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: Yauheni Kaliuta <yauheni.kaliuta@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

3 files changed, 263 insertions, 0 deletions

diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig
index 7201b4e32778..a776c35ca980 100644
--- a/drivers/usb/gadget/Kconfig
+++ b/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
diff --git a/drivers/usb/gadget/Makefile b/drivers/usb/gadget/Makefile
index fbf5db4d456d..55f5e8ae5924 100644
--- a/drivers/usb/gadget/Makefile
+++ b/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
diff --git a/drivers/usb/gadget/ncm.c b/drivers/usb/gadget/ncm.c
new file mode 100644
index 000000000000..99c179ad729d
--- /dev/null
+++ b/drivers/usb/gadget/ncm.c
@@ -0,0 +1,248 @@
+/*
+ * 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);