusy()) {
+               gdrom_getsense(NULL);
+               return;
+       }
+       timeout = jiffies + GDROM_DEFAULT_TIMEOUT;
+       __raw_writeb(GDROM_COM_PACKET, GDROM_STATUSCOMMAND_REG);
+       while (!gdrom_data_request() && time_before(jiffies, timeout))
+               cpu_relax();
+       if (!time_before(jiffies, timeout + 1)) {
+               gdrom_getsense(NULL);
+               return;
+       }
+       outsw(GDROM_DATA_REG, cmd, 6);
+}
+
+
+/* gdrom_command_executediagnostic:
+ * Used to probe for presence of working GDROM
+ * Restarts GDROM device and then applies standard ATA 3
+ * Execute Diagnostic Command: a return of '1' indicates device 0
+ * present and device 1 absent
+ */
+static char gdrom_execute_diagnostic(void)
+{
+       gdrom_hardreset(gd.cd_info);
+       if (!gdrom_wait_clrbusy())
+               return 0;
+       __raw_writeb(GDROM_COM_EXECDIAG, GDROM_STATUSCOMMAND_REG);
+       if (!gdrom_wait_busy_sleeps())
+               return 0;
+       return __raw_readb(GDROM_ERROR_REG);
+}
+
+/*
+ * Prepare disk command
+ * byte 0 = 0x70
+ * byte 1 = 0x1f
+ */
+static int gdrom_preparedisk_cmd(void)
+{
+       struct packet_command *spin_command;
+       spin_command = kzalloc(sizeof(struct packet_command), GFP_KERNEL);
+       if (!spin_command)
+               return -ENOMEM;
+       spin_command->cmd[0] = 0x70;
+       spin_command->cmd[2] = 0x1f;
+       spin_command->buflen = 0;
+       gd.pending = 1;
+       gdrom_packetcommand(gd.cd_info, spin_command);
+       /* 60 second timeout */
+       wait_event_interruptible_timeout(command_queue, gd.pending == 0,
+               GDROM_DEFAULT_TIMEOUT);
+       gd.pending = 0;
+       kfree(spin_command);
+       if (gd.status & 0x01) {
+               /* log an error */
+               gdrom_getsense(NULL);
+               return -EIO;
+       }
+       return 0;
+}
+
+/*
+ * Read TOC command
+ * byte 0 = 0x14
+ * byte 1 = session
+ * byte 3 = sizeof TOC >> 8  ie upper byte
+ * byte 4 = sizeof TOC & 0xff ie lower byte
+ */
+static int gdrom_readtoc_cmd(struct gdromtoc *toc, int session)
+{
+       int tocsize;
+       struct packet_command *toc_command;
+       int err = 0;
+
+       toc_command = kzalloc(sizeof(struct packet_command), GFP_KERNEL);
+       if (!toc_command)
+               return -ENOMEM;
+       tocsize = sizeof(struct gdromtoc);
+       toc_command->cmd[0] = 0x14;
+       toc_command->cmd[1] = session;
+       toc_command->cmd[3] = tocsize >> 8;
+       toc_command->cmd[4] = tocsize & 0xff;
+       toc_command->buflen = tocsize;
+       if (gd.pending) {
+               err = -EBUSY;
+               goto cleanup_readtoc_final;
+       }
+       gd.pending = 1;
+       gdrom_packetcommand(gd.cd_info, toc_command);
+       wait_event_interruptible_timeout(command_queue, gd.pending == 0,
+               GDROM_DEFAULT_TIMEOUT);
+       if (gd.pending) {
+               err = -EINVAL;
+               goto cleanup_readtoc;
+       }
+       insw(GDROM_DATA_REG, toc, tocsize/2);
+       if (gd.status & 0x01)
+               err = -EINVAL;
+
+cleanup_readtoc:
+       gd.pending = 0;
+cleanup_readtoc_final:
+       kfree(toc_command);
+       return err;
+}
+
+/* TOC helpers */
+static int get_entry_lba(int track)
+{
+       return (cpu_to_be32(track & 0xffffff00) - GD_SESSION_OFFSET);
+}
+
+static int get_entry_q_ctrl(int track)
+{
+       return (track & 0x000000f0) >> 4;
+}
+
+static int get_entry_track(int track)
+{
+       return (track & 0x0000ff00) >> 8;
+}
+
+static int gdrom_get_last_session(struct cdrom_device_info *cd_info,
+       struct cdrom_multisession *ms_info)
+{
+       int fentry, lentry, track, data, tocuse, err;
+       if (!gd.toc)
+               return -ENOMEM;
+       tocuse = 1;
+       /* Check if GD-ROM */
+       err = gdrom_readtoc_cmd(gd.toc, 1);
+       /* Not a GD-ROM so check if standard CD-ROM */
