Documentation/usb/gadget_configfs.rst

50 http://www.spinics.net/lists/linux-usb/msg76388.html)
55 	$ mount none $CONFIGFS_HOME -t configfs
60 -----------------------
81 A gadget also needs its serial number, manufacturer and product strings.
82 In order to have a place to store them, a strings subdirectory must be created
85 	$ mkdir strings/0x409
87 Then the strings can be specified::
89 	$ echo <serial number> > strings/0x409/serialnumber
90 	$ echo <manufacturer> > strings/0x409/manufacturer
91 	$ echo <product> > strings/0x409/product
97 	$ mkdir strings/0x409/xu.0
98 	$ echo <string text> > strings/0x409/xu.0/s
101 string descriptors to associate those strings with class descriptors.
104 ------------------------------
120 Each configuration also needs its strings, so a subdirectory must be created
123 	$ mkdir configs/c.1/strings/0x409
127 	$ echo <configuration> > configs/c.1/strings/0x409/configuration
134 -------------------------
150 Each function provides its specific set of attributes, with either read-only
151 or read-write access. Where applicable they need to be written to as
153 Please refer to Documentation/ABI/testing/configfs-usb-gadget for more information.
156 ------------------------------------------------------
164 	$ ln -s functions/<name>.<instance name> configs/<name>.<number>
168 	$ ln -s functions/ncm.usb0 configs/c.1
175 ----------------------
183   ./strings
184   ./strings/0x409
185   ./strings/0x409/serialnumber
186   ./strings/0x409/product
187   ./strings/0x409/manufacturer
190   ./configs/c.1/ncm.usb0 -> ../../../../usb_gadget/g1/functions/ncm.usb0
191   ./configs/c.1/strings
192   ./configs/c.1/strings/0x409
193   ./configs/c.1/strings/0x409/configuration
213 Such a gadget must be finally enabled so that the USB host can enumerate it.
223 	$ echo s3c-hsotg > UDC
227 -----------------------
234 --------------
249 Remove strings directories in configurations:
251 	$ rmdir configs/<config name>.<number>/strings/<lang>
255 	$ rmdir configs/c.1/strings/0x409
285 Remove strings directories in the gadget::
287 	$ rmdir strings/<lang>
291 	$ rmdir strings/0x409
314 which can be read-only or read-write, depending on what they represent.
318 configured elements. However, they are embedded in usage-specific
327      +--sa    (file)
349                          +----------------------------------+
351   +-----------------+    |  (*store)(cs *, buffer, length); |
353   | +-------------+ |    |       +------------------+       |
354   | | struct      |-|----|------>|struct            |       |
356   | +-------------+ |    |       +------------------+       |
357   |                 |    +----------------------------------+
360   +-----------------+                .
364 a number of its default sub-groups created automatically.
372 idProduct etc) and default sub-groups (configs, functions, strings).
374 appropriate locations. In the configs, functions and strings sub-groups
375 a user can create their sub-groups to represent configurations, functions,
376 and groups of strings in a given language.
387 	- gadget's config_group
388 	- gadget's default groups (configs, functions, strings)
389 	- associating functions with configurations (symlinks)