diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /Documentation/usb/gadget_serial.txt |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
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1 | |||
2 | Linux Gadget Serial Driver v2.0 | ||
3 | 11/20/2004 | ||
4 | |||
5 | |||
6 | License and Disclaimer | ||
7 | ---------------------- | ||
8 | This program is free software; you can redistribute it and/or | ||
9 | modify it under the terms of the GNU General Public License as | ||
10 | published by the Free Software Foundation; either version 2 of | ||
11 | the License, or (at your option) any later version. | ||
12 | |||
13 | This program is distributed in the hope that it will be useful, | ||
14 | but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
16 | GNU General Public License for more details. | ||
17 | |||
18 | You should have received a copy of the GNU General Public | ||
19 | License along with this program; if not, write to the Free | ||
20 | Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, | ||
21 | MA 02111-1307 USA. | ||
22 | |||
23 | This document and the the gadget serial driver itself are | ||
24 | Copyright (C) 2004 by Al Borchers (alborchers@steinerpoint.com). | ||
25 | |||
26 | If you have questions, problems, or suggestions for this driver | ||
27 | please contact Al Borchers at alborchers@steinerpoint.com. | ||
28 | |||
29 | |||
30 | Prerequisites | ||
31 | ------------- | ||
32 | Versions of the gadget serial driver are available for the | ||
33 | 2.4 Linux kernels, but this document assumes you are using | ||
34 | version 2.0 or later of the gadget serial driver in a 2.6 | ||
35 | Linux kernel. | ||
36 | |||
37 | This document assumes that you are familiar with Linux and | ||
38 | Windows and know how to configure and build Linux kernels, run | ||
39 | standard utilities, use minicom and HyperTerminal, and work with | ||
40 | USB and serial devices. It also assumes you configure the Linux | ||
41 | gadget and usb drivers as modules. | ||
42 | |||
43 | |||
44 | Overview | ||
45 | -------- | ||
46 | The gadget serial driver is a Linux USB gadget driver, a USB device | ||
47 | side driver. It runs on a Linux system that has USB device side | ||
48 | hardware; for example, a PDA, an embedded Linux system, or a PC | ||
49 | with a USB development card. | ||
50 | |||
51 | The gadget serial driver talks over USB to either a CDC ACM driver | ||
52 | or a generic USB serial driver running on a host PC. | ||
53 | |||
54 | Host | ||
55 | -------------------------------------- | ||
56 | | Host-Side CDC ACM USB Host | | ||
57 | | Operating | or | Controller | USB | ||
58 | | System | Generic USB | Driver |-------- | ||
59 | | (Linux or | Serial | and | | | ||
60 | | Windows) Driver USB Stack | | | ||
61 | -------------------------------------- | | ||
62 | | | ||
63 | | | ||
64 | | | ||
65 | Gadget | | ||
66 | -------------------------------------- | | ||
67 | | Gadget USB Periph. | | | ||
68 | | Device-Side | Gadget | Controller | | | ||
69 | | Linux | Serial | Driver |-------- | ||
70 | | Operating | Driver | and | | ||
71 | | System USB Stack | | ||
72 | -------------------------------------- | ||
73 | |||
74 | On the device-side Linux system, the gadget serial driver looks | ||
75 | like a serial device. | ||
76 | |||
77 | On the host-side system, the gadget serial device looks like a | ||
78 | CDC ACM compliant class device or a simple vendor specific device | ||
79 | with bulk in and bulk out endpoints, and it is treated similarly | ||
80 | to other serial devices. | ||
81 | |||
82 | The host side driver can potentially be any ACM compliant driver | ||
83 | or any driver that can talk to a device with a simple bulk in/out | ||
84 | interface. Gadget serial has been tested with the Linux ACM driver, | ||
85 | the Windows usbser.sys ACM driver, and the Linux USB generic serial | ||
86 | driver. | ||
87 | |||
