xref: /linux/drivers/usb/gadget/legacy/zero.c (revision 9e56ff53b4115875667760445b028357848b4748)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * zero.c -- Gadget Zero, for USB development
4  *
5  * Copyright (C) 2003-2008 David Brownell
6  * Copyright (C) 2008 by Nokia Corporation
7  */
8 
9 /*
10  * Gadget Zero only needs two bulk endpoints, and is an example of how you
11  * can write a hardware-agnostic gadget driver running inside a USB device.
12  * Some hardware details are visible, but don't affect most of the driver.
13  *
14  * Use it with the Linux host side "usbtest" driver to get a basic functional
15  * test of your device-side usb stack, or with "usb-skeleton".
16  *
17  * It supports two similar configurations.  One sinks whatever the usb host
18  * writes, and in return sources zeroes.  The other loops whatever the host
19  * writes back, so the host can read it.
20  *
21  * Many drivers will only have one configuration, letting them be much
22  * simpler if they also don't support high speed operation (like this
23  * driver does).
24  *
25  * Why is *this* driver using two configurations, rather than setting up
26  * two interfaces with different functions?  To help verify that multiple
27  * configuration infrastructure is working correctly; also, so that it can
28  * work with low capability USB controllers without four bulk endpoints.
29  */
30 
31 /*
32  * driver assumes self-powered hardware, and
33  * has no way for users to trigger remote wakeup.
34  */
35 
36 /* #define VERBOSE_DEBUG */
37 
38 #include <linux/kernel.h>
39 #include <linux/slab.h>
40 #include <linux/device.h>
41 #include <linux/module.h>
42 #include <linux/err.h>
43 #include <linux/usb/composite.h>
44 
45 #include "g_zero.h"
46 /*-------------------------------------------------------------------------*/
47 USB_GADGET_COMPOSITE_OPTIONS();
48 
49 #define DRIVER_VERSION		"Cinco de Mayo 2008"
50 
51 static const char longname[] = "Gadget Zero";
52 
53 /*
54  * Normally the "loopback" configuration is second (index 1) so
55  * it's not the default.  Here's where to change that order, to
56  * work better with hosts where config changes are problematic or
57  * controllers (like original superh) that only support one config.
58  */
59 static bool loopdefault = 0;
60 module_param(loopdefault, bool, S_IRUGO|S_IWUSR);
61 
62 static struct usb_zero_options gzero_options = {
63 	.isoc_interval = GZERO_ISOC_INTERVAL,
64 	.isoc_maxpacket = GZERO_ISOC_MAXPACKET,
65 	.bulk_buflen = GZERO_BULK_BUFLEN,
66 	.qlen = GZERO_QLEN,
67 	.ss_bulk_qlen = GZERO_SS_BULK_QLEN,
68 	.ss_iso_qlen = GZERO_SS_ISO_QLEN,
69 };
70 
71 /*-------------------------------------------------------------------------*/
72 
73 /* Thanks to NetChip Technologies for donating this product ID.
74  *
75  * DO NOT REUSE THESE IDs with a protocol-incompatible driver!!  Ever!!
76  * Instead:  allocate your own, using normal USB-IF procedures.
77  */
78 #ifndef	CONFIG_USB_ZERO_HNPTEST
79 #define DRIVER_VENDOR_NUM	0x0525		/* NetChip */
80 #define DRIVER_PRODUCT_NUM	0xa4a0		/* Linux-USB "Gadget Zero" */
81 #define DEFAULT_AUTORESUME	0
82 #else
83 #define DRIVER_VENDOR_NUM	0x1a0a		/* OTG test device IDs */
84 #define DRIVER_PRODUCT_NUM	0xbadd
85 #define DEFAULT_AUTORESUME	5
86 #endif
87 
88 /* If the optional "autoresume" mode is enabled, it provides good
89  * functional coverage for the "USBCV" test harness from USB-IF.
90  * It's always set if OTG mode is enabled.
