ub.c

Linux Kernel 2.6.9 for OMAP1710

			/*
			 * ub_state_stat only not dropping the count...
			 */
			UB_INIT_COMPLETION(sc->work_done);

			sc->last_pipe = sc->recv_bulk_pipe;
			usb_fill_bulk_urb(&sc->work_urb, sc->dev,
			    sc->recv_bulk_pipe, &sc->work_bcs,
			    US_BULK_CS_WRAP_LEN, ub_urb_complete, sc);
			sc->work_urb.transfer_flags = URB_ASYNC_UNLINK;
			sc->work_urb.actual_length = 0;
			sc->work_urb.error_count = 0;
			sc->work_urb.status = 0;

			sc->work_timer.expires = jiffies + UB_URB_TIMEOUT;
			add_timer(&sc->work_timer);

			rc = usb_submit_urb(&sc->work_urb, GFP_ATOMIC);
			if (rc != 0) {
				/* XXX Clear stalls */
				printk("%s: CSW #%d submit failed (%d)\n",
				   sc->name, cmd->tag, rc); /* P3 */
				del_timer(&sc->work_timer);
				ub_complete(&sc->work_done);
				ub_state_done(sc, cmd, rc);
				return;
			}
			return;
		}

		/*
		 * Check the returned Bulk protocol status.
		 */

		bcs = &sc->work_bcs;
		rc = le32_to_cpu(bcs->Residue);
		if (rc != cmd->len - cmd->act_len) {
			/*
			 * It is all right to transfer less, the caller has
			 * to check. But it's not all right if the device
			 * counts disagree with our counts.
			 */
			/* P3 */ printk("%s: resid %d len %d act %d\n",
			    sc->name, rc, cmd->len, cmd->act_len);
			goto Bad_End;
		}

		if (bcs->Signature != cpu_to_le32(US_BULK_CS_SIGN) &&
		    bcs->Signature != cpu_to_le32(US_BULK_CS_OLYMPUS_SIGN)) {
			/* XXX Rate-limit, even for P3 tagged */
			/* P3 */ printk("ub: signature 0x%x\n", bcs->Signature);
			/* Windows ignores signatures, so do we. */
		}

		if (bcs->Tag != cmd->tag) {
			/* P3 */ printk("%s: tag orig 0x%x reply 0x%x\n",
			    sc->name, cmd->tag, bcs->Tag);
			goto Bad_End;
		}

		switch (bcs->Status) {
		case US_BULK_STAT_OK:
			break;
		case US_BULK_STAT_FAIL:
			ub_state_sense(sc, cmd);
			return;
		case US_BULK_STAT_PHASE:
			/* XXX We must reset the transport here */
			/* P3 */ printk("%s: status PHASE\n", sc->name);
			goto Bad_End;
		default:
			printk(KERN_INFO "%s: unknown CSW status 0x%x\n",
			    sc->name, bcs->Status);
			goto Bad_End;
		}

		/* Not zeroing error to preserve a babble indicator */
		cmd->state = UB_CMDST_DONE;
		ub_cmdtr_state(sc, cmd);
		ub_cmdq_pop(sc);
		(*cmd->done)(sc, cmd);

	} else if (cmd->state == UB_CMDST_SENSE) {
		/* 
		 * We do not look at sense, because even if there was no sense,
		 * we get into UB_CMDST_SENSE from a STALL or CSW FAIL only.
		 * We request sense because we want to clear CHECK CONDITION
		 * on devices with delusions of SCSI, and not because we
		 * are curious in any way about the sense itself.
		 */
		/* if ((cmd->top_sense[2] & 0x0F) == NO_SENSE) { foo } */

		ub_state_done(sc, cmd, -EIO);
	} else {
		printk(KERN_WARNING "%s: "
		    "wrong command state %d on device %u\n",
		    sc->name, cmd->state, sc->dev->devnum);
		goto Bad_End;
	}
	return;

Bad_End: /* Little Excel is dead */
	ub_state_done(sc, cmd, -EIO);
}

/*
 * Factorization helper for the command state machine:
 * Finish the command.
 */
static void ub_state_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd, int rc)
{

	cmd->error = rc;
	cmd->state = UB_CMDST_DONE;
	ub_cmdtr_state(sc, cmd);
	ub_cmdq_pop(sc);
	(*cmd->done)(sc, cmd);
}