+       if (err) {
+               tocuse = 0;
+               err = gdrom_readtoc_cmd(gd.toc, 0);
+               if (err) {
+                       pr_info("Could not get CD table of contents\n");
+                       return -ENXIO;
+               }
+       }
+
+       fentry = get_entry_track(gd.toc->first);
+       lentry = get_entry_track(gd.toc->last);
+       /* Find the first data track */
+       track = get_entry_track(gd.toc->last);
+       do {
+               data = gd.toc->entry[track - 1];
+               if (get_entry_q_ctrl(data))
+                       break;  /* ie a real data track */
+               track--;
+       } while (track >= fentry);
+
+       if ((track > 100) || (track < get_entry_track(gd.toc->first))) {
+               pr_info("No data on the last session of the CD\n");
+               gdrom_getsense(NULL);
+               return -ENXIO;
+       }
+
+       ms_info->addr_format = CDROM_LBA;
+       ms_info->addr.lba = get_entry_lba(data);
+       ms_info->xa_flag = 1;
+       return 0;
+}
+
+static int gdrom_open(struct cdrom_device_info *cd_info, int purpose)
+{
+       /* spin up the disk */
+       return gdrom_preparedisk_cmd();
+}
+
+/* this function is required even if empty */
+static void gdrom_release(struct cdrom_device_info *cd_info)
+{
+}
+
+static int gdrom_drivestatus(struct cdrom_device_info *cd_info, int ignore)
+{
+       /* read the sense key */
+       char sense = __raw_readb(GDROM_ERROR_REG);
+       sense &= 0xF0;
+       if (sense == 0)
+               return CDS_DISC_OK;
+       if (sense == 0x20)
+               return CDS_DRIVE_NOT_READY;
+       /* default */
+       return CDS_NO_INFO;
+}
+
+static unsigned int gdrom_check_events(struct cdrom_device_info *cd_info,
+                                      unsigned int clearing, int ignore)
+{
+       /* check the sense key */
+       return (__raw_readb(GDROM_ERROR_REG) & 0xF0) == 0x60 ?
+               DISK_EVENT_MEDIA_CHANGE : 0;
+}
+
+/* reset the G1 bus */
+static int gdrom_hardreset(struct cdrom_device_info *cd_info)
+{
+       int count;
+       __raw_writel(0x1fffff, GDROM_RESET_REG);
+       for (count = 0xa0000000; count < 0xa0200000; count += 4)
+               __raw_readl(count);
+       return 0;
+}
+
+/* keep the function looking like the universal
+ * CD Rom specification  - returning int */
+static int gdrom_packetcommand(struct cdrom_device_info *cd_info,
+       struct packet_command *command)
+{
+       gdrom_spicommand(&command->cmd, command->buflen);
+       return 0;
+}
+
+/* Get Sense SPI command
+ * From Marcus Comstedt
+ * cmd = 0x13
+ * cmd + 4 = length of returned buffer
+ * Returns 5 16 bit words
+ */
+static int gdrom_getsense(short *bufstring)
+{
+       struct packet_command *sense_command;
+       short sense[5];
+       int sense_key;
+       int err = -EIO;
+
+       sense_command = kzalloc(sizeof(struct packet_command), GFP_KERNEL);
+       if (!sense_command)
+               return -ENOMEM;
+       sense_command->cmd[0] = 0x13;
+       sense_command->cmd[4] = 10;
+       sense_command->buflen = 10;
+       /* even if something is pending try to get
+       * the sense key if possible */
+       if (gd.pending && !gdrom_wait_clrbusy()) {
+               err = -EBUSY;
+               goto cleanup_sense_final;
+       }
+       gd.pending = 1;
+       gdrom_packetcommand(gd.cd_info, sense_command);
+       wait_event_interruptible_timeout(command_queue, gd.pending == 0,
+               GDROM_DEFAULT_TIMEOUT);
+       if (gd.pending)
+               goto cleanup_sense;
+       insw(GDROM_DATA_REG, &sense, sense_command->buflen/2);
+       if (sense[1] & 40) {
+               pr_info("Drive not ready - command aborted\n");
+               goto cleanup_sense;
+       }
+       sense_key = sense[1] & 0x0F;
+       if (sense_key < ARRAY_SIZE(sense_texts))
