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authorFrank A Kingswood <frank@kingswood-consulting.co.uk>2007-08-22 15:48:58 -0400
committerGreg Kroah-Hartman <gregkh@suse.de>2007-10-12 17:55:29 -0400
commit6ce76104781a10554129791dc62c3104424f6d48 (patch)
tree0756774b493cce844b1d34f0df45fc6b462e79cf /drivers/usb
parent4ac0718e83821db53451614e098399004694aa81 (diff)
USB: Driver for CH341 USB-serial adaptor
This patch implements a USB serial port driver for the Winchiphead CH341 USB-RS232 Converter. This chip also implements an IEEE 1284 parallel port, I2C and SPI, but that is not supported by the driver. Signed-off-by: Frank A Kingswood <frank@kingswood-consulting.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb')
-rw-r--r--drivers/usb/serial/Kconfig10
-rw-r--r--drivers/usb/serial/Makefile1
-rw-r--r--drivers/usb/serial/ch341.c352
3 files changed, 363 insertions, 0 deletions
diff --git a/drivers/usb/serial/Kconfig b/drivers/usb/serial/Kconfig
index 43d6db696f90..99fefed77919 100644
--- a/drivers/usb/serial/Kconfig
+++ b/drivers/usb/serial/Kconfig
@@ -92,6 +92,16 @@ config USB_SERIAL_BELKIN
92 To compile this driver as a module, choose M here: the 92 To compile this driver as a module, choose M here: the
93 module will be called belkin_sa. 93 module will be called belkin_sa.
94 94
95config USB_SERIAL_CH341
96 tristate "USB Winchiphead CH341 Single Port Serial Driver"
97 depends on USB_SERIAL
98 help
99 Say Y here if you want to use a Winchiphead CH341 single port
100 USB to serial adapter.
101
102 To compile this driver as a module, choose M here: the
103 module will be called ch341.
104
95config USB_SERIAL_WHITEHEAT 105config USB_SERIAL_WHITEHEAT
96 tristate "USB ConnectTech WhiteHEAT Serial Driver" 106 tristate "USB ConnectTech WhiteHEAT Serial Driver"
97 depends on USB_SERIAL 107 depends on USB_SERIAL
diff --git a/drivers/usb/serial/Makefile b/drivers/usb/serial/Makefile
index 07a976eca6b7..d6fb384e52b2 100644
--- a/drivers/usb/serial/Makefile
+++ b/drivers/usb/serial/Makefile
@@ -15,6 +15,7 @@ obj-$(CONFIG_USB_SERIAL_AIRCABLE) += aircable.o
15obj-$(CONFIG_USB_SERIAL_AIRPRIME) += airprime.o 15obj-$(CONFIG_USB_SERIAL_AIRPRIME) += airprime.o
16obj-$(CONFIG_USB_SERIAL_ARK3116) += ark3116.o 16obj-$(CONFIG_USB_SERIAL_ARK3116) += ark3116.o
17obj-$(CONFIG_USB_SERIAL_BELKIN) += belkin_sa.o 17obj-$(CONFIG_USB_SERIAL_BELKIN) += belkin_sa.o
18obj-$(CONFIG_USB_SERIAL_CH341) += ch341.o
18obj-$(CONFIG_USB_SERIAL_CP2101) += cp2101.o 19obj-$(CONFIG_USB_SERIAL_CP2101) += cp2101.o
19obj-$(CONFIG_USB_SERIAL_CYBERJACK) += cyberjack.o 20obj-$(CONFIG_USB_SERIAL_CYBERJACK) += cyberjack.o
20obj-$(CONFIG_USB_SERIAL_CYPRESS_M8) += cypress_m8.o 21obj-$(CONFIG_USB_SERIAL_CYPRESS_M8) += cypress_m8.o
diff --git a/drivers/usb/serial/ch341.c b/drivers/usb/serial/ch341.c
new file mode 100644
index 000000000000..eb681069e24e
--- /dev/null
+++ b/drivers/usb/serial/ch341.c
@@ -0,0 +1,352 @@
1/*
2 * Copyright 2007, Frank A Kingswood <frank@kingswood-consulting.co.uk>
3 *
4 * ch341.c implements a serial port driver for the Winchiphead CH341.
5 *
6 * The CH341 device can be used to implement an RS232 asynchronous
7 * serial port, an IEEE-1284 parallel printer port or a memory-like
8 * interface. In all cases the CH341 supports an I2C interface as well.
9 * This driver only supports the asynchronous serial interface.
10 *
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License version
13 * 2 as published by the Free Software Foundation.
