linux composite Device

http://lxr.free-electrons.com/source/include/linux/usb/composite.h?a=mips

1 /*
  2  * composite.h -- framework for usb gadgets which are composite devices
  3  *
  4  * Copyright (C) 2006-2008 David Brownell
  5  *
  6  * This program is free software; you can redistribute it and/or modify
  7  * it under the terms of the GNU General Public License as published by
  8  * the Free Software Foundation; either version 2 of the License, or
  9  * (at your option) any later version.
 10  *
 11  * This program is distributed in the hope that it will be useful,
 12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
 13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 14  * GNU General Public License for more details.
 15  *
 16  * You should have received a copy of the GNU General Public License
 17  * along with this program; if not, write to the Free Software
 18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 19  */
 20 
 21 #ifndef __LINUX_USB_COMPOSITE_H
 22 #define __LINUX_USB_COMPOSITE_H
 23 
 24 /*
 25  * This framework is an optional layer on top of the USB Gadget interface,
 26  * making it easier to build (a) Composite devices, supporting multiple
 27  * functions within any single configuration, and (b) Multi-configuration
 28  * devices, also supporting multiple functions but without necessarily
 29  * having more than one function per configuration.
 30  *
 31  * Example:  a device with a single configuration supporting both network
 32  * link and mass storage functions is a composite device.  Those functions
 33  * might alternatively be packaged in individual configurations, but in
 34  * the composite model the host can use both functions at the same time.
 35  */
 36 
 37 #include <linux/usb/ch9.h>
 38 #include <linux/usb/gadget.h>
 39 
 40 /*
 41  * USB function drivers should return USB_GADGET_DELAYED_STATUS if they
 42  * wish to delay the data/status stages of the control transfer till they
 43  * are ready. The control transfer will then be kept from completing till
 44  * all the function drivers that requested for USB_GADGET_DELAYED_STAUS
 45  * invoke usb_composite_setup_continue().
 46  */
 47 #define USB_GADGET_DELAYED_STATUS       0x7fff  /* Impossibly large value */
 48 
 49 struct usb_configuration;
 50 
 51 /**
 52  * struct usb_function - describes one function of a configuration
 53  * @name: For diagnostics, identifies the function.
 54  * @strings: tables of strings, keyed by identifiers assigned during bind()
 55  *      and by language IDs provided in control requests
 56  * @descriptors: Table of full (or low) speed descriptors, using interface and
 57  *      string identifiers assigned during @bind().  If this pointer is null,
 58  *      the function will not be available at full speed (or at low speed).
 59  * @hs_descriptors: Table of high speed descriptors, using interface and
 60  *      string identifiers assigned during @bind().  If this pointer is null,
 61  *      the function will not be available at high speed.
 62  * @ss_descriptors: Table of super speed descriptors, using interface and
 63  *      string identifiers assigned during @bind(). If this
 64  *      pointer is null after initiation, the function will not
 65  *      be available at super speed.
 66  * @config: assigned when @usb_add_function() is called; this is the
 67  *      configuration with which this function is associated.
 68  * @bind: Before the gadget can register, all of its functions bind() to the
 69  *      available resources including string and interface identifiers used
 70  *      in interface or class descriptors; endpoints; I/O buffers; and so on.
 71  * @unbind: Reverses @bind; called as a side effect of unregistering the
 72  *      driver which added this function.
 73  * @set_alt: (REQUIRED) Reconfigures altsettings; function drivers may
 74  *      initialize usb_ep.driver data at this time (when it is used).
 75  *      Note that setting an interface to its current altsetting resets
 76  *      interface state, and that all interfaces have a disabled state.
 77  * @get_alt: Returns the active altsetting.  If this is not provided,
 78  *      then only altsetting zero is supported.
 79  * @disable: (REQUIRED) Indicates the function should be disabled.  Reasons
 80  *      include host resetting or reconfiguring the gadget, and disconnection.
 81  * @setup: Used for interface-specific control requests.
 82  * @suspend: Notifies functions when the host stops sending USB traffic.
 83  * @resume: Notifies functions when the host restarts USB traffic.
 84  * @get_status: Returns function status as a reply to
 85  *      GetStatus() request when the recepient is Interface.