+               pr_info("%s\n", sense_texts[sense_key].text);
+       else
+               pr_err("Unknown sense key: %d\n", sense_key);
+       if (bufstring) /* return addional sense data */
+               memcpy(bufstring, &sense[4], 2);
+       if (sense_key < 2)
+               err = 0;
+
+cleanup_sense:
+       gd.pending = 0;
+cleanup_sense_final:
+       kfree(sense_command);
+       return err;
+}
+
+static int gdrom_audio_ioctl(struct cdrom_device_info *cdi, unsigned int cmd,
+                            void *arg)
+{
+       return -EINVAL;
+}
+
+static struct cdrom_device_ops gdrom_ops = {
+       .open                   = gdrom_open,
+       .release                = gdrom_release,
+       .drive_status           = gdrom_drivestatus,
+       .check_events           = gdrom_check_events,
+       .get_last_session       = gdrom_get_last_session,
+       .reset                  = gdrom_hardreset,
+       .audio_ioctl            = gdrom_audio_ioctl,
+       .capability             = CDC_MULTI_SESSION | CDC_MEDIA_CHANGED |
+                                 CDC_RESET | CDC_DRIVE_STATUS | CDC_CD_R,
+       .n_minors               = 1,
+};
+
+static int gdrom_bdops_open(struct block_device *bdev, fmode_t mode)
+{
+       int ret;
+       mutex_lock(&gdrom_mutex);
+       ret = cdrom_open(gd.cd_info, bdev, mode);
+       mutex_unlock(&gdrom_mutex);
+       return ret;
+}
+
+static void gdrom_bdops_release(struct gendisk *disk, fmode_t mode)
+{
+       mutex_lock(&gdrom_mutex);
+       cdrom_release(gd.cd_info, mode);
+       mutex_unlock(&gdrom_mutex);
+}
+
+static unsigned int gdrom_bdops_check_events(struct gendisk *disk,
+                                            unsigned int clearing)
+{
+       return cdrom_check_events(gd.cd_info, clearing);
+}
+
+static int gdrom_bdops_ioctl(struct block_device *bdev, fmode_t mode,
+       unsigned cmd, unsigned long arg)
+{
+       int ret;
+
+       mutex_lock(&gdrom_mutex);
+       ret = cdrom_ioctl(gd.cd_info, bdev, mode, cmd, arg);
+       mutex_unlock(&gdrom_mutex);
+
+       return ret;
+}
+
+static const struct block_device_operations gdrom_bdops = {
+       .owner                  = THIS_MODULE,
+       .open                   = gdrom_bdops_open,
+       .release                = gdrom_bdops_release,
+       .check_events           = gdrom_bdops_check_events,
+       .ioctl                  = gdrom_bdops_ioctl,
+};
+
+static irqreturn_t gdrom_command_interrupt(int irq, void *dev_id)
+{
+       gd.status = __raw_readb(GDROM_STATUSCOMMAND_REG);
+       if (gd.pending != 1)
+               return IRQ_HANDLED;
+       gd.pending = 0;
+       wake_up_interruptible(&command_queue);
+       return IRQ_HANDLED;
+}
+
+static irqreturn_t gdrom_dma_interrupt(int irq, void *dev_id)
+{
+       gd.status = __raw_readb(GDROM_STATUSCOMMAND_REG);
+       if (gd.transfer != 1)
+               return IRQ_HANDLED;
+       gd.transfer = 0;
+       wake_up_interruptible(&request_queue);
+       return IRQ_HANDLED;
+}
+
+static int gdrom_set_interrupt_handlers(void)
+{
+       int err;
+
+       err = request_irq(HW_EVENT_GDROM_CMD, gdrom_command_interrupt,
+               0, "gdrom_command", &gd);
+       if (err)
+               return err;
+       err = request_irq(HW_EVENT_GDROM_DMA, gdrom_dma_interrupt,
+               0, "gdrom_dma", &gd);
+       if (err)
+               free_irq(HW_EVENT_GDROM_CMD, &gd);
+       return err;
+}
+
+/* Implement DMA read using SPI command
+ * 0 -> 0x30
+ * 1 -> mode
+ * 2 -> block >> 16
+ * 3 -> block >> 8
+ * 4 -> block
+ * 8 -> sectors >> 16
+ * 9 -> sectors >> 8
+ * 10 -> sectors
+ */
+static void gdrom_readdisk_dma(struct work_struct *work)
+{
+       int err, block, block_cnt;
+       struct packet_command *read_command;
+       struct list_head *elem, *next;
+       struct request *req;
+       unsigned long timeout;
+
+       if (list_empty(&gdrom_deferred))
