1 // SPDX-License-Identifier: GPL-2.0+
3 * composite.h -- framework for usb gadgets which are composite devices
5 * Copyright (C) 2006-2008 David Brownell
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
22 #ifndef __LINUX_USB_COMPOSITE_H
23 #define __LINUX_USB_COMPOSITE_H
26 * This framework is an optional layer on top of the USB Gadget interface,
27 * making it easier to build (a) Composite devices, supporting multiple
28 * functions within any single configuration, and (b) Multi-configuration
29 * devices, also supporting multiple functions but without necessarily
30 * having more than one function per configuration.
32 * Example: a device with a single configuration supporting both network
33 * link and mass storage functions is a composite device. Those functions
34 * might alternatively be packaged in individual configurations, but in
35 * the composite model the host can use both functions at the same time.
38 #include <linux/bcd.h>
39 #include <linux/version.h>
40 #include <linux/usb/ch9.h>
41 #include <linux/usb/gadget.h>
42 #include <linux/log2.h>
43 #include <linux/configfs.h>
46 * USB function drivers should return USB_GADGET_DELAYED_STATUS if they
47 * wish to delay the data/status stages of the control transfer till they
48 * are ready. The control transfer will then be kept from completing till
49 * all the function drivers that requested for USB_GADGET_DELAYED_STAUS
50 * invoke usb_composite_setup_continue().
52 #define USB_GADGET_DELAYED_STATUS 0x7fff /* Impossibly large value */
54 /* big enough to hold our biggest descriptor */
55 #define USB_COMP_EP0_BUFSIZ 1024
57 #define USB_MS_TO_HS_INTERVAL(x) (ilog2((x * 1000 / 125)) + 1)
58 struct usb_configuration
;
61 * struct usb_os_desc_ext_prop - describes one "Extended Property"
62 * @entry: used to keep a list of extended properties
63 * @type: Extended Property type
64 * @name_len: Extended Property unicode name length, including terminating '\0'
65 * @name: Extended Property name
66 * @data_len: Length of Extended Property blob (for unicode store double len)
67 * @data: Extended Property blob
68 * @item: Represents this Extended Property in configfs
70 struct usb_os_desc_ext_prop
{
71 struct list_head entry
;
77 struct config_item item
;
81 * struct usb_os_desc - describes OS descriptors associated with one interface
82 * @ext_compat_id: 16 bytes of "Compatible ID" and "Subcompatible ID"
83 * @ext_prop: Extended Properties list
84 * @ext_prop_len: Total length of Extended Properties blobs
85 * @ext_prop_count: Number of Extended Properties
86 * @opts_mutex: Optional mutex protecting config data of a usb_function_instance
87 * @group: Represents OS descriptors associated with an interface in configfs
88 * @owner: Module associated with this OS descriptor
92 struct list_head ext_prop
;
95 struct mutex
*opts_mutex
;
96 struct config_group group
;
101 * struct usb_os_desc_table - describes OS descriptors associated with one
102 * interface of a usb_function
103 * @if_id: Interface id
104 * @os_desc: "Extended Compatibility ID" and "Extended Properties" of the
107 * Each interface can have at most one "Extended Compatibility ID" and a
108 * number of "Extended Properties".
110 struct usb_os_desc_table
{
112 struct usb_os_desc
*os_desc
;
116 * struct usb_function - describes one function of a configuration
117 * @name: For diagnostics, identifies the function.
118 * @strings: tables of strings, keyed by identifiers assigned during bind()
119 * and by language IDs provided in control requests
120 * @fs_descriptors: Table of full (or low) speed descriptors, using interface and
121 * string identifiers assigned during @bind(). If this pointer is null,
122 * the function will not be available at full speed (or at low speed).
123 * @hs_descriptors: Table of high speed descriptors, using interface and
124 * string identifiers assigned during @bind(). If this pointer is null,
125 * the function will not be available at high speed.
126 * @ss_descriptors: Table of super speed descriptors, using interface and
127 * string identifiers assigned during @bind(). If this
128 * pointer is null after initiation, the function will not
129 * be available at super speed.
130 * @ssp_descriptors: Table of super speed plus descriptors, using
131 * interface and string identifiers assigned during @bind(). If
132 * this pointer is null after initiation, the function will not
133 * be available at super speed plus.
