usb gadget: composite gadget core
Add <linux/usb/composite.h> interfaces for composite gadget drivers, and
basic implementation support behind it:
- struct usb_function ... groups one or more interfaces into a function
managed as one unit within a configuration, to which it's added by
usb_add_function().
- struct usb_configuration ... groups one or more such functions into
a configuration managed as one unit by a driver, to which it's added
by usb_add_config(). These operate at either high or full/low speeds
and at a given bMaxPower.
- struct usb_composite_driver ... groups one or more such configurations
into a gadget driver, which may be registered or unregistered.
- struct usb_composite_dev ... a usb_composite_driver manages this; it
wraps the usb_gadget exposed by the controller driver.
This also includes some basic kerneldoc.
How to use it (the short version): provide a usb_composite_driver with a
bind() that calls usb_add_config() for each of the needed configurations.
The configurations in turn have bind() calls, which will usb_add_function()
for each function required. Each function's bind() allocates resources
needed to perform its tasks, like endpoints; sometimes configurations will
allocate resources too.
Separate patches will convert most gadget drivers to this infrastructure.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
new file mode 100644
index 0000000..b3d302a
--- /dev/null
+++ b/drivers/usb/gadget/composite.c
@@ -0,0 +1,1040 @@
+/*
+ * composite.c - infrastructure for Composite USB Gadgets
+ *
+ * Copyright (C) 2006-2008 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/kallsyms.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/device.h>
+
+#include <linux/usb/composite.h>
+
+
+/*
+ * The code in this file is utility code, used to build a gadget driver
+ * from one or more "function" drivers, one or more "configuration"
+ * objects, and a "usb_composite_driver" by gluing them together along
+ * with the relevant device-wide data.
+ */
+
+/* big enough to hold our biggest descriptor */
+#define USB_BUFSIZ 512
+
+static struct usb_composite_driver *composite;
+
+/* Some systems will need runtime overrides for the product identifers
+ * published in the device descriptor, either numbers or strings or both.
+ * String parameters are in UTF-8 (superset of ASCII's 7 bit characters).
+ */
+
+static ushort idVendor;
+module_param(idVendor, ushort, 0);
+MODULE_PARM_DESC(idVendor, "USB Vendor ID");
+
+static ushort idProduct;
+module_param(idProduct, ushort, 0);
+MODULE_PARM_DESC(idProduct, "USB Product ID");
+
+static ushort bcdDevice;
+module_param(bcdDevice, ushort, 0);
+MODULE_PARM_DESC(bcdDevice, "USB Device version (BCD)");
+
+static char *iManufacturer;
+module_param(iManufacturer, charp, 0);
+MODULE_PARM_DESC(iManufacturer, "USB Manufacturer string");
+
+static char *iProduct;
+module_param(iProduct, charp, 0);
+MODULE_PARM_DESC(iProduct, "USB Product string");
+
+static char *iSerialNumber;
+module_param(iSerialNumber, charp, 0);
+MODULE_PARM_DESC(iSerialNumber, "SerialNumber string");
+
+/*-------------------------------------------------------------------------*/
+
+/**
+ * usb_add_function() - add a function to a configuration
+ * @config: the configuration
+ * @function: the function being added
+ * Context: single threaded during gadget setup
+ *
+ * After initialization, each configuration must have one or more
+ * functions added to it. Adding a function involves calling its @bind()
+ * method to allocate resources such as interface and string identifiers
+ * and endpoints.
+ *
+ * This function returns the value of the function's bind(), which is
+ * zero for success else a negative errno value.
+ */
+int __init usb_add_function(struct usb_configuration *config,
+ struct usb_function *function)
+{
+ int value = -EINVAL;
+
+ DBG(config->cdev, "adding '%s'/%p to config '%s'/%p\n",
+ function->name, function,
+ config->label, config);
+
+ if (!function->set_alt || !function->disable)
+ goto done;
+
+ function->config = config;
+ list_add_tail(&function->list, &config->functions);
+
+ /* REVISIT *require* function->bind? */
+ if (function->bind) {
+ value = function->bind(config, function);
+ if (value < 0) {
+ list_del(&function->list);
+ function->config = NULL;
+ }
+ } else
+ value = 0;
+
+ /* We allow configurations that don't work at both speeds.
+ * If we run into a lowspeed Linux system, treat it the same
+ * as full speed ... it's the function drivers that will need
+ * to avoid bulk and ISO transfers.
