USB: g_mass_storage: Mass Storage Function created

The f_mass_storage.c has been changed into a composite function.
mass_storage.c file has been introduced which defines a
g_mass_storage gadget based on composite framework.
Signed-off-by: Michal Nazarewicz <m.nazarewicz@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/gadget/Kconfig

@@ -732,6 +732,24 @@ config USB_FILE_STORAGE_TEST
 	  behavior of USB Mass Storage hosts.  Not needed for
 	  normal operation.
 
+config USB_MASS_STORAGE
+	tristate "Mass Storage Gadget"
+	depends on BLOCK
+	help
+	  The Mass Storage Gadget acts as a USB Mass Storage disk drive.
+	  As its storage repository it can use a regular file or a block
+	  device (in much the same way as the "loop" device driver),
+	  specified as a module parameter or sysfs option.
+
+	  This is heavily based on File-backed Storage Gadget and in most
+	  cases you will want to use FSG instead.  This gadget is mostly
+	  here to test the functionality of the Mass Storage Function
+	  which may be used with composite framework.
+
+	  Say "y" to link the driver statically, or "m" to build
+	  a dynamically linked module called "g_file_storage".  If unsure,
+	  consider File-backed Storage Gadget.
+
 config USB_G_SERIAL
 	tristate "Serial Gadget (with CDC ACM and CDC OBEX support)"
 	help

drivers/usb/gadget/Makefile

@@ -39,6 +39,7 @@ g_serial-objs			:= serial.o
 g_midi-objs			:= gmidi.o
 gadgetfs-objs			:= inode.o
 g_file_storage-objs		:= file_storage.o
+g_mass_storage-objs		:= mass_storage.o
 g_printer-objs			:= printer.o
 g_cdc-objs			:= cdc2.o
 
@@ -47,6 +48,7 @@ obj-$(CONFIG_USB_AUDIO)		+= g_audio.o
 obj-$(CONFIG_USB_ETH)		+= g_ether.o
 obj-$(CONFIG_USB_GADGETFS)	+= gadgetfs.o
 obj-$(CONFIG_USB_FILE_STORAGE)	+= g_file_storage.o
+obj-$(CONFIG_USB_MASS_STORAGE)	+= g_mass_storage.o
 obj-$(CONFIG_USB_G_SERIAL)	+= g_serial.o
 obj-$(CONFIG_USB_G_PRINTER)	+= g_printer.o
 obj-$(CONFIG_USB_MIDI_GADGET)	+= g_midi.o

drivers/usb/gadget/file_storage.c

@@ -594,10 +594,9 @@ static int populate_config_buf(struct usb_gadget *gadget,
 
 	if (gadget_is_dualspeed(gadget) && type == USB_DT_OTHER_SPEED_CONFIG)
 		speed = (USB_SPEED_FULL + USB_SPEED_HIGH) - speed;
-	if (gadget_is_dualspeed(gadget) && speed == USB_SPEED_HIGH)
-		function = fsg_hs_function;
-	else
-		function = fsg_fs_function;
+	function = gadget_is_dualspeed(gadget) && speed == USB_SPEED_HIGH
+		? (const struct usb_descriptor_header **)fsg_hs_function
+		: (const struct usb_descriptor_header **)fsg_fs_function;
 
 	/* for now, don't advertise srp-only devices */
 	if (!gadget_is_otg(gadget))