14 */
15
16#include <linux/kernel.h>
17#include <linux/init.h>
18#include <linux/tty.h>
19#include <linux/module.h>
20#include <linux/usb.h>
21#include <linux/usb/serial.h>
22#include <linux/serial.h>
23
24#define DEFAULT_BAUD_RATE 2400
25#define DEFAULT_TIMEOUT 1000
26
27static int debug;
28
29static struct usb_device_id id_table [] = {
30 { USB_DEVICE(0x4348, 0x5523) },
31 { },
32};
33MODULE_DEVICE_TABLE(usb, id_table);
34
35struct ch341_private {
36 unsigned baud_rate;
37 u8 dtr;
38 u8 rts;
39};
40
41static int ch341_control_out(struct usb_device *dev, u8 request,
42 u16 value, u16 index)
43{
44 int r;
45 dbg("ch341_control_out(%02x,%02x,%04x,%04x)", USB_DIR_OUT|0x40,
46 (int)request, (int)value, (int)index);
47
48 r = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), request,
49 USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
50 value, index, NULL, 0, DEFAULT_TIMEOUT);
51
52 return r;
53}
54
55static int ch341_control_in(struct usb_device *dev,
56 u8 request, u16 value, u16 index,
57 char *buf, unsigned bufsize)
58{
59 int r;
60 dbg("ch341_control_in(%02x,%02x,%04x,%04x,%p,%u)", USB_DIR_IN|0x40,
61 (int)request, (int)value, (int)index, buf, (int)bufsize);
62
63 r = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), request,
64 USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
65 value, index, buf, bufsize, DEFAULT_TIMEOUT);
66 return r;
67}
68
69int ch341_set_baudrate(struct usb_device *dev, struct ch341_private *priv)
70{
71 short a, b;
72 int r;
73
74 dbg("ch341_set_baudrate(%d)", priv->baud_rate);
75 switch (priv->baud_rate) {
76 case 2400:
77 a = 0xd901;
78 b = 0x0038;
79 break;
80 case 4800:
81 a = 0x6402;
82 b = 0x001f;
83 break;
84 case 9600:
85 a = 0xb202;
86 b = 0x0013;
87 break;
88 case 19200:
89 a = 0xd902;
90 b = 0x000d;
91 break;
92 case 38400:
93 a = 0x6403;
94 b = 0x000a;
95 break;
96 case 115200:
97 a = 0xcc03;
98 b = 0x0008;
99 break;
100 default:
101 return -EINVAL;
102 }
103
104 r = ch341_control_out(dev, 0x9a, 0x1312, a);
105 if (!r)
106 r = ch341_control_out(dev, 0x9a, 0x0f2c, b);
107
108 return r;
109}
110
111int ch341_set_handshake(struct usb_device *dev, struct ch341_private *priv)
112{
113 dbg("ch341_set_handshake(%d,%d)", priv->dtr, priv->rts);
114 return ch341_control_out(dev, 0xa4,
115 ~((priv->dtr?1<<5:0)|(priv->rts?1<<6:0)), 0);
116}
117
118int ch341_get_status(struct usb_device *dev)
119{
120 char *buffer;
121 int r;
122 const unsigned size = 8;
123
124 dbg("ch341_get_status()");
125
126 buffer = kmalloc(size, GFP_KERNEL);
127 if (!buffer)
128 return -ENOMEM;
129
130 r = ch341_control_in(dev, 0x95, 0x0706, 0, buffer, size);
131 if ( r < 0)
132 goto out;
133
134 /* Not having the datasheet for the CH341, we ignore the bytes returned
135 * from the device. Return error if the device did not respond in time.