+ */
+ if (!config->fullspeed && function->descriptors)
+ config->fullspeed = true;
+ if (!config->highspeed && function->hs_descriptors)
+ config->highspeed = true;
+
+done:
+ if (value)
+ DBG(config->cdev, "adding '%s'/%p --> %d\n",
+ function->name, function, value);
+ return value;
+}
+
+/**
+ * usb_interface_id() - allocate an unused interface ID
+ * @config: configuration associated with the interface
+ * @function: function handling the interface
+ * Context: single threaded during gadget setup
+ *
+ * usb_interface_id() is called from usb_function.bind() callbacks to
+ * allocate new interface IDs. The function driver will then store that
+ * ID in interface, association, CDC union, and other descriptors. It
+ * will also handle any control requests targetted at that interface,
+ * particularly changing its altsetting via set_alt(). There may
+ * also be class-specific or vendor-specific requests to handle.
+ *
+ * All interface identifier should be allocated using this routine, to
+ * ensure that for example different functions don't wrongly assign
+ * different meanings to the same identifier. Note that since interface
+ * identifers are configuration-specific, functions used in more than
+ * one configuration (or more than once in a given configuration) need
+ * multiple versions of the relevant descriptors.
+ *
+ * Returns the interface ID which was allocated; or -ENODEV if no
+ * more interface IDs can be allocated.
+ */
+int __init usb_interface_id(struct usb_configuration *config,
+ struct usb_function *function)
+{
+ unsigned id = config->next_interface_id;
+
+ if (id < MAX_CONFIG_INTERFACES) {
+ config->interface[id] = function;
+ config->next_interface_id = id + 1;
+ return id;
+ }
+ return -ENODEV;
+}
+
+static int config_buf(struct usb_configuration *config,
+ enum usb_device_speed speed, void *buf, u8 type)
+{
+ struct usb_config_descriptor *c = buf;
+ void *next = buf + USB_DT_CONFIG_SIZE;
+ int len = USB_BUFSIZ - USB_DT_CONFIG_SIZE;
+ struct usb_function *f;
+ int status;
+
+ /* write the config descriptor */
+ c = buf;
+ c->bLength = USB_DT_CONFIG_SIZE;
+ c->bDescriptorType = type;
+ /* wTotalLength is written later */
+ c->bNumInterfaces = config->next_interface_id;
+ c->bConfigurationValue = config->bConfigurationValue;
+ c->iConfiguration = config->iConfiguration;
+ c->bmAttributes = USB_CONFIG_ATT_ONE | config->bmAttributes;
+ c->bMaxPower = config->bMaxPower;
+
+ /* There may be e.g. OTG descriptors */
+ if (config->descriptors) {
+ status = usb_descriptor_fillbuf(next, len,
+ config->descriptors);
+ if (status < 0)
+ return status;
+ len -= status;
+ next += status;
+ }
+
+ /* add each function's descriptors */
+ list_for_each_entry(f, &config->functions, list) {
+ struct usb_descriptor_header **descriptors;
+
+ if (speed == USB_SPEED_HIGH)
+ descriptors = f->hs_descriptors;
+ else
+ descriptors = f->descriptors;
+ if (!descriptors)
+ continue;
+ status = usb_descriptor_fillbuf(next, len,
+ (const struct usb_descriptor_header **) descriptors);
+ if (status < 0)
+ return status;
+ len -= status;
+ next += status;
+ }
+
+ len = next - buf;
+ c->wTotalLength = cpu_to_le16(len);
+ return len;
+}
+
+static int config_desc(struct usb_composite_dev *cdev, unsigned w_value)
+{
+ struct usb_gadget *gadget = cdev->gadget;
+ struct usb_configuration *c;
+ u8 type = w_value >> 8;
+ enum usb_device_speed speed = USB_SPEED_UNKNOWN;
+
+ if (gadget_is_dualspeed(gadget)) {
+ int hs = 0;
+
+ if (gadget->speed == USB_SPEED_HIGH)
