blob: 05b176c82cc522b7416b0379915af615b3eac4ec [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0+
/*
* composite.c - infrastructure for Composite USB Gadgets
*
* Copyright (C) 2006-2008 David Brownell
*/
/* #define VERBOSE_DEBUG */
#include <linux/kallsyms.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/utsname.h>
#include <linux/usb/composite.h>
#include <linux/usb/otg.h>
#include <asm/unaligned.h>
#include "u_os_desc.h"
/**
* struct usb_os_string - represents OS String to be reported by a gadget
* @bLength: total length of the entire descritor, always 0x12
* @bDescriptorType: USB_DT_STRING
* @qwSignature: the OS String proper
* @bMS_VendorCode: code used by the host for subsequent requests
* @bPad: not used, must be zero
*/
struct usb_os_string {
__u8 bLength;
__u8 bDescriptorType;
__u8 qwSignature[OS_STRING_QW_SIGN_LEN];
__u8 bMS_VendorCode;
__u8 bPad;
} __packed;
/*
* 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.
*/
static struct usb_gadget_strings **get_containers_gs(
struct usb_gadget_string_container *uc)
{
return (struct usb_gadget_strings **)uc->stash;
}
/**
* function_descriptors() - get function descriptors for speed
* @f: the function
* @speed: the speed
*
* Returns the descriptors or NULL if not set.
*/
static struct usb_descriptor_header **
function_descriptors(struct usb_function *f,
enum usb_device_speed speed)
{
struct usb_descriptor_header **descriptors;
/*
* NOTE: we try to help gadget drivers which might not be setting
* max_speed appropriately.
*/
switch (speed) {
case USB_SPEED_SUPER_PLUS:
descriptors = f->ssp_descriptors;
if (descriptors)
break;
fallthrough;
case USB_SPEED_SUPER:
descriptors = f->ss_descriptors;
if (descriptors)
break;
fallthrough;
case USB_SPEED_HIGH:
descriptors = f->hs_descriptors;
if (descriptors)
break;
fallthrough;
default:
descriptors = f->fs_descriptors;
}
/*
* if we can't find any descriptors at all, then this gadget deserves to
* Oops with a NULL pointer dereference
*/
return descriptors;
}
/**
* next_desc() - advance to the next desc_type descriptor
* @t: currect pointer within descriptor array
* @desc_type: descriptor type
*
* Return: next desc_type descriptor or NULL
*
* Iterate over @t until either desc_type descriptor found or
* NULL (that indicates end of list) encountered
*/
static struct usb_descriptor_header**
next_desc(struct usb_descriptor_header **t, u8 desc_type)
{
for (; *t; t++) {
if ((*t)->bDescriptorType == desc_type)
return t;
}
return NULL;
}
/*
* for_each_desc() - iterate over desc_type descriptors in the
* descriptors list
* @start: pointer within descriptor array.
* @iter_desc: desc_type descriptor to use as the loop cursor
* @desc_type: wanted descriptr type
*/
#define for_each_desc(start, iter_desc, desc_type) \
for (iter_desc = next_desc(start, desc_type); \
iter_desc; iter_desc = next_desc(iter_desc + 1, desc_type))
/**
* config_ep_by_speed_and_alt() - configures the given endpoint
* according to gadget speed.
* @g: pointer to the gadget
* @f: usb function
* @_ep: the endpoint to configure
* @alt: alternate setting number
*
* Return: error code, 0 on success
*
* This function chooses the right descriptors for a given
* endpoint according to gadget speed and saves it in the
* endpoint desc field. If the endpoint already has a descriptor
* assigned to it - overwrites it with currently corresponding
* descriptor. The endpoint maxpacket field is updated according
* to the chosen descriptor.
* Note: the supplied function should hold all the descriptors
* for supported speeds
*/
int config_ep_by_speed_and_alt(struct usb_gadget *g,
struct usb_function *f,
struct usb_ep *_ep,
u8 alt)
{
struct usb_endpoint_descriptor *chosen_desc = NULL;
struct usb_interface_descriptor *int_desc = NULL;
struct usb_descriptor_header **speed_desc = NULL;
struct usb_ss_ep_comp_descriptor *comp_desc = NULL;
int want_comp_desc = 0;
struct usb_descriptor_header **d_spd; /* cursor for speed desc */
if (!g || !f || !_ep)
return -EIO;
/* select desired speed */
switch (g->speed) {
case USB_SPEED_SUPER_PLUS:
if (gadget_is_superspeed_plus(g)) {
speed_desc = f->ssp_descriptors;
want_comp_desc = 1;
break;
}
fallthrough;
case USB_SPEED_SUPER:
if (gadget_is_superspeed(g)) {
speed_desc = f->ss_descriptors;
want_comp_desc = 1;
break;
}
fallthrough;
case USB_SPEED_HIGH:
if (gadget_is_dualspeed(g)) {
speed_desc = f->hs_descriptors;
break;
}
fallthrough;
default:
speed_desc = f->fs_descriptors;
}
/* find correct alternate setting descriptor */
for_each_desc(speed_desc, d_spd, USB_DT_INTERFACE) {
int_desc = (struct usb_interface_descriptor *)*d_spd;
if (int_desc->bAlternateSetting == alt) {
speed_desc = d_spd;
goto intf_found;
}
}
return -EIO;
intf_found:
/* find descriptors */
for_each_desc(speed_desc, d_spd, USB_DT_ENDPOINT) {
chosen_desc = (struct usb_endpoint_descriptor *)*d_spd;
if (chosen_desc->bEndpointAddress == _ep->address)
goto ep_found;
}
return -EIO;
ep_found:
/* commit results */
_ep->maxpacket = usb_endpoint_maxp(chosen_desc);
_ep->desc = chosen_desc;
_ep->comp_desc = NULL;
_ep->maxburst = 0;
_ep->mult = 1;
if (g->speed == USB_SPEED_HIGH && (usb_endpoint_xfer_isoc(_ep->desc) ||
usb_endpoint_xfer_int(_ep->desc)))
_ep->mult = usb_endpoint_maxp_mult(_ep->desc);
if (!want_comp_desc)
return 0;
/*
* Companion descriptor should follow EP descriptor
* USB 3.0 spec, #9.6.7
*/
comp_desc = (struct usb_ss_ep_comp_descriptor *)*(++d_spd);
if (!comp_desc ||
(comp_desc->bDescriptorType != USB_DT_SS_ENDPOINT_COMP))
return -EIO;
_ep->comp_desc = comp_desc;
if (g->speed >= USB_SPEED_SUPER) {
switch (usb_endpoint_type(_ep->desc)) {
case USB_ENDPOINT_XFER_ISOC:
/* mult: bits 1:0 of bmAttributes */
_ep->mult = (comp_desc->bmAttributes & 0x3) + 1;
fallthrough;
case USB_ENDPOINT_XFER_BULK:
case USB_ENDPOINT_XFER_INT:
_ep->maxburst = comp_desc->bMaxBurst + 1;
break;
default:
if (comp_desc->bMaxBurst != 0) {
struct usb_composite_dev *cdev;
cdev = get_gadget_data(g);
ERROR(cdev, "ep0 bMaxBurst must be 0\n");
}
_ep->maxburst = 1;
break;
}
}
return 0;
}
EXPORT_SYMBOL_GPL(config_ep_by_speed_and_alt);
/**
* config_ep_by_speed() - configures the given endpoint
* according to gadget speed.