134 * @config: assigned when @usb_add_function() is called; this is the
135 * configuration with which this function is associated.
136 * @os_desc_table: Table of (interface id, os descriptors) pairs. The function
137 * can expose more than one interface. If an interface is a member of
138 * an IAD, only the first interface of IAD has its entry in the table.
139 * @os_desc_n: Number of entries in os_desc_table
140 * @bind: Before the gadget can register, all of its functions bind() to the
141 * available resources including string and interface identifiers used
142 * in interface or class descriptors; endpoints; I/O buffers; and so on.
143 * @unbind: Reverses @bind; called as a side effect of unregistering the
144 * driver which added this function.
145 * @free_func: free the struct usb_function.
146 * @mod: (internal) points to the module that created this structure.
147 * @set_alt: (REQUIRED) Reconfigures altsettings; function drivers may
148 * initialize usb_ep.driver data at this time (when it is used).
149 * Note that setting an interface to its current altsetting resets
150 * interface state, and that all interfaces have a disabled state.
151 * @get_alt: Returns the active altsetting. If this is not provided,
152 * then only altsetting zero is supported.
153 * @disable: (REQUIRED) Indicates the function should be disabled. Reasons
154 * include host resetting or reconfiguring the gadget, and disconnection.
155 * @setup: Used for interface-specific control requests.
156 * @req_match: Tests if a given class request can be handled by this function.
157 * @suspend: Notifies functions when the host stops sending USB traffic.
158 * @resume: Notifies functions when the host restarts USB traffic.
159 * @get_status: Returns function status as a reply to
160 * GetStatus() request when the recipient is Interface.
161 * @func_suspend: callback to be called when
162 * SetFeature(FUNCTION_SUSPEND) is reseived
164 * A single USB function uses one or more interfaces, and should in most
165 * cases support operation at both full and high speeds. Each function is
166 * associated by @usb_add_function() with a one configuration; that function
167 * causes @bind() to be called so resources can be allocated as part of
168 * setting up a gadget driver. Those resources include endpoints, which
169 * should be allocated using @usb_ep_autoconfig().
171 * To support dual speed operation, a function driver provides descriptors
172 * for both high and full speed operation. Except in rare cases that don't
173 * involve bulk endpoints, each speed needs different endpoint descriptors.
175 * Function drivers choose their own strategies for managing instance data.
176 * The simplest strategy just declares it "static', which means the function
177 * can only be activated once. If the function needs to be exposed in more
178 * than one configuration at a given speed, it needs to support multiple
179 * usb_function structures (one for each configuration).
181 * A more complex strategy might encapsulate a @usb_function structure inside
182 * a driver-specific instance structure to allows multiple activations. An
183 * example of multiple activations might be a CDC ACM function that supports
184 * two or more distinct instances within the same configuration, providing
185 * several independent logical data links to a USB host.
188 struct usb_function
{
190 struct usb_gadget_strings
**strings
;
191 struct usb_descriptor_header
**fs_descriptors
;
192 struct usb_descriptor_header
**hs_descriptors
;
193 struct usb_descriptor_header
**ss_descriptors
;
194 struct usb_descriptor_header
**ssp_descriptors
;
196 struct usb_configuration
*config
;
198 struct usb_os_desc_table
*os_desc_table
;
201 /* REVISIT: bind() functions can be marked __init, which
202 * makes trouble for section mismatch analysis. See if
203 * we can't restructure things to avoid mismatching.
204 * Related: unbind() may kfree() but bind() won't...
