This patch adds support for the CD Rom device (called a "GD Rom") on
the SEGA Dreamcast.This device has a command block similar to a
standard ATA-3 device, though implements Sega's proprietary packet
interface - the so-called "Sega Packet Interface".
There have been previous GD Rom drivers for Linux knocking about
(though never anywhere near the mainline), though this is a new driver
and most importantly uses DMA and not PIO for reads. It also directly
supports the SEGA proprietary GD-Rom format.
This is the second posting and I think I've taken on board all or
almost all the suggestions/change requests made last time. But
grateful for all comments.
This is targetted at Paul Mundt's 2.6.25 queue, but should also
compile against 2.6.24-rc5
I am using it play mp3s off CD even as I write this and it seems to
work pretty well :)
Signed-off by: Adrian McMenamin <[email protected]>
diff -ruN linux-2.6-orig/drivers/block/Kconfig linux-2.6/drivers/block/Kconfig
--- linux-2.6-orig/drivers/block/Kconfig 2007-12-15 22:23:47.000000000 +0000
+++ linux-2.6/drivers/block/Kconfig 2007-12-20 23:36:15.000000000 +0000
@@ -105,6 +105,18 @@
"MicroSolutions backpack protocol", "DataStor Commuter protocol"
etc.).
+config GDROM
+ tristate "SEGA Dreamcast GD-ROM drive"
+ depends on SH_DREAMCAST
+ help
+ A standard SEGA Dreamcast comes with a modified CD ROM drive called a
+ "GD-ROM" by SEGA to signify it is capable of reading special disks
+ with up to 1 GB of data. This drive will also read standard CD ROM
+ disks. Select this option to access any disks in your GD ROM drive.
+ Most users will want to say "Y" here.
+ You can also build this as a module - which will be called gdrom.ko
+
+
source "drivers/block/paride/Kconfig"
config BLK_CPQ_DA
@@ -425,10 +437,4 @@
block device driver. It communicates with a back-end driver
in another domain which drives the actual block device.
-config VIRTIO_BLK
- tristate "Virtio block driver (EXPERIMENTAL)"
- depends on EXPERIMENTAL && VIRTIO
- ---help---
- This is the virtual block driver for lguest. Say Y or M.
-
endif # BLK_DEV
diff -ruN linux-2.6-orig/drivers/cdrom/gdrom.c linux-2.6/drivers/cdrom/gdrom.c
--- linux-2.6-orig/drivers/cdrom/gdrom.c 1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6/drivers/cdrom/gdrom.c 2007-12-20 23:36:15.000000000 +0000
@@ -0,0 +1,810 @@
+/* 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.
+ *
+ */
+
+#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/wait.h>
+#include <linux/workqueue.h>
+#include <linux/platform_device.h>
+#include <asm/io.h>
+#include <asm/dma.h>
+#include <asm/delay.h>
+#include <asm/mach/dma.h>
+#include <asm/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
+
+static struct platform_device *pd;
+static int gdrom_major;
+static wait_queue_head_t command_queue;
+static wait_queue_head_t 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 void gdrom_wait_clrbusy(void)
+{
+ /* long timeouts - typical for a CD Rom */
+ unsigned long timeout = jiffies + HZ * 60;
+ while ((ctrl_inb(GDROM_ALTSTATUS_REG) & 0x80) &&
(time_before(jiffies, timeout)))
+ cpu_relax();
+}
+
+static void gdrom_wait_busy_sleeps(void)
+{
+ unsigned long timeout;
+ /* Wait to get busy first */
+ timeout = jiffies + HZ * 60;
+ while (((ctrl_inb(GDROM_ALTSTATUS_REG) & 0x80) == 0) &&
(time_before(jiffies, timeout)))
+ cpu_relax();
+ /* Now wait for busy to clear */
+ gdrom_wait_clrbusy();
+}
+
+static void gdrom_identifydevice(void *buf)
+{
+ int c;
+ short *data = buf;
+ gdrom_wait_clrbusy();
+ ctrl_outb(GDROM_COM_IDDEV, GDROM_STATUSCOMMAND_REG);
+ gdrom_wait_busy_sleeps();
+ /* now read in the data */
+ for (c = 0; c < 40; c++)
+ data[c] = ctrl_inw(GDROM_DATA_REG);
+}
+
+static void gdrom_spicommand(void *spi_string, int buflen)
+{
+ short *cmd = spi_string;
+ /* ensure IRQ_WAIT is set */
+ ctrl_outb(0x08, GDROM_ALTSTATUS_REG);
+ /* specify how many bytes we expect back */
+ ctrl_outb(buflen & 0xFF, GDROM_BCL_REG);
+ ctrl_outb((buflen >> 8) & 0xFF, GDROM_BCH_REG);
+ /* other parameters */
+ ctrl_outb(0, GDROM_INTSEC_REG);
+ ctrl_outb(0, GDROM_SECNUM_REG);
+ ctrl_outb(0, GDROM_ERROR_REG);
+ /* Wait until we can go */
+ gdrom_wait_clrbusy();
+ ctrl_outb(GDROM_COM_PACKET, GDROM_STATUSCOMMAND_REG);
+ while ((ctrl_inb(GDROM_ALTSTATUS_REG) & 0x88) != 8)
+ ; /* wait for DRQ to be set to 1 */
+ outsw(PHYSADDR(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);
+ gdrom_wait_clrbusy();
+ ctrl_outb(GDROM_COM_EXECDIAG, GDROM_STATUSCOMMAND_REG);
+ gdrom_wait_busy_sleeps();
+ return ctrl_inb(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, HZ * 60);
+
+ gd.pending = 0;
+ kfree(spin_command);
+ if ((gd.status & 0x01) != 0) {
+ /* 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;
+ 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;
+ gd.pending = 1;
+ gdrom_packetcommand(gd.cd_info, toc_command);
+ wait_event_interruptible_timeout(command_queue, gd.pending == 0, HZ * 60);
+ gd.pending = 0;
+ insw(PHYSADDR(GDROM_DATA_REG), toc, tocsize/2);
+ kfree(toc_command);
+ if ((gd.status & 0x01) != 0)
+ return -EINVAL;
+ return 0;
+}
+
+/* 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)
+{
