/* * composite.h -- framework for usb gadgets which are composite devices * * 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ #ifndef __LINUX_USB_COMPOSITE_H #define __LINUX_USB_COMPOSITE_H /* * This framework is an optional layer on top of the USB Gadget interface, * making it easier to build (a) Composite devices, supporting multiple * functions within any single configuration, and (b) Multi-configuration * devices, also supporting multiple functions but without necessarily * having more than one function per configuration. * * Example: a device with a single configuration supporting both network * link and mass storage functions is a composite device. Those functions * might alternatively be packaged in individual configurations, but in * the composite model the host can use both functions at the same time. */ #include #include struct usb_configuration; /** * struct usb_function - describes one function of a configuration * @name: For diagnostics, identifies the function. * @strings: tables of strings, keyed by identifiers assigned during bind() * and by language IDs provided in control requests * @descriptors: Table of full (or low) speed descriptors, using interface and * string identifiers assigned during @bind(). If this pointer is null, * the function will not be available at full speed (or at low speed). * @hs_descriptors: Table of high speed descriptors, using interface and * string identifiers assigned during @bind(). If this pointer is null, * the function will not be available at high speed. * @config: assigned when @usb_add_function() is called; this is the * configuration with which this function is associated. * @bind: Before the gadget can register, all of its functions bind() to the * available resources including string and interface identifiers used * in interface or class descriptors; endpoints; I/O buffers; and so on. * @unbind: Reverses @bind; called as a side effect of unregistering the * driver which added this function. * @set_alt: (REQUIRED) Reconfigures altsettings; function drivers may * initialize usb_ep.driver data at this time (when it is used). * Note that setting an interface to its current altsetting resets * interface state, and that all interfaces have a disabled state. * @get_alt: Returns the active altsetting. If this is not provided, * then only altsetting zero is supported. * @disable: (REQUIRED) Indicates the function should be disabled. Reasons * include host resetting or reconfiguring the gadget, and disconnection. * @setup: Used for interface-specific control requests. * @suspend: Notifies functions when the host stops sending USB traffic. * @resume: Notifies functions when the host restarts USB traffic. * * A single USB function uses one or more interfaces, and should in most * cases support operation at both full and high speeds. Each function is * associated by @usb_add_function() with a one configuration; that function * causes @bind() to be called so resources can be allocated as part of * setting up a gadget driver. Those resources include endpoints, which * should be allocated using @usb_ep_autoconfig(). * * To support dual speed operation, a function driver provides descriptors * for both high and full speed operation. Except in rare cases that don't * involve bulk endpoints, each speed needs different endpoint descriptors. * * Function drivers choose their own strategies for managing instance data. * The simplest strategy just declares it "static', which means the function * can only be activated once. If the function needs to be exposed in more * than one configuration at a given speed, it needs to support multiple * usb_function structures (one for each configuration). * * A more complex strategy might encapsulate a @usb_function structure inside * a driver-specific instance structure to allows multiple activations. An * example of multiple activations might be a CDC ACM function that supports * two or more distinct instances within the same configuration, providing * several independent logical data links to a USB host. */ struct usb_function { const char *name; struct usb_gadget_strings **strings; struct usb_descriptor_header **descriptors; struct usb_descriptor_header **hs_descriptors; struct usb_configuration *config; /* REVISIT: bind() functions can be marked __init, which * makes trouble for section mismatch analysis. See if * we can't restructure things to avoid mismatching. * Related: unbind() may kfree() but bind() won't... */ /* configuration management: bind/unbind */ int (*bind)(struct usb_configuration *, struct usb_function *); void (*unbind)(struct usb_configuration *, struct usb_function *); /* runtime state management */ int (*set_alt)(struct usb_function *, unsigned interface, unsigned alt); int (*get_alt)(struct usb_function *, unsigned interface); void (*disable)(struct usb_function *); int (*setup)(struct usb_function *, const struct usb_ctrlrequest *); void (*suspend)(struct usb_function *); void (*resume)(struct usb_function *); /* private: */ /* internals */ struct list_head list; DECLARE_BITMAP(endpoints, 32); }; int usb_add_function(struct usb_configuration *, struct usb_function *); int usb_function_deactivate(struct usb_function *); int usb_function_activate(struct usb_function *); int usb_interface_id(struct usb_configuration *, struct usb_function *); /** * ep_choose - select descriptor endpoint at current device speed * @g: gadget, connected and running at some speed * @hs: descriptor to use for high speed operation * @fs: descriptor to use for full or low speed operation */ static inline struct usb_endpoint_descriptor * ep_choose(struct usb_gadget *g, struct usb_endpoint_descriptor *hs, struct usb_endpoint_descriptor *fs) { if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH) return hs; return fs; } #define MAX_CONFIG_INTERFACES 16 /* arbitrary; max 255 */ /** * struct usb_configuration - represents one gadget configuration * @label: For diagnostics, describes the configuration. * @strings: Tables of strings, keyed by identifiers assigned during @bind() * and by language IDs provided in control requests. * @descriptors: Table of descriptors preceding all function descriptors. * Examples include OTG and vendor-specific descriptors. * @bind: Called from @usb_add_config() to allocate resources unique to this * configuration and to call @usb_add_function() for each function used. * @unbind: Reverses @bind; called as a side effect of unregistering the * driver which added this configuration. * @setup: Used to delegate control requests that aren't handled by standard * device infrastructure or directed at a specific interface. * @bConfigurationValue: Copied into configuration descriptor. * @iConfiguration: Copied into configuration descriptor. * @bmAttributes: Copied into configuration descriptor. * @bMaxPower: Copied into configuration descriptor. * @cdev: assigned by @usb_add_config() before calling @bind(); this is * the device associated with this configuration. * * Configurations are building blocks for gadget drivers structured around * function drivers. Simple USB gadgets require only one function and one * configuration, and handle dual-speed hardware by always providing the same * functionality. Slightly more complex gadgets may have more than one * single-function configuration at a given speed; or have configurations * that only work at one speed. * * Composite devices are, by definition, ones with configurations which * include more than one function. * * The lifecycle of a usb_configuration includes allocation, initialization * of the fields described above, and calling @usb_add_config() to set up * internal data and bind it to a specific device. The configuration's * @bind() method is then used to initialize all the functions and then * call @usb_add_function() for them. * * Those functions would normally be independant of each other, but that's * not mandatory. CDC WMC devices are an example where functions often * depend on other functions, with some functions subsidiary to others. * Such interdependency may be managed in any way, so long as all of the * descriptors complete by the time the composite driver returns from * its bind() routine. */ struct usb_configuration { const char *label; struct usb_gadget_strings **strings; const struct usb_descriptor_header **descriptors; /* REVISIT: bind() functions can be marked __init, which * makes trouble for section mismatch analysis. See if * we can't restructure things to avoid mismatching... */ /* configuration management: bind/unbind */ int (*bind)(struct usb_configuration *); void (*unbind)(struct usb_configuration *); int (*setup)(struct usb_configuration *, const struct usb_ctrlrequest *); /* fields in the config descriptor */ u8 bConfigurationValue; u8 iConfiguration; u8 bmAttributes; u8 bMaxPower; struct usb_composite_dev *cdev; /* private: */ /* internals */ struct list_head list; struct list_head functions; u8 next_interface_id; unsigned highspeed:1; unsigned fullspeed:1; struct usb_function *interface[MAX_CONFIG_INTERFACES]; }; int usb_add_config(struct usb_composite_dev *, struct usb_configuration *); /** * struct usb_composite_driver - groups configurations into a gadget * @name: For diagnostics, identifies the driver. * @dev: Template descriptor for the device, including default device * identifiers. * @strings: tables of strings, keyed by