usb-storage: prepare for subdriver separation

This patch (as1206) is the first step in converting usb-storage's
subdrivers into separate modules.  It makes the following large-scale
changes:

	Remove a bunch of unnecessary #ifdef's from usb_usual.h.
	Not truly necessary, but it does clean things up.

	Move the USB device-ID table (which is duplicated between
	libusual and usb-storage) into its own source file,
	usual-tables.c, and arrange for this to be linked with
	either libusual or usb-storage according to whether
	USB_LIBUSUAL is configured.

	Add to usual-tables.c a new usb_usual_ignore_device()
	function to detect whether a particular device needs to be
	managed by a subdriver and not by the standard handlers
	in usb-storage.

	Export a whole bunch of functions in usb-storage, renaming
	some of them because their names don't already begin with
	"usb_stor_".  These functions will be needed by the new
	subdriver modules.

	Split usb-storage's probe routine into two functions.
	The subdrivers will call the probe1 routine, then fill in
	their transport and protocol settings, and then call the
	probe2 routine.

	Take the default cases and error checking out of
	get_transport() and get_protocol(), which run during
	probe1, and instead put a check for invalid transport
	or protocol values into the probe2 function.

	Add a new probe routine to be used for standard devices,
	i.e., those that don't need a subdriver.  This new routine
	checks whether the device should be ignored (because it
	should be handled by ub or by a subdriver), and if not,
	calls the probe1 and probe2 functions.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: Matthew Dharm <mdharm-usb@one-eyed-alien.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 111 insertions, 98 deletions

diff --git a/drivers/usb/storage/usb.c b/drivers/usb/storage/usb.c
index b01dade63cb..490ea761398 100644
--- a/drivers/usb/storage/usb.c
+++ b/drivers/usb/storage/usb.c
@@ -5,7 +5,7 @@
  *
  * Developed with the assistance of:
  *   (c) 2000 David L. Brown, Jr. (usb-storage@davidb.org)
- *   (c) 2003 Alan Stern (stern@rowland.harvard.edu)
+ *   (c) 2003-2009 Alan Stern (stern@rowland.harvard.edu)
  *
  * Initial work by:
  *   (c) 1999 Michael Gee (michael@linuxspecific.com)
@@ -118,36 +118,8 @@ MODULE_PARM_DESC(quirks, "supplemental list of device IDs and their quirks");
 
 /*
  * The entries in this table correspond, line for line,
- * with the entries of us_unusual_dev_list[].
+ * with the entries in usb_storage_usb_ids[], defined in usual-tables.c.
  */
-#ifndef CONFIG_USB_LIBUSUAL
-
-#define UNUSUAL_DEV(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax, \
-		    vendorName, productName,useProtocol, useTransport, \
-		    initFunction, flags) \
-{ USB_DEVICE_VER(id_vendor, id_product, bcdDeviceMin,bcdDeviceMax), \
-  .driver_info = (flags)|(USB_US_TYPE_STOR<<24) }
-
-#define COMPLIANT_DEV	UNUSUAL_DEV
-
-#define USUAL_DEV(useProto, useTrans, useType) \
-{ USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, useProto, useTrans), \
-  .driver_info = (USB_US_TYPE_STOR<<24) }
-
-static struct usb_device_id storage_usb_ids [] = {
-
-#	include "unusual_devs.h"
-#undef UNUSUAL_DEV
-#undef COMPLIANT_DEV
-#undef USUAL_DEV
-	/* Terminating entry */
-	{ }
-};
-
-MODULE_DEVICE_TABLE (usb, storage_usb_ids);
-#endif /* CONFIG_USB_LIBUSUAL */
-
-/* This is the list of devices we recognize, along with their flag data */
 
 /* The vendor name should be kept at eight characters or less, and
  * the product name should be kept at 16 characters or less. If a device
@@ -179,18 +151,17 @@ MODULE_DEVICE_TABLE (usb, storage_usb_ids);
 
 static struct us_unusual_dev us_unusual_dev_list[] = {
 #	include "unusual_devs.h" 
-#	undef UNUSUAL_DEV
-#	undef COMPLIANT_DEV
-#	undef USUAL_DEV
-
-	/* Terminating entry */
-	{ NULL }
+	{ }		/* Terminating entry */
 };
 