/*
 * Factorization helper for the command state machine:
 * Submit a CSW read and go to STAT state.
 */
static void ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
{
	int rc;

	UB_INIT_COMPLETION(sc->work_done);

	sc->last_pipe = sc->recv_bulk_pipe;
	usb_fill_bulk_urb(&sc->work_urb, sc->dev, sc->recv_bulk_pipe,
	    &sc->work_bcs, US_BULK_CS_WRAP_LEN, ub_urb_complete, sc);
	sc->work_urb.transfer_flags = URB_ASYNC_UNLINK;
	sc->work_urb.actual_length = 0;
	sc->work_urb.error_count = 0;
	sc->work_urb.status = 0;

	sc->work_timer.expires = jiffies + UB_URB_TIMEOUT;
	add_timer(&sc->work_timer);

	if ((rc = usb_submit_urb(&sc->work_urb, GFP_ATOMIC)) != 0) {
		/* XXX Clear stalls */
		printk("ub: CSW #%d submit failed (%d)\n", cmd->tag, rc); /* P3 */
		del_timer(&sc->work_timer);
		ub_complete(&sc->work_done);
		ub_state_done(sc, cmd, rc);
		return;
	}

	cmd->stat_count = 0;
	cmd->state = UB_CMDST_STAT;
	ub_cmdtr_state(sc, cmd);
}

/*
 * Factorization helper for the command state machine:
 * Submit a REQUEST SENSE and go to SENSE state.
 */
static void ub_state_sense(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
{
	struct ub_scsi_cmd *scmd;
	int rc;

	if (cmd->cdb[0] == REQUEST_SENSE) {
		rc = -EPIPE;
		goto error;
	}

	memset(&sc->top_sense, 0, UB_SENSE_SIZE);
	scmd = &sc->top_rqs_cmd;
	scmd->cdb[0] = REQUEST_SENSE;
	scmd->cdb_len = 6;
	scmd->dir = UB_DIR_READ;
	scmd->state = UB_CMDST_INIT;
	scmd->data = sc->top_sense;
	scmd->len = UB_SENSE_SIZE;
	scmd->done = ub_top_sense_done;
	scmd->back = cmd;

	scmd->tag = sc->tagcnt++;

	cmd->state = UB_CMDST_SENSE;
	ub_cmdtr_state(sc, cmd);

	ub_cmdq_insert(sc, scmd);
	return;

error:
	ub_state_done(sc, cmd, rc);
}

/*
 * A helper for the command's state machine:
 * Submit a stall clear.
 */
static int ub_submit_clear_stall(struct ub_dev *sc, struct ub_scsi_cmd *cmd,
    int stalled_pipe)
{
	int endp;
	struct usb_ctrlrequest *cr;
	int rc;

	endp = usb_pipeendpoint(stalled_pipe);
	if (usb_pipein (stalled_pipe))
		endp |= USB_DIR_IN;

	cr = &sc->work_cr;
	cr->bRequestType = USB_RECIP_ENDPOINT;
	cr->bRequest = USB_REQ_CLEAR_FEATURE;
	cr->wValue = cpu_to_le16(USB_ENDPOINT_HALT);
	cr->wIndex = cpu_to_le16(endp);
	cr->wLength = cpu_to_le16(0);

	UB_INIT_COMPLETION(sc->work_done);

	usb_fill_control_urb(&sc->work_urb, sc->dev, sc->send_ctrl_pipe,
	    (unsigned char*) cr, NULL, 0, ub_urb_complete, sc);
	sc->work_urb.transfer_flags = URB_ASYNC_UNLINK;
	sc->work_urb.actual_length = 0;
	sc->work_urb.error_count = 0;
	sc->work_urb.status = 0;

	sc->work_timer.expires = jiffies + UB_CTRL_TIMEOUT;
	add_timer(&sc->work_timer);

	if ((rc = usb_submit_urb(&sc->work_urb, GFP_ATOMIC)) != 0) {
		del_timer(&sc->work_timer);
		ub_complete(&sc->work_done);
		return rc;
	}
	return 0;
}