+ struct gdromtoc *tocA, *tocB;
+ int fentry, lentry, track, data, tocuse;
+ int err = -ENOMEM;
+ tocA = kzalloc(sizeof(struct gdromtoc), GFP_KERNEL);
+ if (!tocA)
+ goto exit;
+ tocB = kzalloc(sizeof(struct gdromtoc), GFP_KERNEL);
+ if (!tocB)
+ goto clean_tocA;
+ tocuse = 1;
+ err = gdrom_readtoc_cmd(tocB, 1);
+ if (err) {
+ tocuse = 0;
+ err = gdrom_readtoc_cmd(tocA, 0);
+ if (err) {
+ err = -ENXIO;
+ printk(KERN_INFO "Could not get CD table of contents\n");
+ goto clean_tocB;
+ }
+ } else
+ printk(KERN_DEBUG "Disk is GDROM\n");
+
+ kfree(gd.toc);
+
+ if (tocuse) {
+ gd.toc = tocB;
+ kfree(tocA);
+ } else {
+ gd.toc = tocA;
+ kfree(tocB);
+ }
+
+ 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))) {
+ gdrom_getsense(NULL);
+ printk(KERN_INFO "GDROM: No data on the last session of the CD\n");
+ return -ENXIO;
+ }
+
+ ms_info->addr_format = CDROM_LBA;
+ ms_info->addr.lba = get_entry_lba(data);
+ ms_info->xa_flag = 1;
+ return 0;
+
+clean_tocB:
+ kfree(tocB);
+clean_tocA:
+ kfree(tocA);
+exit:
+ return err;
+}
+
+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 = ctrl_inb(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 int gdrom_mediachanged(struct cdrom_device_info *cd_info, int ignore)
+{
+ /* check the sense key */
+ return ((ctrl_inb(GDROM_ERROR_REG) & 0xF0) == 0x60);
+}
+
+/* reset the G1 bus */
+static int gdrom_hardreset(struct cdrom_device_info * cd_info)
+{
+ int count;
+ ctrl_outl(0x1fffff, GDROM_RESET_REG);
+ for (count = 0xa0000000; count < 0xa0200000; count += 4)
+ ctrl_inl(count);
+ return 0;
+}
+
+static int gdrom_packetcommand(struct cdrom_device_info * cd_info,
struct packet_command *command)
+{
+ gdrom_spicommand(&command->cmd, command->buflen);
+ /* keep the function like the universal CD Rom one
+ * though the return value is meaningless */
+ 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];
+ char sense_key;
+ if (gd.pending)
+ return -EIO;
+
+ /* allocate command and buffer */
+ 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;
+
+ gd.pending = 1;
+ gdrom_packetcommand(gd.cd_info, sense_command);
+ /* 60 second timeout */
+ wait_event_interruptible_timeout(command_queue, gd.pending == 0, HZ * 60);
+ gd.pending = 0;
+ kfree(sense_command);
+ insw(PHYSADDR(GDROM_DATA_REG), &sense, 5);
+ if (sense[1] & 40) {
+ printk(KERN_INFO "GDROM: Drive not ready - command aborted\n");
+ return -EIO;
+ }
+ sense_key = sense[1] & 0x0F;
+ switch (sense_key){
+ case 0xB:
+ printk(KERN_INFO "GDROM: Command aborted\n");
+ break;
+ case 0x7:
+ printk(KERN_INFO "GDROM: Data protection error\n");
+ break;
+ case 0x6:
+ printk(KERN_NOTICE "GDROM: Unit needs attention - possible disk switch\n");
+ break;
+ case 0x5:
+ printk(KERN_INFO "GDROM: Illegal request - command has failed\n");
+ break;
+ case 0x4:
+ printk(KERN_CRIT "GDROM: Hardware error\n");
+ break;
+ case 0x3:
+ printk(KERN_WARNING "GDROM: Disk read error\n");
+ break;
+ case 0x2:
+ printk(KERN_INFO "GDROM: Not ready\n");
+ break;
+ case 0x1:
+ printk(KERN_DEBUG "GDROM: Recovered from error\n");
+ break;
+ case 0x0:
+ /*success - stay silent*/
+ break;
+
+ default:
+ printk(KERN_INFO "GDROM: Unknown error\n");
+ }
+
+ if (bufstring)
+ memcpy(bufstring, &sense[4], 2); /* return additional sense data */
+
+ if (sense_key < 2)
+ return 0;
+ return -EIO;
+}
+
+static struct cdrom_device_ops gdrom_ops = {
+ .open = gdrom_open,
+ .release = gdrom_release,
+ .drive_status = gdrom_drivestatus,
+ .media_changed = gdrom_mediachanged,
+ .get_last_session = gdrom_get_last_session,
+ .reset = gdrom_hardreset,
+ .capability = CDC_MULTI_SESSION | CDC_MEDIA_CHANGED |
+ CDC_RESET | CDC_DRIVE_STATUS | CDC_CD_R,
+ .n_minors = 1,
+};
+
+static int gdrom_bdops_open(struct inode *inode, struct file *file)
+{
+ return cdrom_open(gd.cd_info, inode, file);
+}
+
+static int gdrom_bdops_release(struct inode *inode, struct file *file)
+{
+ return cdrom_release(gd.cd_info, file);
+}
+
+static int gdrom_bdops_mediachanged(struct gendisk *disk)
+{
+ return cdrom_media_changed(gd.cd_info);
+}
+
+static int gdrom_bdops_ioctl(struct inode *inode, struct file *file,
unsigned cmd, unsigned long arg)
+{
+ return cdrom_ioctl(file, gd.cd_info, inode, cmd, arg);
+}
+
+static struct block_device_operations gdrom_bdops = {
+ .owner = THIS_MODULE,
+ .open = gdrom_bdops_open,
+ .release = gdrom_bdops_release,
+ .media_changed = gdrom_bdops_mediachanged,
+ .ioctl = gdrom_bdops_ioctl,
+};
+
+static irqreturn_t gdrom_command_interrupt(int irq, void *dev_id)
+{
+ gd.status = ctrl_inb(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 = ctrl_inb(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_command_interrupt_handler(void)
+{
+ /* need a queue to wait in */
+ init_waitqueue_head(&command_queue);
+ return request_irq(HW_EVENT_GDROM_CMD, gdrom_command_interrupt,
IRQF_DISABLED, "gdrom_command", &gd);
+}
+
+static int gdrom_set_dma_interrupt_handler(void)
+{
+ init_waitqueue_head(&request_queue);
+ return request_irq(HW_EVENT_GDROM_DMA, gdrom_dma_interrupt,
IRQF_DISABLED, "gdrom_dma", &gd);
+}
+
+/* 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;
+ list_for_each_safe(elem, next, &gdrom_deferred) {