* @g: pointer to the gadget
* @f: usb function
* @_ep: the endpoint to configure
*
* Return: error code, 0 on success
*
* This function chooses the right descriptors for a given
* endpoint according to gadget speed and saves it in the
* endpoint desc field. If the endpoint already has a descriptor
* assigned to it - overwrites it with currently corresponding
* descriptor. The endpoint maxpacket field is updated according
* to the chosen descriptor.
* Note: the supplied function should hold all the descriptors
* for supported speeds
*/
int config_ep_by_speed(struct usb_gadget *g,
struct usb_function *f,
struct usb_ep *_ep)
{
return config_ep_by_speed_and_alt(g, f, _ep, 0);
}
EXPORT_SYMBOL_GPL(config_ep_by_speed);
/**
* 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 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);
if (function->bind_deactivated) {
value = usb_function_deactivate(function);
if (value)
goto done;
}
/* 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->fs_descriptors)
config->fullspeed = true;
if (!config->highspeed && function->hs_descriptors)
config->highspeed = true;
if (!config->superspeed && function->ss_descriptors)
config->superspeed = true;
if (!config->superspeed_plus && function->ssp_descriptors)
config->superspeed_plus = true;
done:
if (value)
DBG(config->cdev, "adding '%s'/%p --> %d\n",
function->name, function, value);
return value;
}
EXPORT_SYMBOL_GPL(usb_add_function);
void usb_remove_function(struct usb_configuration *c, struct usb_function *f)
{
if (f->disable)
f->disable(f);
bitmap_zero(f->endpoints, 32);
list_del(&f->list);
if (f->unbind)
f->unbind(c, f);
if (f->bind_deactivated)
usb_function_activate(f);
}
EXPORT_SYMBOL_GPL(usb_remove_function);
/**
* 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;
unsigned long flags;
int status = 0;
spin_lock_irqsave(&cdev->lock, flags);
if (cdev->deactivations == 0)
status = usb_gadget_deactivate(cdev->gadget);
if (status == 0)
cdev->deactivations++;
spin_unlock_irqrestore(&cdev->lock, flags);
return status;
}
EXPORT_SYMBOL_GPL(usb_function_deactivate);
/**
* 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;
unsigned long flags;
int status = 0;
spin_lock_irqsave(&cdev->lock, flags);
if (WARN_ON(cdev->deactivations == 0))
status = -EINVAL;
else {
cdev->deactivations--;
if (cdev->deactivations == 0)
status = usb_gadget_activate(cdev->gadget);
}
spin_unlock_irqrestore(&cdev->lock, flags);
return status;
}
EXPORT_SYMBOL_GPL(usb_function_activate);
/**
* 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 targeted 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
* identifiers 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 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;
}
EXPORT_SYMBOL_GPL(usb_interface_id);
static u8 encode_bMaxPower(enum usb_device_speed speed,
struct usb_configuration *c)
{
unsigned val;
if (c->MaxPower)
val = c->MaxPower;
else
val = CONFIG_USB_GADGET_VBUS_DRAW;
if (!val)
return 0;
if (speed < USB_SPEED_SUPER)
return min(val, 500U) / 2;
else
/*
* USB 3.x supports up to 900mA, but since 900 isn't divisible
* by 8 the integral division will effectively cap to 896mA.
*/
return min(val, 900U) / 8;
}
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;
struct usb_function *f;
int status;
len = USB_COMP_EP0_BUFSIZ - USB_DT_CONFIG_SIZE;
/* 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 = encode_bMaxPower(speed, config);
/* 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;
descriptors = function_descriptors(f, speed);
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;
struct list_head *pos;
u8 type = w_value >> 8;
enum usb_device_speed speed = USB_SPEED_UNKNOWN;
if (gadget->speed >= USB_SPEED_SUPER)
speed = gadget->speed;
else 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;
pos = &cdev->configs;
c = cdev->os_desc_config;
if (c)
goto check_config;
while ((pos = pos->next) != &cdev->configs) {
c = list_entry(pos, typeof(*c), list);
/* skip OS Descriptors config which is handled separately */
if (c == cdev->os_desc_config)
continue;
check_config:
/* ignore configs that won't work at this speed */
switch (speed) {
case USB_SPEED_SUPER_PLUS:
if (!c->superspeed_plus)
continue;
break;
case USB_SPEED_SUPER:
if (!c->superspeed)
continue;
break;
case USB_SPEED_HIGH:
if (!c->highspeed)
continue;
break;
default:
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;
int ss = 0;
int ssp = 0;
if (gadget_is_dualspeed(gadget)) {
if (gadget->speed == USB_SPEED_HIGH)
hs = 1;
if (gadget->speed == USB_SPEED_SUPER)
ss = 1;
if (gadget->speed == USB_SPEED_SUPER_PLUS)
ssp = 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 (ssp) {
if (!c->superspeed_plus)
continue;
} else if (ss) {
if (!c->superspeed)
continue;
} else if (hs) {
if (!c->highspeed)
continue;
} else {
if (!c->fullspeed)
continue;
}
count++;
}
return count;
}
/**
* bos_desc() - prepares the BOS descriptor.
* @cdev: pointer to usb_composite device to generate the bos
* descriptor for
*
* This function generates the BOS (Binary Device Object)
* descriptor and its device capabilities descriptors. The BOS
* descriptor should be supported by a SuperSpeed device.
*/
static int bos_desc(struct usb_composite_dev *cdev)
{
struct usb_ext_cap_descriptor *usb_ext;
struct usb_dcd_config_params dcd_config_params;
struct usb_bos_descriptor *bos = cdev->req->buf;
unsigned int besl = 0;
bos->bLength = USB_DT_BOS_SIZE;
bos->bDescriptorType = USB_DT_BOS;
bos->wTotalLength = cpu_to_le16(USB_DT_BOS_SIZE);
bos->bNumDeviceCaps = 0;
/* Get Controller configuration */
if (cdev->gadget->ops->get_config_params) {
cdev->gadget->ops->get_config_params(cdev->gadget,
&dcd_config_params);
} else {
dcd_config_params.besl_baseline =
USB_DEFAULT_BESL_UNSPECIFIED;
dcd_config_params.besl_deep =
USB_DEFAULT_BESL_UNSPECIFIED;
dcd_config_params.bU1devExitLat =
USB_DEFAULT_U1_DEV_EXIT_LAT;
dcd_config_params.bU2DevExitLat =
cpu_to_le16(USB_DEFAULT_U2_DEV_EXIT_LAT);
}
if (dcd_config_params.besl_baseline != USB_DEFAULT_BESL_UNSPECIFIED)
besl = USB_BESL_BASELINE_VALID |
USB_SET_BESL_BASELINE(dcd_config_params.besl_baseline);
if (dcd_config_params.besl_deep != USB_DEFAULT_BESL_UNSPECIFIED)
besl |= USB_BESL_DEEP_VALID |
USB_SET_BESL_DEEP(dcd_config_params.besl_deep);
/*
* A SuperSpeed device shall include the USB2.0 extension descriptor
* and shall support LPM when operating in USB2.0 HS mode.