identifiers assigned during bind() * and language IDs provided in control requests * @bind: (REQUIRED) Used to allocate resources that are shared across the * whole device, such as string IDs, and add its configurations using * @usb_add_config(). This may fail by returning a negative errno * value; it should return zero on successful initialization. * @unbind: Reverses @bind(); called as a side effect of unregistering * this driver. * @disconnect: optional driver disconnect method * @suspend: Notifies when the host stops sending USB traffic, * after function notifications * @resume: Notifies configuration when the host restarts USB traffic, * before function notifications * * Devices default to reporting self powered operation. Devices which rely * on bus powered operation should report this in their @bind() method. * * Before returning from @bind, various fields in the template descriptor * may be overridden. These include the idVendor/idProduct/bcdDevice values * normally to bind the appropriate host side driver, and the three strings * (iManufacturer, iProduct, iSerialNumber) normally used to provide user * meaningful device identifiers. (The strings will not be defined unless * they are defined in @dev and @strings.) The correct ep0 maxpacket size * is also reported, as defined by the underlying controller driver. */ struct usb_composite_driver { const char *name; const struct usb_device_descriptor *dev; struct usb_gadget_strings **strings; /* REVISIT: bind() functions can be marked __init, which * makes trouble for section mismatch analysis. See if * we can't restructure things to avoid mismatching... */ int (*bind)(struct usb_composite_dev *); int (*unbind)(struct usb_composite_dev *); void (*disconnect)(struct usb_composite_dev *); /* global suspend hooks */ void (*suspend)(struct usb_composite_dev *); void (*resume)(struct usb_composite_dev *); }; extern int usb_composite_register(struct usb_composite_driver *); extern void usb_composite_unregister(struct usb_composite_driver *); /** * struct usb_composite_device - represents one composite usb gadget * @gadget: read-only, abstracts the gadget's usb peripheral controller * @req: used for control responses; buffer is pre-allocated * @bufsiz: size of buffer pre-allocated in @req * @config: the currently active configuration * * One of these devices is allocated and initialized before the * associated device driver's bind() is called. * * OPEN ISSUE: it appears that some WUSB devices will need to be * built by combining a normal (wired) gadget with a wireless one. * This revision of the gadget framework should probably try to make * sure doing that won't hurt too much. * * One notion for how to handle Wireless USB devices involves: * (a) a second gadget here, discovery mechanism TBD, but likely * needing separate "register/unregister WUSB gadget" calls; * (b) updates to usb_gadget to include flags "is it wireless", * "is it wired", plus (presumably in a wrapper structure) * bandgroup and PHY info; * (c) presumably a wireless_ep wrapping a usb_ep, and reporting * wireless-specific parameters like maxburst and maxsequence; * (d) configurations that are specific to wireless links; * (e) function drivers that understand wireless configs and will * support wireless for (additional) function instances; * (f) a function to support association setup (like CBAF), not * necessarily requiring a wireless adapter; * (g) composite device setup that can create one or more wireless * configs, including appropriate association setup support; * (h) more, TBD. */ struct usb_composite_dev { struct usb_gadget *gadget; struct usb_request *req; unsigned bufsiz; struct usb_configuration *config; /* private: */ /* internals */ unsigned int suspended:1; struct usb_device_descriptor desc; struct list_head configs; struct usb_composite_driver *driver; u8 next_string_id; /* the gadget driver won't enable the data pullup * while the deactivation count is nonzero. */ unsigned deactivations; /* protects at least deactivation count */ spinlock_t lock; }; extern int usb_string_id(struct usb_composite_dev *c); extern int usb_string_ids_tab(struct usb_composite_dev *c, struct usb_string *str); extern int usb_string_ids_n(struct usb_composite_dev *c, unsigned n); /* messaging utils */ #define DBG(d, fmt, args...) \ dev_dbg(&(d)->gadget->dev , fmt , ## args) #define VDBG(d, fmt, args...) \ dev_vdbg(&(d)->gadget->dev , fmt , ## args) #define ERROR(d, fmt, args...) \ dev_err(&(d)->gadget->dev , fmt , ## args) #define WARNING(d, fmt, args...) \ dev_warn(&(d)->gadget->dev , fmt , ## args) #define INFO(d, fmt, args...) \ dev_info(&(d)->gadget->dev , fmt , ## args) #endif /* __LINUX_USB_COMPOSITE_H */