91  */
92 static unsigned autoresume = DEFAULT_AUTORESUME;
93 module_param(autoresume, uint, S_IRUGO);
94 MODULE_PARM_DESC(autoresume, "zero, or seconds before remote wakeup");
95 
96 /* Maximum Autoresume time */
97 static unsigned max_autoresume;
98 module_param(max_autoresume, uint, S_IRUGO);
99 MODULE_PARM_DESC(max_autoresume, "maximum seconds before remote wakeup");
100 
101 /* Interval between two remote wakeups */
102 static unsigned autoresume_interval_ms;
103 module_param(autoresume_interval_ms, uint, S_IRUGO);
104 MODULE_PARM_DESC(autoresume_interval_ms,
105 		"milliseconds to increase successive wakeup delays");
106 
107 static unsigned autoresume_step_ms;
108 /*-------------------------------------------------------------------------*/
109 
110 static struct usb_device_descriptor device_desc = {
111 	.bLength =		sizeof device_desc,
112 	.bDescriptorType =	USB_DT_DEVICE,
113 
114 	/* .bcdUSB = DYNAMIC */
115 	.bDeviceClass =		USB_CLASS_VENDOR_SPEC,
116 
117 	.idVendor =		cpu_to_le16(DRIVER_VENDOR_NUM),
118 	.idProduct =		cpu_to_le16(DRIVER_PRODUCT_NUM),
119 	.bNumConfigurations =	2,
120 };
121 
122 static const struct usb_descriptor_header *otg_desc[2];
123 
124 /* string IDs are assigned dynamically */
125 /* default serial number takes at least two packets */
126 static char serial[] = "0123456789.0123456789.0123456789";
127 
128 #define USB_GZERO_SS_DESC	(USB_GADGET_FIRST_AVAIL_IDX + 0)
129 #define USB_GZERO_LB_DESC	(USB_GADGET_FIRST_AVAIL_IDX + 1)
130 
131 static struct usb_string strings_dev[] = {
132 	[USB_GADGET_MANUFACTURER_IDX].s = "",
133 	[USB_GADGET_PRODUCT_IDX].s = longname,
134 	[USB_GADGET_SERIAL_IDX].s = serial,
135 	[USB_GZERO_SS_DESC].s	= "source and sink data",
136 	[USB_GZERO_LB_DESC].s	= "loop input to output",
137 	{  }			/* end of list */
138 };
139 
140 static struct usb_gadget_strings stringtab_dev = {
141 	.language	= 0x0409,	/* en-us */
142 	.strings	= strings_dev,
143 };
144 
145 static struct usb_gadget_strings *dev_strings[] = {
146 	&stringtab_dev,
147 	NULL,
148 };
149 
150 /*-------------------------------------------------------------------------*/
151 
152 static struct timer_list	autoresume_timer;
153 static struct usb_composite_dev *autoresume_cdev;
154 
155 static void zero_autoresume(struct timer_list *unused)
156 {
157 	struct usb_composite_dev	*cdev = autoresume_cdev;
158 	struct usb_gadget		*g = cdev->gadget;
159 
160 	/* unconfigured devices can't issue wakeups */
161 	if (!cdev->config)
162 		return;
163 
164 	/* Normally the host would be woken up for something
165 	 * more significant than just a timer firing; likely
166 	 * because of some direct user request.
167 	 */
168 	if (g->speed != USB_SPEED_UNKNOWN) {
169 		int status = usb_gadget_wakeup(g);
170 		INFO(cdev, "%s --> %d\n", __func__, status);
171 	}
172 }
173 
174 static void zero_suspend(struct usb_composite_dev *cdev)
175 {
176 	if (cdev->gadget->speed == USB_SPEED_UNKNOWN)
177 		return;
178 
179 	if (autoresume) {
180 		if (max_autoresume &&
181 			(autoresume_step_ms > max_autoresume * 1000))
182 				autoresume_step_ms = autoresume * 1000;
183 
184 		mod_timer(&autoresume_timer, jiffies +
185 			msecs_to_jiffies(autoresume_step_ms));
186 		DBG(cdev, "suspend, wakeup in %d milliseconds\n",
187 			autoresume_step_ms);
188 
189 		autoresume_step_ms += autoresume_interval_ms;
190 	} else
191 		DBG(cdev, "%s\n", __func__);
192 }
193 
194 static void zero_resume(struct usb_composite_dev *cdev)
195 {
196 	DBG(cdev, "%s\n", __func__);
197 	del_timer(&autoresume_timer);
198 }
199 
200 /*-------------------------------------------------------------------------*/
201 
202 static struct usb_configuration loopback_driver = {
203 	.label          = "loopback",
204 	.bConfigurationValue = 2,
205 	.bmAttributes   = USB_CONFIG_ATT_SELFPOWER,