+ req = list_entry(elem, struct request, queuelist);
+ block = req->sector/GD_TO_BLK + GD_SESSION_OFFSET;
+ block_cnt = req->nr_sectors/GD_TO_BLK;
+ ctrl_outl(PHYSADDR(req->buffer), GDROM_DMA_STARTADDR_REG);
+ ctrl_outl(block_cnt * GDROM_HARD_SECTOR, GDROM_DMA_LENGTH_REG);
+ ctrl_outl(1, GDROM_DMA_DIRECTION_REG);
+ ctrl_outl(1, GDROM_DMA_ENABLE_REG);
+ /* send command */
+ read_command = kzalloc(sizeof(struct packet_command), GFP_KERNEL);
+ if (!read_command) {
+ err = -ENOMEM;
+ goto end_request;
+ }
+ read_command->cmd[0] = 0x30;
+ read_command->cmd[1] = 0x20;
+ 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 */
+ ctrl_outb(1, GDROM_ERROR_REG);
+ /* other parameters */
+ ctrl_outb(0, GDROM_SECNUM_REG);
+ ctrl_outb(0, GDROM_BCL_REG);
+ ctrl_outb(0, GDROM_BCH_REG);
+ ctrl_outb(0, GDROM_DSEL_REG);
+ ctrl_outb(0, GDROM_INTSEC_REG);
+ /* In multiple DMA transfers need to wait */
+ timeout = jiffies + HZ / 2;
+ while ((ctrl_inb(GDROM_ALTSTATUS_REG) & 0x80) &&
(time_before(jiffies, timeout)))
+ cpu_relax();
+ ctrl_outb(GDROM_COM_PACKET, GDROM_STATUSCOMMAND_REG);
+ timeout = jiffies + HZ / 2;
+ while (((ctrl_inb(GDROM_ALTSTATUS_REG) & 0x88) != 8) &&
(time_before(jiffies, timeout)))
+ cpu_relax(); /* wait for DRQ to be set to 1 */
+ gd.pending = 1;
+ gd.transfer = 1;
+ outsw(PHYSADDR(GDROM_DATA_REG), &read_command->cmd, 6);
+ timeout = jiffies + HZ / 2;
+ while ((ctrl_inb(GDROM_DMA_STATUS_REG)) && (time_before(jiffies, timeout)))
+ cpu_relax();
+ ctrl_outb(1, GDROM_DMA_STATUS_REG);
+ /* 5 second error margin here seems more reasonable */
+ wait_event_interruptible_timeout(request_queue, gd.transfer == 0, HZ * 5);
+ err = ctrl_inb(GDROM_DMA_STATUS_REG);
+ err = gd.transfer;
+ gd.transfer = 0;
+ gd.pending = 0;
+ kfree(read_command);
+ /* now seek to take the request spinlock
+ * before handling ending the request */
+end_request:
+ spin_lock(&gdrom_lock);
+ list_del_init(&req->queuelist);
+ blk_requeue_request(gd.gdrom_rq, req);
+ if (err)
+ end_request(req, 0);
+ else
+ end_request(req, 1);
+ spin_unlock(&gdrom_lock);
+ }
+}
+
+static void gdrom_request_handler_dma(struct request *req)
+{
+ /* dequeue, add to list of deferred work
+ * and then schedule workqueue */
+ blkdev_dequeue_request(req);
+ list_add_tail(&req->queuelist, &gdrom_deferred);
+ schedule_work(&work);
+}
+
+static void gdrom_request(struct request_queue *rq)
+{
+ struct request *req;
+ unsigned long pages;
+ pages = rq->backing_dev_info.ra_pages;
+ while ((req = elv_next_request(rq)) != NULL) {
+ if (! blk_fs_request(req)) {
+ printk(KERN_DEBUG "GDROM: Non-fs request ignored\n");
+ end_request(req, 0);
+ }
+ if (rq_data_dir(req) != READ) {
+ printk(KERN_NOTICE "GDROM: Read only device - write request ignored\n");
+ end_request(req, 0);
+ }
+ if (req->nr_sectors)
+ gdrom_request_handler_dma(req);
+ else
+ end_request(req, 0);
+ }
+}
+
+/* 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;
+ printk(KERN_INFO "GDROM: %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 void __init gdrom_init_dma_mode(void)
+{
+ ctrl_outb(0x13, GDROM_ERROR_REG);
+ ctrl_outb(0x22, GDROM_INTSEC_REG);
+ gdrom_wait_clrbusy();
+ ctrl_outb(0xEF, GDROM_STATUSCOMMAND_REG);
+ gdrom_wait_busy_sleeps();
+ ctrl_outl(0x8843407F, GDROM_DMA_ACCESS_CTRL_REG); /* memory setting */
+ ctrl_outl(9, GDROM_DMA_WAIT_REG); /* DMA word setting */
+}
+
+/*
+ * register this as a block device and as compliant with the
+ * universal CD Rom driver interface
+ */
+static int __init probe_gdrom(struct platform_device *devptr)
+{
+ char err;
+ gd.toc = NULL;
+ err = gdrom_execute_diagnostic();
+ if (err == 1){
+ if (gdrom_outputversion())
+ return -ENOMEM;
+ } else {
+ printk(KERN_WARNING "Probe for GDROM failed with error 0x%X\n", err);
+ return -ENODEV;
+ }
+ gdrom_major = register_blkdev(0, GDROM_DEV_NAME);
+ if (gdrom_major <= 0)
+ return gdrom_major;
+ printk(KERN_INFO "GDROM: Block device is registered with major
number %d\n", gdrom_major);
+ gd.cd_info = kzalloc(sizeof(struct cdrom_device_info), GFP_KERNEL);
+ if (!gd.cd_info) {
+ err = -ENOMEM;
+ goto probe_fail_no_mem;
+ }
+ gd.cd_info->ops = &gdrom_ops;
+ gd.cd_info->capacity = 1;
+ sprintf(gd.cd_info->name, GDROM_DEV_NAME);
+ gd.cd_info->mask = CDC_CLOSE_TRAY|CDC_OPEN_TRAY|CDC_LOCK|CDC_SELECT_DISC;
+ gd.disk = alloc_disk(1);
+ if (!gd.disk) {
+ err = -ENODEV;
+ goto probe_fail_no_disk;
+ }
+ gd.disk->major = gdrom_major;
+ gd.disk->first_minor = 1;
+ gd.disk->minors = 1;
+ sprintf(gd.disk->disk_name, GDROM_DEV_NAME);
+
+ 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_command_interrupt_handler();
+ if (err)
+ goto probe_fail_cmdirq_register;
+ err = gdrom_set_dma_interrupt_handler();
+ if (err)
+ goto probe_fail_dmairq_register;
+ gd.gdrom_rq = blk_init_queue(gdrom_request, &gdrom_lock);
+ if (!gd.gdrom_rq)
+ goto probe_fail_requestq;
+ blk_queue_hardsect_size(gd.gdrom_rq, GDROM_HARD_SECTOR);
+ /* using DMA so memory will need to be contiguous */
+ blk_queue_max_hw_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;
+ gdrom_init_dma_mode();
+ add_disk(gd.disk);
+ return 0;
+
+probe_fail_requestq:
+ free_irq(HW_EVENT_GDROM_DMA, &gd);