+#undef UNUSUAL_DEV
+#undef COMPLIANT_DEV
+#undef USUAL_DEV
+
 
 #ifdef CONFIG_PM	/* Minimal support for suspend and resume */
 
-static int storage_suspend(struct usb_interface *iface, pm_message_t message)
+int usb_stor_suspend(struct usb_interface *iface, pm_message_t message)
 {
 	struct us_data *us = usb_get_intfdata(iface);
 
@@ -207,8 +178,9 @@ static int storage_suspend(struct usb_interface *iface, pm_message_t message)
 	mutex_unlock(&us->dev_mutex);
 	return 0;
 }
+EXPORT_SYMBOL_GPL(usb_stor_suspend);
 
-static int storage_resume(struct usb_interface *iface)
+int usb_stor_resume(struct usb_interface *iface)
 {
 	struct us_data *us = usb_get_intfdata(iface);
 
@@ -221,8 +193,9 @@ static int storage_resume(struct usb_interface *iface)
 	mutex_unlock(&us->dev_mutex);
 	return 0;
 }
+EXPORT_SYMBOL_GPL(usb_stor_resume);
 
-static int storage_reset_resume(struct usb_interface *iface)
+int usb_stor_reset_resume(struct usb_interface *iface)
 {
 	struct us_data *us = usb_get_intfdata(iface);
 
@@ -235,6 +208,7 @@ static int storage_reset_resume(struct usb_interface *iface)
 	 * the device */
 	return 0;
 }
+EXPORT_SYMBOL_GPL(usb_stor_reset_resume);
 
 #endif /* CONFIG_PM */
 
@@ -243,7 +217,7 @@ static int storage_reset_resume(struct usb_interface *iface)
  * a USB port reset, whether from this driver or a different one.
  */
 
-static int storage_pre_reset(struct usb_interface *iface)
+int usb_stor_pre_reset(struct usb_interface *iface)
 {
 	struct us_data *us = usb_get_intfdata(iface);
 
@@ -253,8 +227,9 @@ static int storage_pre_reset(struct usb_interface *iface)
 	mutex_lock(&us->dev_mutex);
 	return 0;
 }
+EXPORT_SYMBOL_GPL(usb_stor_pre_reset);
 
-static int storage_post_reset(struct usb_interface *iface)
+int usb_stor_post_reset(struct usb_interface *iface)
 {
 	struct us_data *us = usb_get_intfdata(iface);
 
@@ -269,6 +244,7 @@ static int storage_post_reset(struct usb_interface *iface)
 	mutex_unlock(&us->dev_mutex);
 	return 0;
 }
+EXPORT_SYMBOL_GPL(usb_stor_post_reset);
 
 /*
  * fill_inquiry_response takes an unsigned char array (which must
@@ -311,6 +287,7 @@ void fill_inquiry_response(struct us_data *us, unsigned char *data,
 
 	usb_stor_set_xfer_buf(data, data_len, us->srb);
 }
+EXPORT_SYMBOL_GPL(fill_inquiry_response);
 
 static int usb_stor_control_thread(void * __us)
 {
@@ -551,20 +528,13 @@ static void adjust_quirks(struct us_data *us)
 			vid, pid, f);
 }
 
-/* Find an unusual_dev descriptor (always succeeds in the current code) */
-static struct us_unusual_dev *find_unusual(const struct usb_device_id *id)
-{
-	const int id_index = id - storage_usb_ids;
-	return &us_unusual_dev_list[id_index];
-}
-
 /* Get the unusual_devs entries and the string descriptors */
-static int get_device_info(struct us_data *us, const struct usb_device_id *id)
+static int get_device_info(struct us_data *us, const struct usb_device_id *id,
+		struct us_unusual_dev *unusual_dev)
 {
 	struct usb_device *dev = us->pusb_dev;
 	struct usb_interface_descriptor *idesc =
 		&us->pusb_intf->cur_altsetting->desc;
-	struct us_unusual_dev *unusual_dev = find_unusual(id);
 