136 */
137 r = 0;
138
139out: kfree(buffer);
140 return r;
141}
142
143/* -------------------------------------------------------------------------- */
144
145int ch341_configure(struct usb_device *dev, struct ch341_private *priv)
146{
147 char *buffer;
148 int r;
149 const unsigned size = 8;
150
151 dbg("ch341_configure()");
152
153 buffer = kmalloc(size, GFP_KERNEL);
154 if (!buffer)
155 return -ENOMEM;
156
157 /* expect two bytes 0x27 0x00 */
158 r = ch341_control_in(dev, 0x5f, 0, 0, buffer, size);
159 if (r < 0)
160 goto out;
161
162 r = ch341_control_out(dev, 0xa1, 0, 0);
163 if (r < 0)
164 goto out;
165
166 r = ch341_set_baudrate(dev, priv);
167 if (r < 0)
168 goto out;
169
170 /* expect two bytes 0x56 0x00 */
171 r = ch341_control_in(dev, 0x95, 0x2518, 0, buffer, size);
172 if (r < 0)
173 goto out;
174
175 r = ch341_control_out(dev, 0x9a, 0x2518, 0x0050);
176 if (r < 0)
177 goto out;
178
179 /* expect 0xff 0xee */
180 r = ch341_get_status(dev);
181 if (r < 0)
182 goto out;
183
184 r = ch341_control_out(dev, 0xa1, 0x501f, 0xd90a);
185 if (r < 0)
186 goto out;
187
188 r = ch341_set_baudrate(dev, priv);
189 if (r < 0)
190 goto out;
191
192 r = ch341_set_handshake(dev, priv);
193 if (r < 0)
194 goto out;
195
196 /* expect 0x9f 0xee */
197 r = ch341_get_status(dev);
198
199out: kfree(buffer);
200 return r;
201}
202
203/* allocate private data */
204static int ch341_attach(struct usb_serial *serial)
205{
206 struct ch341_private *priv;
207 int r;
208
209 dbg("ch341_attach()");
210
211 /* private data */
212 priv = kzalloc(sizeof(struct ch341_private), GFP_KERNEL);
213 if (!priv)
214 return -ENOMEM;
215
216 priv->baud_rate = DEFAULT_BAUD_RATE;
217 priv->dtr = 1;
218 priv->rts = 1;
219
220 r = ch341_configure(serial->dev, priv);
221 if (r < 0)
222 goto error;
223
224 usb_set_serial_port_data(serial->port[0], priv);
225 return 0;
226
227error: kfree(priv);
228 return r;
229}
230
231/* open this device, set default parameters */
232static int ch341_open(struct usb_serial_port *port, struct file *filp)
233{
234 struct usb_serial *serial = port->serial;
235 struct ch341_private *priv = usb_get_serial_port_data(serial->port[0]);
236 int r;
237
238 dbg("ch341_open()");
239
240 priv->baud_rate = DEFAULT_BAUD_RATE;
241 priv->dtr = 1;
242 priv->rts = 1;
243
244 r = ch341_configure(serial->dev, priv);
245 if (r)
246 goto out;
247
248 r = ch341_set_handshake(serial->dev, priv);
249 if (r)
250 goto out;
251
252 r = ch341_set_baudrate(serial->dev, priv);
253 if (r)
254 goto out;
255
256 r = usb_serial_generic_open(port, filp);
257
258out: return r;
259}
260
261/* Old_termios contains the original termios settings and
262 * tty->termios contains the new setting to be used.
263 */
264static void ch341_set_termios(struct usb_serial_port *port,
265 struct ktermios *old_termios)
266{
267 struct ch341_private *priv = usb_get_serial_port_data(port);
268 struct tty_struct *tty = port->tty;
269 unsigned baud_rate;
270
271 dbg("ch341_set_termios()");
272
273 if (!tty || !tty->termios)
274 return;
275
276 baud_rate = tty_get_baud_rate(tty);
277
278 switch (baud_rate) {
279 case 2400:
280 case 4800:
281 case 9600:
282 case 19200:
283 case 38400:
284 case 115200:
285 priv->baud_rate = baud_rate;
286 break;
287 default:
288 dbg("Rate %d not supported, using %d",
289 baud_rate, DEFAULT_BAUD_RATE);
290 priv->baud_rate = DEFAULT_BAUD_RATE;
291 }
292
293 ch341_set_baudrate(port->serial->dev, priv);
294
295 /* Unimplemented:
296 * (cflag & CSIZE) : data bits [5, 8]
297 * (cflag & PARENB) : parity {NONE, EVEN, ODD}
298 * (cflag & CSTOPB) : stop bits [1, 2]
299 */
300}
301
302static struct usb_driver ch341_driver = {
303 .name = "ch341",
304 .probe = usb_serial_probe,
305 .disconnect = usb_serial_disconnect,
306 .id_table = id_table,
307 .no_dynamic_id = 1,
308};
309
310static struct usb_serial_driver ch341_device = {
311 .driver = {
312 .owner = THIS_MODULE,
313 .name = "ch341-uart",
314 },
315 .id_table = id_table,
316 .usb_driver = &ch341_driver,
317 .num_interrupt_in = NUM_DONT_CARE,
318 .num_bulk_in = 1,
319 .num_bulk_out = 1,
320 .num_ports = 1,
321 .open = ch341_open,
322 .set_termios = ch341_set_termios,
323 .attach = ch341_attach,
324};
325
326static int __init ch341_init(void)
327{
328 int retval;
329
330 retval = usb_serial_register(&ch341_device);
331 if (retval)
332 return retval;
333 retval = usb_register(&ch341_driver);
334 if (retval)
335 usb_serial_deregister(&ch341_device);
336 return retval;
337}
338
339static void __exit ch341_exit(void)
340{
341 usb_deregister(&ch341_driver);
342 usb_serial_deregister(&ch341_device);
343}
344
345module_init(ch341_init);
346module_exit(ch341_exit);
347MODULE_LICENSE("GPL");
348
349module_param(debug, bool, S_IRUGO | S_IWUSR);
350MODULE_PARM_DESC(debug, "Debug enabled or not");
351
352/* EOF ch341.c */