1 /*
2 * dbgp.c -- EHCI Debug Port device gadget
3 *
4 * Copyright (C) 2010 Stephane Duverger
5 *
6 * Released under the GPLv2.
7 */
8
9 /* verbose messages */
10 #include <linux/kernel.h>
11 #include <linux/device.h>
12 #include <linux/module.h>
13 #include <linux/usb/ch9.h>
14 #include <linux/usb/gadget.h>
15
16 #include "u_serial.h"
17
18 #define DRIVER_VENDOR_ID 0x0525 /* NetChip */
19 #define DRIVER_PRODUCT_ID 0xc0de /* undefined */
20
21 #define USB_DEBUG_MAX_PACKET_SIZE 8
22 #define DBGP_REQ_EP0_LEN 128
23 #define DBGP_REQ_LEN 512
24
25 static struct dbgp {
26 struct usb_gadget *gadget;
27 struct usb_request *req;
28 struct usb_ep *i_ep;
29 struct usb_ep *o_ep;
30 #ifdef CONFIG_USB_G_DBGP_SERIAL
31 struct gserial *serial;
32 #endif
33 } dbgp;
34
35 static struct usb_device_descriptor device_desc = {
36 .bLength = sizeof device_desc,
37 .bDescriptorType = USB_DT_DEVICE,
38 .bcdUSB = __constant_cpu_to_le16(0x0200),
39 .bDeviceClass = USB_CLASS_VENDOR_SPEC,
40 .idVendor = __constant_cpu_to_le16(DRIVER_VENDOR_ID),
41 .idProduct = __constant_cpu_to_le16(DRIVER_PRODUCT_ID),
42 .bNumConfigurations = 1,
43 };
44
45 static struct usb_debug_descriptor dbg_desc = {
46 .bLength = sizeof dbg_desc,
47 .bDescriptorType = USB_DT_DEBUG,
48 };
49
50 static struct usb_endpoint_descriptor i_desc = {
51 .bLength = USB_DT_ENDPOINT_SIZE,
52 .bDescriptorType = USB_DT_ENDPOINT,
53 .bmAttributes = USB_ENDPOINT_XFER_BULK,
54 .bEndpointAddress = USB_DIR_IN,
55 };
56
57 static struct usb_endpoint_descriptor o_desc = {
58 .bLength = USB_DT_ENDPOINT_SIZE,
59 .bDescriptorType = USB_DT_ENDPOINT,
60 .bmAttributes = USB_ENDPOINT_XFER_BULK,
61 .bEndpointAddress = USB_DIR_OUT,
62 };
63
64 #ifdef CONFIG_USB_G_DBGP_PRINTK
dbgp_consume(char * buf,unsigned len)65 static int dbgp_consume(char *buf, unsigned len)
66 {
67 char c;
68
69 if (!len)
70 return 0;
71
72 c = buf[len-1];
73 if (c != 0)
74 buf[len-1] = 0;
75
76 printk(KERN_NOTICE "%s%c", buf, c);
77 return 0;
78 }
79
__disable_ep(struct usb_ep * ep)80 static void __disable_ep(struct usb_ep *ep)
81 {
82 if (ep && ep->driver_data == dbgp.gadget) {
83 usb_ep_disable(ep);
84 ep->driver_data = NULL;
85 }
86 }
87
dbgp_disable_ep(void)88 static void dbgp_disable_ep(void)
89 {
90 __disable_ep(dbgp.i_ep);
91 __disable_ep(dbgp.o_ep);
92 }
93
dbgp_complete(struct usb_ep * ep,struct usb_request * req)94 static void dbgp_complete(struct usb_ep *ep, struct usb_request *req)
95 {
96 int stp;
97 int err = 0;
98 int status = req->status;
99
100 if (ep == dbgp.i_ep) {
101 stp = 1;
102 goto fail;
103 }
104
105 if (status != 0) {
106 stp = 2;
107 goto release_req;
108 }
109
110 dbgp_consume(req->buf, req->actual);
111
112 req->length = DBGP_REQ_LEN;
113 err = usb_ep_queue(ep, req, GFP_ATOMIC);
114 if (err < 0) {
115 stp = 3;
116 goto release_req;
117 }
118
119 return;
120
121 release_req:
122 kfree(req->buf);
123 usb_ep_free_request(dbgp.o_ep, req);
124 dbgp_disable_ep();
125 fail:
126 dev_dbg(&dbgp.gadget->dev,
127 "complete: failure (%d:%d) ==> %d\n", stp, err, status);
128 }
129
dbgp_enable_ep_req(struct usb_ep * ep)130 static int dbgp_enable_ep_req(struct usb_ep *ep)
131 {
132 int err, stp;
133 struct usb_request *req;
134
135 req = usb_ep_alloc_request(ep, GFP_KERNEL);
136 if (!req) {
137 err = -ENOMEM;
138 stp = 1;
139 goto fail_1;
140 }
141
142 req->buf = kmalloc(DBGP_REQ_LEN, GFP_KERNEL);
143 if (!req->buf) {
144 err = -ENOMEM;
145 stp = 2;
146 goto fail_2;
147 }
148
149 req->complete = dbgp_complete;
150 req->length = DBGP_REQ_LEN;
