usb gadget: cdc obex glue
The following patch introduces a new f_obex.c function driver.
It allows userspace obex servers to use usb as transport layer
for their messages.
[ dbrownell@users.sourceforge.net: various fixes and cleanups ]
Signed-off-by: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/gadget/f_obex.c b/drivers/usb/gadget/f_obex.c
new file mode 100644
index 0000000..86241b2
--- /dev/null
+++ b/drivers/usb/gadget/f_obex.c
@@ -0,0 +1,446 @@
+/*
+ * f_obex.c -- USB CDC OBEX function driver
+ *
+ * Copyright (C) 2008 Nokia Corporation
+ * Contact: Felipe Balbi <felipe.balbi@nokia.com>
+ *
+ * Based on f_acm.c by Al Borchers and David Brownell.
+ *
+ * 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 VERBOSE_DEBUG */
+
+#include <linux/kernel.h>
+#include <linux/utsname.h>
+#include <linux/device.h>
+
+#include "u_serial.h"
+#include "gadget_chips.h"
+
+
+/*
+ * This CDC OBEX function support just packages a TTY-ish byte stream.
+ * A user mode server will put it into "raw" mode and handle all the
+ * relevant protocol details ... this is just a kernel passthrough.
+ *
+ * REVISIT this driver shouldn't actually activate before that user mode
+ * server is ready to respond! When the "serial gadget" utility code
+ * adds open/close notifications, this driver should use them with new
+ * (TBS) composite gadget hooks that wrap usb_gadget_disconnect() and
+ * usb_gadget_connect() calls with refcounts ... disconnect() when we
+ * bind, then connect() when the user server code is ready to respond.
+ */
+
+struct obex_ep_descs {
+ struct usb_endpoint_descriptor *obex_in;
+ struct usb_endpoint_descriptor *obex_out;
+};
+
+struct f_obex {
+ struct gserial port;
+ u8 ctrl_id;
+ u8 data_id;
+ u8 port_num;
+
+ struct obex_ep_descs fs;
+ struct obex_ep_descs hs;
+};
+
+static inline struct f_obex *func_to_obex(struct usb_function *f)
+{
+ return container_of(f, struct f_obex, port.func);
+}
+
+/*-------------------------------------------------------------------------*/
+
+#define OBEX_CTRL_IDX 0
+#define OBEX_DATA_IDX 1
+
+static struct usb_string obex_string_defs[] = {
+ [OBEX_CTRL_IDX].s = "CDC Object Exchange (OBEX)",
+ [OBEX_DATA_IDX].s = "CDC OBEX Data",
+ { }, /* end of list */
+};
+
+static struct usb_gadget_strings obex_string_table = {
+ .language = 0x0409, /* en-US */
+ .strings = obex_string_defs,
+};
+
+static struct usb_gadget_strings *obex_strings[] = {
+ &obex_string_table,
+ NULL,
+};
+
+/*-------------------------------------------------------------------------*/
+
+static struct usb_interface_descriptor obex_control_intf __initdata = {
+ .bLength = sizeof(obex_control_intf),
+ .bDescriptorType = USB_DT_INTERFACE,
+ .bInterfaceNumber = 0,
+
+ .bAlternateSetting = 0,
+ .bNumEndpoints = 0,
+ .bInterfaceClass = USB_CLASS_COMM,
+ .bInterfaceSubClass = USB_CDC_SUBCLASS_OBEX,
+};
+
+static struct usb_interface_descriptor obex_data_nop_intf __initdata = {
+ .bLength = sizeof(obex_data_nop_intf),
+ .bDescriptorType = USB_DT_INTERFACE,
+ .bInterfaceNumber = 1,
+
+ .bAlternateSetting = 0,
+ .bNumEndpoints = 0,
+ .bInterfaceClass = USB_CLASS_CDC_DATA,
+};
+
+static struct usb_interface_descriptor obex_data_intf __initdata = {