+ hs = 1;
+ if (type == USB_DT_OTHER_SPEED_CONFIG)
+ hs = !hs;
+ if (hs)
+ speed = USB_SPEED_HIGH;
+
+ }
+
+ /* This is a lookup by config *INDEX* */
+ w_value &= 0xff;
+ list_for_each_entry(c, &cdev->configs, list) {
+ /* ignore configs that won't work at this speed */
+ if (speed == USB_SPEED_HIGH) {
+ if (!c->highspeed)
+ continue;
+ } else {
+ if (!c->fullspeed)
+ continue;
+ }
+ if (w_value == 0)
+ return config_buf(c, speed, cdev->req->buf, type);
+ w_value--;
+ }
+ return -EINVAL;
+}
+
+static int count_configs(struct usb_composite_dev *cdev, unsigned type)
+{
+ struct usb_gadget *gadget = cdev->gadget;
+ struct usb_configuration *c;
+ unsigned count = 0;
+ int hs = 0;
+
+ if (gadget_is_dualspeed(gadget)) {
+ if (gadget->speed == USB_SPEED_HIGH)
+ hs = 1;
+ if (type == USB_DT_DEVICE_QUALIFIER)
+ hs = !hs;
+ }
+ list_for_each_entry(c, &cdev->configs, list) {
+ /* ignore configs that won't work at this speed */
+ if (hs) {
+ if (!c->highspeed)
+ continue;
+ } else {
+ if (!c->fullspeed)
+ continue;
+ }
+ count++;
+ }
+ return count;
+}
+
+static void device_qual(struct usb_composite_dev *cdev)
+{
+ struct usb_qualifier_descriptor *qual = cdev->req->buf;
+
+ qual->bLength = sizeof(*qual);
+ qual->bDescriptorType = USB_DT_DEVICE_QUALIFIER;
+ /* POLICY: same bcdUSB and device type info at both speeds */
+ qual->bcdUSB = cdev->desc.bcdUSB;
+ qual->bDeviceClass = cdev->desc.bDeviceClass;
+ qual->bDeviceSubClass = cdev->desc.bDeviceSubClass;
+ qual->bDeviceProtocol = cdev->desc.bDeviceProtocol;
+ /* ASSUME same EP0 fifo size at both speeds */
+ qual->bMaxPacketSize0 = cdev->desc.bMaxPacketSize0;
+ qual->bNumConfigurations = count_configs(cdev, USB_DT_DEVICE_QUALIFIER);
+}
+
+/*-------------------------------------------------------------------------*/
+
+static void reset_config(struct usb_composite_dev *cdev)
+{
+ struct usb_function *f;
+
+ DBG(cdev, "reset config\n");
+
+ list_for_each_entry(f, &cdev->config->functions, list) {
+ if (f->disable)
+ f->disable(f);
+ }
+ cdev->config = NULL;
+}
+
+static int set_config(struct usb_composite_dev *cdev,
+ const struct usb_ctrlrequest *ctrl, unsigned number)
+{
+ struct usb_gadget *gadget = cdev->gadget;
+ struct usb_configuration *c = NULL;
+ int result = -EINVAL;
+ unsigned power = gadget_is_otg(gadget) ? 8 : 100;
+ int tmp;
+
+ if (cdev->config)
+ reset_config(cdev);
+
+ if (number) {
+ list_for_each_entry(c, &cdev->configs, list) {
+ if (c->bConfigurationValue == number) {
+ result = 0;
+ break;
+ }
+ }
+ if (result < 0)
+ goto done;
+ } else
+ result = 0;
+
+ INFO(cdev, "%s speed config #%d: %s\n",
+ ({ char *speed;
+ switch (gadget->speed) {
+ case USB_SPEED_LOW: speed = "low"; break;
+ case USB_SPEED_FULL: speed = "full"; break;
+ case USB_SPEED_HIGH: speed = "high"; break;
+ default: speed = "?"; break;
+ } ; speed; }), number, c ? c->label : "unconfigured");
+
+ if (!c)
+ goto done;
+
+ cdev->config = c;
+
+ /* Initialize all interfaces by setting them to altsetting zero. */
+ for (tmp = 0; tmp < MAX_CONFIG_INTERFACES; tmp++) {
+ struct usb_function *f = c->interface[tmp];
+
+ if (!f)
+ break;
+
+ result = f->set_alt(f, tmp, 0);
+ if (result < 0) {
+ DBG(cdev, "interface %d (%s/%p) alt 0 --> %d\n",
+ tmp, f->name, f, result);
+
+ reset_config(cdev);
+ goto done;
+ }
+ }
+
+ /* when we return, be sure our power usage is valid */
+ power = 2 * c->bMaxPower;
+done:
+ usb_gadget_vbus_draw(gadget, power);
+ return result;
+}
+
+/**
+ * usb_add_config() - add a configuration to a device.