206 	/* .iConfiguration = DYNAMIC */
207 };
208 
209 static struct usb_function *func_ss;
210 static struct usb_function_instance *func_inst_ss;
211 
212 static int ss_config_setup(struct usb_configuration *c,
213 		const struct usb_ctrlrequest *ctrl)
214 {
215 	switch (ctrl->bRequest) {
216 	case 0x5b:
217 	case 0x5c:
218 		return func_ss->setup(func_ss, ctrl);
219 	default:
220 		return -EOPNOTSUPP;
221 	}
222 }
223 
224 static struct usb_configuration sourcesink_driver = {
225 	.label                  = "source/sink",
226 	.setup                  = ss_config_setup,
227 	.bConfigurationValue    = 3,
228 	.bmAttributes           = USB_CONFIG_ATT_SELFPOWER,
229 	/* .iConfiguration      = DYNAMIC */
230 };
231 
232 module_param_named(buflen, gzero_options.bulk_buflen, uint, 0);
233 module_param_named(pattern, gzero_options.pattern, uint, S_IRUGO|S_IWUSR);
234 MODULE_PARM_DESC(pattern, "0 = all zeroes, 1 = mod63, 2 = none");
235 
236 module_param_named(isoc_interval, gzero_options.isoc_interval, uint,
237 		S_IRUGO|S_IWUSR);
238 MODULE_PARM_DESC(isoc_interval, "1 - 16");
239 
240 module_param_named(isoc_maxpacket, gzero_options.isoc_maxpacket, uint,
241 		S_IRUGO|S_IWUSR);
242 MODULE_PARM_DESC(isoc_maxpacket, "0 - 1023 (fs), 0 - 1024 (hs/ss)");
243 
244 module_param_named(isoc_mult, gzero_options.isoc_mult, uint, S_IRUGO|S_IWUSR);
245 MODULE_PARM_DESC(isoc_mult, "0 - 2 (hs/ss only)");
246 
247 module_param_named(isoc_maxburst, gzero_options.isoc_maxburst, uint,
248 		S_IRUGO|S_IWUSR);
249 MODULE_PARM_DESC(isoc_maxburst, "0 - 15 (ss only)");
250 
251 static struct usb_function *func_lb;
252 static struct usb_function_instance *func_inst_lb;
253 
254 module_param_named(qlen, gzero_options.qlen, uint, S_IRUGO|S_IWUSR);
255 MODULE_PARM_DESC(qlen, "depth of loopback queue");
256 
257 module_param_named(ss_bulk_qlen, gzero_options.ss_bulk_qlen, uint,
258 		S_IRUGO|S_IWUSR);
259 MODULE_PARM_DESC(bulk_qlen, "depth of sourcesink queue for bulk transfer");
260 
261 module_param_named(ss_iso_qlen, gzero_options.ss_iso_qlen, uint,
262 		S_IRUGO|S_IWUSR);
263 MODULE_PARM_DESC(iso_qlen, "depth of sourcesink queue for iso transfer");
264 
265 static int zero_bind(struct usb_composite_dev *cdev)
266 {
267 	struct f_ss_opts	*ss_opts;
268 	struct f_lb_opts	*lb_opts;
269 	int			status;
270 
271 	/* Allocate string descriptor numbers ... note that string
272 	 * contents can be overridden by the composite_dev glue.
273 	 */
274 	status = usb_string_ids_tab(cdev, strings_dev);
275 	if (status < 0)
276 		return status;
277 
278 	device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id;
279 	device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id;
280 	device_desc.iSerialNumber = strings_dev[USB_GADGET_SERIAL_IDX].id;
281 
282 	autoresume_cdev = cdev;
283 	timer_setup(&autoresume_timer, zero_autoresume, 0);
284 
285 	func_inst_ss = usb_get_function_instance("SourceSink");
286 	if (IS_ERR(func_inst_ss))
287 		return PTR_ERR(func_inst_ss);
288 
289 	ss_opts =  container_of(func_inst_ss, struct f_ss_opts, func_inst);
290 	ss_opts->pattern = gzero_options.pattern;
291 	ss_opts->isoc_interval = gzero_options.isoc_interval;
292 	ss_opts->isoc_maxpacket = gzero_options.isoc_maxpacket;
293 	ss_opts->isoc_mult = gzero_options.isoc_mult;
294 	ss_opts->isoc_maxburst = gzero_options.isoc_maxburst;
295 	ss_opts->bulk_buflen = gzero_options.bulk_buflen;
296 	ss_opts->bulk_qlen = gzero_options.ss_bulk_qlen;
297 	ss_opts->iso_qlen = gzero_options.ss_iso_qlen;
298 
299 	func_ss = usb_get_function(func_inst_ss);
300 	if (IS_ERR(func_ss)) {
301 		status = PTR_ERR(func_ss);
302 		goto err_put_func_inst_ss;
303 	}
304 
305 	func_inst_lb = usb_get_function_instance("Loopback");
306 	if (IS_ERR(func_inst_lb)) {
307 		status = PTR_ERR(func_inst_lb);