+               return;
+       read_command = kzalloc(sizeof(struct packet_command), GFP_KERNEL);
+       if (!read_command)
+               return; /* get more memory later? */
+       read_command->cmd[0] = 0x30;
+       read_command->cmd[1] = 0x20;
+       spin_lock(&gdrom_lock);
+       list_for_each_safe(elem, next, &gdrom_deferred) {
+               req = list_entry(elem, struct request, queuelist);
+               spin_unlock(&gdrom_lock);
+               block = blk_rq_pos(req)/GD_TO_BLK + GD_SESSION_OFFSET;
+               block_cnt = blk_rq_sectors(req)/GD_TO_BLK;
+               __raw_writel(virt_to_phys(bio_data(req->bio)), GDROM_DMA_STARTADDR_REG);
+               __raw_writel(block_cnt * GDROM_HARD_SECTOR, GDROM_DMA_LENGTH_REG);
+               __raw_writel(1, GDROM_DMA_DIRECTION_REG);
+               __raw_writel(1, GDROM_DMA_ENABLE_REG);
+               read_command->cmd[2] = (block >> 16) & 0xFF;
+               read_command->cmd[3] = (block >> 8) & 0xFF;
+               read_command->cmd[4] = block & 0xFF;
+               read_command->cmd[8] = (block_cnt >> 16) & 0xFF;
+               read_command->cmd[9] = (block_cnt >> 8) & 0xFF;
+               read_command->cmd[10] = block_cnt & 0xFF;
+               /* set for DMA */
+               __raw_writeb(1, GDROM_ERROR_REG);
+               /* other registers */
+               __raw_writeb(0, GDROM_SECNUM_REG);
+               __raw_writeb(0, GDROM_BCL_REG);
+               __raw_writeb(0, GDROM_BCH_REG);
+               __raw_writeb(0, GDROM_DSEL_REG);
+               __raw_writeb(0, GDROM_INTSEC_REG);
+               /* Wait for registers to reset after any previous activity */
+               timeout = jiffies + HZ / 2;
+               while (gdrom_is_busy() && time_before(jiffies, timeout))
+                       cpu_relax();
+               __raw_writeb(GDROM_COM_PACKET, GDROM_STATUSCOMMAND_REG);
+               timeout = jiffies + HZ / 2;
+               /* Wait for packet command to finish */
+               while (gdrom_is_busy() && time_before(jiffies, timeout))
+                       cpu_relax();
+               gd.pending = 1;
+               gd.transfer = 1;
+               outsw(GDROM_DATA_REG, &read_command->cmd, 6);
+               timeout = jiffies + HZ / 2;
+               /* Wait for any pending DMA to finish */
+               while (__raw_readb(GDROM_DMA_STATUS_REG) &&
+                       time_before(jiffies, timeout))
+                       cpu_relax();
+               /* start transfer */
+               __raw_writeb(1, GDROM_DMA_STATUS_REG);
+               wait_event_interruptible_timeout(request_queue,
+                       gd.transfer == 0, GDROM_DEFAULT_TIMEOUT);
+               err = gd.transfer ? -EIO : 0;
+               gd.transfer = 0;
+               gd.pending = 0;
+               /* now seek to take the request spinlock
+               * before handling ending the request */
+               spin_lock(&gdrom_lock);
+               list_del_init(&req->queuelist);
+               __blk_end_request_all(req, err);
+       }
+       spin_unlock(&gdrom_lock);
+       kfree(read_command);
+}
+
+static void gdrom_request(struct request_queue *rq)
+{
+       struct request *req;
+
+       while ((req = blk_fetch_request(rq)) != NULL) {
+               if (req->cmd_type != REQ_TYPE_FS) {
+                       printk(KERN_DEBUG "gdrom: Non-fs request ignored\n");
+                       __blk_end_request_all(req, -EIO);
+                       continue;
+               }
+               if (rq_data_dir(req) != READ) {
+                       pr_notice("Read only device - write request ignored\n");
+                       __blk_end_request_all(req, -EIO);
+                       continue;
+               }
+
+               /*
+                * Add to list of deferred work and then schedule
+                * workqueue.