+ * @cdev: wraps the USB gadget
+ * @config: the configuration, with bConfigurationValue assigned
+ * Context: single threaded during gadget setup
+ *
+ * One of the main tasks of a composite driver's bind() routine is to
+ * add each of the configurations it supports, using this routine.
+ *
+ * This function returns the value of the configuration's bind(), which
+ * is zero for success else a negative errno value. Binding configurations
+ * assigns global resources including string IDs, and per-configuration
+ * resources such as interface IDs and endpoints.
+ */
+int __init usb_add_config(struct usb_composite_dev *cdev,
+ struct usb_configuration *config)
+{
+ int status = -EINVAL;
+ struct usb_configuration *c;
+
+ DBG(cdev, "adding config #%u '%s'/%p\n",
+ config->bConfigurationValue,
+ config->label, config);
+
+ if (!config->bConfigurationValue || !config->bind)
+ goto done;
+
+ /* Prevent duplicate configuration identifiers */
+ list_for_each_entry(c, &cdev->configs, list) {
+ if (c->bConfigurationValue == config->bConfigurationValue) {
+ status = -EBUSY;
+ goto done;
+ }
+ }
+
+ config->cdev = cdev;
+ list_add_tail(&config->list, &cdev->configs);
+
+ INIT_LIST_HEAD(&config->functions);
+ config->next_interface_id = 0;
+
+ status = config->bind(config);
+ if (status < 0) {
+ list_del(&config->list);
+ config->cdev = NULL;
+ } else {
+ unsigned i;
+
+ DBG(cdev, "cfg %d/%p speeds:%s%s\n",
+ config->bConfigurationValue, config,
+ config->highspeed ? " high" : "",
+ config->fullspeed
+ ? (gadget_is_dualspeed(cdev->gadget)
+ ? " full"
+ : " full/low")
+ : "");
+
+ for (i = 0; i < MAX_CONFIG_INTERFACES; i++) {
+ struct usb_function *f = config->interface[i];
+
+ if (!f)
+ continue;
+ DBG(cdev, " interface %d = %s/%p\n",
+ i, f->name, f);
+ }
+ }
+
+ /* set_alt(), or next config->bind(), sets up
+ * ep->driver_data as needed.
+ */
+ usb_ep_autoconfig_reset(cdev->gadget);
+
+done:
+ if (status)
+ DBG(cdev, "added config '%s'/%u --> %d\n", config->label,
+ config->bConfigurationValue, status);
+ return status;
+}
+
+/*-------------------------------------------------------------------------*/
+
+/* We support strings in multiple languages ... string descriptor zero
+ * says which languages are supported. The typical case will be that
+ * only one language (probably English) is used, with I18N handled on
+ * the host side.
+ */
+
+static void collect_langs(struct usb_gadget_strings **sp, __le16 *buf)
+{
+ const struct usb_gadget_strings *s;
+ u16 language;
+ __le16 *tmp;
+
+ while (*sp) {
+ s = *sp;
+ language = cpu_to_le16(s->language);
+ for (tmp = buf; *tmp && tmp < &buf[126]; tmp++) {
+ if (*tmp == language)
+ goto repeat;
+ }
+ *tmp++ = language;
+repeat:
+ sp++;
+ }
+}
+
+static int lookup_string(
+ struct usb_gadget_strings **sp,
+ void *buf,
+ u16 language,
+ int id
+)
+{
+ struct usb_gadget_strings *s;
+ int value;
+
+ while (*sp) {
+ s = *sp++;
+ if (s->language != language)
+ continue;
+ value = usb_gadget_get_string(s, id, buf);
+ if (value > 0)
+ return value;
+ }
+ return -EINVAL;
+}
+
+static int get_string(struct usb_composite_dev *cdev,
+ void *buf, u16 language, int id)
+{
+ struct usb_configuration *c;
+ struct usb_function *f;
+ int len;
+
+ /* Yes, not only is USB's I18N support probably more than most
+ * folk will ever care about ... also, it's all supported here.
+ * (Except for UTF8 support for Unicode's "Astral Planes".)