*/
usb_ext = cdev->req->buf + le16_to_cpu(bos->wTotalLength);
bos->bNumDeviceCaps++;
le16_add_cpu(&bos->wTotalLength, USB_DT_USB_EXT_CAP_SIZE);
usb_ext->bLength = USB_DT_USB_EXT_CAP_SIZE;
usb_ext->bDescriptorType = USB_DT_DEVICE_CAPABILITY;
usb_ext->bDevCapabilityType = USB_CAP_TYPE_EXT;
usb_ext->bmAttributes = cpu_to_le32(USB_LPM_SUPPORT |
USB_BESL_SUPPORT | besl);
/*
* The Superspeed USB Capability descriptor shall be implemented by all
* SuperSpeed devices.
*/
if (gadget_is_superspeed(cdev->gadget)) {
struct usb_ss_cap_descriptor *ss_cap;
ss_cap = cdev->req->buf + le16_to_cpu(bos->wTotalLength);
bos->bNumDeviceCaps++;
le16_add_cpu(&bos->wTotalLength, USB_DT_USB_SS_CAP_SIZE);
ss_cap->bLength = USB_DT_USB_SS_CAP_SIZE;
ss_cap->bDescriptorType = USB_DT_DEVICE_CAPABILITY;
ss_cap->bDevCapabilityType = USB_SS_CAP_TYPE;
ss_cap->bmAttributes = 0; /* LTM is not supported yet */
ss_cap->wSpeedSupported = cpu_to_le16(USB_LOW_SPEED_OPERATION |
USB_FULL_SPEED_OPERATION |
USB_HIGH_SPEED_OPERATION |
USB_5GBPS_OPERATION);
ss_cap->bFunctionalitySupport = USB_LOW_SPEED_OPERATION;
ss_cap->bU1devExitLat = dcd_config_params.bU1devExitLat;
ss_cap->bU2DevExitLat = dcd_config_params.bU2DevExitLat;
}
/* The SuperSpeedPlus USB Device Capability descriptor */
if (gadget_is_superspeed_plus(cdev->gadget)) {
struct usb_ssp_cap_descriptor *ssp_cap;
ssp_cap = cdev->req->buf + le16_to_cpu(bos->wTotalLength);
bos->bNumDeviceCaps++;
/*
* Report typical values.
*/
le16_add_cpu(&bos->wTotalLength, USB_DT_USB_SSP_CAP_SIZE(1));
ssp_cap->bLength = USB_DT_USB_SSP_CAP_SIZE(1);
ssp_cap->bDescriptorType = USB_DT_DEVICE_CAPABILITY;
ssp_cap->bDevCapabilityType = USB_SSP_CAP_TYPE;
ssp_cap->bReserved = 0;
ssp_cap->wReserved = 0;
/* SSAC = 1 (2 attributes) */
ssp_cap->bmAttributes = cpu_to_le32(1);
/* Min RX/TX Lane Count = 1 */
ssp_cap->wFunctionalitySupport =
cpu_to_le16((1 << 8) | (1 << 12));
/*
* bmSublinkSpeedAttr[0]:
* ST = Symmetric, RX
* LSE = 3 (Gbps)
* LP = 1 (SuperSpeedPlus)
* LSM = 10 (10 Gbps)
*/
ssp_cap->bmSublinkSpeedAttr[0] =
cpu_to_le32((3 << 4) | (1 << 14) | (0xa << 16));
/*
* bmSublinkSpeedAttr[1] =
* ST = Symmetric, TX
* LSE = 3 (Gbps)
* LP = 1 (SuperSpeedPlus)
* LSM = 10 (10 Gbps)
*/
ssp_cap->bmSublinkSpeedAttr[1] =
cpu_to_le32((3 << 4) | (1 << 14) |
(0xa << 16) | (1 << 7));
}
return le16_to_cpu(bos->wTotalLength);
}
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->gadget->ep0->maxpacket;
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);
bitmap_zero(f->endpoints, 32);
}
cdev->config = NULL;
cdev->delayed_status = 0;
}
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 (number) {
list_for_each_entry(c, &cdev->configs, list) {
if (c->bConfigurationValue == number) {
/*
* We disable the FDs of the previous
* configuration only if the new configuration
* is a valid one
*/
if (cdev->config)
reset_config(cdev);
result = 0;
break;
}
}
if (result < 0)
goto done;
} else { /* Zero configuration value - need to reset the config */
if (cdev->config)
reset_config(cdev);
result = 0;
}
DBG(cdev, "%s config #%d: %s\n",
usb_speed_string(gadget->speed),
number, c ? c->label : "unconfigured");
if (!c)
goto done;
usb_gadget_set_state(gadget, USB_STATE_CONFIGURED);
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];
struct usb_descriptor_header **descriptors;
if (!f)
break;
/*
* Record which endpoints are used by the function. This is used
* to dispatch control requests targeted at that endpoint to the
* function's setup callback instead of the current
* configuration's setup callback.
*/
descriptors = function_descriptors(f, gadget->speed);
for (; *descriptors; ++descriptors) {
struct usb_endpoint_descriptor *ep;
int addr;
if ((*descriptors)->bDescriptorType != USB_DT_ENDPOINT)
continue;
ep = (struct usb_endpoint_descriptor *)*descriptors;
addr = ((ep->bEndpointAddress & 0x80) >> 3)
| (ep->bEndpointAddress & 0x0f);
set_bit(addr, f->endpoints);
}
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;
}
if (result == USB_GADGET_DELAYED_STATUS) {
DBG(cdev,
"%s: interface %d (%s) requested delayed status\n",
__func__, tmp, f->name);
cdev->delayed_status++;
DBG(cdev, "delayed_status count %d\n",
cdev->delayed_status);
}
}
/* when we return, be sure our power usage is valid */
power = c->MaxPower ? c->MaxPower : CONFIG_USB_GADGET_VBUS_DRAW;
if (gadget->speed < USB_SPEED_SUPER)
power = min(power, 500U);
else
power = min(power, 900U);
done:
if (power <= USB_SELF_POWER_VBUS_MAX_DRAW)
usb_gadget_set_selfpowered(gadget);
else
usb_gadget_clear_selfpowered(gadget);
usb_gadget_vbus_draw(gadget, power);
if (result >= 0 && cdev->delayed_status)
result = USB_GADGET_DELAYED_STATUS;
return result;
}
int usb_add_config_only(struct usb_composite_dev *cdev,
struct usb_configuration *config)
{
struct usb_configuration *c;
if (!config->bConfigurationValue)
return -EINVAL;
/* Prevent duplicate configuration identifiers */
list_for_each_entry(c, &cdev->configs, list) {
if (c->bConfigurationValue == config->bConfigurationValue)
return -EBUSY;
}
config->cdev = cdev;
list_add_tail(&config->list, &cdev->configs);
INIT_LIST_HEAD(&config->functions);
config->next_interface_id = 0;
memset(config->interface, 0, sizeof(config->interface));
return 0;
}
EXPORT_SYMBOL_GPL(usb_add_config_only);
/**
* usb_add_config() - add a configuration to a device.