207 /* configuration management: bind/unbind */
208 int (*bind
)(struct usb_configuration
*,
209 struct usb_function
*);
210 void (*unbind
)(struct usb_configuration
*,
211 struct usb_function
*);
212 void (*free_func
)(struct usb_function
*f
);
215 /* runtime state management */
216 int (*set_alt
)(struct usb_function
*,
217 unsigned interface
, unsigned alt
);
218 int (*get_alt
)(struct usb_function
*,
220 void (*disable
)(struct usb_function
*);
221 int (*setup
)(struct usb_function
*,
222 const struct usb_ctrlrequest
*);
223 bool (*req_match
)(struct usb_function
*,
224 const struct usb_ctrlrequest
*,
226 void (*suspend
)(struct usb_function
*);
227 void (*resume
)(struct usb_function
*);
229 /* USB 3.0 additions */
230 int (*get_status
)(struct usb_function
*);
231 int (*func_suspend
)(struct usb_function
*,
235 struct list_head list
;
236 DECLARE_BITMAP(endpoints
, 32);
237 const struct usb_function_instance
*fi
;
239 unsigned int bind_deactivated
:1;
242 int usb_add_function(struct usb_configuration
*, struct usb_function
*);
244 int usb_function_deactivate(struct usb_function
*);
245 int usb_function_activate(struct usb_function
*);
247 int usb_interface_id(struct usb_configuration
*, struct usb_function
*);
249 int config_ep_by_speed(struct usb_gadget
*g
, struct usb_function
*f
,
252 #define MAX_CONFIG_INTERFACES 16 /* arbitrary; max 255 */
255 * struct usb_configuration - represents one gadget configuration
256 * @label: For diagnostics, describes the configuration.
257 * @strings: Tables of strings, keyed by identifiers assigned during @bind()
258 * and by language IDs provided in control requests.
259 * @descriptors: Table of descriptors preceding all function descriptors.
260 * Examples include OTG and vendor-specific descriptors.
261 * @unbind: Reverses @bind; called as a side effect of unregistering the
262 * driver which added this configuration.
263 * @setup: Used to delegate control requests that aren't handled by standard
264 * device infrastructure or directed at a specific interface.
265 * @bConfigurationValue: Copied into configuration descriptor.
266 * @iConfiguration: Copied into configuration descriptor.
267 * @bmAttributes: Copied into configuration descriptor.
268 * @MaxPower: Power consumtion in mA. Used to compute bMaxPower in the
269 * configuration descriptor after considering the bus speed.
270 * @cdev: assigned by @usb_add_config() before calling @bind(); this is
271 * the device associated with this configuration.
273 * Configurations are building blocks for gadget drivers structured around
274 * function drivers. Simple USB gadgets require only one function and one
275 * configuration, and handle dual-speed hardware by always providing the same
276 * functionality. Slightly more complex gadgets may have more than one
277 * single-function configuration at a given speed; or have configurations
278 * that only work at one speed.
280 * Composite devices are, by definition, ones with configurations which
281 * include more than one function.
283 * The lifecycle of a usb_configuration includes allocation, initialization
284 * of the fields described above, and calling @usb_add_config() to set up
285 * internal data and bind it to a specific device. The configuration's
286 * @bind() method is then used to initialize all the functions and then
287 * call @usb_add_function() for them.
289 * Those functions would normally be independent of each other, but that's
290 * not mandatory. CDC WMC devices are an example where functions often
291 * depend on other functions, with some functions subsidiary to others.
292 * Such interdependency may be managed in any way, so long as all of the
293 * descriptors complete by the time the composite driver returns from
294 * its bind() routine.
296 struct usb_configuration
{
298 struct usb_gadget_strings
**strings
;
299 const struct usb_descriptor_header
**descriptors
;
301 /* REVISIT: bind() functions can be marked __init, which
302 * makes trouble for section mismatch analysis. See if
303 * we can't restructure things to avoid mismatching...
306 /* configuration management: unbind/setup */
307 void (*unbind
)(struct usb_configuration
*);
308 int (*setup
)(struct usb_configuration
*,
309 const struct usb_ctrlrequest
*);
311 /* fields in the config descriptor */
312 u8 bConfigurationValue
;
317 struct usb_composite_dev
*cdev
;
321 struct list_head list
;
322 struct list_head functions
;
323 u8 next_interface_id
;
324 unsigned superspeed
:1;
325 unsigned highspeed
:1;
326 unsigned fullspeed
:1;
327 unsigned superspeed_plus
:1;
328 struct usb_function
*interface
[MAX_CONFIG_INTERFACES
];
331 int usb_add_config(struct usb_composite_dev
*,
332 struct usb_configuration
*,
333 int (*)(struct usb_configuration
*));
335 void usb_remove_config(struct usb_composite_dev
*,
336 struct usb_configuration
*);
338 /* predefined index for usb_composite_driver */
340 USB_GADGET_MANUFACTURER_IDX
= 0,
341 USB_GADGET_PRODUCT_IDX
,
342 USB_GADGET_SERIAL_IDX
,
343 USB_GADGET_FIRST_AVAIL_IDX
,
347 * struct usb_composite_driver - groups configurations into a gadget
348 * @name: For diagnostics, identifies the driver.
