Initial import

1 files changed, 888 insertions, 0 deletions

diff --git a/drivers/cdrom/gdrom.c b/drivers/cdrom/gdrom.c
new file mode 100644
index 000000000..584bc3126
--- /dev/null
+++ b/drivers/cdrom/gdrom.c
@@ -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");