Documentation/usb/gadget_serial.rst

7 (updated 8-May-2008 for v2.3)
11 ----------------------
14 published by the Free Software Foundation; either version 2 of
15 the License, or (at your option) any later version.
25 MA 02111-1307 USA.
35 -------------
38 version 2.3 or later of the gadget serial driver in a 2.6
44 USB and serial devices.  It also assumes you configure the Linux
45 gadget and usb drivers as modules.
47 With version 2.3 of the driver, major and minor device nodes are
55 --------
56 The gadget serial driver is a Linux USB gadget driver, a USB device
57 side driver.  It runs on a Linux system that has USB device side
59 with a USB development card.
61 The gadget serial driver talks over USB to either a CDC ACM driver
62 or a generic USB serial driver running on a host PC::
65    --------------------------------------
66   | Host-Side   CDC ACM       USB Host   |
67   | Operating |   or        | Controller |   USB
68   | System    | Generic USB | Driver     |--------
70   | Windows)    Driver        USB Stack  |        |
71    --------------------------------------         |
76    --------------------------------------         |
77   | Gadget                   USB Periph. |        |
78   | Device-Side |  Gadget  | Controller  |        |
79   | Linux       |  Serial  | Driver      |--------
81   | System                   USB Stack   |
82    --------------------------------------
84 On the device-side Linux system, the gadget serial driver looks
87 On the host-side system, the gadget serial device looks like a
95 the Windows usbser.sys ACM driver, and the Linux USB generic serial
109 -----------------------------------
111 side kernel for "Support for USB Gadgets", for a "USB Peripheral
113 driver.  All this are listed under "USB Gadget Support" when
135   # ls -l /dev/ttyGS0 | cat
136   crw-rw----    1 root     root     253,   0 May  8 14:10 /dev/ttyGS0
139 Note that the major number (253, above) is system-specific.  If
156 --------------------------------------
157 To use the Windows ACM driver you must have the "linux-cdc-acm.inf"
161 When the gadget serial driver is loaded and the USB device connected
162 to the Windows host with a USB cable, Windows should recognize the
164 driver in the folder that contains the "linux-cdc-acm.inf" file.
170 path or browse to the folder containing the "linux-cdc-acm.inf" file.
186 ------------------------------------
188 kernel for "Support for Host-side USB" and for "USB Modem (CDC ACM)
191 Once the gadget serial driver is loaded and the USB device connected
192 to the Linux host with a USB cable, the host system should recognize
195   cat /sys/kernel/debug/usb/devices
217 Installing the Linux Host Generic USB Serial Driver
218 ---------------------------------------------------
219 To use the Linux generic USB serial driver you must configure the
220 Linux host side kernel for "Support for Host-side USB", for "USB
221 Serial Converter support", and for the "USB Generic Serial Driver".
223 Once the gadget serial driver is loaded and the USB device connected
224 to the Linux host with a USB cable, the host system should recognize
227   cat /sys/kernel/debug/usb/devices
245   echo 0x0525 0xA4A6 >/sys/bus/usb-serial/drivers/generic/new_id
257 -------------------------------------
259 and a USB cable connects the gadget device to the host, you should
260 be able to communicate over USB between the gadget and host systems.
263 On the gadget side run "minicom -s" to configure a new minicom
266 to 9600, 8, none, and 1--these settings mostly do not matter.
273 On a Linux host running the USB generic serial driver, configure
275 (If you have other USB serial devices connected, change the device
281 device, so you can leave them set to the default values--these