* @cdev: wraps the USB gadget
* @config: the configuration, with bConfigurationValue assigned
* @bind: the configuration's bind function
* Context: single threaded during gadget setup
*
* One of the main tasks of a composite @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 usb_add_config(struct usb_composite_dev *cdev,
struct usb_configuration *config,
int (*bind)(struct usb_configuration *))
{
int status = -EINVAL;
if (!bind)
goto done;
DBG(cdev, "adding config #%u '%s'/%p\n",
config->bConfigurationValue,
config->label, config);
status = usb_add_config_only(cdev, config);
if (status)
goto done;
status = bind(config);
if (status < 0) {
while (!list_empty(&config->functions)) {
struct usb_function *f;
f = list_first_entry(&config->functions,
struct usb_function, list);
list_del(&f->list);
if (f->unbind) {
DBG(cdev, "unbind function '%s'/%p\n",
f->name, f);
f->unbind(config, f);
/* may free memory for "f" */
}
}
list_del(&config->list);
config->cdev = NULL;
} else {
unsigned i;
DBG(cdev, "cfg %d/%p speeds:%s%s%s%s\n",
config->bConfigurationValue, config,
config->superspeed_plus ? " superplus" : "",
config->superspeed ? " super" : "",
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 bind(), sets up ep->claimed 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;
}
EXPORT_SYMBOL_GPL(usb_add_config);
static void remove_config(struct usb_composite_dev *cdev,
struct usb_configuration *config)
{
while (!list_empty(&config->functions)) {
struct usb_function *f;
f = list_first_entry(&config->functions,
struct usb_function, list);
usb_remove_function(config, f);
}
list_del(&config->list);
if (config->unbind) {
DBG(cdev, "unbind config '%s'/%p\n", config->label, config);
config->unbind(config);
/* may free memory for "c" */
}
}
/**
* usb_remove_config() - remove a configuration from a device.
* @cdev: wraps the USB gadget
* @config: the configuration
*
* Drivers must call usb_gadget_disconnect before calling this function
* to disconnect the device from the host and make sure the host will not
* try to enumerate the device while we are changing the config list.
*/
void usb_remove_config(struct usb_composite_dev *cdev,
struct usb_configuration *config)
{
unsigned long flags;
spin_lock_irqsave(&cdev->lock, flags);
if (cdev->config == config)
reset_config(cdev);
spin_unlock_irqrestore(&cdev->lock, flags);
remove_config(cdev, config);
}
/*-------------------------------------------------------------------------*/
/* 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;
__le16 language;
__le16 *tmp;
while (*sp) {
s = *sp;
language = cpu_to_le16(s->language);
for (tmp = buf; *tmp && tmp < &buf[USB_MAX_STRING_LEN]; 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_composite_driver *composite = cdev->driver;
struct usb_gadget_string_container *uc;
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);
}
}
list_for_each_entry(uc, &cdev->gstrings, list) {
struct usb_gadget_strings **sp;
sp = get_containers_gs(uc);
collect_langs(sp, s->wData);
}
for (len = 0; len <= USB_MAX_STRING_LEN && s->wData[len]; len++)
continue;
if (!len)
return -EINVAL;
s->bLength = 2 * (len + 1);
return s->bLength;
}
if (cdev->use_os_string && language == 0 && id == OS_STRING_IDX) {
struct usb_os_string *b = buf;
b->bLength = sizeof(*b);
b->bDescriptorType = USB_DT_STRING;
compiletime_assert(
sizeof(b->qwSignature) == sizeof(cdev->qw_sign),
"qwSignature size must be equal to qw_sign");
memcpy(&b->qwSignature, cdev->qw_sign, sizeof(b->qwSignature));
b->bMS_VendorCode = cdev->b_vendor_code;
b->bPad = 0;
return sizeof(*b);
}
list_for_each_entry(uc, &cdev->gstrings, list) {
struct usb_gadget_strings **sp;
sp = get_containers_gs(uc);
len = lookup_string(sp, buf, language, id);
if (len > 0)
return len;
}
/* 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,
* @usb_string_ids_tab() or @usb_string_ids_n() routine, to ensure
* that for example different functions don't wrongly assign different
* meanings to the same identifier.
*/
int usb_string_id(struct usb_composite_dev *cdev)
{
if (cdev->next_string_id < 254) {
/* string id 0 is reserved by USB spec for list of
* supported languages */
/* 255 reserved as well? -- mina86 */
cdev->next_string_id++;
return cdev->next_string_id;
}
return -ENODEV;
}
EXPORT_SYMBOL_GPL(usb_string_id);
/**
* usb_string_ids() - allocate unused string IDs in batch
* @cdev: the device whose string descriptor IDs are being allocated
* @str: an array of usb_string objects to assign numbers to
* Context: single threaded during gadget setup
*
* @usb_string_ids() is called from bind() callbacks to allocate
* string IDs. Drivers for functions, configurations, or gadgets will
* then copy IDs from the string table to the appropriate descriptors
* and string table for other languages.
*
* All string identifier should be allocated using this,
* @usb_string_id() or @usb_string_ids_n() routine, to ensure that for
* example different functions don't wrongly assign different meanings
* to the same identifier.
*/
int usb_string_ids_tab(struct usb_composite_dev *cdev, struct usb_string *str)
{
int next = cdev->next_string_id;
for (; str->s; ++str) {
if (unlikely(next >= 254))
return -ENODEV;
str->id = ++next;
}
cdev->next_string_id = next;
return 0;
}
EXPORT_SYMBOL_GPL(usb_string_ids_tab);
static struct usb_gadget_string_container *copy_gadget_strings(
struct usb_gadget_strings **sp, unsigned n_gstrings,
unsigned n_strings)
{
struct usb_gadget_string_container *uc;
struct usb_gadget_strings **gs_array;
struct usb_gadget_strings *gs;
struct usb_string *s;
unsigned mem;
unsigned n_gs;
unsigned n_s;
void *stash;
mem = sizeof(*uc);
mem += sizeof(void *) * (n_gstrings + 1);
mem += sizeof(struct usb_gadget_strings) * n_gstrings;
mem += sizeof(struct usb_string) * (n_strings + 1) * (n_gstrings);
uc = kmalloc(mem, GFP_KERNEL);
if (!uc)
return ERR_PTR(-ENOMEM);
gs_array = get_containers_gs(uc);
stash = uc->stash;
stash += sizeof(void *) * (n_gstrings + 1);
for (n_gs = 0; n_gs < n_gstrings; n_gs++) {
struct usb_string *org_s;
gs_array[n_gs] = stash;
gs = gs_array[n_gs];
stash += sizeof(struct usb_gadget_strings);
gs->language = sp[n_gs]->language;
gs->strings = stash;
org_s = sp[n_gs]->strings;
for (n_s = 0; n_s < n_strings; n_s++) {
s = stash;
stash += sizeof(struct usb_string);
if (org_s->s)
s->s = org_s->s;
else
s->s = "";
org_s++;
}
s = stash;
s->s = NULL;
stash += sizeof(struct usb_string);
}
gs_array[n_gs] = NULL;
return uc;
}
/**
* usb_gstrings_attach() - attach gadget strings to a cdev and assign ids
* @cdev: the device whose string descriptor IDs are being allocated
* and attached.
* @sp: an array of usb_gadget_strings to attach.
* @n_strings: number of entries in each usb_strings array (sp[]->strings)
*
* This function will create a deep copy of usb_gadget_strings and usb_string
* and attach it to the cdev. The actual string (usb_string.s) will not be
* copied but only a referenced will be made. The struct usb_gadget_strings
* array may contain multiple languages and should be NULL terminated.
* The ->language pointer of each struct usb_gadget_strings has to contain the
* same amount of entries.