+ .bLength = sizeof(obex_data_intf),
+ .bDescriptorType = USB_DT_INTERFACE,
+ .bInterfaceNumber = 2,
+
+ .bAlternateSetting = 1,
+ .bNumEndpoints = 2,
+ .bInterfaceClass = USB_CLASS_CDC_DATA,
+};
+
+static struct usb_cdc_header_desc obex_cdc_header_desc __initdata = {
+ .bLength = sizeof(obex_cdc_header_desc),
+ .bDescriptorType = USB_DT_CS_INTERFACE,
+ .bDescriptorSubType = USB_CDC_HEADER_TYPE,
+ .bcdCDC = __constant_cpu_to_le16(0x0120),
+};
+
+static struct usb_cdc_union_desc obex_cdc_union_desc __initdata = {
+ .bLength = sizeof(obex_cdc_union_desc),
+ .bDescriptorType = USB_DT_CS_INTERFACE,
+ .bDescriptorSubType = USB_CDC_UNION_TYPE,
+ .bMasterInterface0 = 1,
+ .bSlaveInterface0 = 2,
+};
+
+static struct usb_cdc_obex_desc obex_desc __initdata = {
+ .bLength = sizeof(obex_desc),
+ .bDescriptorType = USB_DT_CS_INTERFACE,
+ .bDescriptorSubType = USB_CDC_OBEX_TYPE,
+ .bcdVersion = __constant_cpu_to_le16(0x0100),
+};
+
+/* High-Speed Support */
+
+static struct usb_endpoint_descriptor obex_hs_ep_out_desc __initdata = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+
+ .bEndpointAddress = USB_DIR_OUT,
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+ .wMaxPacketSize = __constant_cpu_to_le16(512),
+};
+
+static struct usb_endpoint_descriptor obex_hs_ep_in_desc __initdata = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+
+ .bEndpointAddress = USB_DIR_IN,
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+ .wMaxPacketSize = __constant_cpu_to_le16(512),
+};
+
+static struct usb_descriptor_header *hs_function[] __initdata = {
+ (struct usb_descriptor_header *) &obex_control_intf,
+ (struct usb_descriptor_header *) &obex_cdc_header_desc,
+ (struct usb_descriptor_header *) &obex_desc,
+ (struct usb_descriptor_header *) &obex_cdc_union_desc,
+
+ (struct usb_descriptor_header *) &obex_data_nop_intf,
+ (struct usb_descriptor_header *) &obex_data_intf,
+ (struct usb_descriptor_header *) &obex_hs_ep_in_desc,
+ (struct usb_descriptor_header *) &obex_hs_ep_out_desc,
+ NULL,
+};
+
+/* Full-Speed Support */
+
+static struct usb_endpoint_descriptor obex_fs_ep_in_desc __initdata = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+
+ .bEndpointAddress = USB_DIR_IN,
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+};
+
+static struct usb_endpoint_descriptor obex_fs_ep_out_desc __initdata = {
+ .bLength = USB_DT_ENDPOINT_SIZE,
+ .bDescriptorType = USB_DT_ENDPOINT,
+
+ .bEndpointAddress = USB_DIR_OUT,
+ .bmAttributes = USB_ENDPOINT_XFER_BULK,
+};
+
+static struct usb_descriptor_header *fs_function[] __initdata = {
+ (struct usb_descriptor_header *) &obex_control_intf,
+ (struct usb_descriptor_header *) &obex_cdc_header_desc,
+ (struct usb_descriptor_header *) &obex_desc,
+ (struct usb_descriptor_header *) &obex_cdc_union_desc,
+
+ (struct usb_descriptor_header *) &obex_data_nop_intf,
+ (struct usb_descriptor_header *) &obex_data_intf,
+ (struct usb_descriptor_header *) &obex_fs_ep_in_desc,
+ (struct usb_descriptor_header *) &obex_fs_ep_out_desc,
+ NULL,
+};
+
+/*-------------------------------------------------------------------------*/
+
+static int obex_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