349 * @dev: Template descriptor for the device, including default device
351 * @strings: tables of strings, keyed by identifiers assigned during @bind
352 * and language IDs provided in control requests. Note: The first entries
353 * are predefined. The first entry that may be used is
354 * USB_GADGET_FIRST_AVAIL_IDX
355 * @max_speed: Highest speed the driver supports.
356 * @needs_serial: set to 1 if the gadget needs userspace to provide
357 * a serial number. If one is not provided, warning will be printed.
358 * @bind: (REQUIRED) Used to allocate resources that are shared across the
359 * whole device, such as string IDs, and add its configurations using
360 * @usb_add_config(). This may fail by returning a negative errno
361 * value; it should return zero on successful initialization.
362 * @unbind: Reverses @bind; called as a side effect of unregistering
364 * @disconnect: optional driver disconnect method
365 * @suspend: Notifies when the host stops sending USB traffic,
366 * after function notifications
367 * @resume: Notifies configuration when the host restarts USB traffic,
368 * before function notifications
369 * @gadget_driver: Gadget driver controlling this driver
371 * Devices default to reporting self powered operation. Devices which rely
372 * on bus powered operation should report this in their @bind method.
374 * Before returning from @bind, various fields in the template descriptor
375 * may be overridden. These include the idVendor/idProduct/bcdDevice values
376 * normally to bind the appropriate host side driver, and the three strings
377 * (iManufacturer, iProduct, iSerialNumber) normally used to provide user
378 * meaningful device identifiers. (The strings will not be defined unless
379 * they are defined in @dev and @strings.) The correct ep0 maxpacket size
380 * is also reported, as defined by the underlying controller driver.
382 struct usb_composite_driver
{
384 const struct usb_device_descriptor
*dev
;
385 struct usb_gadget_strings
**strings
;
386 enum usb_device_speed max_speed
;
387 unsigned needs_serial
:1;
389 int (*bind
)(struct usb_composite_dev
*cdev
);
390 int (*unbind
)(struct usb_composite_dev
*);
392 void (*disconnect
)(struct usb_composite_dev
*);
394 /* global suspend hooks */
395 void (*suspend
)(struct usb_composite_dev
*);
396 void (*resume
)(struct usb_composite_dev
*);
397 struct usb_gadget_driver gadget_driver
;
400 extern int usb_composite_probe(struct usb_composite_driver
*driver
);
401 extern void usb_composite_unregister(struct usb_composite_driver
*driver
);
404 * module_usb_composite_driver() - Helper macro for registering a USB gadget
406 * @__usb_composite_driver: usb_composite_driver struct
408 * Helper macro for USB gadget composite drivers which do not do anything
409 * special in module init/exit. This eliminates a lot of boilerplate. Each
410 * module may only use this macro once, and calling it replaces module_init()
413 #define module_usb_composite_driver(__usb_composite_driver) \
414 module_driver(__usb_composite_driver, usb_composite_probe, \
415 usb_composite_unregister)
417 extern void usb_composite_setup_continue(struct usb_composite_dev
*cdev
);
418 extern int composite_dev_prepare(struct usb_composite_driver
*composite
,
419 struct usb_composite_dev
*cdev
);
420 extern int composite_os_desc_req_prepare(struct usb_composite_dev
*cdev
,
422 void composite_dev_cleanup(struct usb_composite_dev
*cdev
);
424 static inline struct usb_composite_driver
*to_cdriver(
425 struct usb_gadget_driver
*gdrv
)
427 return container_of(gdrv
, struct usb_composite_driver
, gadget_driver
);
430 #define OS_STRING_QW_SIGN_LEN 14
431 #define OS_STRING_IDX 0xEE
434 * struct usb_composite_device - represents one composite usb gadget
435 * @gadget: read-only, abstracts the gadget's usb peripheral controller
436 * @req: used for control responses; buffer is pre-allocated
437 * @os_desc_req: used for OS descriptors responses; buffer is pre-allocated
438 * @config: the currently active configuration
439 * @qw_sign: qwSignature part of the OS string
440 * @b_vendor_code: bMS_VendorCode part of the OS string
441 * @use_os_string: false by default, interested gadgets set it
442 * @os_desc_config: the configuration to be used with OS descriptors
443 * @setup_pending: true when setup request is queued but not completed
444 * @os_desc_pending: true when os_desc request is queued but not completed
446 * One of these devices is allocated and initialized before the
447 * associated device driver's bind() is called.