drivers/usb/gadget/mass_storage.c

+/*
+ * mass_storage.c -- File-backed USB Storage Gadget, for USB development
+ *
+ * Copyright (C) 2003-2008 Alan Stern
+ *
+ * Copyright (C) 2009 Samsung Electronics
+ *                    Author: Michal Nazarewicz <m.nazarewicz@samsung.com>
+ *
+ * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+
+/*
+ * The Mass Storage Gadget acts as a USB Mass Storage device,
+ * appearing to the host as a disk drive or as a CD-ROM drive.  In
+ * addition to providing an example of a genuinely useful gadget
+ * driver for a USB device, it also illustrates a technique of
+ * double-buffering for increased throughput.  Last but not least, it
+ * gives an easy way to probe the behavior of the Mass Storage drivers
+ * in a USB host.
+ *
+ * Since this file serves only administrative purposes and all the
+ * business logic is implemented in f_mass_storage.* file.  Read
+ * comments in this file for more detailed description.
+ */
+
+
+#include <linux/kernel.h>
+#include <linux/utsname.h>
+#include <linux/usb/ch9.h>
+
+
+/*-------------------------------------------------------------------------*/
+
+#define DRIVER_DESC		"Mass Storage Gadget"
+#define DRIVER_VERSION		"2009/07/21"
+
+/*-------------------------------------------------------------------------*/
+
+/*
+ * kbuild is not very cooperative with respect to linking separately
+ * compiled library objects into one module.  So for now we won't use
+ * separate compilation ... ensuring init/exit sections work to shrink
+ * the runtime footprint, and giving us at least some parts of what
+ * a "gcc --combine ... part1.c part2.c part3.c ... " build would.
+ */
+
+#include "composite.c"
+#include "usbstring.c"
+#include "config.c"
+#include "epautoconf.c"
+#include "f_mass_storage.c"
+
+/*-------------------------------------------------------------------------*/
+
+static struct usb_device_descriptor msg_device_desc = {
+	.bLength =		sizeof msg_device_desc,
+	.bDescriptorType =	USB_DT_DEVICE,
+
+	.bcdUSB =		cpu_to_le16(0x0200),
+	.bDeviceClass =		USB_CLASS_PER_INTERFACE,
+
+	/* Vendor and product id can be overridden by module parameters.  */
+	.idVendor =		cpu_to_le16(FSG_VENDOR_ID),
+	.idProduct =		cpu_to_le16(FSG_PRODUCT_ID),
+	/* .bcdDevice = f(hardware) */
+	/* .iManufacturer = DYNAMIC */
+	/* .iProduct = DYNAMIC */
+	/* NO SERIAL NUMBER */
+	.bNumConfigurations =	1,
+};
+
+static struct usb_otg_descriptor otg_descriptor = {
+	.bLength =		sizeof otg_descriptor,
+	.bDescriptorType =	USB_DT_OTG,
+
+	/* REVISIT SRP-only hardware is possible, although
+	 * it would not be called "OTG" ...
+	 */
+	.bmAttributes =		USB_OTG_SRP | USB_OTG_HNP,
+};
+
+static const struct usb_descriptor_header *otg_desc[] = {
+	(struct usb_descriptor_header *) &otg_descriptor,
+	NULL,
+};
+
+
+/* string IDs are assigned dynamically */
+
+#define STRING_MANUFACTURER_IDX		0
+#define STRING_PRODUCT_IDX		1
+#define STRING_CONFIGURATION_IDX	2
+
+static char manufacturer[50];
+
+static struct usb_string strings_dev[] = {
+	[STRING_MANUFACTURER_IDX].s = manufacturer,
+	[STRING_PRODUCT_IDX].s = DRIVER_DESC,
+	[STRING_CONFIGURATION_IDX].s = "Self Powered",
+	{  } /* end of list */
+};
+
+static struct usb_gadget_strings stringtab_dev = {
+	.language	= 0x0409,	/* en-us */
+	.strings	= strings_dev,
+};
+
+static struct usb_gadget_strings *dev_strings[] = {
+	&stringtab_dev,
+	NULL,
+};
+
+
+
+/****************************** Configurations ******************************/
+
+static int __init msg_do_config(struct usb_configuration *c)
+{
+	struct fsg_common *common;
+	int ret;
+
+	if (gadget_is_otg(c->cdev->gadget)) {
+		c->descriptors = otg_desc;
+		c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
+	}
+
+	common = fsg_common_init(0, c->cdev);
+	if (IS_ERR(common))
+		return PTR_ERR(common);
+
+	ret = fsg_add(c->cdev, c, common);
+	fsg_common_put(common);
+	return ret;
+}
+
+static struct usb_configuration msg_config_driver = {
+	.label			= "Linux File-Backed Storage",
+	.bind			= msg_do_config,
+	.bConfigurationValue	= 1,
+	/* .iConfiguration = DYNAMIC */
+	.bmAttributes		= USB_CONFIG_ATT_SELFPOWER,
+};
+
+
+
+/****************************** Gadget Bind ******************************/
+
+
+static int __init msg_bind(struct usb_composite_dev *cdev)
+{
+	struct usb_gadget *gadget = cdev->gadget;
+	int status;
+
+	/* Allocate string descriptor numbers ... note that string
+	 * contents can be overridden by the composite_dev glue.
+	 */
+
+	/* device descriptor strings: manufacturer, product */
+	snprintf(manufacturer, sizeof manufacturer, "%s %s with %s",
+	         init_utsname()->sysname, init_utsname()->release,
+	         gadget->name);
+	status = usb_string_id(cdev);
+	if (status < 0)
+		return status;
+	strings_dev[STRING_MANUFACTURER_IDX].id = status;
+	msg_device_desc.iManufacturer = status;
+
+	status = usb_string_id(cdev);
+	if (status < 0)
+		return status;
+	strings_dev[STRING_PRODUCT_IDX].id = status;
+	msg_device_desc.iProduct = status;
+
+	status = usb_string_id(cdev);
+	if (status < 0)
+		return status;
+	strings_dev[STRING_CONFIGURATION_IDX].id = status;
+	msg_config_driver.iConfiguration = status;
+
+	/* register our second configuration */
+	status = usb_add_config(cdev, &msg_config_driver);
+	if (status < 0)
+		return status;
+
+	dev_info(&gadget->dev, DRIVER_DESC ", version: " DRIVER_VERSION "\n");
+	return 0;
+}
+
+static int __exit msg_unbind(struct usb_composite_dev *cdev)
+{
+	return 0;
+}
+
+
+/****************************** Some noise ******************************/
+
+
+static struct usb_composite_driver msg_driver = {
+	.name		= "g_mass_storage",
+	.dev		= &msg_device_desc,
+	.strings	= dev_strings,
+	.bind		= msg_bind,
+	.unbind		= __exit_p(msg_unbind),
+};
+
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_AUTHOR("Michal Nazarewicz");
+MODULE_LICENSE("GPL");
+
+static int __init msg_init(void)
+{
+	return usb_composite_register(&msg_driver);
+}
+module_init(msg_init);
+
+static void __exit msg_cleanup(void)
+{
+	usb_composite_unregister(&msg_driver);
+}
+module_exit(msg_cleanup);