+probe_fail_dmairq_register:
+ 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);
+ unregister_blkdev(gdrom_major, GDROM_DEV_NAME);
+ gdrom_major = 0;
+probe_fail_no_mem:
+ printk(KERN_WARNING "GDROM: Could not probe for device - error is
0x%X\n", err);
+ return err;
+}
+
+static int remove_gdrom(struct platform_device *devptr)
+{
+ 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);
+ return unregister_cdrom(gd.cd_info);
+}
+
+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;
+
+ rc = platform_driver_register(&gdrom_driver);
+ if (rc) {
+ printk(KERN_INFO "Could not register GDROM driver - error 0x%X\n", rc);
+ return -EPERM;
+ }
+ pd = platform_device_register_simple(GDROM_DEV_NAME, -1, NULL, 0);
+ if (IS_ERR(pd)) {
+ platform_driver_unregister(&gdrom_driver);
+ return -ENODEV;
+ }
+ 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 <[email protected]>");
+MODULE_DESCRIPTION("SEGA Dreamcast GD-ROM Driver");
+MODULE_LICENSE("GPL");
diff -ruN linux-2.6-orig/drivers/cdrom/Makefile linux-2.6/drivers/cdrom/Makefile
--- linux-2.6-orig/drivers/cdrom/Makefile 2007-12-15 22:23:47.000000000 +0000
+++ linux-2.6/drivers/cdrom/Makefile 2007-12-20 23:36:15.000000000 +0000
@@ -11,3 +11,4 @@
obj-$(CONFIG_CDROM_PKTCDVD) += cdrom.o
obj-$(CONFIG_VIOCD) += viocd.o cdrom.o
On 20/12/2007, Adrian McMenamin <[email protected]> wrote:
> This patch adds support for the CD Rom device (called a "GD Rom") on
> the SEGA Dreamcast.This device has a command block similar to a
> standard ATA-3 device, though implements Sega's proprietary packet
> interface - the so-called "Sega Packet Interface".
>
Fairly typically, I noticed I had chopped the final line from the
patch as soon as I had sent it.
I've also fixed a small difference in the Kconfig
diff -ruN linux-2.6-orig/drivers/block/Kconfig linux-2.6/drivers/block/Kconfig
--- linux-2.6-orig/drivers/block/Kconfig 2007-12-15 22:23:47.000000000 +0000
+++ linux-2.6/drivers/block/Kconfig 2007-12-20 23:36:15.000000000 +0000
@@ -105,6 +105,18 @@
"MicroSolutions backpack protocol", "DataStor Commuter protocol"
etc.).
+config GDROM
+ tristate "SEGA Dreamcast GD-ROM drive"
+ depends on SH_DREAMCAST
+ help
+ A standard SEGA Dreamcast comes with a modified CD ROM drive called a
+ "GD-ROM" by SEGA to signify it is capable of reading special disks
+ with up to 1 GB of data. This drive will also read standard CD ROM
+ disks. Select this option to access any disks in your GD ROM drive.
+ Most users will want to say "Y" here.
+ You can also build this as a module - which will be called gdrom.ko
+
+
source "drivers/block/paride/Kconfig"
config BLK_CPQ_DA
diff -ruN linux-2.6-orig/drivers/cdrom/gdrom.c linux-2.6/drivers/cdrom/gdrom.c
--- linux-2.6-orig/drivers/cdrom/gdrom.c 1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6/drivers/cdrom/gdrom.c 2007-12-20 23:36:15.000000000 +0000
@@ -0,0 +1,810 @@
+/* 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.
+ *
+ */
+
+#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/wait.h>
+#include <linux/workqueue.h>
+#include <linux/platform_device.h>
+#include <asm/io.h>
+#include <asm/dma.h>
+#include <asm/delay.h>
+#include <asm/mach/dma.h>
+#include <asm/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
+
+static struct platform_device *pd;
+static int gdrom_major;
+static wait_queue_head_t command_queue;
+static wait_queue_head_t 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 void gdrom_wait_clrbusy(void)
+{
+ /* long timeouts - typical for a CD Rom */
+ unsigned long timeout = jiffies + HZ * 60;
+ while ((ctrl_inb(GDROM_ALTSTATUS_REG) & 0x80) &&
(time_before(jiffies, timeout)))
+ cpu_relax();
+}
+
+static void gdrom_wait_busy_sleeps(void)
+{
+ unsigned long timeout;
+ /* Wait to get busy first */
+ timeout = jiffies + HZ * 60;
+ while (((ctrl_inb(GDROM_ALTSTATUS_REG) & 0x80) == 0) &&
(time_before(jiffies, timeout)))
+ cpu_relax();
+ /* Now wait for busy to clear */
+ gdrom_wait_clrbusy();
+}
+
+static void gdrom_identifydevice(void *buf)
+{
+ int c;
+ short *data = buf;
+ gdrom_wait_clrbusy();
+ ctrl_outb(GDROM_COM_IDDEV, GDROM_STATUSCOMMAND_REG);
+ gdrom_wait_busy_sleeps();
+ /* now read in the data */
+ for (c = 0; c < 40; c++)
+ data[c] = ctrl_inw(GDROM_DATA_REG);
+}
+
+static void gdrom_spicommand(void *spi_string, int buflen)
+{
+ short *cmd = spi_string;
+ /* ensure IRQ_WAIT is set */
+ ctrl_outb(0x08, GDROM_ALTSTATUS_REG);
+ /* specify how many bytes we expect back */
+ ctrl_outb(buflen & 0xFF, GDROM_BCL_REG);
+ ctrl_outb((buflen >> 8) & 0xFF, GDROM_BCH_REG);
+ /* other parameters */
+ ctrl_outb(0, GDROM_INTSEC_REG);
+ ctrl_outb(0, GDROM_SECNUM_REG);
+ ctrl_outb(0, GDROM_ERROR_REG);
+ /* Wait until we can go */
+ gdrom_wait_clrbusy();
+ ctrl_outb(GDROM_COM_PACKET, GDROM_STATUSCOMMAND_REG);
+ while ((ctrl_inb(GDROM_ALTSTATUS_REG) & 0x88) != 8)
+ ; /* wait for DRQ to be set to 1 */
+ outsw(PHYSADDR(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);
+ gdrom_wait_clrbusy();
+ ctrl_outb(GDROM_COM_EXECDIAG, GDROM_STATUSCOMMAND_REG);
+ gdrom_wait_busy_sleeps();
+ return ctrl_inb(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, HZ * 60);
+
+ gd.pending = 0;