+ */
+
+ /* 0 == report all available language codes */
+ if (id == 0) {
+ struct usb_string_descriptor *s = buf;
+ struct usb_gadget_strings **sp;
+
+ memset(s, 0, 256);
+ s->bDescriptorType = USB_DT_STRING;
+
+ sp = composite->strings;
+ if (sp)
+ collect_langs(sp, s->wData);
+
+ list_for_each_entry(c, &cdev->configs, list) {
+ sp = c->strings;
+ if (sp)
+ collect_langs(sp, s->wData);
+
+ list_for_each_entry(f, &c->functions, list) {
+ sp = f->strings;
+ if (sp)
+ collect_langs(sp, s->wData);
+ }
+ }
+
+ for (len = 0; s->wData[len] && len <= 126; len++)
+ continue;
+ if (!len)
+ return -EINVAL;
+
+ s->bLength = 2 * (len + 1);
+ return s->bLength;
+ }
+
+ /* Otherwise, look up and return a specified string. String IDs
+ * are device-scoped, so we look up each string table we're told
+ * about. These lookups are infrequent; simpler-is-better here.
+ */
+ if (composite->strings) {
+ len = lookup_string(composite->strings, buf, language, id);
+ if (len > 0)
+ return len;
+ }
+ list_for_each_entry(c, &cdev->configs, list) {
+ if (c->strings) {
+ len = lookup_string(c->strings, buf, language, id);
+ if (len > 0)
+ return len;
+ }
+ list_for_each_entry(f, &c->functions, list) {
+ if (!f->strings)
+ continue;
+ len = lookup_string(f->strings, buf, language, id);
+ if (len > 0)
+ return len;
+ }
+ }
+ return -EINVAL;
+}
+
+/**
+ * usb_string_id() - allocate an unused string ID
+ * @cdev: the device whose string descriptor IDs are being allocated
+ * Context: single threaded during gadget setup
+ *
+ * @usb_string_id() is called from bind() callbacks to allocate
+ * string IDs. Drivers for functions, configurations, or gadgets will
+ * then store that ID in the appropriate descriptors and string table.
+ *
+ * All string identifier should be allocated using this routine, to
+ * ensure that for example different functions don't wrongly assign
+ * different meanings to the same identifier.
+ */
+int __init usb_string_id(struct usb_composite_dev *cdev)
+{
+ if (cdev->next_string_id < 254) {
+ /* string id 0 is reserved */
+ cdev->next_string_id++;
+ return cdev->next_string_id;
+ }
+ return -ENODEV;
+}
+
+/*-------------------------------------------------------------------------*/
+
+static void composite_setup_complete(struct usb_ep *ep, struct usb_request *req)
+{
+ if (req->status || req->actual != req->length)
+ DBG((struct usb_composite_dev *) ep->driver_data,
+ "setup complete --> %d, %d/%d\n",
+ req->status, req->actual, req->length);
+}
+
+/*
+ * The setup() callback implements all the ep0 functionality that's
+ * not handled lower down, in hardware or the hardware driver(like
+ * device and endpoint feature flags, and their status). It's all
+ * housekeeping for the gadget function we're implementing. Most of
+ * the work is in config and function specific setup.
+ */
+static int
+composite_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
+{
+ struct usb_composite_dev *cdev = get_gadget_data(gadget);
+ struct usb_request *req = cdev->req;
+ int value = -EOPNOTSUPP;
+ u16 w_index = le16_to_cpu(ctrl->wIndex);
+ u16 w_value = le16_to_cpu(ctrl->wValue);
+ u16 w_length = le16_to_cpu(ctrl->wLength);
+ struct usb_function *f = NULL;
+
+ /* partial re-init of the response message; the function or the
+ * gadget might need to intercept e.g. a control-OUT completion
+ * when we delegate to it.