* For instance: sp[0] is en-US, sp[1] is es-ES. It is expected that the first
* usb_string entry of es-ES contains the translation of the first usb_string
* entry of en-US. Therefore both entries become the same id assign.
*/
struct usb_string *usb_gstrings_attach(struct usb_composite_dev *cdev,
struct usb_gadget_strings **sp, unsigned n_strings)
{
struct usb_gadget_string_container *uc;
struct usb_gadget_strings **n_gs;
unsigned n_gstrings = 0;
unsigned i;
int ret;
for (i = 0; sp[i]; i++)
n_gstrings++;
if (!n_gstrings)
return ERR_PTR(-EINVAL);
uc = copy_gadget_strings(sp, n_gstrings, n_strings);
if (IS_ERR(uc))
return ERR_CAST(uc);
n_gs = get_containers_gs(uc);
ret = usb_string_ids_tab(cdev, n_gs[0]->strings);
if (ret)
goto err;
for (i = 1; i < n_gstrings; i++) {
struct usb_string *m_s;
struct usb_string *s;
unsigned n;
m_s = n_gs[0]->strings;
s = n_gs[i]->strings;
for (n = 0; n < n_strings; n++) {
s->id = m_s->id;
s++;
m_s++;
}
}
list_add_tail(&uc->list, &cdev->gstrings);
return n_gs[0]->strings;
err:
kfree(uc);
return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(usb_gstrings_attach);
/**
* usb_string_ids_n() - allocate unused string IDs in batch
* @c: the device whose string descriptor IDs are being allocated
* @n: number of string IDs to allocate
* Context: single threaded during gadget setup
*
* Returns the first requested ID. This ID and next @n-1 IDs are now
* valid IDs. At least provided that @n is non-zero because if it
* is, returns last requested ID which is now very useful information.
*
* @usb_string_ids_n() 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,
* @usb_string_id() or @usb_string_ids_n() routine, to ensure that for
* example different functions don't wrongly assign different meanings
* to the same identifier.
*/
int usb_string_ids_n(struct usb_composite_dev *c, unsigned n)
{
unsigned next = c->next_string_id;
if (unlikely(n > 254 || (unsigned)next + n > 254))
return -ENODEV;
c->next_string_id += n;
return next + 1;
}
EXPORT_SYMBOL_GPL(usb_string_ids_n);
/*-------------------------------------------------------------------------*/
static void composite_setup_complete(struct usb_ep *ep, struct usb_request *req)
{
struct usb_composite_dev *cdev;
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);
/*
* REVIST The same ep0 requests are shared with function drivers
* so they don't have to maintain the same ->complete() stubs.
*
* Because of that, we need to check for the validity of ->context
* here, even though we know we've set it to something useful.
*/
if (!req->context)
return;
cdev = req->context;
if (cdev->req == req)
cdev->setup_pending = false;
else if (cdev->os_desc_req == req)
cdev->os_desc_pending = false;
else
WARN(1, "unknown request %p\n", req);
}
static int composite_ep0_queue(struct usb_composite_dev *cdev,
struct usb_request *req, gfp_t gfp_flags)
{
int ret;
ret = usb_ep_queue(cdev->gadget->ep0, req, gfp_flags);
if (ret == 0) {
if (cdev->req == req)
cdev->setup_pending = true;
else if (cdev->os_desc_req == req)
cdev->os_desc_pending = true;
else
WARN(1, "unknown request %p\n", req);
}
return ret;
}
static int count_ext_compat(struct usb_configuration *c)
{
int i, res;
res = 0;
for (i = 0; i < c->next_interface_id; ++i) {
struct usb_function *f;
int j;
f = c->interface[i];
for (j = 0; j < f->os_desc_n; ++j) {
struct usb_os_desc *d;
if (i != f->os_desc_table[j].if_id)
continue;
d = f->os_desc_table[j].os_desc;
if (d && d->ext_compat_id)
++res;
}
}
BUG_ON(res > 255);
return res;
}
static int fill_ext_compat(struct usb_configuration *c, u8 *buf)
{
int i, count;
count = 16;
buf += 16;
for (i = 0; i < c->next_interface_id; ++i) {
struct usb_function *f;
int j;
f = c->interface[i];
for (j = 0; j < f->os_desc_n; ++j) {
struct usb_os_desc *d;
if (i != f->os_desc_table[j].if_id)
continue;
d = f->os_desc_table[j].os_desc;
if (d && d->ext_compat_id) {
*buf++ = i;
*buf++ = 0x01;
memcpy(buf, d->ext_compat_id, 16);
buf += 22;
} else {
++buf;
*buf = 0x01;
buf += 23;
}
count += 24;
if (count + 24 >= USB_COMP_EP0_OS_DESC_BUFSIZ)
return count;
}
}
return count;
}
static int count_ext_prop(struct usb_configuration *c, int interface)
{
struct usb_function *f;
int j;
f = c->interface[interface];
for (j = 0; j < f->os_desc_n; ++j) {
struct usb_os_desc *d;
if (interface != f->os_desc_table[j].if_id)
continue;
d = f->os_desc_table[j].os_desc;
if (d && d->ext_compat_id)
return d->ext_prop_count;
}
return 0;
}
static int len_ext_prop(struct usb_configuration *c, int interface)
{
struct usb_function *f;
struct usb_os_desc *d;
int j, res;
res = 10; /* header length */
f = c->interface[interface];
for (j = 0; j < f->os_desc_n; ++j) {
if (interface != f->os_desc_table[j].if_id)
continue;
d = f->os_desc_table[j].os_desc;
if (d)
return min(res + d->ext_prop_len, 4096);
}
return res;
}
static int fill_ext_prop(struct usb_configuration *c, int interface, u8 *buf)
{
struct usb_function *f;
struct usb_os_desc *d;
struct usb_os_desc_ext_prop *ext_prop;
int j, count, n, ret;
f = c->interface[interface];
count = 10; /* header length */
buf += 10;
for (j = 0; j < f->os_desc_n; ++j) {
if (interface != f->os_desc_table[j].if_id)
continue;
d = f->os_desc_table[j].os_desc;
if (d)
list_for_each_entry(ext_prop, &d->ext_prop, entry) {
n = ext_prop->data_len +
ext_prop->name_len + 14;
if (count + n >= USB_COMP_EP0_OS_DESC_BUFSIZ)
return count;
usb_ext_prop_put_size(buf, n);
usb_ext_prop_put_type(buf, ext_prop->type);
ret = usb_ext_prop_put_name(buf, ext_prop->name,
ext_prop->name_len);
if (ret < 0)
return ret;
switch (ext_prop->type) {
case USB_EXT_PROP_UNICODE:
case USB_EXT_PROP_UNICODE_ENV:
case USB_EXT_PROP_UNICODE_LINK:
usb_ext_prop_put_unicode(buf, ret,
ext_prop->data,
ext_prop->data_len);
break;
case USB_EXT_PROP_BINARY:
usb_ext_prop_put_binary(buf, ret,
ext_prop->data,
ext_prop->data_len);
break;
case USB_EXT_PROP_LE32:
/* not implemented */
case USB_EXT_PROP_BE32:
/* not implemented */
default:
return -EINVAL;
}
buf += n;
count += n;
}
}
return count;
}
/*
* 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.