449 * OPEN ISSUE: it appears that some WUSB devices will need to be
450 * built by combining a normal (wired) gadget with a wireless one.
451 * This revision of the gadget framework should probably try to make
452 * sure doing that won't hurt too much.
454 * One notion for how to handle Wireless USB devices involves:
456 * (a) a second gadget here, discovery mechanism TBD, but likely
457 * needing separate "register/unregister WUSB gadget" calls;
458 * (b) updates to usb_gadget to include flags "is it wireless",
459 * "is it wired", plus (presumably in a wrapper structure)
460 * bandgroup and PHY info;
461 * (c) presumably a wireless_ep wrapping a usb_ep, and reporting
462 * wireless-specific parameters like maxburst and maxsequence;
463 * (d) configurations that are specific to wireless links;
464 * (e) function drivers that understand wireless configs and will
465 * support wireless for (additional) function instances;
466 * (f) a function to support association setup (like CBAF), not
467 * necessarily requiring a wireless adapter;
468 * (g) composite device setup that can create one or more wireless
469 * configs, including appropriate association setup support;
472 struct usb_composite_dev
{
473 struct usb_gadget
*gadget
;
474 struct usb_request
*req
;
475 struct usb_request
*os_desc_req
;
477 struct usb_configuration
*config
;
479 /* OS String is a custom (yet popular) extension to the USB standard. */
480 u8 qw_sign
[OS_STRING_QW_SIGN_LEN
];
482 struct usb_configuration
*os_desc_config
;
483 unsigned int use_os_string
:1;
487 unsigned int suspended
:1;
488 struct usb_device_descriptor desc
;
489 struct list_head configs
;
490 struct list_head gstrings
;
491 struct usb_composite_driver
*driver
;
493 char *def_manufacturer
;
495 /* the gadget driver won't enable the data pullup
496 * while the deactivation count is nonzero.
498 unsigned deactivations
;
500 /* the composite driver won't complete the control transfer's
501 * data/status stages till delayed_status is zero.
505 /* protects deactivations and delayed_status counts*/
509 unsigned int setup_pending
:1;
510 unsigned int os_desc_pending
:1;
513 extern int usb_string_id(struct usb_composite_dev
*c
);
514 extern int usb_string_ids_tab(struct usb_composite_dev
*c
,
515 struct usb_string
*str
);
516 extern struct usb_string
*usb_gstrings_attach(struct usb_composite_dev
*cdev
,
517 struct usb_gadget_strings
**sp
, unsigned n_strings
);
519 extern int usb_string_ids_n(struct usb_composite_dev
*c
, unsigned n
);
521 extern void composite_disconnect(struct usb_gadget
*gadget
);
522 extern int composite_setup(struct usb_gadget
*gadget
,
523 const struct usb_ctrlrequest
*ctrl
);
524 extern void composite_suspend(struct usb_gadget
*gadget
);
525 extern void composite_resume(struct usb_gadget
*gadget
);
528 * Some systems will need runtime overrides for the product identifiers
529 * published in the device descriptor, either numbers or strings or both.
530 * String parameters are in UTF-8 (superset of ASCII's 7 bit characters).