+                */
+               list_add_tail(&req->queuelist, &gdrom_deferred);
+               schedule_work(&work);
+       }
+}
+
+/* Print string identifying GD ROM device */
+static int gdrom_outputversion(void)
+{
+       struct gdrom_id *id;
+       char *model_name, *manuf_name, *firmw_ver;
+       int err = -ENOMEM;
+
+       /* query device ID */
+       id = kzalloc(sizeof(struct gdrom_id), GFP_KERNEL);
+       if (!id)
+               return err;
+       gdrom_identifydevice(id);
+       model_name = kstrndup(id->modname, 16, GFP_KERNEL);
+       if (!model_name)
+               goto free_id;
+       manuf_name = kstrndup(id->mname, 16, GFP_KERNEL);
+       if (!manuf_name)
+               goto free_model_name;
+       firmw_ver = kstrndup(id->firmver, 16, GFP_KERNEL);
+       if (!firmw_ver)
+               goto free_manuf_name;
+       pr_info("%s from %s with firmware %s\n",
+               model_name, manuf_name, firmw_ver);
+       err = 0;
+       kfree(firmw_ver);
+free_manuf_name:
+       kfree(manuf_name);
+free_model_name:
+       kfree(model_name);
+free_id:
+       kfree(id);
+       return err;
+}
+
+/* set the default mode for DMA transfer */
+static int gdrom_init_dma_mode(void)
+{
+       __raw_writeb(0x13, GDROM_ERROR_REG);
+       __raw_writeb(0x22, GDROM_INTSEC_REG);
+       if (!gdrom_wait_clrbusy())
+               return -EBUSY;
+       __raw_writeb(0xEF, GDROM_STATUSCOMMAND_REG);
+       if (!gdrom_wait_busy_sleeps())
+               return -EBUSY;
+       /* Memory protection setting for GDROM DMA
+       * Bits 31 - 16 security: 0x8843
+       * Bits 15 and 7 reserved (0)
+       * Bits 14 - 8 start of transfer range in 1 MB blocks OR'ed with 0x80
+       * Bits 6 - 0 end of transfer range in 1 MB blocks OR'ed with 0x80
+       * (0x40 | 0x80) = start range at 0x0C000000
+       * (0x7F | 0x80) = end range at 0x0FFFFFFF */
+       __raw_writel(0x8843407F, GDROM_DMA_ACCESS_CTRL_REG);
+       __raw_writel(9, GDROM_DMA_WAIT_REG); /* DMA word setting */
+       return 0;
+}
+
+static void probe_gdrom_setupcd(void)
+{
+       gd.cd_info->ops = &gdrom_ops;
+       gd.cd_info->capacity = 1;
+       strcpy(gd.cd_info->name, GDROM_DEV_NAME);
+       gd.cd_info->mask = CDC_CLOSE_TRAY|CDC_OPEN_TRAY|CDC_LOCK|
+               CDC_SELECT_DISC;
+}
+
+static void probe_gdrom_setupdisk(void)
+{
+       gd.disk->major = gdrom_major;
+       gd.disk->first_minor = 1;
+       gd.disk->minors = 1;
+       strcpy(gd.disk->disk_name, GDROM_DEV_NAME);
+}
+
+static int probe_gdrom_setupqueue(void)
+{
+       blk_queue_logical_block_size(gd.gdrom_rq, GDROM_HARD_SECTOR);
+       /* using DMA so memory will need to be contiguous */
+       blk_queue_max_segments(gd.gdrom_rq, 1);
+       /* set a large max size to get most from DMA */
+       blk_queue_max_segment_size(gd.gdrom_rq, 0x40000);
+       gd.disk->queue = gd.gdrom_rq;
+       return gdrom_init_dma_mode();
+}
+
+/*
+ * register this as a block device and as compliant with the
+ * universal CD Rom driver interface
+ */
+static int probe_gdrom(struct platform_device *devptr)
+{
+       int err;
+       /* Start the device */
+       if (gdrom_execute_diagnostic() != 1) {
+               pr_warning("ATA Probe for GDROM failed\n");
+               return -ENODEV;
+       }