*/
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;
int status = 0;
u16 w_index = le16_to_cpu(ctrl->wIndex);
u8 intf = w_index & 0xFF;
u16 w_value = le16_to_cpu(ctrl->wValue);
u16 w_length = le16_to_cpu(ctrl->wLength);
struct usb_function *f = NULL;
u8 endp;
/* 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->context = cdev;
req->complete = composite_setup_complete;
req->length = 0;
gadget->ep0->driver_data = cdev;
/*
* Don't let non-standard requests match any of the cases below
* by accident.
*/
if ((ctrl->bRequestType & USB_TYPE_MASK) != USB_TYPE_STANDARD)
goto unknown;
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);
cdev->desc.bMaxPacketSize0 =
cdev->gadget->ep0->maxpacket;
if (gadget_is_superspeed(gadget)) {
if (gadget->speed >= USB_SPEED_SUPER) {
cdev->desc.bcdUSB = cpu_to_le16(0x0320);
cdev->desc.bMaxPacketSize0 = 9;
} else {
cdev->desc.bcdUSB = cpu_to_le16(0x0210);
}
} else {
if (gadget->lpm_capable)
cdev->desc.bcdUSB = cpu_to_le16(0x0201);
else
cdev->desc.bcdUSB = cpu_to_le16(0x0200);
}
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) ||
gadget->speed >= USB_SPEED_SUPER)
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) ||
gadget->speed >= USB_SPEED_SUPER)
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;
case USB_DT_BOS:
if (gadget_is_superspeed(gadget) ||
gadget->lpm_capable) {
value = bos_desc(cdev);
value = min(w_length, (u16) value);
}
break;
case USB_DT_OTG:
if (gadget_is_otg(gadget)) {
struct usb_configuration *config;
int otg_desc_len = 0;
if (cdev->config)
config = cdev->config;
else
config = list_first_entry(
&cdev->configs,
struct usb_configuration, list);
if (!config)
goto done;
if (gadget->otg_caps &&
(gadget->otg_caps->otg_rev >= 0x0200))
otg_desc_len += sizeof(
struct usb_otg20_descriptor);
else
otg_desc_len += sizeof(
struct usb_otg_descriptor);
value = min_t(int, w_length, otg_desc_len);
memcpy(req->buf, config->descriptors[0], 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 */
case USB_REQ_SET_INTERFACE:
if (ctrl->bRequestType != USB_RECIP_INTERFACE)
goto unknown;
if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
break;
f = cdev->config->interface[intf];
if (!f)
break;
/*
* If there's no get_alt() method, we know only altsetting zero
* works. There is no need to check if set_alt() is not NULL
* as we check this in usb_add_function().
*/
if (w_value && !f->get_alt)
break;
spin_lock(&cdev->lock);
value = f->set_alt(f, w_index, w_value);
if (value == USB_GADGET_DELAYED_STATUS) {
DBG(cdev,
"%s: interface %d (%s) requested delayed status\n",
__func__, intf, f->name);
cdev->delayed_status++;
DBG(cdev, "delayed_status count %d\n",
cdev->delayed_status);
}
spin_unlock(&cdev->lock);
break;
case USB_REQ_GET_INTERFACE:
if (ctrl->bRequestType != (USB_DIR_IN|USB_RECIP_INTERFACE))
goto unknown;
if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
break;
f = cdev->config->interface[intf];
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;
case USB_REQ_GET_STATUS:
if (gadget_is_otg(gadget) && gadget->hnp_polling_support &&
(w_index == OTG_STS_SELECTOR)) {
if (ctrl->bRequestType != (USB_DIR_IN |
USB_RECIP_DEVICE))
goto unknown;
*((u8 *)req->buf) = gadget->host_request_flag;
value = 1;
break;
}
/*
* USB 3.0 additions:
* Function driver should handle get_status request. If such cb
* wasn't supplied we respond with default value = 0
* Note: function driver should supply such cb only for the
* first interface of the function
*/
if (!gadget_is_superspeed(gadget))
goto unknown;
if (ctrl->bRequestType != (USB_DIR_IN | USB_RECIP_INTERFACE))
goto unknown;
value = 2; /* This is the length of the get_status reply */
put_unaligned_le16(0, req->buf);
if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
break;
f = cdev->config->interface[intf];
if (!f)
break;
status = f->get_status ? f->get_status(f) : 0;
if (status < 0)
break;
put_unaligned_le16(status & 0x0000ffff, req->buf);
break;
/*
* Function drivers should handle SetFeature/ClearFeature
* (FUNCTION_SUSPEND) request. function_suspend cb should be supplied
* only for the first interface of the function
*/
case USB_REQ_CLEAR_FEATURE:
case USB_REQ_SET_FEATURE:
if (!gadget_is_superspeed(gadget))
goto unknown;
if (ctrl->bRequestType != (USB_DIR_OUT | USB_RECIP_INTERFACE))
goto unknown;
switch (w_value) {
case USB_INTRF_FUNC_SUSPEND:
if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
break;
f = cdev->config->interface[intf];
if (!f)
break;
value = 0;
if (f->func_suspend)
value = f->func_suspend(f, w_index >> 8);
if (value < 0) {
ERROR(cdev,
"func_suspend() returned error %d\n",
value);
value = 0;
}
break;
}
break;
default:
unknown:
/*
* OS descriptors handling
*/
if (cdev->use_os_string && cdev->os_desc_config &&
(ctrl->bRequestType & USB_TYPE_VENDOR) &&
ctrl->bRequest == cdev->b_vendor_code) {
struct usb_configuration *os_desc_cfg;
u8 *buf;
int interface;
int count = 0;
req = cdev->os_desc_req;
req->context = cdev;
req->complete = composite_setup_complete;
buf = req->buf;
os_desc_cfg = cdev->os_desc_config;
w_length = min_t(u16, w_length, USB_COMP_EP0_OS_DESC_BUFSIZ);
memset(buf, 0, w_length);
buf[5] = 0x01;
switch (ctrl->bRequestType & USB_RECIP_MASK) {
case USB_RECIP_DEVICE:
if (w_index != 0x4 || (w_value >> 8))
break;
buf[6] = w_index;
/* Number of ext compat interfaces */
count = count_ext_compat(os_desc_cfg);
buf[8] = count;
count *= 24; /* 24 B/ext compat desc */
count += 16; /* header */
put_unaligned_le32(count, buf);
value = w_length;
if (w_length > 0x10) {
value = fill_ext_compat(os_desc_cfg, buf);
value = min_t(u16, w_length, value);
}
break;
case USB_RECIP_INTERFACE:
if (w_index != 0x5 || (w_value >> 8))
break;
interface = w_value & 0xFF;
buf[6] = w_index;
count = count_ext_prop(os_desc_cfg,
interface);
put_unaligned_le16(count, buf + 8);
count = len_ext_prop(os_desc_cfg,
interface);
put_unaligned_le32(count, buf);
value = w_length;
if (w_length > 0x0A) {
value = fill_ext_prop(os_desc_cfg,
interface, buf);
if (value >= 0)
value = min_t(u16, w_length, value);
}
break;
}
goto check_value;
}
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 and endpoints...
* punt other recipients (other, WUSB, ...) to the current
* configuration code.