+ kfree(spin_command);
+ if ((gd.status & 0x01) != 0) {
+ /* 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;
+ 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;
+ gd.pending = 1;
+ gdrom_packetcommand(gd.cd_info, toc_command);
+ wait_event_interruptible_timeout(command_queue, gd.pending == 0, HZ * 60);
+ gd.pending = 0;
+ insw(PHYSADDR(GDROM_DATA_REG), toc, tocsize/2);
+ kfree(toc_command);
+ if ((gd.status & 0x01) != 0)
+ return -EINVAL;
+ return 0;
+}
+
+/* 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)
+{
+ struct gdromtoc *tocA, *tocB;
+ int fentry, lentry, track, data, tocuse;
+ int err = -ENOMEM;
+ tocA = kzalloc(sizeof(struct gdromtoc), GFP_KERNEL);
+ if (!tocA)
+ goto exit;
+ tocB = kzalloc(sizeof(struct gdromtoc), GFP_KERNEL);
+ if (!tocB)
+ goto clean_tocA;
+ tocuse = 1;
+ err = gdrom_readtoc_cmd(tocB, 1);
+ if (err) {
+ tocuse = 0;
+ err = gdrom_readtoc_cmd(tocA, 0);
+ if (err) {
+ err = -ENXIO;
+ printk(KERN_INFO "Could not get CD table of contents\n");
+ goto clean_tocB;
+ }
+ } else
+ printk(KERN_DEBUG "Disk is GDROM\n");
+
+ kfree(gd.toc);
+
+ if (tocuse) {
+ gd.toc = tocB;
+ kfree(tocA);
+ } else {
+ gd.toc = tocA;
+ kfree(tocB);
+ }
+
+ 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))) {
+ gdrom_getsense(NULL);
+ printk(KERN_INFO "GDROM: No data on the last session of the CD\n");
+ return -ENXIO;
+ }
+
+ ms_info->addr_format = CDROM_LBA;
+ ms_info->addr.lba = get_entry_lba(data);
+ ms_info->xa_flag = 1;
+ return 0;
+
+clean_tocB:
+ kfree(tocB);
+clean_tocA:
+ kfree(tocA);
+exit:
+ return err;
+}
+
+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 = ctrl_inb(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 int gdrom_mediachanged(struct cdrom_device_info *cd_info, int ignore)
+{
+ /* check the sense key */
+ return ((ctrl_inb(GDROM_ERROR_REG) & 0xF0) == 0x60);
+}
+
+/* reset the G1 bus */
+static int gdrom_hardreset(struct cdrom_device_info * cd_info)
+{
+ int count;
+ ctrl_outl(0x1fffff, GDROM_RESET_REG);
+ for (count = 0xa0000000; count < 0xa0200000; count += 4)
+ ctrl_inl(count);
+ return 0;
+}
+
+static int gdrom_packetcommand(struct cdrom_device_info * cd_info,
struct packet_command *command)
+{
+ gdrom_spicommand(&command->cmd, command->buflen);
+ /* keep the function like the universal CD Rom one
+ * though the return value is meaningless */
+ 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];
+ char sense_key;
+ if (gd.pending)
+ return -EIO;
+
+ /* allocate command and buffer */
+ 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;
+
+ gd.pending = 1;
+ gdrom_packetcommand(gd.cd_info, sense_command);
+ /* 60 second timeout */
+ wait_event_interruptible_timeout(command_queue, gd.pending == 0, HZ * 60);
+ gd.pending = 0;
+ kfree(sense_command);
+ insw(PHYSADDR(GDROM_DATA_REG), &sense, 5);
+ if (sense[1] & 40) {
+ printk(KERN_INFO "GDROM: Drive not ready - command aborted\n");
+ return -EIO;
+ }
+ sense_key = sense[1] & 0x0F;
+ switch (sense_key){
+ case 0xB:
+ printk(KERN_INFO "GDROM: Command aborted\n");
+ break;
+ case 0x7:
+ printk(KERN_INFO "GDROM: Data protection error\n");
+ break;
+ case 0x6:
+ printk(KERN_NOTICE "GDROM: Unit needs attention - possible disk switch\n");
+ break;
+ case 0x5:
+ printk(KERN_INFO "GDROM: Illegal request - command has failed\n");
+ break;
+ case 0x4:
+ printk(KERN_CRIT "GDROM: Hardware error\n");
+ break;
+ case 0x3:
+ printk(KERN_WARNING "GDROM: Disk read error\n");
+ break;
+ case 0x2:
+ printk(KERN_INFO "GDROM: Not ready\n");
+ break;
+ case 0x1:
+ printk(KERN_DEBUG "GDROM: Recovered from error\n");
+ break;
+ case 0x0:
+ /*success - stay silent*/
+ break;
+
+ default:
+ printk(KERN_INFO "GDROM: Unknown error\n");
+ }
+
+ if (bufstring)
+ memcpy(bufstring, &sense[4], 2); /* return additional sense data */
+
+ if (sense_key < 2)
+ return 0;
+ return -EIO;
+}
+
+static struct cdrom_device_ops gdrom_ops = {
+ .open = gdrom_open,
+ .release = gdrom_release,
+ .drive_status = gdrom_drivestatus,
+ .media_changed = gdrom_mediachanged,
+ .get_last_session = gdrom_get_last_session,
+ .reset = gdrom_hardreset,
+ .capability = CDC_MULTI_SESSION | CDC_MEDIA_CHANGED |
+ CDC_RESET | CDC_DRIVE_STATUS | CDC_CD_R,
+ .n_minors = 1,
+};
+
+static int gdrom_bdops_open(struct inode *inode, struct file *file)
+{
+ return cdrom_open(gd.cd_info, inode, file);
+}
+
+static int gdrom_bdops_release(struct inode *inode, struct file *file)
+{
+ return cdrom_release(gd.cd_info, file);
+}
+
+static int gdrom_bdops_mediachanged(struct gendisk *disk)
+{
+ return cdrom_media_changed(gd.cd_info);
+}
+
+static int gdrom_bdops_ioctl(struct inode *inode, struct file *file,
unsigned cmd, unsigned long arg)
+{
+ return cdrom_ioctl(file, gd.cd_info, inode, cmd, arg);
+}
+
+static struct block_device_operations gdrom_bdops = {
+ .owner = THIS_MODULE,
+ .open = gdrom_bdops_open,
+ .release = gdrom_bdops_release,
+ .media_changed = gdrom_bdops_mediachanged,
+ .ioctl = gdrom_bdops_ioctl,
+};
+
+static irqreturn_t gdrom_command_interrupt(int irq, void *dev_id)
+{
+ gd.status = ctrl_inb(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 = ctrl_inb(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_command_interrupt_handler(void)