 86  * @func_suspend: callback to be called when
 87  *      SetFeature(FUNCTION_SUSPEND) is reseived
 88  *
 89  * A single USB function uses one or more interfaces, and should in most
 90  * cases support operation at both full and high speeds.  Each function is
 91  * associated by @usb_add_function() with a one configuration; that function
 92  * causes @bind() to be called so resources can be allocated as part of
 93  * setting up a gadget driver.  Those resources include endpoints, which
 94  * should be allocated using @usb_ep_autoconfig().
 95  *
 96  * To support dual speed operation, a function driver provides descriptors
 97  * for both high and full speed operation.  Except in rare cases that don't
 98  * involve bulk endpoints, each speed needs different endpoint descriptors.
 99  *
100  * Function drivers choose their own strategies for managing instance data.
101  * The simplest strategy just declares it "static', which means the function
102  * can only be activated once.  If the function needs to be exposed in more
103  * than one configuration at a given speed, it needs to support multiple
104  * usb_function structures (one for each configuration).
105  *
106  * A more complex strategy might encapsulate a @usb_function structure inside
107  * a driver-specific instance structure to allows multiple activations.  An
108  * example of multiple activations might be a CDC ACM function that supports
109  * two or more distinct instances within the same configuration, providing
110  * several independent logical data links to a USB host.
111  */
112 struct usb_function {
113         const char                      *name;
114         struct usb_gadget_strings       **strings;
115         struct usb_descriptor_header    **descriptors;
116         struct usb_descriptor_header    **hs_descriptors;
117         struct usb_descriptor_header    **ss_descriptors;
118 
119         struct usb_configuration        *config;
120 
121         /* REVISIT:  bind() functions can be marked __init, which
122          * makes trouble for section mismatch analysis.  See if
123          * we can't restructure things to avoid mismatching.
124          * Related:  unbind() may kfree() but bind() won't...
125          */
126 
127         /* configuration management:  bind/unbind */
128         int                     (*bind)(struct usb_configuration *,
129                                         struct usb_function *);
130         void                    (*unbind)(struct usb_configuration *,
131                                         struct usb_function *);
132 
133         /* runtime state management */
134         int                     (*set_alt)(struct usb_function *,
135                                         unsigned interface, unsigned alt);
136         int                     (*get_alt)(struct usb_function *,
137                                         unsigned interface);
138         void                    (*disable)(struct usb_function *);
139         int                     (*setup)(struct usb_function *,
140                                         const struct usb_ctrlrequest *);
141         void                    (*suspend)(struct usb_function *);
142         void                    (*resume)(struct usb_function *);
143 
144         /* USB 3.0 additions */
145         int                     (*get_status)(struct usb_function *);
146         int                     (*func_suspend)(struct usb_function *,
147                                                 u8 suspend_opt);
148         /* private: */
149         /* internals */
150         struct list_head                list;
151         DECLARE_BITMAP(endpoints, 32);
152 };
153 
154 int usb_add_function(struct usb_configuration *, struct usb_function *);
155 
156 int usb_function_deactivate(struct usb_function *);
157 int usb_function_activate(struct usb_function *);
158 
159 int usb_interface_id(struct usb_configuration *, struct usb_function *);
160 
161 int config_ep_by_speed(struct usb_gadget *g, struct usb_function *f,
162                         struct usb_ep *_ep);
163 
164 #define MAX_CONFIG_INTERFACES           16      /* arbitrary; max 255 */
165 
166 /**
167  * struct usb_configuration - represents one gadget configuration
168  * @label: For diagnostics, describes the configuration.
169  * @strings: Tables of strings, keyed by identifiers assigned during @bind()
170  *      and by language IDs provided in control requests.
171  * @descriptors: Table of descriptors preceding all function descriptors.
172  *      Examples include OTG and vendor-specific descriptors.
173  * @unbind: Reverses @bind; called as a side effect of unregistering the
174  *      driver which added this configuration.
175  * @setup: Used to delegate control requests that aren't handled by standard
176  *      device infrastructure or directed at a specific interface.
177  * @bConfigurationValue: Copied into configuration descriptor.
178  * @iConfiguration: Copied into configuration descriptor.
179  * @bmAttributes: Copied into configuration descriptor.
180  * @bMaxPower: Copied into configuration descriptor.
181  * @cdev: assigned by @usb_add_config() before calling @bind(); this is
182  *      the device associated with this configuration.