151 err = usb_ep_queue(ep, req, GFP_ATOMIC);
152 if (err < 0) {
153 stp = 3;
154 goto fail_3;
155 }
156
157 return 0;
158
159 fail_3:
160 kfree(req->buf);
161 fail_2:
162 usb_ep_free_request(dbgp.o_ep, req);
163 fail_1:
164 dev_dbg(&dbgp.gadget->dev,
165 "enable ep req: failure (%d:%d)\n", stp, err);
166 return err;
167 }
168
__enable_ep(struct usb_ep * ep,struct usb_endpoint_descriptor * desc)169 static int __enable_ep(struct usb_ep *ep, struct usb_endpoint_descriptor *desc)
170 {
171 int err;
172 ep->desc = desc;
173 err = usb_ep_enable(ep);
174 ep->driver_data = dbgp.gadget;
175 return err;
176 }
177
dbgp_enable_ep(void)178 static int dbgp_enable_ep(void)
179 {
180 int err, stp;
181
182 err = __enable_ep(dbgp.i_ep, &i_desc);
183 if (err < 0) {
184 stp = 1;
185 goto fail_1;
186 }
187
188 err = __enable_ep(dbgp.o_ep, &o_desc);
189 if (err < 0) {
190 stp = 2;
191 goto fail_2;
192 }
193
194 err = dbgp_enable_ep_req(dbgp.o_ep);
195 if (err < 0) {
196 stp = 3;
197 goto fail_3;
198 }
199
200 return 0;
201
202 fail_3:
203 __disable_ep(dbgp.o_ep);
204 fail_2:
205 __disable_ep(dbgp.i_ep);
206 fail_1:
207 dev_dbg(&dbgp.gadget->dev, "enable ep: failure (%d:%d)\n", stp, err);
208 return err;
209 }
210 #endif
211
dbgp_disconnect(struct usb_gadget * gadget)212 static void dbgp_disconnect(struct usb_gadget *gadget)
213 {
214 #ifdef CONFIG_USB_G_DBGP_PRINTK
215 dbgp_disable_ep();
216 #else
217 gserial_disconnect(dbgp.serial);
218 #endif
219 }
220
dbgp_unbind(struct usb_gadget * gadget)221 static void dbgp_unbind(struct usb_gadget *gadget)
222 {
223 #ifdef CONFIG_USB_G_DBGP_SERIAL
224 kfree(dbgp.serial);
225 dbgp.serial = NULL;
226 #endif
227 if (dbgp.req) {
228 kfree(dbgp.req->buf);
229 usb_ep_free_request(gadget->ep0, dbgp.req);
230 dbgp.req = NULL;
231 }
232
233 gadget->ep0->driver_data = NULL;
234 }
235
236 #ifdef CONFIG_USB_G_DBGP_SERIAL
237 static unsigned char tty_line;
238 #endif
239
dbgp_configure_endpoints(struct usb_gadget * gadget)240 static int __init dbgp_configure_endpoints(struct usb_gadget *gadget)
241 {
242 int stp;
243
244 usb_ep_autoconfig_reset(gadget);
245
246 dbgp.i_ep = usb_ep_autoconfig(gadget, &i_desc);
247 if (!dbgp.i_ep) {
248 stp = 1;
249 goto fail_1;
250 }
251
252 dbgp.i_ep->driver_data = gadget;
253 i_desc.wMaxPacketSize =
254 __constant_cpu_to_le16(USB_DEBUG_MAX_PACKET_SIZE);
255
256 dbgp.o_ep = usb_ep_autoconfig(gadget, &o_desc);
257 if (!dbgp.o_ep) {
258 dbgp.i_ep->driver_data = NULL;
259 stp = 2;
260 goto fail_2;
261 }
262
263 dbgp.o_ep->driver_data = gadget;
264 o_desc.wMaxPacketSize =
265 __constant_cpu_to_le16(USB_DEBUG_MAX_PACKET_SIZE);
266
267 dbg_desc.bDebugInEndpoint = i_desc.bEndpointAddress;
268 dbg_desc.bDebugOutEndpoint = o_desc.bEndpointAddress;
269
270 #ifdef CONFIG_USB_G_DBGP_SERIAL
271 dbgp.serial->in = dbgp.i_ep;
272 dbgp.serial->out = dbgp.o_ep;
273
274 dbgp.serial->in->desc = &i_desc;
275 dbgp.serial->out->desc = &o_desc;
276
277 if (gserial_alloc_line(&tty_line)) {
278 stp = 3;
279 goto fail_3;
280 }
281
282 return 0;
283
284 fail_3:
285 dbgp.o_ep->driver_data = NULL;
286 #else
287 return 0;
288 #endif
289 fail_2:
290 dbgp.i_ep->driver_data = NULL;
291 fail_1:
292 dev_dbg(&dbgp.gadget->dev, "ep config: failure (%d)\n", stp);
293 return -ENODEV;
294 }
295
dbgp_bind(struct usb_gadget * gadget,struct usb_gadget_driver * driver)296 static int __init dbgp_bind(struct usb_gadget *gadget,
297 struct usb_gadget_driver *driver)
298 {
299 int err, stp;
300
301 dbgp.gadget = gadget;
302