+{
+ /* need a queue to wait in */
+ init_waitqueue_head(&command_queue);
+ return request_irq(HW_EVENT_GDROM_CMD, gdrom_command_interrupt,
IRQF_DISABLED, "gdrom_command", &gd);
+}
+
+static int gdrom_set_dma_interrupt_handler(void)
+{
+ init_waitqueue_head(&request_queue);
+ return request_irq(HW_EVENT_GDROM_DMA, gdrom_dma_interrupt,
IRQF_DISABLED, "gdrom_dma", &gd);
+}
+
+/* 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;
+ list_for_each_safe(elem, next, &gdrom_deferred) {
+ req = list_entry(elem, struct request, queuelist);
+ block = req->sector/GD_TO_BLK + GD_SESSION_OFFSET;
+ block_cnt = req->nr_sectors/GD_TO_BLK;
+ ctrl_outl(PHYSADDR(req->buffer), GDROM_DMA_STARTADDR_REG);
+ ctrl_outl(block_cnt * GDROM_HARD_SECTOR, GDROM_DMA_LENGTH_REG);
+ ctrl_outl(1, GDROM_DMA_DIRECTION_REG);
+ ctrl_outl(1, GDROM_DMA_ENABLE_REG);
+ /* send command */
+ read_command = kzalloc(sizeof(struct packet_command), GFP_KERNEL);
+ if (!read_command) {
+ err = -ENOMEM;
+ goto end_request;
+ }
+ read_command->cmd[0] = 0x30;
+ read_command->cmd[1] = 0x20;
+ 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 */
+ ctrl_outb(1, GDROM_ERROR_REG);
+ /* other parameters */
+ ctrl_outb(0, GDROM_SECNUM_REG);
+ ctrl_outb(0, GDROM_BCL_REG);
+ ctrl_outb(0, GDROM_BCH_REG);
+ ctrl_outb(0, GDROM_DSEL_REG);
+ ctrl_outb(0, GDROM_INTSEC_REG);
+ /* In multiple DMA transfers need to wait */
+ timeout = jiffies + HZ / 2;
+ while ((ctrl_inb(GDROM_ALTSTATUS_REG) & 0x80) &&
(time_before(jiffies, timeout)))
+ cpu_relax();
+ ctrl_outb(GDROM_COM_PACKET, GDROM_STATUSCOMMAND_REG);
+ timeout = jiffies + HZ / 2;
+ while (((ctrl_inb(GDROM_ALTSTATUS_REG) & 0x88) != 8) &&
(time_before(jiffies, timeout)))
+ cpu_relax(); /* wait for DRQ to be set to 1 */
+ gd.pending = 1;
+ gd.transfer = 1;
+ outsw(PHYSADDR(GDROM_DATA_REG), &read_command->cmd, 6);
+ timeout = jiffies + HZ / 2;
+ while ((ctrl_inb(GDROM_DMA_STATUS_REG)) && (time_before(jiffies, timeout)))
+ cpu_relax();
+ ctrl_outb(1, GDROM_DMA_STATUS_REG);
+ /* 5 second error margin here seems more reasonable */
+ wait_event_interruptible_timeout(request_queue, gd.transfer == 0, HZ * 5);
+ err = ctrl_inb(GDROM_DMA_STATUS_REG);
+ err = gd.transfer;
+ gd.transfer = 0;
+ gd.pending = 0;
+ kfree(read_command);
+ /* now seek to take the request spinlock
+ * before handling ending the request */
+end_request:
+ spin_lock(&gdrom_lock);
+ list_del_init(&req->queuelist);
+ blk_requeue_request(gd.gdrom_rq, req);
+ if (err)
+ end_request(req, 0);
+ else
+ end_request(req, 1);
+ spin_unlock(&gdrom_lock);
+ }
+}
+
+static void gdrom_request_handler_dma(struct request *req)
+{
+ /* dequeue, add to list of deferred work
+ * and then schedule workqueue */
+ blkdev_dequeue_request(req);
+ list_add_tail(&req->queuelist, &gdrom_deferred);
+ schedule_work(&work);
+}
+
+static void gdrom_request(struct request_queue *rq)
+{
+ struct request *req;
+ unsigned long pages;
+ pages = rq->backing_dev_info.ra_pages;
+ while ((req = elv_next_request(rq)) != NULL) {
+ if (! blk_fs_request(req)) {
+ printk(KERN_DEBUG "GDROM: Non-fs request ignored\n");
+ end_request(req, 0);
+ }
+ if (rq_data_dir(req) != READ) {
+ printk(KERN_NOTICE "GDROM: Read only device - write request ignored\n");
+ end_request(req, 0);
+ }
+ if (req->nr_sectors)
+ gdrom_request_handler_dma(req);
+ else
+ end_request(req, 0);
+ }
+}
+
+/* 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;
+ printk(KERN_INFO "GDROM: %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 void __init gdrom_init_dma_mode(void)
+{
+ ctrl_outb(0x13, GDROM_ERROR_REG);
+ ctrl_outb(0x22, GDROM_INTSEC_REG);
+ gdrom_wait_clrbusy();
+ ctrl_outb(0xEF, GDROM_STATUSCOMMAND_REG);
+ gdrom_wait_busy_sleeps();
+ ctrl_outl(0x8843407F, GDROM_DMA_ACCESS_CTRL_REG); /* memory setting */
+ ctrl_outl(9, GDROM_DMA_WAIT_REG); /* DMA word setting */
+}
+
+/*
+ * register this as a block device and as compliant with the
+ * universal CD Rom driver interface
+ */
+static int __init probe_gdrom(struct platform_device *devptr)
+{
+ char err;
+ gd.toc = NULL;
+ err = gdrom_execute_diagnostic();
+ if (err == 1){
+ if (gdrom_outputversion())
+ return -ENOMEM;
+ } else {
+ printk(KERN_WARNING "Probe for GDROM failed with error 0x%X\n", err);
+ return -ENODEV;
+ }
+ gdrom_major = register_blkdev(0, GDROM_DEV_NAME);
+ if (gdrom_major <= 0)
+ return gdrom_major;
+ printk(KERN_INFO "GDROM: Block device is registered with major
number %d\n", gdrom_major);
+ gd.cd_info = kzalloc(sizeof(struct cdrom_device_info), GFP_KERNEL);
+ if (!gd.cd_info) {
+ err = -ENOMEM;
+ goto probe_fail_no_mem;
+ }
+ gd.cd_info->ops = &gdrom_ops;
+ gd.cd_info->capacity = 1;
+ sprintf(gd.cd_info->name, GDROM_DEV_NAME);
+ gd.cd_info->mask = CDC_CLOSE_TRAY|CDC_OPEN_TRAY|CDC_LOCK|CDC_SELECT_DISC;
+ gd.disk = alloc_disk(1);
+ if (!gd.disk) {
+ err = -ENODEV;
+ goto probe_fail_no_disk;
+ }
+ gd.disk->major = gdrom_major;
+ gd.disk->first_minor = 1;
+ gd.disk->minors = 1;
+ sprintf(gd.disk->disk_name, GDROM_DEV_NAME);
+
+ 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_command_interrupt_handler();
+ if (err)
+ goto probe_fail_cmdirq_register;