/*
 */
static void ub_top_sense_done(struct ub_dev *sc, struct ub_scsi_cmd *scmd)
{
	unsigned char *sense = scmd->data;
	struct ub_scsi_cmd *cmd;

	ub_cmdtr_sense(sc, scmd, sense);

	if ((cmd = ub_cmdq_peek(sc)) == NULL) {
		printk(KERN_WARNING "%s: sense done while idle\n", sc->name);
		return;
	}
	if (cmd != scmd->back) {
		printk(KERN_WARNING "%s: "
		    "sense done for wrong command 0x%x on device %u\n",
		    sc->name, cmd->tag, sc->dev->devnum);
		return;
	}
	if (cmd->state != UB_CMDST_SENSE) {
		printk(KERN_WARNING "%s: "
		    "sense done with bad cmd state %d on device %u\n",
		    sc->name, cmd->state, sc->dev->devnum);
		return;
	}

	ub_scsi_urb_compl(sc, cmd);
}

#if 0
/* Determine what the maximum LUN supported is */
int usb_stor_Bulk_max_lun(struct us_data *us)
{
	int result;

	/* issue the command */
	result = usb_stor_control_msg(us, us->recv_ctrl_pipe,
				 US_BULK_GET_MAX_LUN, 
				 USB_DIR_IN | USB_TYPE_CLASS | 
				 USB_RECIP_INTERFACE,
				 0, us->ifnum, us->iobuf, 1, HZ);

	/* 
	 * Some devices (i.e. Iomega Zip100) need this -- apparently
	 * the bulk pipes get STALLed when the GetMaxLUN request is
	 * processed.   This is, in theory, harmless to all other devices
	 * (regardless of if they stall or not).
	 */
	if (result < 0) {
		usb_stor_clear_halt(us, us->recv_bulk_pipe);
		usb_stor_clear_halt(us, us->send_bulk_pipe);
	}

	US_DEBUGP("GetMaxLUN command result is %d, data is %d\n", 
		  result, us->iobuf[0]);

	/* if we have a successful request, return the result */
	if (result == 1)
		return us->iobuf[0];

	/* return the default -- no LUNs */
	return 0;
}
#endif

/*
 * This is called from a process context.
 */
static void ub_revalidate(struct ub_dev *sc)
{

	sc->readonly = 0;	/* XXX Query this from the device */

	/*
	 * XXX sd.c sets capacity to zero in such case. However, it doesn't
	 * work for us. In case of zero capacity, block layer refuses to
	 * have the /dev/uba opened (why?) Set capacity to some random value.
	 */
	sc->capacity.nsec = 50;
	sc->capacity.bsize = 512;
	sc->capacity.bshift = 0;

	if (ub_sync_tur(sc) != 0)
		return;			/* Not ready */
	sc->changed = 0;

	if (ub_sync_read_cap(sc, &sc->capacity) != 0) {
		/*
		 * The retry here means something is wrong, either with the
		 * device, with the transport, or with our code.
		 * We keep this because sd.c has retries for capacity.
		 */
		if (ub_sync_read_cap(sc, &sc->capacity) != 0) {
			sc->capacity.nsec = 100;
			sc->capacity.bsize = 512;
			sc->capacity.bshift = 0;
		}
	}
}

/*
 * The open funcion.
 * This is mostly needed to keep refcounting, but also to support
 * media checks on removable media drives.
 */
static int ub_bd_open(struct inode *inode, struct file *filp)
{
	struct gendisk *disk = inode->i_bdev->bd_disk;
	struct ub_dev *sc;
	unsigned long flags;
	int rc;

	if ((sc = disk->private_data) == NULL)
		return -ENXIO;
	spin_lock_irqsave(&ub_lock, flags);
	if (atomic_read(&sc->poison)) {
		spin_unlock_irqrestore(&ub_lock, flags);
		return -ENXIO;
	}
	sc->openc++;
	spin_unlock_irqrestore(&ub_lock, flags);

	if (sc->removable || sc->readonly)
		check_disk_change(inode->i_bdev);

	/* XXX sd.c and floppy.c bail on open if media is not present. */

	if (sc->readonly && (filp->f_mode & FMODE_WRITE)) {
		rc = -EROFS;
		goto err_open;
	}

	return 0;

err_open:
	spin_lock_irqsave(&ub_lock, flags);
	--sc->openc;
	if (sc->openc == 0 && atomic_read(&sc->poison))
		ub_cleanup(sc);
	spin_unlock_irqrestore(&ub_lock, flags);
	return rc;
}