532 struct usb_composite_overwrite
{
540 #define USB_GADGET_COMPOSITE_OPTIONS() \
541 static struct usb_composite_overwrite coverwrite; \
543 module_param_named(idVendor, coverwrite.idVendor, ushort, S_IRUGO); \
544 MODULE_PARM_DESC(idVendor, "USB Vendor ID"); \
546 module_param_named(idProduct, coverwrite.idProduct, ushort, S_IRUGO); \
547 MODULE_PARM_DESC(idProduct, "USB Product ID"); \
549 module_param_named(bcdDevice, coverwrite.bcdDevice, ushort, S_IRUGO); \
550 MODULE_PARM_DESC(bcdDevice, "USB Device version (BCD)"); \
552 module_param_named(iSerialNumber, coverwrite.serial_number, charp, \
554 MODULE_PARM_DESC(iSerialNumber, "SerialNumber string"); \
556 module_param_named(iManufacturer, coverwrite.manufacturer, charp, \
558 MODULE_PARM_DESC(iManufacturer, "USB Manufacturer string"); \
560 module_param_named(iProduct, coverwrite.product, charp, S_IRUGO); \
561 MODULE_PARM_DESC(iProduct, "USB Product string")
563 void usb_composite_overwrite_options(struct usb_composite_dev
*cdev
,
564 struct usb_composite_overwrite
*covr
);
566 static inline u16
get_default_bcdDevice(void)
570 bcdDevice
= bin2bcd((LINUX_VERSION_CODE
>> 16 & 0xff)) << 8;
571 bcdDevice
|= bin2bcd((LINUX_VERSION_CODE
>> 8 & 0xff));
575 struct usb_function_driver
{
578 struct list_head list
;
579 struct usb_function_instance
*(*alloc_inst
)(void);
580 struct usb_function
*(*alloc_func
)(struct usb_function_instance
*inst
);
583 struct usb_function_instance
{
584 struct config_group group
;
585 struct list_head cfs_list
;
586 struct usb_function_driver
*fd
;
587 int (*set_inst_name
)(struct usb_function_instance
*inst
,
589 void (*free_func_inst
)(struct usb_function_instance
*inst
);
592 void usb_function_unregister(struct usb_function_driver
*f
);
593 int usb_function_register(struct usb_function_driver
*newf
);
594 void usb_put_function_instance(struct usb_function_instance
*fi
);
595 void usb_put_function(struct usb_function
*f
);
596 struct usb_function_instance
*usb_get_function_instance(const char *name
);
597 struct usb_function
*usb_get_function(struct usb_function_instance
*fi
);
599 struct usb_configuration
*usb_get_config(struct usb_composite_dev
*cdev
,
601 int usb_add_config_only(struct usb_composite_dev
*cdev
,
602 struct usb_configuration
*config
);
603 void usb_remove_function(struct usb_configuration
*c
, struct usb_function
*f
);
605 #define DECLARE_USB_FUNCTION(_name, _inst_alloc, _func_alloc) \
606 static struct usb_function_driver _name ## usb_func = { \
607 .name = __stringify(_name), \
608 .mod = THIS_MODULE, \
609 .alloc_inst = _inst_alloc, \
610 .alloc_func = _func_alloc, \
612 MODULE_ALIAS("usbfunc:"__stringify(_name));
614 #define DECLARE_USB_FUNCTION_INIT(_name, _inst_alloc, _func_alloc) \
615 DECLARE_USB_FUNCTION(_name, _inst_alloc, _func_alloc) \
616 static int __init _name ## mod_init(void) \
618 return usb_function_register(&_name ## usb_func); \
620 static void __exit _name ## mod_exit(void) \
622 usb_function_unregister(&_name ## usb_func); \
624 module_init(_name ## mod_init); \
625 module_exit(_name ## mod_exit)
627 /* messaging utils */
628 #define DBG(d, fmt, args...) \
629 dev_dbg(&(d)->gadget->dev , fmt , ## args)
630 #define VDBG(d, fmt, args...) \
631 dev_vdbg(&(d)->gadget->dev , fmt , ## args)
632 #define ERROR(d, fmt, args...) \
633 dev_err(&(d)->gadget->dev , fmt , ## args)
634 #define WARNING(d, fmt, args...) \
635 dev_warn(&(d)->gadget->dev , fmt , ## args)
636 #define INFO(d, fmt, args...) \
637 dev_info(&(d)->gadget->dev , fmt , ## args)
639 #endif /* __LINUX_USB_COMPOSITE_H */