usb gadget: new "CDC Composite" gadget driver
This is a simple example of a composite gadget, combining two
Communications Class Device (CDC) functions: ECM and ACM.
This provides a clear example of how the composite gadget framework
is intended to work. It's surprising that MS-Windows (or at least,
XP and previous) won't "just work" with something this simple...
One /proc/bus/usb/devices listing looks like:
T: Bus=03 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#= 46 Spd=480 MxCh= 0
D: Ver= 2.00 Cls=02(comm.) Sub=00 Prot=00 MxPS=64 #Cfgs= 1
P: Vendor=0525 ProdID=a4aa Rev= 3.01
S: Manufacturer=Linux 2.6.26-rc6-pnut with net2280
S: Product=CDC Composite Gadget
C:* #Ifs= 4 Cfg#= 1 Atr=c0 MxPwr= 2mA
I:* If#= 0 Alt= 0 #EPs= 1 Cls=02(comm.) Sub=06 Prot=00 Driver=cdc_ether
E: Ad=83(I) Atr=03(Int.) MxPS= 16 Ivl=32ms
I: If#= 1 Alt= 0 #EPs= 0 Cls=0a(data ) Sub=00 Prot=00 Driver=cdc_ether
I:* If#= 1 Alt= 1 #EPs= 2 Cls=0a(data ) Sub=00 Prot=00 Driver=cdc_ether
E: Ad=81(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
E: Ad=02(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
I:* If#= 2 Alt= 0 #EPs= 1 Cls=02(comm.) Sub=02 Prot=01 Driver=cdc_acm
E: Ad=86(I) Atr=03(Int.) MxPS= 8 Ivl=32ms
I:* If#= 3 Alt= 0 #EPs= 2 Cls=0a(data ) Sub=00 Prot=00 Driver=cdc_acm
E: Ad=84(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
E: Ad=05(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
Not all USB peripheral controller hardware can support this driver.
All the highspeed-capable peripheral controllers with drivers now in
the mainline kernel seem to support this, as does omap_udc. But
many full speed controllers don't have enough endpoints, or (as with
the PXA controllers) don't support altsettings.
Lightly tested.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/gadget/cdc2.c b/drivers/usb/gadget/cdc2.c
new file mode 100644
index 0000000..289c752
--- /dev/null
+++ b/drivers/usb/gadget/cdc2.c
@@ -0,0 +1,246 @@
+/*
+ * cdc2.c -- CDC Composite driver, with ECM and ACM support
+ *
+ * Copyright (C) 2008 David Brownell
+ * 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
+ */
+
+#include <linux/kernel.h>
+#include <linux/utsname.h>
+
+#include "u_ether.h"
+#include "u_serial.h"
+
+
+#define DRIVER_DESC "CDC Composite Gadget"
+#define DRIVER_VERSION "King Kamehameha Day 2008"
+
+/*-------------------------------------------------------------------------*/
+
+/* 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 this composite CDC configuration.
+ */
+#define CDC_VENDOR_NUM 0x0525 /* NetChip */
+#define CDC_PRODUCT_NUM 0xa4aa /* CDC Composite: ECM + ACM */
+
+/*-------------------------------------------------------------------------*/
+
+static struct usb_device_descriptor device_desc = {
+ .bLength = sizeof device_desc,
+ .bDescriptorType = USB_DT_DEVICE,
+
+ .bcdUSB = __constant_cpu_to_le16(0x0200),
+
+ .bDeviceClass = USB_CLASS_COMM,
+ .bDeviceSubClass = 0,
+ .bDeviceProtocol = 0,
+ /* .bMaxPacketSize0 = f(hardware) */
+
+ /* Vendor and product id can be overridden by module parameters. */
+ .idVendor = __constant_cpu_to_le16(CDC_VENDOR_NUM),
+ .idProduct = __constant_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];
+
+/*-------------------------------------------------------------------------*/
+
+/*
+ * We _always_ have both CDC ECM and CDC ACM functions.
+ */
+static int __init cdc_do_config(struct usb_configuration *c)
+{
+ int status;
+
+ if (gadget_is_otg(c->cdev->gadget)) {
+ c->descriptors = otg_desc;
+ c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
+ }
+
+ status = ecm_bind_config(c, hostaddr);
+ if (status < 0)
+ return status;
+
+ status = acm_bind_config(c, 0);
+ if (status == 0)
+ return status;
+
+ return 0;
+}
+
+static struct usb_configuration cdc_config_driver = {
+ .label = "CDC Composite (ECM + ACM)",
+ .bind = cdc_do_config,
+ .bConfigurationValue = 1,
+ /* .iConfiguration = DYNAMIC */
+ .bmAttributes = USB_CONFIG_ATT_SELFPOWER,
+ .bMaxPower = 1, /* 2 mA, minimal */
+};
+
+/*-------------------------------------------------------------------------*/
+
+static int __init cdc_bind(struct usb_composite_dev *cdev)
+{
+ int gcnum;
+ struct usb_gadget *gadget = cdev->gadget;
+ int status;
+
+ if (!can_support_ecm(cdev->gadget)) {
+ ERROR(cdev, "controller '%s' not usable\n", gadget->name);
+ return -EINVAL;
+ }
+
+ /* set up network link layer */
+ status = gether_setup(cdev->gadget, hostaddr);
+ if (status < 0)
+ return status;
+
+ /* set up serial link layer */
+ status = gserial_setup(cdev->gadget, 1);
+ if (status < 0)
+ goto fail0;
+
+ 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.
+ */
+ WARN(cdev, "controller '%s' not recognized; trying %s\n",
+ gadget->name,
+ cdc_config_driver.label);
+ device_desc.bcdDevice =
+ __constant_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 fail1;
+ strings_dev[STRING_MANUFACTURER_IDX].id = status;
+ device_desc.iManufacturer = status;
+
+ status = usb_string_id(cdev);
+ if (status < 0)
+ goto fail1;
+ strings_dev[STRING_PRODUCT_IDX].id = status;
+ device_desc.iProduct = status;
+
+ /* register our configuration */
+ status = usb_add_config(cdev, &cdc_config_driver);
+ if (status < 0)
+ goto fail1;
+
+ INFO(cdev, "%s, version: " DRIVER_VERSION "\n", DRIVER_DESC);
+
+ return 0;
+
+fail1:
+ gserial_cleanup();
+fail0:
+ gether_cleanup();
+ return status;
+}
+
+static int __exit cdc_unbind(struct usb_composite_dev *cdev)
+{
+ gserial_cleanup();
+ gether_cleanup();
+ return 0;
+}
+
+static struct usb_composite_driver cdc_driver = {
+ .name = "g_cdc",
+ .dev = &device_desc,
+ .strings = dev_strings,
+ .bind = cdc_bind,
+ .unbind = __exit_p(cdc_unbind),
+};
+
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_AUTHOR("David Brownell");
+MODULE_LICENSE("GPL");
+
+static int __init init(void)
+{
+ return usb_composite_register(&cdc_driver);
+}
+module_init(init);
+
+static void __exit cleanup(void)
+{
+ usb_composite_unregister(&cdc_driver);
+}
+module_exit(cleanup);