/*
 */
static int ub_bd_release(struct inode *inode, struct file *filp)
{
	struct gendisk *disk = inode->i_bdev->bd_disk;
	struct ub_dev *sc = disk->private_data;
	unsigned long flags;

	spin_lock_irqsave(&ub_lock, flags);
	--sc->openc;
	if (sc->openc == 0 && atomic_read(&sc->poison))
		ub_cleanup(sc);
	spin_unlock_irqrestore(&ub_lock, flags);
	return 0;
}

/*
 * The ioctl interface.
 */
static int ub_bd_ioctl(struct inode *inode, struct file *filp,
    unsigned int cmd, unsigned long arg)
{
// void __user *usermem = (void *) arg;
// struct carm_port *port = ino->i_bdev->bd_disk->private_data;
// struct hd_geometry geom;

#if 0
	switch (cmd) {
	case HDIO_GETGEO:
		if (usermem == NULL)		// XXX Bizzare. Why?
			return -EINVAL;

		geom.heads = (u8) port->dev_geom_head;
		geom.sectors = (u8) port->dev_geom_sect;
		geom.cylinders = port->dev_geom_cyl;
		geom.start = get_start_sect(ino->i_bdev);

		if (copy_to_user(usermem, &geom, sizeof(geom)))
			return -EFAULT;
		return 0;

	default: ;
	}
#endif

	return -ENOTTY;
}

/*
 * This is called once a new disk was seen by the block layer or by ub_probe().
 * The main onjective here is to discover the features of the media such as
 * the capacity, read-only status, etc. USB storage generally does not
 * need to be spun up, but if we needed it, this would be the place.
 *
 * This call can sleep.
 *
 * The return code is not used.
 */
static int ub_bd_revalidate(struct gendisk *disk)
{
	struct ub_dev *sc = disk->private_data;

	ub_revalidate(sc);
	/* This is pretty much a long term P3 */
	printk(KERN_INFO "%s: device %u capacity nsec %ld bsize %u\n",
	    sc->name, sc->dev->devnum, sc->capacity.nsec, sc->capacity.bsize);

	set_capacity(disk, sc->capacity.nsec);
	// set_disk_ro(sdkp->disk, sc->readonly);
	return 0;
}

/*
 * The check is called by the block layer to verify if the media
 * is still available. It is supposed to be harmless, lightweight and
 * non-intrusive in case the media was not changed.
 *
 * This call can sleep.
 *
 * The return code is bool!
 */
static int ub_bd_media_changed(struct gendisk *disk)
{
	struct ub_dev *sc = disk->private_data;

	if (!sc->removable)
		return 0;

	/*
	 * We clean checks always after every command, so this is not
	 * as dangerous as it looks. If the TEST_UNIT_READY fails here,
	 * the device is actually not ready with operator or software
	 * intervention required. One dangerous item might be a drive which
	 * spins itself down, and come the time to write dirty pages, this
	 * will fail, then block layer discards the data. Since we never
	 * spin drives up, such devices simply cannot be used with ub anyway.
	 */
	if (ub_sync_tur(sc) != 0) {
		sc->changed = 1;
		/* P3 */ printk("%s: made changed\n", sc->name);
		return 1;
	}

	/* The sd.c clears this before returning (one-shot flag). Why? */
	/* P3 */ printk("%s: %s changed\n", sc->name,
	    sc->changed? "is": "was not");
	return sc->changed;
}

static struct block_device_operations ub_bd_fops = {
	.owner		= THIS_MODULE,
	.open		= ub_bd_open,
	.release	= ub_bd_release,
	.ioctl		= ub_bd_ioctl,
	.media_changed	= ub_bd_media_changed,
	.revalidate_disk = ub_bd_revalidate,
};

/*
 * Common ->done routine for commands executed synchronously.
 */
static void ub_probe_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
{
	struct completion *cop = cmd->back;
	complete(cop);
}

/*
 * Test if the device has a check condition on it, synchronously.
 */
static int ub_sync_tur(struct ub_dev *sc)
{
	struct ub_scsi_cmd *cmd;
	enum { ALLOC_SIZE = sizeof(struct ub_scsi_cmd) };
	unsigned long flags;
	struct completion compl;
	int rc;

	init_completion(&compl);

	rc = -ENOMEM;
	if ((cmd = kmalloc(ALLOC_SIZE, GFP_KERNEL)) == NULL)
		goto err_alloc;
	memset(cmd, 0, ALLOC_SIZE);

	cmd->cdb[0] = TEST_UNIT_READY;
	cmd->cdb_len = 6;
	cmd->dir = UB_DIR_NONE;