drivers/usb/gadget/storage_common.c

@@ -84,11 +84,19 @@
 #define LWARN(lun, fmt, args...)  dev_warn(&(lun)->dev, fmt, ## args)
 #define LINFO(lun, fmt, args...)  dev_info(&(lun)->dev, fmt, ## args)
 
-#define DBG(d, fmt, args...)      dev_dbg (&(d)->gadget->dev, fmt, ## args)
-#define VDBG(d, fmt, args...)     dev_vdbg(&(d)->gadget->dev, fmt, ## args)
-#define ERROR(d, fmt, args...)    dev_err (&(d)->gadget->dev, fmt, ## args)
-#define WARNING(d, fmt, args...)  dev_warn(&(d)->gadget->dev, fmt, ## args)
-#define INFO(d, fmt, args...)     dev_info(&(d)->gadget->dev, fmt, ## args)
+/* Keep those macros in sync with thos in
+ * include/linux/ubs/composite.h or else GCC will complain.  If they
+ * are identical (the same names of arguments, white spaces in the
+ * same places) GCC will allow redefinition otherwise (even if some
+ * white space is removed or added) warning will be issued.  No
+ * checking if those symbols is defined is performed because warning
+ * is desired when those macros were defined by someone else to mean
+ * something else. */
+#define DBG(d, fmt, args...)     dev_dbg(&(d)->gadget->dev , fmt , ## args)
+#define VDBG(d, fmt, args...)    dev_vdbg(&(d)->gadget->dev , fmt , ## args)
+#define ERROR(d, fmt, args...)   dev_err(&(d)->gadget->dev , fmt , ## args)
+#define WARNING(d, fmt, args...) dev_warn(&(d)->gadget->dev , fmt , ## args)
+#define INFO(d, fmt, args...)    dev_info(&(d)->gadget->dev , fmt , ## args)
 
 
 
@@ -429,7 +437,7 @@ fsg_fs_intr_in_desc = {
 
 #endif
 
-static const struct usb_descriptor_header *fsg_fs_function[] = {
+static struct usb_descriptor_header *fsg_fs_function[] = {
 #ifndef FSG_NO_OTG
 	(struct usb_descriptor_header *) &fsg_otg_desc,
 #endif
@@ -493,7 +501,7 @@ fsg_hs_intr_in_desc = {
 
 #endif
 
-static const struct usb_descriptor_header *fsg_hs_function[] = {
+static struct usb_descriptor_header *fsg_hs_function[] = {
 #ifndef FSG_NO_OTG
 	(struct usb_descriptor_header *) &fsg_otg_desc,
 #endif