+{
+ struct f_obex *obex = func_to_obex(f);
+ struct usb_composite_dev *cdev = f->config->cdev;
+
+ if (intf == obex->ctrl_id) {
+ if (alt != 0)
+ goto fail;
+ /* NOP */
+ DBG(cdev, "reset obex ttyGS%d control\n", obex->port_num);
+
+ } else if (intf == obex->data_id) {
+ if (alt > 1)
+ goto fail;
+
+ if (obex->port.in->driver_data) {
+ DBG(cdev, "reset obex ttyGS%d\n", obex->port_num);
+ gserial_disconnect(&obex->port);
+ }
+
+ if (!obex->port.in_desc) {
+ DBG(cdev, "init obex ttyGS%d\n", obex->port_num);
+ obex->port.in_desc = ep_choose(cdev->gadget,
+ obex->hs.obex_in, obex->fs.obex_in);
+ obex->port.out_desc = ep_choose(cdev->gadget,
+ obex->hs.obex_out, obex->fs.obex_out);
+ }
+
+ if (alt == 1) {
+ DBG(cdev, "activate obex ttyGS%d\n", obex->port_num);
+ gserial_connect(&obex->port, obex->port_num);
+ }
+
+ } else
+ goto fail;
+
+ return 0;
+
+fail:
+ return -EINVAL;
+}
+
+static int obex_get_alt(struct usb_function *f, unsigned intf)
+{
+ struct f_obex *obex = func_to_obex(f);
+
+ if (intf == obex->ctrl_id)
+ return 0;
+
+ return obex->port.in->driver_data ? 1 : 0;
+}
+
+static void obex_disable(struct usb_function *f)
+{
+ struct f_obex *obex = func_to_obex(f);
+ struct usb_composite_dev *cdev = f->config->cdev;
+
+ DBG(cdev, "obex ttyGS%d disable\n", obex->port_num);
+ gserial_disconnect(&obex->port);
+}
+
+/*-------------------------------------------------------------------------*/
+
+static int __init
+obex_bind(struct usb_configuration *c, struct usb_function *f)
+{
+ struct usb_composite_dev *cdev = c->cdev;
+ struct f_obex *obex = func_to_obex(f);
+ int status;
+ struct usb_ep *ep;
+
+ /* allocate instance-specific interface IDs, and patch descriptors */
+
+ status = usb_interface_id(c, f);
+ if (status < 0)
+ goto fail;
+ obex->ctrl_id = status;
+
+ obex_control_intf.bInterfaceNumber = status;
+ obex_cdc_union_desc.bMasterInterface0 = status;
+
+ status = usb_interface_id(c, f);
+ if (status < 0)
+ goto fail;
+ obex->data_id = status;
+
+ obex_data_nop_intf.bInterfaceNumber = status;
+ obex_data_intf.bInterfaceNumber = status;
+ obex_cdc_union_desc.bSlaveInterface0 = status;
+
+ /* allocate instance-specific endpoints */
+
+ ep = usb_ep_autoconfig(cdev->gadget, &obex_fs_ep_in_desc);
+ if (!ep)
+ goto fail;
+ obex->port.in = ep;
+ ep->driver_data = cdev; /* claim */
+
+ ep = usb_ep_autoconfig(cdev->gadget, &obex_fs_ep_out_desc);
+ if (!ep)
+ goto fail;
+ obex->port.out = ep;
+ ep->driver_data = cdev; /* claim */
+
+ /* copy descriptors, and track endpoint copies */
+ f->descriptors = usb_copy_descriptors(fs_function);
+
+ obex->fs.obex_in = usb_find_endpoint(fs_function,
+ f->descriptors, &obex_fs_ep_in_desc);
+ obex->fs.obex_out = usb_find_endpoint(fs_function,
+ f->descriptors, &obex_fs_ep_out_desc);
+
+ /* support all relevant hardware speeds... we expect that when
+ * hardware is dual speed, all bulk-capable endpoints work at
+ * both speeds
+ */
+ if (gadget_is_dualspeed(c->cdev->gadget)) {
+
+ obex_hs_ep_in_desc.bEndpointAddress =
+ obex_fs_ep_in_desc.bEndpointAddress;
+ obex_hs_ep_out_desc.bEndpointAddress =
+ obex_fs_ep_out_desc.bEndpointAddress;
+
