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
30static 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
40static 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
50static struct usb_debug_descriptor dbg_desc = {
51	.bLength = sizeof dbg_desc,
52	.bDescriptorType = USB_DT_DEBUG,
53};
54
55static 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
62static 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
70static 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
85static 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
93static void dbgp_disable_ep(void)
94{
95	__disable_ep(dbgp.i_ep);
96	__disable_ep(dbgp.o_ep);
97}
98
99static 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
126release_req:
127	kfree(req->buf);
128	usb_ep_free_request(dbgp.o_ep, req);
129	dbgp_disable_ep();
130fail:
131	dev_dbg(&dbgp.gadget->dev,
132		"complete: failure (%d:%d) ==> %d\n", stp, err, status);
133}
134
135static 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
164fail_3:
165	kfree(req->buf);
166fail_2:
167	usb_ep_free_request(dbgp.o_ep, req);
168fail_1:
169	dev_dbg(&dbgp.gadget->dev,
170		"enable ep req: failure (%d:%d)\n", stp, err);
171	return err;
172}
173
174static 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
183static 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
207fail_3:
208	__disable_ep(dbgp.o_ep);
209fail_2:
210	__disable_ep(dbgp.i_ep);
211fail_1:
212	dev_dbg(&dbgp.gadget->dev, "enable ep: failure (%d:%d)\n", stp, err);
213	return err;
214}
215#endif
216
217static 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
226static 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
239static 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
283fail_3:
284	dbgp.o_ep->driver_data = NULL;
285#else
286	return 0;
287#endif
288fail_2:
289	dbgp.i_ep->driver_data = NULL;
290fail_1:
291	dev_dbg(&dbgp.gadget->dev, "ep config: failure (%d)\n", stp);
292	return -ENODEV;
293}
294
295static 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
335fail:
336	dev_dbg(&gadget->dev, "bind: failure (%d:%d)\n", stp, err);
337	dbgp_unbind(gadget);
338	return err;
339}
340
341static 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
348static 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
399fail:
400	dev_dbg(&dbgp.gadget->dev,
401		"setup: failure req %x v %x\n", request, value);
402	return err;
403}
404
405static 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
417static int __init dbgp_init(void)
418{
419	return usb_gadget_probe_driver(&dbgp_driver, dbgp_bind);
420}
421
422static 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
430MODULE_AUTHOR("Stephane Duverger");
431MODULE_LICENSE("GPL");
432module_init(dbgp_init);
433module_exit(dbgp_exit);
434