+ err = gdrom_set_dma_interrupt_handler();
+ if (err)
+ goto probe_fail_dmairq_register;
+ gd.gdrom_rq = blk_init_queue(gdrom_request, &gdrom_lock);
+ if (!gd.gdrom_rq)
+ goto probe_fail_requestq;
+ blk_queue_hardsect_size(gd.gdrom_rq, GDROM_HARD_SECTOR);
+ /* using DMA so memory will need to be contiguous */
+ blk_queue_max_hw_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;
+ gdrom_init_dma_mode();
+ add_disk(gd.disk);
+ return 0;
+
+probe_fail_requestq:
+ free_irq(HW_EVENT_GDROM_DMA, &gd);
+probe_fail_dmairq_register:
+ 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);
+ unregister_blkdev(gdrom_major, GDROM_DEV_NAME);
+ gdrom_major = 0;
+probe_fail_no_mem:
+ printk(KERN_WARNING "GDROM: Could not probe for device - error is
0x%X\n", err);
+ return err;
+}
+
+static int remove_gdrom(struct platform_device *devptr)
+{
+ 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);
+ return unregister_cdrom(gd.cd_info);
+}
+
+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;
+
+ rc = platform_driver_register(&gdrom_driver);
+ if (rc) {
+ printk(KERN_INFO "Could not register GDROM driver - error 0x%X\n", rc);
+ return -EPERM;
+ }
+ pd = platform_device_register_simple(GDROM_DEV_NAME, -1, NULL, 0);
+ if (IS_ERR(pd)) {
+ platform_driver_unregister(&gdrom_driver);
+ return -ENODEV;
+ }
+ 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 <[email protected]>");
+MODULE_DESCRIPTION("SEGA Dreamcast GD-ROM Driver");
+MODULE_LICENSE("GPL");
diff -ruN linux-2.6-orig/drivers/cdrom/Makefile linux-2.6/drivers/cdrom/Makefile
--- linux-2.6-orig/drivers/cdrom/Makefile 2007-12-15 22:23:47.000000000 +0000
+++ linux-2.6/drivers/cdrom/Makefile 2007-12-20 23:36:15.000000000 +0000
@@ -11,3 +11,4 @@
obj-$(CONFIG_CDROM_PKTCDVD) += cdrom.o
obj-$(CONFIG_VIOCD) += viocd.o cdrom.o
+obj-$(CONFIG_GDROM) += gdrom.o cdrom.o
On Fri, Dec 21 2007, Adrian McMenamin wrote:
> On 20/12/2007, Adrian McMenamin <[email protected]> wrote:
> > This patch adds support for the CD Rom device (called a "GD Rom") on
> > the SEGA Dreamcast.This device has a command block similar to a
> > standard ATA-3 device, though implements Sega's proprietary packet
> > interface - the so-called "Sega Packet Interface".
> >
>
> Fairly typically, I noticed I had chopped the final line from the
> patch as soon as I had sent it.
>
> I've also fixed a small difference in the Kconfig
You should properly protect gdrom_deferred, the locking is not clear
there. In gdrom_readdisk_dma() I would do:
static void gdrom_readdisk_dma(struct work_struct *work)
{
...
read_command = kzalloc(sizeof(struct packet_command), GFP_KERNEL);
if (!read_command)
probably just defer the work to some time later
spin_lock(&gdrom_lock);
while (!list_empty(&gdrom_deferred)) {
req = list_entry(gdrom_deferred.next, struct request, queuelist);
list_del_init(&req->queuelist);
spin_unlock(&gdrom_lock);
...
spin_lock(&gdrom_lock);
};
kfree(read_command);
}
That's a lot more obvious imho and doesn't suffer from potential races
or list reordering. Your read_command allocation and free for every
command also seems pretty pointless, so move that outside the loop.
What is pages doing in gdrom_request()?
Your design is also heavily geared towards there just being a single
CDROM, I'm assuming this wont be a problem given your hw (it sets a bad
example for others to follow though, lots of violations against normal
programming practice for multiple devices and smp).
--
Jens Axboe
On Fri, Dec 21 2007, Jens Axboe wrote:
> static void gdrom_readdisk_dma(struct work_struct *work)
> {
> ...
>
> read_command = kzalloc(sizeof(struct packet_command), GFP_KERNEL);
> if (!read_command)
> probably just defer the work to some time later
>
> spin_lock(&gdrom_lock);
> while (!list_empty(&gdrom_deferred)) {
> req = list_entry(gdrom_deferred.next, struct request, queuelist);
> list_del_init(&req->queuelist);
> spin_unlock(&gdrom_lock);
>
> ...
>
> spin_lock(&gdrom_lock);
> };
>
+ spin_unlock(&gdrom_lock);
> kfree(read_command);
> }
is missing, of course.
--
Jens Axboe
On 21/12/2007, Jens Axboe <[email protected]> wrote:
>
> Your design is also heavily geared towards there just being a single
> CDROM, I'm assuming this wont be a problem given your hw (it sets a bad
> example for others to follow though, lots of violations against normal
> programming practice for multiple devices and smp).
Yes, because is there only one device and there will only ever be one
device (unless you know of somebody doing Dreamcast hardware
development).
I understand the point you are making but adding in additional code
would only diminish resource availability or slow performance on a
small machine without actually delivering any better outcomes for
kernel users..
Is it reaslly necessary?
On Fri, Dec 21 2007, Adrian McMenamin wrote:
> On 21/12/2007, Jens Axboe <[email protected]> wrote:
> >
> > Your design is also heavily geared towards there just being a single
> > CDROM, I'm assuming this wont be a problem given your hw (it sets a bad
> > example for others to follow though, lots of violations against normal
> > programming practice for multiple devices and smp).