88 | With the gadget serial driver and the host side ACM or generic | ||
89 | serial driver running, you should be able to communicate between | ||
90 | the host and the gadget side systems as if they were connected by a | ||
91 | serial cable. | ||
92 | |||
93 | The gadget serial driver only provides simple unreliable data | ||
94 | communication. It does not yet handle flow control or many other | ||
95 | features of normal serial devices. | ||
96 | |||
97 | |||
98 | Installing the Gadget Serial Driver | ||
99 | ----------------------------------- | ||
100 | To use the gadget serial driver you must configure the Linux gadget | ||
101 | side kernel for "Support for USB Gadgets", for a "USB Peripheral | ||
102 | Controller" (for example, net2280), and for the "Serial Gadget" | ||
103 | driver. All this are listed under "USB Gadget Support" when | ||
104 | configuring the kernel. Then rebuild and install the kernel or | ||
105 | modules. | ||
106 | |||
107 | The gadget serial driver uses major number 127, for now. So you | ||
108 | will need to create a device node for it, like this: | ||
109 | |||
110 | mknod /dev/ttygserial c 127 0 | ||
111 | |||
112 | You only need to do this once. | ||
113 | |||
114 | Then you must load the gadget serial driver. To load it as an | ||
115 | ACM device, do this: | ||
116 | |||
117 | modprobe g_serial use_acm=1 | ||
118 | |||
119 | To load it as a vendor specific bulk in/out device, do this: | ||
120 | |||
121 | modprobe g_serial | ||
122 | |||
123 | This will also automatically load the underlying gadget peripheral | ||
124 | controller driver. This must be done each time you reboot the gadget | ||
125 | side Linux system. You can add this to the start up scripts, if | ||
126 | desired. | ||
127 | |||
128 | If gadget serial is loaded as an ACM device you will want to use | ||
129 | either the Windows or Linux ACM driver on the host side. If gadget | ||
130 | serial is loaded as a bulk in/out device, you will want to use the | ||
131 | Linux generic serial driver on the host side. Follow the appropriate | ||
132 | instructions below to install the host side driver. | ||
133 | |||
134 | |||
135 | Installing the Windows Host ACM Driver | ||
136 | -------------------------------------- | ||
137 | To use the Windows ACM driver you must have the files "gserial.inf" | ||
138 | and "usbser.sys" together in a folder on the Windows machine. | ||
139 | |||
140 | The "gserial.inf" file is given here. | ||
141 | |||
142 | -------------------- CUT HERE -------------------- | ||
143 | [Version] | ||
144 | Signature="$Windows NT$" | ||
145 | Class=Ports | ||
146 | ClassGuid={4D36E978-E325-11CE-BFC1-08002BE10318} | ||
147 | Provider=%LINUX% | ||
148 | DriverVer=08/17/2004,0.0.2.0 | ||
149 | ; Copyright (C) 2004 Al Borchers (alborchers@steinerpoint.com) | ||
150 | |||
151 | [Manufacturer] | ||
152 | %LINUX%=GSerialDeviceList | ||
153 | |||
154 | [GSerialDeviceList] | ||
155 | %GSERIAL%=GSerialInstall, USB\VID_0525&PID_A4A7 | ||
156 | |||
157 | [DestinationDirs] | ||
158 | DefaultDestDir=10,System32\Drivers | ||
159 | |||
160 | [GSerialInstall] | ||
161 | CopyFiles=GSerialCopyFiles | ||
162 | AddReg=GSerialAddReg | ||
163 | |||
164 | [GSerialCopyFiles] | ||
165 | usbser.sys | ||
166 | |||
167 | [GSerialAddReg] | ||
168 | HKR,,DevLoader,,*ntkern | ||
169 | HKR,,NTMPDriver,,usbser.sys | ||
170 | HKR,,EnumPropPages32,,"MsPorts.dll,SerialPortPropPageProvider" | ||
171 | |||
172 | [GSerialInstall.Services] | ||
173 | AddService = usbser,0x0002,GSerialService | ||
174 | |||
175 | [GSerialService] | ||
176 | DisplayName = %GSERIAL_DISPLAY_NAME% | ||
177 | ServiceType = 1 ; SERVICE_KERNEL_DRIVER | ||
178 | StartType = 3 ; SERVICE_DEMAND_START | ||
179 | ErrorControl = 1 ; SERVICE_ERROR_NORMAL | ||
180 | ServiceBinary = %10%\System32\Drivers\usbser.sys | ||
181 | LoadOrderGroup = Base | ||
182 | |||
183 | [Strings] | ||