308 		goto err_put_func_ss;
309 	}
310 
311 	lb_opts = container_of(func_inst_lb, struct f_lb_opts, func_inst);
312 	lb_opts->bulk_buflen = gzero_options.bulk_buflen;
313 	lb_opts->qlen = gzero_options.qlen;
314 
315 	func_lb = usb_get_function(func_inst_lb);
316 	if (IS_ERR(func_lb)) {
317 		status = PTR_ERR(func_lb);
318 		goto err_put_func_inst_lb;
319 	}
320 
321 	sourcesink_driver.iConfiguration = strings_dev[USB_GZERO_SS_DESC].id;
322 	loopback_driver.iConfiguration = strings_dev[USB_GZERO_LB_DESC].id;
323 
324 	/* support autoresume for remote wakeup testing */
325 	sourcesink_driver.bmAttributes &= ~USB_CONFIG_ATT_WAKEUP;
326 	loopback_driver.bmAttributes &= ~USB_CONFIG_ATT_WAKEUP;
327 	sourcesink_driver.descriptors = NULL;
328 	loopback_driver.descriptors = NULL;
329 	if (autoresume) {
330 		sourcesink_driver.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
331 		loopback_driver.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
332 		autoresume_step_ms = autoresume * 1000;
333 	}
334 
335 	/* support OTG systems */
336 	if (gadget_is_otg(cdev->gadget)) {
337 		if (!otg_desc[0]) {
338 			struct usb_descriptor_header *usb_desc;
339 
340 			usb_desc = usb_otg_descriptor_alloc(cdev->gadget);
341 			if (!usb_desc) {
342 				status = -ENOMEM;
343 				goto err_conf_flb;
344 			}
345 			usb_otg_descriptor_init(cdev->gadget, usb_desc);
346 			otg_desc[0] = usb_desc;
347 			otg_desc[1] = NULL;
348 		}
349 		sourcesink_driver.descriptors = otg_desc;
350 		sourcesink_driver.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
351 		loopback_driver.descriptors = otg_desc;
352 		loopback_driver.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
353 	}
354 
355 	/* Register primary, then secondary configuration.  Note that
356 	 * SH3 only allows one config...
357 	 */
358 	if (loopdefault) {
359 		usb_add_config_only(cdev, &loopback_driver);
360 		usb_add_config_only(cdev, &sourcesink_driver);
361 	} else {
362 		usb_add_config_only(cdev, &sourcesink_driver);
363 		usb_add_config_only(cdev, &loopback_driver);
364 	}
365 	status = usb_add_function(&sourcesink_driver, func_ss);
366 	if (status)
367 		goto err_free_otg_desc;
368 
369 	usb_ep_autoconfig_reset(cdev->gadget);
370 	status = usb_add_function(&loopback_driver, func_lb);
371 	if (status)
372 		goto err_free_otg_desc;
373 
374 	usb_ep_autoconfig_reset(cdev->gadget);
375 	usb_composite_overwrite_options(cdev, &coverwrite);
376 
377 	INFO(cdev, "%s, version: " DRIVER_VERSION "\n", longname);
378 
379 	return 0;
380 
381 err_free_otg_desc:
382 	kfree(otg_desc[0]);
383 	otg_desc[0] = NULL;
384 err_conf_flb:
385 	usb_put_function(func_lb);
386 	func_lb = NULL;
387 err_put_func_inst_lb:
388 	usb_put_function_instance(func_inst_lb);
389 	func_inst_lb = NULL;
390 err_put_func_ss:
391 	usb_put_function(func_ss);
392 	func_ss = NULL;
393 err_put_func_inst_ss:
394 	usb_put_function_instance(func_inst_ss);
395 	func_inst_ss = NULL;
396 	return status;
397 }
398 
399 static int zero_unbind(struct usb_composite_dev *cdev)
400 {
401 	del_timer_sync(&autoresume_timer);
402 	if (!IS_ERR_OR_NULL(func_ss))
403 		usb_put_function(func_ss);
404 	usb_put_function_instance(func_inst_ss);
405 	if (!IS_ERR_OR_NULL(func_lb))
406 		usb_put_function(func_lb);
407 	usb_put_function_instance(func_inst_lb);
408 	kfree(otg_desc[0]);
409 	otg_desc[0] = NULL;
410 
411 	return 0;
412 }
413 
414 static struct usb_composite_driver zero_driver = {
415 	.name		= "zero",
416 	.dev		= &device_desc,
417 	.strings	= dev_strings,
418 	.max_speed	= USB_SPEED_SUPER,
419 	.bind		= zero_bind,
420 	.unbind		= zero_unbind,
421 	.suspend	= zero_suspend,
422 	.resume		= zero_resume,
423 };
424 
425 module_usb_composite_driver(zero_driver);
426 
427 MODULE_AUTHOR("David Brownell");
428 MODULE_LICENSE("GPL");
429