*/
if (cdev->config) {
list_for_each_entry(f, &cdev->config->functions, list)
if (f->req_match &&
f->req_match(f, ctrl, false))
goto try_fun_setup;
} else {
struct usb_configuration *c;
list_for_each_entry(c, &cdev->configs, list)
list_for_each_entry(f, &c->functions, list)
if (f->req_match &&
f->req_match(f, ctrl, true))
goto try_fun_setup;
}
f = NULL;
switch (ctrl->bRequestType & USB_RECIP_MASK) {
case USB_RECIP_INTERFACE:
if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
break;
f = cdev->config->interface[intf];
break;
case USB_RECIP_ENDPOINT:
if (!cdev->config)
break;
endp = ((w_index & 0x80) >> 3) | (w_index & 0x0f);
list_for_each_entry(f, &cdev->config->functions, list) {
if (test_bit(endp, f->endpoints))
break;
}
if (&f->list == &cdev->config->functions)
f = NULL;
break;
}
try_fun_setup:
if (f && f->setup)
value = f->setup(f, ctrl);
else {
struct usb_configuration *c;
c = cdev->config;
if (!c)
goto done;
/* try current config's setup */
if (c->setup) {
value = c->setup(c, ctrl);
goto done;
}
/* try the only function in the current config */
if (!list_is_singular(&c->functions))
goto done;
f = list_first_entry(&c->functions, struct usb_function,
list);
if (f->setup)
value = f->setup(f, ctrl);
}
goto done;
}
check_value:
/* respond with data transfer before status phase? */
if (value >= 0 && value != USB_GADGET_DELAYED_STATUS) {
req->length = value;
req->context = cdev;
req->zero = value < w_length;
value = composite_ep0_queue(cdev, req, GFP_ATOMIC);
if (value < 0) {
DBG(cdev, "ep_queue --> %d\n", value);
req->status = 0;
composite_setup_complete(gadget->ep0, req);
}
} else if (value == USB_GADGET_DELAYED_STATUS && w_length != 0) {
WARN(cdev,
"%s: Delayed status not supported for w_length != 0",
__func__);
}
done:
/* device either stalls (value < 0) or reports success */
return value;
}
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);
cdev->suspended = 0;
if (cdev->config)
reset_config(cdev);
if (cdev->driver->disconnect)
cdev->driver->disconnect(cdev);
spin_unlock_irqrestore(&cdev->lock, flags);
}
/*-------------------------------------------------------------------------*/
static ssize_t suspended_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct usb_gadget *gadget = dev_to_usb_gadget(dev);
struct usb_composite_dev *cdev = get_gadget_data(gadget);
return sprintf(buf, "%d\n", cdev->suspended);
}
static DEVICE_ATTR_RO(suspended);
static void __composite_unbind(struct usb_gadget *gadget, bool unbind_driver)
{
struct usb_composite_dev *cdev = get_gadget_data(gadget);
struct usb_gadget_strings *gstr = cdev->driver->strings[0];
struct usb_string *dev_str = gstr->strings;
/* 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);
remove_config(cdev, c);
}
if (cdev->driver->unbind && unbind_driver)
cdev->driver->unbind(cdev);
composite_dev_cleanup(cdev);
if (dev_str[USB_GADGET_MANUFACTURER_IDX].s == cdev->def_manufacturer)
dev_str[USB_GADGET_MANUFACTURER_IDX].s = "";
kfree(cdev->def_manufacturer);
kfree(cdev);
set_gadget_data(gadget, NULL);
}
static void composite_unbind(struct usb_gadget *gadget)
{
__composite_unbind(gadget, true);
}
static void update_unchanged_dev_desc(struct usb_device_descriptor *new,
const struct usb_device_descriptor *old)
{
__le16 idVendor;
__le16 idProduct;
__le16 bcdDevice;
u8 iSerialNumber;
u8 iManufacturer;
u8 iProduct;
/*
* these variables may have been set in
* usb_composite_overwrite_options()
*/
idVendor = new->idVendor;
idProduct = new->idProduct;
bcdDevice = new->bcdDevice;
iSerialNumber = new->iSerialNumber;
iManufacturer = new->iManufacturer;
iProduct = new->iProduct;
*new = *old;
if (idVendor)
new->idVendor = idVendor;
if (idProduct)
new->idProduct = idProduct;
if (bcdDevice)
new->bcdDevice = bcdDevice;
else
new->bcdDevice = cpu_to_le16(get_default_bcdDevice());
if (iSerialNumber)
new->iSerialNumber = iSerialNumber;
if (iManufacturer)
new->iManufacturer = iManufacturer;
if (iProduct)
new->iProduct = iProduct;
}
int composite_dev_prepare(struct usb_composite_driver *composite,
struct usb_composite_dev *cdev)
{
struct usb_gadget *gadget = cdev->gadget;
int ret = -ENOMEM;
/* preallocate control response and buffer */
cdev->req = usb_ep_alloc_request(gadget->ep0, GFP_KERNEL);
if (!cdev->req)
return -ENOMEM;
cdev->req->buf = kmalloc(USB_COMP_EP0_BUFSIZ, GFP_KERNEL);
if (!cdev->req->buf)
goto fail;
ret = device_create_file(&gadget->dev, &dev_attr_suspended);
if (ret)
goto fail_dev;
cdev->req->complete = composite_setup_complete;
cdev->req->context = cdev;
gadget->ep0->driver_data = cdev;
cdev->driver = composite;
/*
* As per USB compliance update, a device that is actively drawing
* more than 100mA from USB must report itself as bus-powered in
* the GetStatus(DEVICE) call.
*/
if (CONFIG_USB_GADGET_VBUS_DRAW <= USB_SELF_POWER_VBUS_MAX_DRAW)
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(gadget);
return 0;
fail_dev:
kfree(cdev->req->buf);
fail:
usb_ep_free_request(gadget->ep0, cdev->req);
cdev->req = NULL;
return ret;
}
int composite_os_desc_req_prepare(struct usb_composite_dev *cdev,
struct usb_ep *ep0)
{
int ret = 0;
cdev->os_desc_req = usb_ep_alloc_request(ep0, GFP_KERNEL);
if (!cdev->os_desc_req) {
ret = -ENOMEM;
goto end;
}
cdev->os_desc_req->buf = kmalloc(USB_COMP_EP0_OS_DESC_BUFSIZ,
GFP_KERNEL);
if (!cdev->os_desc_req->buf) {
ret = -ENOMEM;
usb_ep_free_request(ep0, cdev->os_desc_req);
goto end;
}
cdev->os_desc_req->context = cdev;
cdev->os_desc_req->complete = composite_setup_complete;
end:
return ret;
}
void composite_dev_cleanup(struct usb_composite_dev *cdev)
{
struct usb_gadget_string_container *uc, *tmp;
struct usb_ep *ep, *tmp_ep;
list_for_each_entry_safe(uc, tmp, &cdev->gstrings, list) {
list_del(&uc->list);
kfree(uc);
}
if (cdev->os_desc_req) {
if (cdev->os_desc_pending)
usb_ep_dequeue(cdev->gadget->ep0, cdev->os_desc_req);
kfree(cdev->os_desc_req->buf);
cdev->os_desc_req->buf = NULL;
usb_ep_free_request(cdev->gadget->ep0, cdev->os_desc_req);
cdev->os_desc_req = NULL;
}
if (cdev->req) {
if (cdev->setup_pending)
usb_ep_dequeue(cdev->gadget->ep0, cdev->req);
kfree(cdev->req->buf);
cdev->req->buf = NULL;
usb_ep_free_request(cdev->gadget->ep0, cdev->req);
cdev->req = NULL;
}
cdev->next_string_id = 0;
device_remove_file(&cdev->gadget->dev, &dev_attr_suspended);
/*
* Some UDC backends have a dynamic EP allocation scheme.