303 dbgp.req = usb_ep_alloc_request(gadget->ep0, GFP_KERNEL);
304 if (!dbgp.req) {
305 err = -ENOMEM;
306 stp = 1;
307 goto fail;
308 }
309
310 dbgp.req->buf = kmalloc(DBGP_REQ_EP0_LEN, GFP_KERNEL);
311 if (!dbgp.req->buf) {
312 err = -ENOMEM;
313 stp = 2;
314 goto fail;
315 }
316
317 dbgp.req->length = DBGP_REQ_EP0_LEN;
318 gadget->ep0->driver_data = gadget;
319
320 #ifdef CONFIG_USB_G_DBGP_SERIAL
321 dbgp.serial = kzalloc(sizeof(struct gserial), GFP_KERNEL);
322 if (!dbgp.serial) {
323 stp = 3;
324 err = -ENOMEM;
325 goto fail;
326 }
327 #endif
328 err = dbgp_configure_endpoints(gadget);
329 if (err < 0) {
330 stp = 4;
331 goto fail;
332 }
333
334 dev_dbg(&dbgp.gadget->dev, "bind: success\n");
335 return 0;
336
337 fail:
338 dev_dbg(&gadget->dev, "bind: failure (%d:%d)\n", stp, err);
339 dbgp_unbind(gadget);
340 return err;
341 }
342
dbgp_setup_complete(struct usb_ep * ep,struct usb_request * req)343 static void dbgp_setup_complete(struct usb_ep *ep,
344 struct usb_request *req)
345 {
346 dev_dbg(&dbgp.gadget->dev, "setup complete: %d, %d/%d\n",
347 req->status, req->actual, req->length);
348 }
349
dbgp_setup(struct usb_gadget * gadget,const struct usb_ctrlrequest * ctrl)350 static int dbgp_setup(struct usb_gadget *gadget,
351 const struct usb_ctrlrequest *ctrl)
352 {
353 struct usb_request *req = dbgp.req;
354 u8 request = ctrl->bRequest;
355 u16 value = le16_to_cpu(ctrl->wValue);
356 u16 length = le16_to_cpu(ctrl->wLength);
357 int err = -EOPNOTSUPP;
358 void *data = NULL;
359 u16 len = 0;
360
361 gadget->ep0->driver_data = gadget;
362
363 if (request == USB_REQ_GET_DESCRIPTOR) {
364 switch (value>>8) {
365 case USB_DT_DEVICE:
366 dev_dbg(&dbgp.gadget->dev, "setup: desc device\n");
367 len = sizeof device_desc;
368 data = &device_desc;
369 device_desc.bMaxPacketSize0 = gadget->ep0->maxpacket;
370 break;
371 case USB_DT_DEBUG:
372 dev_dbg(&dbgp.gadget->dev, "setup: desc debug\n");
373 len = sizeof dbg_desc;
374 data = &dbg_desc;
375 break;
376 default:
377 goto fail;
378 }
379 err = 0;
380 } else if (request == USB_REQ_SET_FEATURE &&
381 value == USB_DEVICE_DEBUG_MODE) {
382 dev_dbg(&dbgp.gadget->dev, "setup: feat debug\n");
383 #ifdef CONFIG_USB_G_DBGP_PRINTK
384 err = dbgp_enable_ep();
385 #else
386 err = gserial_connect(dbgp.serial, tty_line);
387 #endif
388 if (err < 0)
389 goto fail;
390 } else
391 goto fail;
392
393 req->length = min(length, len);
394 req->zero = len < req->length;
395 if (data && req->length)
396 memcpy(req->buf, data, req->length);
397
398 req->complete = dbgp_setup_complete;
399 return usb_ep_queue(gadget->ep0, req, GFP_ATOMIC);
400
401 fail:
402 dev_dbg(&dbgp.gadget->dev,
403 "setup: failure req %x v %x\n", request, value);
404 return err;
405 }
406
407 static __refdata struct usb_gadget_driver dbgp_driver = {
408 .function = "dbgp",
409 .max_speed = USB_SPEED_HIGH,
410 .bind = dbgp_bind,
411 .unbind = dbgp_unbind,
412 .setup = dbgp_setup,
413 .reset = dbgp_disconnect,
414 .disconnect = dbgp_disconnect,
415 .driver = {
416 .owner = THIS_MODULE,
417 .name = "dbgp"
418 },
419 };
420
dbgp_init(void)421 static int __init dbgp_init(void)
422 {
423 return usb_gadget_probe_driver(&dbgp_driver);
424 }
425
dbgp_exit(void)426 static void __exit dbgp_exit(void)
427 {
428 usb_gadget_unregister_driver(&dbgp_driver);
429 #ifdef CONFIG_USB_G_DBGP_SERIAL
430 gserial_free_line(tty_line);
431 #endif
432 }
433
434 MODULE_AUTHOR("Stephane Duverger");
435 MODULE_LICENSE("GPL");
436 module_init(dbgp_init);
437 module_exit(dbgp_exit);
438