+ */
+ req->zero = 0;
+ req->complete = composite_setup_complete;
+ req->length = USB_BUFSIZ;
+ gadget->ep0->driver_data = cdev;
+
+ switch (ctrl->bRequest) {
+
+ /* we handle all standard USB descriptors */
+ case USB_REQ_GET_DESCRIPTOR:
+ if (ctrl->bRequestType != USB_DIR_IN)
+ goto unknown;
+ switch (w_value >> 8) {
+
+ case USB_DT_DEVICE:
+ cdev->desc.bNumConfigurations =
+ count_configs(cdev, USB_DT_DEVICE);
+ value = min(w_length, (u16) sizeof cdev->desc);
+ memcpy(req->buf, &cdev->desc, value);
+ break;
+ case USB_DT_DEVICE_QUALIFIER:
+ if (!gadget_is_dualspeed(gadget))
+ break;
+ device_qual(cdev);
+ value = min_t(int, w_length,
+ sizeof(struct usb_qualifier_descriptor));
+ break;
+ case USB_DT_OTHER_SPEED_CONFIG:
+ if (!gadget_is_dualspeed(gadget))
+ break;
+ /* FALLTHROUGH */
+ case USB_DT_CONFIG:
+ value = config_desc(cdev, w_value);
+ if (value >= 0)
+ value = min(w_length, (u16) value);
+ break;
+ case USB_DT_STRING:
+ value = get_string(cdev, req->buf,
+ w_index, w_value & 0xff);
+ if (value >= 0)
+ value = min(w_length, (u16) value);
+ break;
+ }
+ break;
+
+ /* any number of configs can work */
+ case USB_REQ_SET_CONFIGURATION:
+ if (ctrl->bRequestType != 0)
+ goto unknown;
+ if (gadget_is_otg(gadget)) {
+ if (gadget->a_hnp_support)
+ DBG(cdev, "HNP available\n");
+ else if (gadget->a_alt_hnp_support)
+ DBG(cdev, "HNP on another port\n");
+ else
+ VDBG(cdev, "HNP inactive\n");
+ }
+ spin_lock(&cdev->lock);
+ value = set_config(cdev, ctrl, w_value);
+ spin_unlock(&cdev->lock);
+ break;
+ case USB_REQ_GET_CONFIGURATION:
+ if (ctrl->bRequestType != USB_DIR_IN)
+ goto unknown;
+ if (cdev->config)
+ *(u8 *)req->buf = cdev->config->bConfigurationValue;
+ else
+ *(u8 *)req->buf = 0;
+ value = min(w_length, (u16) 1);
+ break;
+
+ /* function drivers must handle get/set altsetting; if there's
+ * no get() method, we know only altsetting zero works.
+ */
+ case USB_REQ_SET_INTERFACE:
+ if (ctrl->bRequestType != USB_RECIP_INTERFACE)
+ goto unknown;
+ if (!cdev->config || w_index >= MAX_CONFIG_INTERFACES)
+ break;
+ f = cdev->config->interface[w_index];
+ if (!f)
+ break;
+ if (w_value && !f->get_alt)
+ break;
+ value = f->set_alt(f, w_index, w_value);
+ break;
+ case USB_REQ_GET_INTERFACE:
+ if (ctrl->bRequestType != (USB_DIR_IN|USB_RECIP_INTERFACE))
+ goto unknown;
+ if (!cdev->config || w_index >= MAX_CONFIG_INTERFACES)
+ break;
+ f = cdev->config->interface[w_index];
+ if (!f)
+ break;
+ /* lots of interfaces only need altsetting zero... */
+ value = f->get_alt ? f->get_alt(f, w_index) : 0;
+ if (value < 0)
+ break;
+ *((u8 *)req->buf) = value;
+ value = min(w_length, (u16) 1);
+ break;
+ default:
+unknown:
+ VDBG(cdev,
+ "non-core control req%02x.%02x v%04x i%04x l%d\n",
+ ctrl->bRequestType, ctrl->bRequest,
+ w_value, w_index, w_length);
+
+ /* functions always handle their interfaces ... punt other
+ * recipients (endpoint, other, WUSB, ...) to the current
+ * configuration code.
+ *
+ * REVISIT it could make sense to let the composite device
+ * take such requests too, if that's ever needed: to work
+ * in config 0, etc.
+ */
+ if ((ctrl->bRequestType & USB_RECIP_MASK)
+ == USB_RECIP_INTERFACE) {
+ f = cdev->config->interface[w_index];
+ if (f && f->setup)
+ value = f->setup(f, ctrl);
+ else
+ f = NULL;
+ }
+ if (value < 0 && !f) {
+ struct usb_configuration *c;
+
+ c = cdev->config;
+ if (c && c->setup)
+ value = c->setup(c, ctrl);
+ }
+
+ goto done;
+ }
+
+ /* respond with data transfer before status phase? */
+ if (value >= 0) {
+ req->length = value;
+ req->zero = value < w_length;
+ value = usb_ep_queue(gadget->ep0, req, GFP_ATOMIC);
+ if (value < 0) {
+ DBG(cdev, "ep_queue --> %d\n", value);
+ req->status = 0;
+ composite_setup_complete(gadget->ep0, req);
+ }
+ }
+
+done:
+ /* device either stalls (value < 0) or reports success */
+ return value;
+}
+
+static void composite_disconnect(struct usb_gadget *gadget)
+{
+ struct usb_composite_dev *cdev = get_gadget_data(gadget);
+ unsigned long flags;
+
+ /* REVISIT: should we have config and device level
+ * disconnect callbacks?
