usb: gadget: g_ncm added

This patches makes possible to use composite framework and f_ncm
NCM function driver to build a standalone NCM gadget device.
Signed-off-by: NYauheni Kaliuta <yauheni.kaliuta@nokia.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/usb/gadget/Kconfig

@@ -741,6 +741,19 @@ config USB_ETH_EEM
          If you say "y" here, the Ethernet gadget driver will use the EEM
          protocol rather than ECM.  If unsure, say "n".
 
+config USB_G_NCM
+	tristate "Network Control Model (NCM) support"
+	depends on NET
+	select CRC32
+	help
+	  This driver implements USB CDC NCM subclass standard. NCM is
+	  an advanced protocol for Ethernet encapsulation, allows grouping
+	  of several ethernet frames into one USB transfer and diffferent
+	  alignment possibilities.
+
+	  Say "y" to link the driver statically, or "m" to build a
+	  dynamically linked module called "g_ncm".
+
 config USB_GADGETFS
 	tristate "Gadget Filesystem (EXPERIMENTAL)"
 	depends on EXPERIMENTAL

drivers/usb/gadget/Makefile

@@ -47,6 +47,7 @@ g_hid-y				:= hid.o
 g_dbgp-y			:= dbgp.o
 g_nokia-y			:= nokia.o
 g_webcam-y			:= webcam.o
+g_ncm-y				:= ncm.o
 
 obj-$(CONFIG_USB_ZERO)		+= g_zero.o
 obj-$(CONFIG_USB_AUDIO)		+= g_audio.o
@@ -64,3 +65,4 @@ obj-$(CONFIG_USB_G_DBGP)	+= g_dbgp.o
 obj-$(CONFIG_USB_G_MULTI)	+= g_multi.o
 obj-$(CONFIG_USB_G_NOKIA)	+= g_nokia.o
 obj-$(CONFIG_USB_G_WEBCAM)	+= g_webcam.o
+obj-$(CONFIG_USB_G_NCM)		+= g_ncm.o