 	/* Store the entries */
 	us->unusual_dev = unusual_dev;
@@ -629,7 +599,7 @@ static int get_device_info(struct us_data *us, const struct usb_device_id *id)
 }
 
 /* Get the transport settings */
-static int get_transport(struct us_data *us)
+static void get_transport(struct us_data *us)
 {
 	switch (us->protocol) {
 	case US_PR_CB:
@@ -732,19 +702,11 @@ static int get_transport(struct us_data *us)
 		break;
 #endif
 
-	default:
-		return -EIO;
 	}
-	US_DEBUGP("Transport: %s\n", us->transport_name);
-
-	/* fix for single-lun devices */
-	if (us->fflags & US_FL_SINGLE_LUN)
-		us->max_lun = 0;
-	return 0;
 }
 
 /* Get the protocol settings */
-static int get_protocol(struct us_data *us)
+static void get_protocol(struct us_data *us)
 {
 	switch (us->subclass) {
 	case US_SC_RBC:
@@ -794,11 +756,7 @@ static int get_protocol(struct us_data *us)
 		break;
 #endif
 
-	default:
-		return -EIO;
 	}
-	US_DEBUGP("Protocol: %s\n", us->protocol_name);
-	return 0;
 }
 
 /* Get the pipe settings */
@@ -1012,17 +970,15 @@ static int usb_stor_scan_thread(void * __us)
 }
 
 
-/* Probe to see if we can drive a newly-connected USB device */
-static int storage_probe(struct usb_interface *intf,
-			 const struct usb_device_id *id)
+/* First part of general USB mass-storage probing */
+int usb_stor_probe1(struct us_data **pus,
+		struct usb_interface *intf,
+		const struct usb_device_id *id,
+		struct us_unusual_dev *unusual_dev)
 {
 	struct Scsi_Host *host;
 	struct us_data *us;
 	int result;
-	struct task_struct *th;
-
-	if (usb_usual_check_type(id, USB_US_TYPE_STOR))
-		return -ENXIO;
 
 	US_DEBUGP("USB Mass Storage device detected\n");
 
@@ -1041,7 +997,7 @@ static int storage_probe(struct usb_interface *intf,
 	 * Allow 16-byte CDBs and thus > 2TB
 	 */
 	host->max_cmd_len = 16;
-	us = host_to_us(host);
+	*pus = us = host_to_us(host);
 	memset(us, 0, sizeof(struct us_data));
 	mutex_init(&(us->dev_mutex));
 	init_completion(&us->cmnd_ready);
@@ -1054,24 +1010,46 @@ static int storage_probe(struct usb_interface *intf,
 	if (result)
 		goto BadDevice;
 
-	/*
-	 * Get the unusual_devs entries and the descriptors
-	 *
-	 * id_index is calculated in the declaration to be the index number
-	 * of the match from the usb_device_id table, so we can find the
-	 * corresponding entry in the private table.
-	 */
-	result = get_device_info(us, id);
+	/* Get the unusual_devs entries and the descriptors */
+	result = get_device_info(us, id, unusual_dev);
 	if (result)
 		goto BadDevice;
 