>
>
> Yes, because is there only one device and there will only ever be one
> device (unless you know of somebody doing Dreamcast hardware
> development).
>
> I understand the point you are making but adding in additional code
> would only diminish resource availability or slow performance on a
> small machine without actually delivering any better outcomes for
> kernel users..
>
> Is it reaslly necessary?
No it's not necessary, it was just a general reflection on how it could
have been done more in style with "regular" drivers.
--
Jens Axboe
On Fri, December 21, 2007 2:22 pm, Jens Axboe wrote:
> On Fri, Dec 21 2007, Adrian McMenamin wrote:
>> On 21/12/2007, Jens Axboe <[email protected]> wrote:
>> >
>> > Your design is also heavily geared towards there just being a single
>> > CDROM, I'm assuming this wont be a problem given your hw (it sets a
>> bad
>> > example for others to follow though, lots of violations against normal
>> > programming practice for multiple devices and smp).
>>
>>
>> Yes, because is there only one device and there will only ever be one
>> device (unless you know of somebody doing Dreamcast hardware
>> development).
>>
>> I understand the point you are making but adding in additional code
>> would only diminish resource availability or slow performance on a
>> small machine without actually delivering any better outcomes for
>> kernel users..
>>
>> Is it reaslly necessary?
>
> No it's not necessary, it was just a general reflection on how it could
> have been done more in style with "regular" drivers.
>
I have another look at the code, though i am anxious not to add to the
driver's footprint if it is not bring any real benefit. Let me see if
there is a way round that.
On Fri, Dec 21 2007, Adrian McMenamin wrote:
> On Fri, December 21, 2007 2:22 pm, Jens Axboe wrote:
> > On Fri, Dec 21 2007, Adrian McMenamin wrote:
> >> On 21/12/2007, Jens Axboe <[email protected]> wrote:
> >> >
> >> > Your design is also heavily geared towards there just being a single
> >> > CDROM, I'm assuming this wont be a problem given your hw (it sets a
> >> bad
> >> > example for others to follow though, lots of violations against normal
> >> > programming practice for multiple devices and smp).
> >>
> >>
> >> Yes, because is there only one device and there will only ever be one
> >> device (unless you know of somebody doing Dreamcast hardware
> >> development).
> >>
> >> I understand the point you are making but adding in additional code
> >> would only diminish resource availability or slow performance on a
> >> small machine without actually delivering any better outcomes for
> >> kernel users..
> >>
> >> Is it reaslly necessary?
> >
> > No it's not necessary, it was just a general reflection on how it could
> > have been done more in style with "regular" drivers.
> >
>
>
> I have another look at the code, though i am anxious not to add to the
> driver's footprint if it is not bring any real benefit. Let me see if
> there is a way round that.
Don't break your neck over it, it was nothing more than an observation
:-)
BTW, I saw something else - you should always use sector_div() to do
divisions on a sector_t type.
--
Jens Axboe
On Fri, 2007-12-21 at 13:14 +0100, Jens Axboe wrote:
>
> What is pages doing in gdrom_request()?
>
As the device doesn't do scatter-gather I've set
blk_queue_max_segment_size to 1 and am not bothering with pages - is
that wrong?
On Fri, Dec 21 2007, Adrian McMenamin wrote:
>
> On Fri, 2007-12-21 at 13:14 +0100, Jens Axboe wrote:
>
> >
> > What is pages doing in gdrom_request()?
> >
>
> As the device doesn't do scatter-gather I've set
> blk_queue_max_segment_size to 1 and am not bothering with pages - is
> that wrong?
I mean this:
unsigned long pages;
pages = rq->backing_dev_info.ra_pages;
and you never use 'pages'.
--
Jens Axboe
On Fri, 2007-12-21 at 20:35 +0100, Jens Axboe wrote:
> backing_dev_info
Sorry, I know what you mean now ... left over from an earlier
experiments with read ahead. Will delete it now: didn't realise it was
still lurking there)
On Thursday 20 December 2007, Adrian McMenamin wrote:
> On 20/12/2007, Adrian McMenamin <[email protected]> wrote:
> > This patch adds support for the CD Rom device (called a "GD Rom") on
> > the SEGA Dreamcast.This device has a command block similar to a
> > standard ATA-3 device, though implements Sega's proprietary packet
> > interface - the so-called "Sega Packet Interface".
thanks for keeping the dc port up to date :)
> diff -ruN linux-2.6-orig/drivers/block/Kconfig
> +config GDROM
most people use a space here *shrug*
> + tristate "SEGA Dreamcast GD-ROM drive"
> + depends on SH_DREAMCAST
> + help
> + A standard SEGA Dreamcast comes with a modified CD ROM drive called a
> + "GD-ROM" by SEGA to signify it is capable of reading special disks
> + with up to 1 GB of data. This drive will also read standard CD ROM
> + disks. Select this option to access any disks in your GD ROM drive.
> + Most users will want to say "Y" here.
this line has broken whitespace at the start
> + You can also build this as a module - which will be called gdrom.ko
no need for the - there ...
> +static int gdrom_preparedisk_cmd(void)
> + if ((gd.status & 0x01) != 0) {
no need for the compare i dont think ?
if (gd.status & 0x01)
> +static int gdrom_readtoc_cmd(struct gdromtoc *toc, int session)
> + if ((gd.status & 0x01) != 0)
same here
> +static int gdrom_drivestatus(struct cdrom_device_info *cd_info, int
> + sense &=0xF0;
missing a space after the = ...
> +static void gdrom_request(struct request_queue *rq)
> + if (! blk_fs_request(req)) {
extraneous space with the ! there
> +static int __init probe_gdrom(struct platform_device *devptr)
> + sprintf(gd.cd_info->name, GDROM_DEV_NAME);
> + sprintf(gd.disk->disk_name, GDROM_DEV_NAME);
strcpy() prob runs with lower overhead
> +static int __init init_gdrom(void)
> +{
> + rc = platform_driver_register(&gdrom_driver);
> + if (rc) {
> + printk(KERN_INFO "Could not register GDROM driver - error 0x%X\n", rc);
> + return -EPERM;
shoudnt you return rc ? then there's probably no need to display the rc value
in the printk() as it'd get passed back to higher levels ...
> + pd = platform_device_register_simple(GDROM_DEV_NAME, -1, NULL, 0);
> + if (IS_ERR(pd)) {
> + platform_driver_unregister(&gdrom_driver);
> + return -ENODEV;
similar thing ... return the error stored in pd
-mike