drivers/usb/gadget/ncm.c

+/*
+ * ncm.c -- NCM gadget driver
+ *
+ * Copyright (C) 2010 Nokia Corporation
+ * Contact: Yauheni Kaliuta <yauheni.kaliuta@nokia.com>
+ *
+ * The driver borrows from ether.c which is:
+ *
+ * Copyright (C) 2003-2005,2008 David Brownell
+ * Copyright (C) 2003-2004 Robert Schwebel, Benedikt Spranger
+ * Copyright (C) 2008 Nokia Corporation
+ *
+ * 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
+ */
+
+/* #define DEBUG */
+/* #define VERBOSE_DEBUG */
+
+#include <linux/kernel.h>
+#include <linux/utsname.h>
+
+
+#include "u_ether.h"
+
+#define DRIVER_DESC		"NCM Gadget"
+
+/*-------------------------------------------------------------------------*/
+
+/*
+ * 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_ncm.c"
+#include "u_ether.c"
+
+/*-------------------------------------------------------------------------*/
+
+/* DO NOT REUSE THESE IDs with a protocol-incompatible driver!!  Ever!!
+ * Instead:  allocate your own, using normal USB-IF procedures.
+ */
+
+/* Thanks to NetChip Technologies for donating this product ID.
+ * It's for devices with only CDC Ethernet configurations.
+ */
+#define CDC_VENDOR_NUM		0x0525	/* NetChip */
+#define CDC_PRODUCT_NUM		0xa4a1	/* Linux-USB Ethernet Gadget */
+
+/*-------------------------------------------------------------------------*/
+
+static struct usb_device_descriptor device_desc = {
+	.bLength =		sizeof device_desc,
+	.bDescriptorType =	USB_DT_DEVICE,
+
+	.bcdUSB =		cpu_to_le16 (0x0200),
+
+	.bDeviceClass =		USB_CLASS_COMM,
+	.bDeviceSubClass =	0,
+	.bDeviceProtocol =	0,
+	/* .bMaxPacketSize0 = f(hardware) */
+
+	/* Vendor and product id defaults change according to what configs
+	 * we support.  (As does bNumConfigurations.)  These values can
+	 * also be overridden by module parameters.
+	 */
+	.idVendor =		cpu_to_le16 (CDC_VENDOR_NUM),
+	.idProduct =		cpu_to_le16 (CDC_PRODUCT_NUM),
+	/* .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
+
+static char manufacturer[50];
+
+static struct usb_string strings_dev[] = {
+	[STRING_MANUFACTURER_IDX].s = manufacturer,
+	[STRING_PRODUCT_IDX].s = DRIVER_DESC,
+	{  } /* 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,
+};
+
+static u8 hostaddr[ETH_ALEN];
+
+/*-------------------------------------------------------------------------*/
+
+static int __init ncm_do_config(struct usb_configuration *c)
+{
+	/* FIXME alloc iConfiguration string, set it in c->strings */
+
+	if (gadget_is_otg(c->cdev->gadget)) {
+		c->descriptors = otg_desc;
+		c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
+	}
+
+	return ncm_bind_config(c, hostaddr);
+}
+
+static struct usb_configuration ncm_config_driver = {
+	/* .label = f(hardware) */
+	.label			= "CDC Ethernet (NCM)",
+	.bConfigurationValue	= 1,
+	/* .iConfiguration = DYNAMIC */
+	.bmAttributes		= USB_CONFIG_ATT_SELFPOWER,
+};
+
+/*-------------------------------------------------------------------------*/
+
+static int __init gncm_bind(struct usb_composite_dev *cdev)
+{
+	int			gcnum;
+	struct usb_gadget	*gadget = cdev->gadget;
+	int			status;
+
+	/* set up network link layer */
+	status = gether_setup(cdev->gadget, hostaddr);
+	if (status < 0)
+		return status;
+
+	gcnum = usb_gadget_controller_number(gadget);
+	if (gcnum >= 0)
+		device_desc.bcdDevice = cpu_to_le16(0x0300 | gcnum);
+	else {
+		/* We assume that can_support_ecm() tells the truth;
+		 * but if the controller isn't recognized at all then
+		 * that assumption is a bit more likely to be wrong.
+		 */
+		dev_warn(&gadget->dev,
+			 "controller '%s' not recognized; trying %s\n",
+			 gadget->name,
+			 ncm_config_driver.label);
+		device_desc.bcdDevice =
+			cpu_to_le16(0x0300 | 0x0099);
+	}
+
+
+	/* 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)
+		goto fail;
+	strings_dev[STRING_MANUFACTURER_IDX].id = status;
+	device_desc.iManufacturer = status;
+
+	status = usb_string_id(cdev);
+	if (status < 0)
+		goto fail;
+	strings_dev[STRING_PRODUCT_IDX].id = status;
+	device_desc.iProduct = status;
+
+	status = usb_add_config(cdev, &ncm_config_driver,
+				ncm_do_config);
+	if (status < 0)
+		goto fail;
+
+	dev_info(&gadget->dev, "%s\n", DRIVER_DESC);
+
+	return 0;
+
+fail:
+	gether_cleanup();
+	return status;
+}
+
+static int __exit gncm_unbind(struct usb_composite_dev *cdev)
+{
+	gether_cleanup();
+	return 0;
+}
+
+static struct usb_composite_driver ncm_driver = {
+	.name		= "g_ncm",
+	.dev		= &device_desc,
+	.strings	= dev_strings,
+	.unbind		= __exit_p(gncm_unbind),
+};
+
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_AUTHOR("Yauheni Kaliuta");
+MODULE_LICENSE("GPL");
+
+static int __init init(void)
+{
+	return usb_composite_probe(&ncm_driver, gncm_bind);
+}
+module_init(init);
+
+static void __exit cleanup(void)
+{
+	usb_composite_unregister(&ncm_driver);
+}
+module_exit(cleanup);