-	/* Get the transport, protocol, and pipe settings */
-	result = get_transport(us);
-	if (result)
-		goto BadDevice;
-	result = get_protocol(us);
-	if (result)
+	/* Get standard transport and protocol settings */
+	get_transport(us);
+	get_protocol(us);
+
+	/* Give the caller a chance to fill in specialized transport
+	 * or protocol settings.
+	 */
+	return 0;
+
+BadDevice:
+	US_DEBUGP("storage_probe() failed\n");
+	release_everything(us);
+	return result;
+}
+EXPORT_SYMBOL_GPL(usb_stor_probe1);
+
+/* Second part of general USB mass-storage probing */
+int usb_stor_probe2(struct us_data *us)
+{
+	struct task_struct *th;
+	int result;
+
+	/* Make sure the transport and protocol have both been set */
+	if (!us->transport || !us->proto_handler) {
+		result = -ENXIO;
 		goto BadDevice;
+	}
+	US_DEBUGP("Transport: %s\n", us->transport_name);
+	US_DEBUGP("Protocol: %s\n", us->protocol_name);
+
+	/* fix for single-lun devices */
+	if (us->fflags & US_FL_SINGLE_LUN)
+		us->max_lun = 0;
+
+	/* Find the endpoints and calculate pipe values */
 	result = get_pipes(us);
 	if (result)
 		goto BadDevice;
@@ -1080,7 +1058,7 @@ static int storage_probe(struct usb_interface *intf,
 	result = usb_stor_acquire_resources(us);
 	if (result)
 		goto BadDevice;
-	result = scsi_add_host(host, &intf->dev);
+	result = scsi_add_host(us_to_host(us), &us->pusb_intf->dev);
 	if (result) {
 		printk(KERN_WARNING USB_STORAGE
 			"Unable to add the scsi host\n");
@@ -1108,9 +1086,10 @@ BadDevice:
 	release_everything(us);
 	return result;
 }
+EXPORT_SYMBOL_GPL(usb_stor_probe2);
 
-/* Handle a disconnect event from the USB core */
-static void storage_disconnect(struct usb_interface *intf)
+/* Handle a USB mass-storage disconnect */
+void usb_stor_disconnect(struct usb_interface *intf)
 {
 	struct us_data *us = usb_get_intfdata(intf);
 
@@ -1118,6 +1097,42 @@ static void storage_disconnect(struct usb_interface *intf)
 	quiesce_and_remove_host(us);
 	release_everything(us);
 }
+EXPORT_SYMBOL_GPL(usb_stor_disconnect);
+
+/* The main probe routine for standard devices */
+static int storage_probe(struct usb_interface *intf,
+			 const struct usb_device_id *id)
+{
+	struct us_data *us;
+	int result;
+
+	/*
+	 * If libusual is configured, let it decide whether a standard
+	 * device should be handled by usb-storage or by ub.
+	 * If the device isn't standard (is handled by a subdriver
+	 * module) then don't accept it.
+	 */
+	if (usb_usual_check_type(id, USB_US_TYPE_STOR) ||
+			usb_usual_ignore_device(intf))
+		return -ENXIO;
+
+	/*
+	 * Call the general probe procedures.
+	 *
+	 * The unusual_dev_list array is parallel to the usb_storage_usb_ids
+	 * table, so we use the index of the id entry to find the
+	 * corresponding unusual_devs entry.
+	 */
+	result = usb_stor_probe1(&us, intf, id,
+			(id - usb_storage_usb_ids) + us_unusual_dev_list);
+	if (result)
+		return result;
+
+	/* No special transport or protocol settings in the main module */
+
+	result = usb_stor_probe2(us);
+	return result;
+}
 
 /***********************************************************************
  * Initialization and registration
@@ -1126,15 +1141,13 @@ static void storage_disconnect(struct usb_interface *intf)
 static struct usb_driver usb_storage_driver = {
 	.name =		"usb-storage",
 	.probe =	storage_probe,
-	.disconnect =	storage_disconnect,
-#ifdef CONFIG_PM
-	.suspend =	storage_suspend,
-	.resume =	storage_resume,
-	.reset_resume =	storage_reset_resume,
-#endif
-	.pre_reset =	storage_pre_reset,
-	.post_reset =	storage_post_reset,
-	.id_table =	storage_usb_ids,
+	.disconnect =	usb_stor_disconnect,
+	.suspend =	usb_stor_suspend,
+	.resume =	usb_stor_resume,
+	.reset_resume =	usb_stor_reset_resume,
+	.pre_reset =	usb_stor_pre_reset,
+	.post_reset =	usb_stor_post_reset,
+	.id_table =	usb_storage_usb_ids,
 	.soft_unbind =	1,
 };