+ */
+ spin_lock_irqsave(&cdev->lock, flags);
+ if (cdev->config)
+ reset_config(cdev);
+ spin_unlock_irqrestore(&cdev->lock, flags);
+}
+
+/*-------------------------------------------------------------------------*/
+
+static void /* __init_or_exit */
+composite_unbind(struct usb_gadget *gadget)
+{
+ struct usb_composite_dev *cdev = get_gadget_data(gadget);
+
+ /* composite_disconnect() must already have been called
+ * by the underlying peripheral controller driver!
+ * so there's no i/o concurrency that could affect the
+ * state protected by cdev->lock.
+ */
+ WARN_ON(cdev->config);
+
+ while (!list_empty(&cdev->configs)) {
+ struct usb_configuration *c;
+
+ c = list_first_entry(&cdev->configs,
+ struct usb_configuration, list);
+ while (!list_empty(&c->functions)) {
+ struct usb_function *f;
+
+ f = list_first_entry(&c->functions,
+ struct usb_function, list);
+ list_del(&f->list);
+ if (f->unbind) {
+ DBG(cdev, "unbind function '%s'/%p\n",
+ f->name, f);
+ f->unbind(c, f);
+ /* may free memory for "f" */
+ }
+ }
+ list_del(&c->list);
+ if (c->unbind) {
+ DBG(cdev, "unbind config '%s'/%p\n", c->label, c);
+ c->unbind(c);
+ /* may free memory for "c" */
+ }
+ }
+ if (composite->unbind)
+ composite->unbind(cdev);
+
+ if (cdev->req) {
+ kfree(cdev->req->buf);
+ usb_ep_free_request(gadget->ep0, cdev->req);
+ }
+ kfree(cdev);
+ set_gadget_data(gadget, NULL);
+ composite = NULL;
+}
+
+static void __init
+string_override_one(struct usb_gadget_strings *tab, u8 id, const char *s)
+{
+ struct usb_string *str = tab->strings;
+
+ for (str = tab->strings; str->s; str++) {
+ if (str->id == id) {
+ str->s = s;
+ return;
+ }
+ }
+}
+
+static void __init
+string_override(struct usb_gadget_strings **tab, u8 id, const char *s)
+{
+ while (*tab) {
+ string_override_one(*tab, id, s);
+ tab++;
+ }
+}
+
+static int __init composite_bind(struct usb_gadget *gadget)
+{
+ struct usb_composite_dev *cdev;
+ int status = -ENOMEM;
+
+ cdev = kzalloc(sizeof *cdev, GFP_KERNEL);
+ if (!cdev)
+ return status;
+
+ spin_lock_init(&cdev->lock);
+ cdev->gadget = gadget;
+ set_gadget_data(gadget, cdev);
+ INIT_LIST_HEAD(&cdev->configs);
+
+ /* preallocate control response and buffer */
+ cdev->req = usb_ep_alloc_request(gadget->ep0, GFP_KERNEL);
+ if (!cdev->req)
+ goto fail;
+ cdev->req->buf = kmalloc(USB_BUFSIZ, GFP_KERNEL);
+ if (!cdev->req->buf)
+ goto fail;
+ cdev->req->complete = composite_setup_complete;
+ gadget->ep0->driver_data = cdev;
+
+ cdev->bufsiz = USB_BUFSIZ;
+ cdev->driver = composite;
+
+ usb_gadget_set_selfpowered(gadget);
+
+ /* interface and string IDs start at zero via kzalloc.
+ * we force endpoints to start unassigned; few controller
+ * drivers will zero ep->driver_data.