*
* In that case, the dispose() callback is used to notify the
* backend that the EPs are no longer in use.
*
* Note: The UDC backend can remove the EP from the ep_list as
* a result, so we need to use the _safe list iterator.
*/
list_for_each_entry_safe(ep, tmp_ep,
&cdev->gadget->ep_list, ep_list) {
if (ep->ops->dispose)
ep->ops->dispose(ep);
}
}
static int composite_bind(struct usb_gadget *gadget,
struct usb_gadget_driver *gdriver)
{
struct usb_composite_dev *cdev;
struct usb_composite_driver *composite = to_cdriver(gdriver);
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);
INIT_LIST_HEAD(&cdev->gstrings);
status = composite_dev_prepare(composite, cdev);
if (status)
goto fail;
/* 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;
if (cdev->use_os_string) {
status = composite_os_desc_req_prepare(cdev, gadget->ep0);
if (status)
goto fail;
}
update_unchanged_dev_desc(&cdev->desc, composite->dev);
/* has userspace failed to provide a serial number? */
if (composite->needs_serial && !cdev->desc.iSerialNumber)
WARNING(cdev, "userspace failed to provide iSerialNumber\n");
INFO(cdev, "%s ready\n", composite->name);
return 0;
fail:
__composite_unbind(gadget, false);
return status;
}
/*-------------------------------------------------------------------------*/
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 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);
}
}
if (cdev->driver->suspend)
cdev->driver->suspend(cdev);
cdev->suspended = 1;
usb_gadget_set_selfpowered(gadget);
usb_gadget_vbus_draw(gadget, 2);
}
void composite_resume(struct usb_gadget *gadget)
{
struct usb_composite_dev *cdev = get_gadget_data(gadget);
struct usb_function *f;
unsigned maxpower;
/* REVISIT: should we have config level
* suspend/resume callbacks?
*/
DBG(cdev, "resume\n");
if (cdev->driver->resume)
cdev->driver->resume(cdev);
if (cdev->config) {
list_for_each_entry(f, &cdev->config->functions, list) {
if (f->resume)
f->resume(f);
}
maxpower = cdev->config->MaxPower ?
cdev->config->MaxPower : CONFIG_USB_GADGET_VBUS_DRAW;
if (gadget->speed < USB_SPEED_SUPER)
maxpower = min(maxpower, 500U);
else
maxpower = min(maxpower, 900U);
if (maxpower > USB_SELF_POWER_VBUS_MAX_DRAW)
usb_gadget_clear_selfpowered(gadget);
usb_gadget_vbus_draw(gadget, maxpower);
}
cdev->suspended = 0;
}
/*-------------------------------------------------------------------------*/
static const struct usb_gadget_driver composite_driver_template = {
.bind = composite_bind,
.unbind = composite_unbind,
.setup = composite_setup,
.reset = composite_disconnect,
.disconnect = composite_disconnect,
.suspend = composite_suspend,
.resume = composite_resume,
.driver = {
.owner = THIS_MODULE,
},
};
/**
* usb_composite_probe() - 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 usb_composite_probe(struct usb_composite_driver *driver)
{
struct usb_gadget_driver *gadget_driver;
if (!driver || !driver->dev || !driver->bind)
return -EINVAL;
if (!driver->name)
driver->name = "composite";
driver->gadget_driver = composite_driver_template;
gadget_driver = &driver->gadget_driver;
gadget_driver->function = (char *) driver->name;
gadget_driver->driver.name = driver->name;
gadget_driver->max_speed = driver->max_speed;
return usb_gadget_probe_driver(gadget_driver);
}
EXPORT_SYMBOL_GPL(usb_composite_probe);
/**
* 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 usb_composite_unregister(struct usb_composite_driver *driver)
{
usb_gadget_unregister_driver(&driver->gadget_driver);
}
EXPORT_SYMBOL_GPL(usb_composite_unregister);
/**
* usb_composite_setup_continue() - Continue with the control transfer
* @cdev: the composite device who's control transfer was kept waiting
*
* This function must be called by the USB function driver to continue
* with the control transfer's data/status stage in case it had requested to
* delay the data/status stages. A USB function's setup handler (e.g. set_alt())
* can request the composite framework to delay the setup request's data/status
* stages by returning USB_GADGET_DELAYED_STATUS.
*/
void usb_composite_setup_continue(struct usb_composite_dev *cdev)
{
int value;
struct usb_request *req = cdev->req;
unsigned long flags;
DBG(cdev, "%s\n", __func__);
spin_lock_irqsave(&cdev->lock, flags);
if (cdev->delayed_status == 0) {
WARN(cdev, "%s: Unexpected call\n", __func__);
} else if (--cdev->delayed_status == 0) {
DBG(cdev, "%s: Completing delayed status\n", __func__);
req->length = 0;
req->context = cdev;
value = composite_ep0_queue(cdev, req, GFP_ATOMIC);
if (value < 0) {
DBG(cdev, "ep_queue --> %d\n", value);
req->status = 0;
composite_setup_complete(cdev->gadget->ep0, req);
}
}
spin_unlock_irqrestore(&cdev->lock, flags);
}
EXPORT_SYMBOL_GPL(usb_composite_setup_continue);
static char *composite_default_mfr(struct usb_gadget *gadget)
{
return kasprintf(GFP_KERNEL, "%s %s with %s", init_utsname()->sysname,
init_utsname()->release, gadget->name);
}
void usb_composite_overwrite_options(struct usb_composite_dev *cdev,
struct usb_composite_overwrite *covr)
{
struct usb_device_descriptor *desc = &cdev->desc;
struct usb_gadget_strings *gstr = cdev->driver->strings[0];
struct usb_string *dev_str = gstr->strings;
if (covr->idVendor)
desc->idVendor = cpu_to_le16(covr->idVendor);
if (covr->idProduct)
desc->idProduct = cpu_to_le16(covr->idProduct);
if (covr->bcdDevice)
desc->bcdDevice = cpu_to_le16(covr->bcdDevice);
if (covr->serial_number) {
desc->iSerialNumber = dev_str[USB_GADGET_SERIAL_IDX].id;
dev_str[USB_GADGET_SERIAL_IDX].s = covr->serial_number;
}
if (covr->manufacturer) {
desc->iManufacturer = dev_str[USB_GADGET_MANUFACTURER_IDX].id;
dev_str[USB_GADGET_MANUFACTURER_IDX].s = covr->manufacturer;
} else if (!strlen(dev_str[USB_GADGET_MANUFACTURER_IDX].s)) {
desc->iManufacturer = dev_str[USB_GADGET_MANUFACTURER_IDX].id;
cdev->def_manufacturer = composite_default_mfr(cdev->gadget);
dev_str[USB_GADGET_MANUFACTURER_IDX].s = cdev->def_manufacturer;
}
if (covr->product) {
desc->iProduct = dev_str[USB_GADGET_PRODUCT_IDX].id;
dev_str[USB_GADGET_PRODUCT_IDX].s = covr->product;
}
}
EXPORT_SYMBOL_GPL(usb_composite_overwrite_options);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("David Brownell");