+ /* copy descriptors, and track endpoint copies */
+ f->hs_descriptors = usb_copy_descriptors(hs_function);
+
+ obex->hs.obex_in = usb_find_endpoint(hs_function,
+ f->descriptors, &obex_hs_ep_in_desc);
+ obex->hs.obex_out = usb_find_endpoint(hs_function,
+ f->descriptors, &obex_hs_ep_out_desc);
+ }
+
+ DBG(cdev, "obex ttyGS%d: %s speed IN/%s OUT/%s\n",
+ obex->port_num,
+ gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
+ obex->port.in->name, obex->port.out->name);
+
+ return 0;
+
+fail:
+ /* we might as well release our claims on endpoints */
+ if (obex->port.out)
+ obex->port.out->driver_data = NULL;
+ if (obex->port.in)
+ obex->port.in->driver_data = NULL;
+
+ ERROR(cdev, "%s/%p: can't bind, err %d\n", f->name, f, status);
+
+ return status;
+}
+
+static void
+obex_unbind(struct usb_configuration *c, struct usb_function *f)
+{
+ if (gadget_is_dualspeed(c->cdev->gadget))
+ usb_free_descriptors(f->hs_descriptors);
+ usb_free_descriptors(f->descriptors);
+ kfree(func_to_obex(f));
+}
+
+/* Some controllers can't support CDC OBEX ... */
+static inline bool can_support_obex(struct usb_configuration *c)
+{
+ /* Since the first interface is a NOP, we can ignore the
+ * issue of multi-interface support on most controllers.
+ *
+ * Altsettings are mandatory, however...
+ */
+ if (!gadget_supports_altsettings(c->cdev->gadget))
+ return false;
+
+ /* everything else is *probably* fine ... */
+ return true;
+}
+
+/**
+ * obex_bind_config - add a CDC OBEX function to a configuration
+ * @c: the configuration to support the CDC OBEX instance
+ * @port_num: /dev/ttyGS* port this interface will use
+ * Context: single threaded during gadget setup
+ *
+ * Returns zero on success, else negative errno.
+ *
+ * Caller must have called @gserial_setup() with enough ports to
+ * handle all the ones it binds. Caller is also responsible
+ * for calling @gserial_cleanup() before module unload.
+ */
+int __init obex_bind_config(struct usb_configuration *c, u8 port_num)
+{
+ struct f_obex *obex;
+ int status;
+
+ if (!can_support_obex(c))
+ return -EINVAL;
+
+ /* maybe allocate device-global string IDs, and patch descriptors */
+ if (obex_string_defs[OBEX_CTRL_IDX].id == 0) {
+ status = usb_string_id(c->cdev);
+ if (status < 0)
+ return status;
+ obex_string_defs[OBEX_CTRL_IDX].id = status;
+
+ obex_control_intf.iInterface = status;
+
+ status = usb_string_id(c->cdev);
+ if (status < 0)
+ return status;
+ obex_string_defs[OBEX_DATA_IDX].id = status;
+
+ obex_data_nop_intf.iInterface =
+ obex_data_intf.iInterface = status;
+ }
+
+ /* allocate and initialize one new instance */
+ obex = kzalloc(sizeof *obex, GFP_KERNEL);
+ if (!obex)
+ return -ENOMEM;
+
+ obex->port_num = port_num;
+
+ obex->port.func.name = "obex";
+ obex->port.func.strings = obex_strings;
+ /* descriptors are per-instance copies */
+ obex->port.func.bind = obex_bind;
+ obex->port.func.unbind = obex_unbind;
+ obex->port.func.set_alt = obex_set_alt;
+ obex->port.func.get_alt = obex_get_alt;
+ obex->port.func.disable = obex_disable;
+
+ status = usb_add_function(c, &obex->port.func);
+ if (status)
+ kfree(obex);
+
+ return status;
+}
+
+MODULE_AUTHOR("Felipe Balbi");
+MODULE_LICENSE("GPL");