+ */
+ usb_ep_autoconfig_reset(cdev->gadget);
+
+ /* composite gadget needs to assign strings for whole device (like
+ * serial number), register function drivers, potentially update
+ * power state and consumption, etc
+ */
+ status = composite->bind(cdev);
+ if (status < 0)
+ goto fail;
+
+ cdev->desc = *composite->dev;
+ cdev->desc.bMaxPacketSize0 = gadget->ep0->maxpacket;
+
+ /* standardized runtime overrides for device ID data */
+ if (idVendor)
+ cdev->desc.idVendor = cpu_to_le16(idVendor);
+ if (idProduct)
+ cdev->desc.idProduct = cpu_to_le16(idProduct);
+ if (bcdDevice)
+ cdev->desc.bcdDevice = cpu_to_le16(bcdDevice);
+
+ /* strings can't be assigned before bind() allocates the
+ * releavnt identifiers
+ */
+ if (cdev->desc.iManufacturer && iManufacturer)
+ string_override(composite->strings,
+ cdev->desc.iManufacturer, iManufacturer);
+ if (cdev->desc.iProduct && iProduct)
+ string_override(composite->strings,
+ cdev->desc.iProduct, iProduct);
+ if (cdev->desc.iSerialNumber && iSerialNumber)
+ string_override(composite->strings,
+ cdev->desc.iSerialNumber, iSerialNumber);
+
+ INFO(cdev, "%s ready\n", composite->name);
+ return 0;
+
+fail:
+ composite_unbind(gadget);
+ return status;
+}
+
+/*-------------------------------------------------------------------------*/
+
+static void
+composite_suspend(struct usb_gadget *gadget)
+{
+ struct usb_composite_dev *cdev = get_gadget_data(gadget);
+ struct usb_function *f;
+
+ /* REVISIT: should we have config and device level
+ * suspend/resume callbacks?
+ */
+ DBG(cdev, "suspend\n");
+ if (cdev->config) {
+ list_for_each_entry(f, &cdev->config->functions, list) {
+ if (f->suspend)
+ f->suspend(f);
+ }
+ }
+}
+
+static void
+composite_resume(struct usb_gadget *gadget)
+{
+ struct usb_composite_dev *cdev = get_gadget_data(gadget);
+ struct usb_function *f;
+
+ /* REVISIT: should we have config and device level
+ * suspend/resume callbacks?
+ */
+ DBG(cdev, "resume\n");
+ if (cdev->config) {
+ list_for_each_entry(f, &cdev->config->functions, list) {
+ if (f->resume)
+ f->resume(f);
+ }
+ }
+}
+
+/*-------------------------------------------------------------------------*/
+
+static struct usb_gadget_driver composite_driver = {
+ .speed = USB_SPEED_HIGH,
+
+ .bind = composite_bind,
+ .unbind = __exit_p(composite_unbind),
+
+ .setup = composite_setup,
+ .disconnect = composite_disconnect,
+
+ .suspend = composite_suspend,
+ .resume = composite_resume,
+
+ .driver = {
+ .owner = THIS_MODULE,
+ },
+};
+
+/**
+ * usb_composite_register() - register a composite driver
+ * @driver: the driver to register
+ * Context: single threaded during gadget setup
+ *
+ * This function is used to register drivers using the composite driver
+ * framework. The return value is zero, or a negative errno value.
+ * Those values normally come from the driver's @bind method, which does
+ * all the work of setting up the driver to match the hardware.
+ *
+ * On successful return, the gadget is ready to respond to requests from
+ * the host, unless one of its components invokes usb_gadget_disconnect()
+ * while it was binding. That would usually be done in order to wait for
+ * some userspace participation.
+ */
+int __init usb_composite_register(struct usb_composite_driver *driver)
+{
+ if (!driver || !driver->dev || !driver->bind || composite)
+ return -EINVAL;
+
+ if (!driver->name)
+ driver->name = "composite";
+ composite_driver.function = (char *) driver->name;
+ composite_driver.driver.name = driver->name;
+ composite = driver;
+
+ return usb_gadget_register_driver(&composite_driver);
+}
+
+/**
+ * usb_composite_unregister() - unregister a composite driver
+ * @driver: the driver to unregister
+ *
+ * This function is used to unregister drivers using the composite
+ * driver framework.
+ */
+void __exit usb_composite_unregister(struct usb_composite_driver *driver)
+{
+ if (composite != driver)
+ return;
+ usb_gadget_unregister_driver(&composite_driver);
+}