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