184 | LINUX = "Linux" | ||
185 | GSERIAL = "Gadget Serial" | ||
186 | GSERIAL_DISPLAY_NAME = "USB Gadget Serial Driver" | ||
187 | -------------------- CUT HERE -------------------- | ||
188 | |||
189 | The "usbser.sys" file comes with various versions of Windows. | ||
190 | For example, it can be found on Windows XP typically in | ||
191 | |||
192 | C:\WINDOWS\Driver Cache\i386\driver.cab | ||
193 | |||
194 | Or it can be found on the Windows 98SE CD in the "win98" folder | ||
195 | in the "DRIVER11.CAB" through "DRIVER20.CAB" cab files. You will | ||
196 | need the DOS "expand" program, the Cygwin "cabextract" program, or | ||
197 | a similar program to unpack these cab files and extract "usbser.sys". | ||
198 | |||
199 | For example, to extract "usbser.sys" into the current directory | ||
200 | on Windows XP, open a DOS window and run a command like | ||
201 | |||
202 | expand C:\WINDOWS\Driver~1\i386\driver.cab -F:usbser.sys . | ||
203 | |||
204 | (Thanks to Nishant Kamat for pointing out this DOS command.) | ||
205 | |||
206 | When the gadget serial driver is loaded and the USB device connected | ||
207 | to the Windows host with a USB cable, Windows should recognize the | ||
208 | gadget serial device and ask for a driver. Tell Windows to find the | ||
209 | driver in the folder that contains "gserial.inf" and "usbser.sys". | ||
210 | |||
211 | For example, on Windows XP, when the gadget serial device is first | ||
212 | plugged in, the "Found New Hardware Wizard" starts up. Select | ||
213 | "Install from a list or specific location (Advanced)", then on | ||
214 | the next screen select "Include this location in the search" and | ||
215 | enter the path or browse to the folder containing "gserial.inf" and | ||
216 | "usbser.sys". Windows will complain that the Gadget Serial driver | ||
217 | has not passed Windows Logo testing, but select "Continue anyway" | ||
218 | and finish the driver installation. | ||
219 | |||
220 | On Windows XP, in the "Device Manager" (under "Control Panel", | ||
221 | "System", "Hardware") expand the "Ports (COM & LPT)" entry and you | ||
222 | should see "Gadget Serial" listed as the driver for one of the COM | ||
223 | ports. | ||
224 | |||
225 | To uninstall the Windows XP driver for "Gadget Serial", right click | ||
226 | on the "Gadget Serial" entry in the "Device Manager" and select | ||
227 | "Uninstall". | ||
228 | |||
229 | |||
230 | Installing the Linux Host ACM Driver | ||
231 | ------------------------------------ | ||
232 | To use the Linux ACM driver you must configure the Linux host side | ||
233 | kernel for "Support for Host-side USB" and for "USB Modem (CDC ACM) | ||
234 | support". | ||
235 | |||
236 | Once the gadget serial driver is loaded and the USB device connected | ||
237 | to the Linux host with a USB cable, the host system should recognize | ||
238 | the gadget serial device. For example, the command | ||
239 | |||
240 | cat /proc/bus/usb/devices | ||
241 | |||
242 | should show something like this: | ||
243 | |||
244 | T: Bus=01 Lev=01 Prnt=01 Port=01 Cnt=02 Dev#= 5 Spd=480 MxCh= 0 | ||
245 | D: Ver= 2.00 Cls=02(comm.) Sub=00 Prot=00 MxPS=64 #Cfgs= 1 | ||
246 | P: Vendor=0525 ProdID=a4a7 Rev= 2.01 | ||
247 | S: Manufacturer=Linux 2.6.8.1 with net2280 | ||
248 | S: Product=Gadget Serial | ||
249 | S: SerialNumber=0 | ||
250 | C:* #Ifs= 2 Cfg#= 2 Atr=c0 MxPwr= 2mA | ||
251 | I: If#= 0 Alt= 0 #EPs= 1 Cls=02(comm.) Sub=02 Prot=01 Driver=acm | ||
252 | E: Ad=83(I) Atr=03(Int.) MxPS= 8 Ivl=32ms | ||
253 | I: If#= 1 Alt= 0 #EPs= 2 Cls=0a(data ) Sub=00 Prot=00 Driver=acm | ||
254 | E: Ad=81(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms | ||
255 | E: Ad=02(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms | ||
256 | |||
257 | If the host side Linux system is configured properly, the ACM driver | ||
258 | should be loaded automatically. The command "lsmod" should show the | ||