+       /* Print out firmware ID */
+       if (gdrom_outputversion())
+               return -ENOMEM;
+       /* Register GDROM */
+       gdrom_major = register_blkdev(0, GDROM_DEV_NAME);
+       if (gdrom_major <= 0)
+               return gdrom_major;
+       pr_info("Registered with major number %d\n",
+               gdrom_major);
+       /* Specify basic properties of drive */
+       gd.cd_info = kzalloc(sizeof(struct cdrom_device_info), GFP_KERNEL);
+       if (!gd.cd_info) {
+               err = -ENOMEM;
+               goto probe_fail_no_mem;
+       }
+       probe_gdrom_setupcd();
+       gd.disk = alloc_disk(1);
+       if (!gd.disk) {
+               err = -ENODEV;
+               goto probe_fail_no_disk;
+       }
+       probe_gdrom_setupdisk();
+       if (register_cdrom(gd.cd_info)) {
+               err = -ENODEV;
+               goto probe_fail_cdrom_register;
+       }
+       gd.disk->fops = &gdrom_bdops;
+       /* latch on to the interrupt */
+       err = gdrom_set_interrupt_handlers();
+       if (err)
+               goto probe_fail_cmdirq_register;
+       gd.gdrom_rq = blk_init_queue(gdrom_request, &gdrom_lock);
+       if (!gd.gdrom_rq)
+               goto probe_fail_requestq;
+
+       err = probe_gdrom_setupqueue();
+       if (err)
+               goto probe_fail_toc;
+
+       gd.toc = kzalloc(sizeof(struct gdromtoc), GFP_KERNEL);
+       if (!gd.toc)
+               goto probe_fail_toc;
+       add_disk(gd.disk);
+       return 0;
+
+probe_fail_toc:
+       blk_cleanup_queue(gd.gdrom_rq);
+probe_fail_requestq:
+       free_irq(HW_EVENT_GDROM_DMA, &gd);
+       free_irq(HW_EVENT_GDROM_CMD, &gd);
+probe_fail_cmdirq_register:
+probe_fail_cdrom_register:
+       del_gendisk(gd.disk);
+probe_fail_no_disk:
+       kfree(gd.cd_info);
+probe_fail_no_mem:
+       unregister_blkdev(gdrom_major, GDROM_DEV_NAME);
+       gdrom_major = 0;
+       pr_warning("Probe failed - error is 0x%X\n", err);
+       return err;
+}
+
+static int remove_gdrom(struct platform_device *devptr)
+{
+       flush_work(&work);
+       blk_cleanup_queue(gd.gdrom_rq);
+       free_irq(HW_EVENT_GDROM_CMD, &gd);
+       free_irq(HW_EVENT_GDROM_DMA, &gd);
+       del_gendisk(gd.disk);
+       if (gdrom_major)
+               unregister_blkdev(gdrom_major, GDROM_DEV_NAME);
+       unregister_cdrom(gd.cd_info);
+
+       return 0;
+}
+
+static struct platform_driver gdrom_driver = {
+       .probe = probe_gdrom,
+       .remove = remove_gdrom,
+       .driver = {
+                       .name = GDROM_DEV_NAME,
+       },
+};
+
+static int __init init_gdrom(void)
+{
+       int rc;
+       gd.toc = NULL;
+       rc = platform_driver_register(&gdrom_driver);
+       if (rc)
+               return rc;
+       pd = platform_device_register_simple(GDROM_DEV_NAME, -1, NULL, 0);
+       if (IS_ERR(pd)) {
+               platform_driver_unregister(&gdrom_driver);
+               return PTR_ERR(pd);
+       }
+       return 0;
+}
+
+static void __exit exit_gdrom(void)
+{
+       platform_device_unregister(pd);
+       platform_driver_unregister(&gdrom_driver);
+       kfree(gd.toc);
+}
+
+module_init(init_gdrom);
+module_exit(exit_gdrom);
+MODULE_AUTHOR("Adrian McMenamin <adrian@mcmen.demon.co.uk>");
+MODULE_DESCRIPTION("SEGA Dreamcast GD-ROM Driver");
+MODULE_LICENSE("GPL");