183  *
184  * Configurations are building blocks for gadget drivers structured around
185  * function drivers.  Simple USB gadgets require only one function and one
186  * configuration, and handle dual-speed hardware by always providing the same
187  * functionality.  Slightly more complex gadgets may have more than one
188  * single-function configuration at a given speed; or have configurations
189  * that only work at one speed.
190  *
191  * Composite devices are, by definition, ones with configurations which
192  * include more than one function.
193  *
194  * The lifecycle of a usb_configuration includes allocation, initialization
195  * of the fields described above, and calling @usb_add_config() to set up
196  * internal data and bind it to a specific device.  The configuration's
197  * @bind() method is then used to initialize all the functions and then
198  * call @usb_add_function() for them.
199  *
200  * Those functions would normally be independent of each other, but that's
201  * not mandatory.  CDC WMC devices are an example where functions often
202  * depend on other functions, with some functions subsidiary to others.
203  * Such interdependency may be managed in any way, so long as all of the
204  * descriptors complete by the time the composite driver returns from
205  * its bind() routine.
206  */
207 struct usb_configuration {
208         const char                      *label;
209         struct usb_gadget_strings       **strings;
210         const struct usb_descriptor_header **descriptors;
211 
212         /* REVISIT:  bind() functions can be marked __init, which
213          * makes trouble for section mismatch analysis.  See if
214          * we can't restructure things to avoid mismatching...
215          */
216 
217         /* configuration management: unbind/setup */
218         void                    (*unbind)(struct usb_configuration *);
219         int                     (*setup)(struct usb_configuration *,
220                                         const struct usb_ctrlrequest *);
221 
222         /* fields in the config descriptor */
223         u8                      bConfigurationValue;
224         u8                      iConfiguration;
225         u8                      bmAttributes;
226         u8                      bMaxPower;
227 
228         struct usb_composite_dev        *cdev;
229 
230         /* private: */
231         /* internals */
232         struct list_head        list;
233         struct list_head        functions;
234         u8                      next_interface_id;
235         unsigned                superspeed:1;
236         unsigned                highspeed:1;
237         unsigned                fullspeed:1;
238         struct usb_function     *interface[MAX_CONFIG_INTERFACES];
239 };
240 
241 int usb_add_config(struct usb_composite_dev *,
242                 struct usb_configuration *,
243                 int (*)(struct usb_configuration *));
244 
245 void usb_remove_config(struct usb_composite_dev *,
246                 struct usb_configuration *);
247 
248 /**
249  * struct usb_composite_driver - groups configurations into a gadget
250  * @name: For diagnostics, identifies the driver.
251  * @iProduct: Used as iProduct override if @dev->iProduct is not set.
252  *      If NULL value of @name is taken.
253  * @iManufacturer: Used as iManufacturer override if @dev->iManufacturer is
254  *      not set. If NULL a default "<system> <release> with <udc>" value
255  *      will be used.
256  * @iSerialNumber: Used as iSerialNumber override if @dev->iSerialNumber is
257  *      not set.
258  * @dev: Template descriptor for the device, including default device
259  *      identifiers.
260  * @strings: tables of strings, keyed by identifiers assigned during bind()
261  *      and language IDs provided in control requests
262  * @max_speed: Highest speed the driver supports.
263  * @needs_serial: set to 1 if the gadget needs userspace to provide
264  *      a serial number.  If one is not provided, warning will be printed.
265  * @unbind: Reverses bind; called as a side effect of unregistering
266  *      this driver.
267  * @disconnect: optional driver disconnect method
268  * @suspend: Notifies when the host stops sending USB traffic,
269  *      after function notifications
270  * @resume: Notifies configuration when the host restarts USB traffic,
271  *      before function notifications
272  *
273  * Devices default to reporting self powered operation.  Devices which rely
274  * on bus powered operation should report this in their @bind() method.
275  *
276  * Before returning from bind, various fields in the template descriptor
277  * may be overridden.  These include the idVendor/idProduct/bcdDevice values
278  * normally to bind the appropriate host side driver, and the three strings
279  * (iManufacturer, iProduct, iSerialNumber) normally used to provide user
280  * meaningful device identifiers.  (The strings will not be defined unless
281  * they are defined in @dev and @strings.)  The correct ep0 maxpacket size
282  * is also reported, as defined by the underlying controller driver.