259 | "acm" module is loaded. | ||
260 | |||
261 | |||
262 | Installing the Linux Host Generic USB Serial Driver | ||
263 | --------------------------------------------------- | ||
264 | To use the Linux generic USB serial driver you must configure the | ||
265 | Linux host side kernel for "Support for Host-side USB", for "USB | ||
266 | Serial Converter support", and for the "USB Generic Serial Driver". | ||
267 | |||
268 | Once the gadget serial driver is loaded and the USB device connected | ||
269 | to the Linux host with a USB cable, the host system should recognize | ||
270 | the gadget serial device. For example, the command | ||
271 | |||
272 | cat /proc/bus/usb/devices | ||
273 | |||
274 | should show something like this: | ||
275 | |||
276 | T: Bus=01 Lev=01 Prnt=01 Port=01 Cnt=02 Dev#= 6 Spd=480 MxCh= 0 | ||
277 | D: Ver= 2.00 Cls=ff(vend.) Sub=00 Prot=00 MxPS=64 #Cfgs= 1 | ||
278 | P: Vendor=0525 ProdID=a4a6 Rev= 2.01 | ||
279 | S: Manufacturer=Linux 2.6.8.1 with net2280 | ||
280 | S: Product=Gadget Serial | ||
281 | S: SerialNumber=0 | ||
282 | C:* #Ifs= 1 Cfg#= 1 Atr=c0 MxPwr= 2mA | ||
283 | I: If#= 0 Alt= 0 #EPs= 2 Cls=0a(data ) Sub=00 Prot=00 Driver=serial | ||
284 | E: Ad=81(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms | ||
285 | E: Ad=02(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms | ||
286 | |||
287 | You must explicitly load the usbserial driver with parameters to | ||
288 | configure it to recognize the gadget serial device, like this: | ||
289 | |||
290 | modprobe usbserial vendor=0x0525 product=0xA4A6 | ||
291 | |||
292 | If everything is working, usbserial will print a message in the | ||
293 | system log saying something like "Gadget Serial converter now | ||
294 | attached to ttyUSB0". | ||
295 | |||
296 | |||
297 | Testing with Minicom or HyperTerminal | ||
298 | ------------------------------------- | ||
299 | Once the gadget serial driver and the host driver are both installed, | ||
300 | and a USB cable connects the gadget device to the host, you should | ||
301 | be able to communicate over USB between the gadget and host systems. | ||
302 | You can use minicom or HyperTerminal to try this out. | ||
303 | |||
304 | On the gadget side run "minicom -s" to configure a new minicom | ||
305 | session. Under "Serial port setup" set "/dev/ttygserial" as the | ||
306 | "Serial Device". Set baud rate, data bits, parity, and stop bits, | ||
307 | to 9600, 8, none, and 1--these settings mostly do not matter. | ||
308 | Under "Modem and dialing" erase all the modem and dialing strings. | ||
309 | |||
310 | On a Linux host running the ACM driver, configure minicom similarly | ||
311 | but use "/dev/ttyACM0" as the "Serial Device". (If you have other | ||
312 | ACM devices connected, change the device name appropriately.) | ||
313 | |||
314 | On a Linux host running the USB generic serial driver, configure | ||
315 | minicom similarly, but use "/dev/ttyUSB0" as the "Serial Device". | ||
316 | (If you have other USB serial devices connected, change the device | ||
317 | name appropriately.) | ||
318 | |||
319 | On a Windows host configure a new HyperTerminal session to use the | ||
320 | COM port assigned to Gadget Serial. The "Port Settings" will be | ||
321 | set automatically when HyperTerminal connects to the gadget serial | ||
322 | device, so you can leave them set to the default values--these | ||
323 | settings mostly do not matter. | ||
324 | |||
325 | With minicom configured and running on the gadget side and with | ||
326 | minicom or HyperTerminal configured and running on the host side, | ||
327 | you should be able to send data back and forth between the gadget | ||
328 | side and host side systems. Anything you type on the terminal | ||
329 | window on the gadget side should appear in the terminal window on | ||
330 | the host side and vice versa. | ||
331 | |||
332 | |||