linux/drivers/usb/gadget/composite.c
David Brownell 60beed95e3 usb gadget: function activation/deactivation
Add a new mechanism to the composite gadget framework, letting
functions deactivate (and reactivate) themselves.  Think of it
as a refcounted wrapper for the software pullup control.

A key example of why to use this mechanism involves functions that
require a userspace daemon.  Those functions shuld use this new
mechanism to prevent the gadget from enumerating until those daemons
are activated.  Without this mechanism, hosts would see devices that
malfunction until the relevant daemons start.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-10-17 14:40:53 -07:00

1105 lines
29 KiB
C

/*
* 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_function_deactivate - prevent function and gadget enumeration
* @function: the function that isn't yet ready to respond
*
* Blocks response of the gadget driver to host enumeration by
* preventing the data line pullup from being activated. This is
* normally called during @bind() processing to change from the
* initial "ready to respond" state, or when a required resource
* becomes available.
*
* For example, drivers that serve as a passthrough to a userspace
* daemon can block enumeration unless that daemon (such as an OBEX,
* MTP, or print server) is ready to handle host requests.
*
* Not all systems support software control of their USB peripheral
* data pullups.
*
* Returns zero on success, else negative errno.
*/
int usb_function_deactivate(struct usb_function *function)
{
struct usb_composite_dev *cdev = function->config->cdev;
int status = 0;
spin_lock(&cdev->lock);
if (cdev->deactivations == 0)
status = usb_gadget_disconnect(cdev->gadget);
if (status == 0)
cdev->deactivations++;
spin_unlock(&cdev->lock);
return status;
}
/**
* usb_function_activate - allow function and gadget enumeration
* @function: function on which usb_function_activate() was called
*
* Reverses effect of usb_function_deactivate(). If no more functions
* are delaying their activation, the gadget driver will respond to
* host enumeration procedures.
*
* Returns zero on success, else negative errno.
*/
int usb_function_activate(struct usb_function *function)
{
struct usb_composite_dev *cdev = function->config->cdev;
int status = 0;
spin_lock(&cdev->lock);
if (WARN_ON(cdev->deactivations == 0))
status = -EINVAL;
else {
cdev->deactivations--;
if (cdev->deactivations == 0)
status = usb_gadget_connect(cdev->gadget);
}
spin_unlock(&cdev->lock);
return status;
}
/**
* 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);
qual->bRESERVED = 0;
}
/*-------------------------------------------------------------------------*/
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);
}