283  */
284 struct usb_composite_driver {
285         const char                              *name;
286         const char                              *iProduct;
287         const char                              *iManufacturer;
288         const char                              *iSerialNumber;
289         const struct usb_device_descriptor      *dev;
290         struct usb_gadget_strings               **strings;
291         enum usb_device_speed                   max_speed;
292         unsigned                needs_serial:1;
293 
294         int                     (*unbind)(struct usb_composite_dev *);
295 
296         void                    (*disconnect)(struct usb_composite_dev *);
297 
298         /* global suspend hooks */
299         void                    (*suspend)(struct usb_composite_dev *);
300         void                    (*resume)(struct usb_composite_dev *);
301 };
302 
303 extern int usb_composite_probe(struct usb_composite_driver *driver,
304                                int (*bind)(struct usb_composite_dev *cdev));
305 extern void usb_composite_unregister(struct usb_composite_driver *driver);
306 extern void usb_composite_setup_continue(struct usb_composite_dev *cdev);
307 
308 
309 /**
310  * struct usb_composite_device - represents one composite usb gadget
311  * @gadget: read-only, abstracts the gadget's usb peripheral controller
312  * @req: used for control responses; buffer is pre-allocated
313  * @bufsiz: size of buffer pre-allocated in @req
314  * @config: the currently active configuration
315  *
316  * One of these devices is allocated and initialized before the
317  * associated device driver's bind() is called.
318  *
319  * OPEN ISSUE:  it appears that some WUSB devices will need to be
320  * built by combining a normal (wired) gadget with a wireless one.
321  * This revision of the gadget framework should probably try to make
322  * sure doing that won't hurt too much.
323  *
324  * One notion for how to handle Wireless USB devices involves:
325  * (a) a second gadget here, discovery mechanism TBD, but likely
326  *     needing separate "register/unregister WUSB gadget" calls;
327  * (b) updates to usb_gadget to include flags "is it wireless",
328  *     "is it wired", plus (presumably in a wrapper structure)
329  *     bandgroup and PHY info;
330  * (c) presumably a wireless_ep wrapping a usb_ep, and reporting
331  *     wireless-specific parameters like maxburst and maxsequence;
332  * (d) configurations that are specific to wireless links;
333  * (e) function drivers that understand wireless configs and will
334  *     support wireless for (additional) function instances;
335  * (f) a function to support association setup (like CBAF), not
336  *     necessarily requiring a wireless adapter;
337  * (g) composite device setup that can create one or more wireless
338  *     configs, including appropriate association setup support;
339  * (h) more, TBD.
340  */
341 struct usb_composite_dev {
342         struct usb_gadget               *gadget;
343         struct usb_request              *req;
344         unsigned                        bufsiz;
345 
346         struct usb_configuration        *config;
347 
348         /* private: */
349         /* internals */
350         unsigned int                    suspended:1;
351         struct usb_device_descriptor    desc;
352         struct list_head                configs;
353         struct usb_composite_driver     *driver;
354         u8                              next_string_id;
355         u8                              manufacturer_override;
356         u8                              product_override;
357         u8                              serial_override;
358 
359         /* the gadget driver won't enable the data pullup
360          * while the deactivation count is nonzero.
361          */
362         unsigned                        deactivations;
363 
364         /* the composite driver won't complete the control transfer's
365          * data/status stages till delayed_status is zero.
366          */
367         int                             delayed_status;
368 
369         /* protects deactivations and delayed_status counts*/
370         spinlock_t                      lock;
371 };
372 
373 extern int usb_string_id(struct usb_composite_dev *c);
374 extern int usb_string_ids_tab(struct usb_composite_dev *c,
375                               struct usb_string *str);
376 extern int usb_string_ids_n(struct usb_composite_dev *c, unsigned n);
377 
378 
379 /* messaging utils */
380 #define DBG(d, fmt, args...) \
381         dev_dbg(&(d)->gadget->dev , fmt , ## args)
382 #define VDBG(d, fmt, args...) \
383         dev_vdbg(&(d)->gadget->dev , fmt , ## args)
384 #define ERROR(d, fmt, args...) \
385         dev_err(&(d)->gadget->dev , fmt , ## args)
386 #define WARNING(d, fmt, args...) \
387         dev_warn(&(d)->gadget->dev , fmt , ## args)
388 #define INFO(d, fmt, args...) \
389         dev_info(&(d)->gadget->dev , fmt , ## args)
390 
391 #endif  /* __LINUX_USB_COMPOSITE_H */
392 

http://lxr.free-electrons.com/source/drivers/usb/gadget/?a=mips