xref: /linux/drivers/usb/common/common.c (revision cbac924200b838cfb8d8b1415113d788089dc50b)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Provides code common for host and device side USB.
4  *
5  * If either host side (ie. CONFIG_USB=y) or device side USB stack
6  * (ie. CONFIG_USB_GADGET=y) is compiled in the kernel, this module is
7  * compiled-in as well.  Otherwise, if either of the two stacks is
8  * compiled as module, this file is compiled as module as well.
9  */
10 
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/of.h>
14 #include <linux/usb/ch9.h>
15 #include <linux/usb/of.h>
16 #include <linux/usb/otg.h>
17 #include <linux/of_platform.h>
18 #include <linux/debugfs.h>
19 #include "common.h"
20 
21 static const char *const ep_type_names[] = {
22 	[USB_ENDPOINT_XFER_CONTROL] = "ctrl",
23 	[USB_ENDPOINT_XFER_ISOC] = "isoc",
24 	[USB_ENDPOINT_XFER_BULK] = "bulk",
25 	[USB_ENDPOINT_XFER_INT] = "intr",
26 };
27 
28 /**
29  * usb_ep_type_string() - Returns human readable-name of the endpoint type.
30  * @ep_type: The endpoint type to return human-readable name for.  If it's not
31  *   any of the types: USB_ENDPOINT_XFER_{CONTROL, ISOC, BULK, INT},
32  *   usually got by usb_endpoint_type(), the string 'unknown' will be returned.
33  */
34 const char *usb_ep_type_string(int ep_type)
35 {
36 	if (ep_type < 0 || ep_type >= ARRAY_SIZE(ep_type_names))
37 		return "unknown";
38 
39 	return ep_type_names[ep_type];
40 }
41 EXPORT_SYMBOL_GPL(usb_ep_type_string);
42 
43 const char *usb_otg_state_string(enum usb_otg_state state)
44 {
45 	static const char *const names[] = {
46 		[OTG_STATE_A_IDLE] = "a_idle",
47 		[OTG_STATE_A_WAIT_VRISE] = "a_wait_vrise",
48 		[OTG_STATE_A_WAIT_BCON] = "a_wait_bcon",
49 		[OTG_STATE_A_HOST] = "a_host",
50 		[OTG_STATE_A_SUSPEND] = "a_suspend",
51 		[OTG_STATE_A_PERIPHERAL] = "a_peripheral",
52 		[OTG_STATE_A_WAIT_VFALL] = "a_wait_vfall",
53 		[OTG_STATE_A_VBUS_ERR] = "a_vbus_err",
54 		[OTG_STATE_B_IDLE] = "b_idle",
55 		[OTG_STATE_B_SRP_INIT] = "b_srp_init",
56 		[OTG_STATE_B_PERIPHERAL] = "b_peripheral",
57 		[OTG_STATE_B_WAIT_ACON] = "b_wait_acon",
58 		[OTG_STATE_B_HOST] = "b_host",
59 	};
60 
61 	if (state < 0 || state >= ARRAY_SIZE(names))
62 		return "UNDEFINED";
63 
64 	return names[state];
65 }
66 EXPORT_SYMBOL_GPL(usb_otg_state_string);
67 
68 static const char *const speed_names[] = {
69 	[USB_SPEED_UNKNOWN] = "UNKNOWN",
70 	[USB_SPEED_LOW] = "low-speed",
71 	[USB_SPEED_FULL] = "full-speed",
72 	[USB_SPEED_HIGH] = "high-speed",
73 	[USB_SPEED_WIRELESS] = "wireless",
74 	[USB_SPEED_SUPER] = "super-speed",
75 	[USB_SPEED_SUPER_PLUS] = "super-speed-plus",
76 };
77 
78 static const char *const ssp_rate[] = {
79 	[USB_SSP_GEN_UNKNOWN] = "UNKNOWN",
80 	[USB_SSP_GEN_2x1] = "super-speed-plus-gen2x1",
81 	[USB_SSP_GEN_1x2] = "super-speed-plus-gen1x2",
82 	[USB_SSP_GEN_2x2] = "super-speed-plus-gen2x2",
83 };
84 
85 /**
86  * usb_speed_string() - Returns human readable-name of the speed.
87  * @speed: The speed to return human-readable name for.  If it's not
88  *   any of the speeds defined in usb_device_speed enum, string for
89  *   USB_SPEED_UNKNOWN will be returned.
90  */
91 const char *usb_speed_string(enum usb_device_speed speed)
92 {
93 	if (speed < 0 || speed >= ARRAY_SIZE(speed_names))
94 		speed = USB_SPEED_UNKNOWN;
95 	return speed_names[speed];
96 }
97 EXPORT_SYMBOL_GPL(usb_speed_string);
98 
99 /**
100  * usb_get_maximum_speed - Get maximum requested speed for a given USB
101  * controller.
102  * @dev: Pointer to the given USB controller device
103  *
104  * The function gets the maximum speed string from property "maximum-speed",
105  * and returns the corresponding enum usb_device_speed.
106  */
107 enum usb_device_speed usb_get_maximum_speed(struct device *dev)
108 {
109 	const char *maximum_speed;
110 	int ret;
111 
112 	ret = device_property_read_string(dev, "maximum-speed", &maximum_speed);
113 	if (ret < 0)
114 		return USB_SPEED_UNKNOWN;
115 
116 	ret = match_string(ssp_rate, ARRAY_SIZE(ssp_rate), maximum_speed);
117 	if (ret > 0)
118 		return USB_SPEED_SUPER_PLUS;
119 
120 	ret = match_string(speed_names, ARRAY_SIZE(speed_names), maximum_speed);
121 	return (ret < 0) ? USB_SPEED_UNKNOWN : ret;
122 }
123 EXPORT_SYMBOL_GPL(usb_get_maximum_speed);
124 
125 /**
126  * usb_get_maximum_ssp_rate - Get the signaling rate generation and lane count
127  *	of a SuperSpeed Plus capable device.
128  * @dev: Pointer to the given USB controller device
129  *
130  * If the string from "maximum-speed" property is super-speed-plus-genXxY where
131  * 'X' is the generation number and 'Y' is the number of lanes, then this
132  * function returns the corresponding enum usb_ssp_rate.
133  */
134 enum usb_ssp_rate usb_get_maximum_ssp_rate(struct device *dev)
135 {
136 	const char *maximum_speed;
137 	int ret;
138 
139 	ret = device_property_read_string(dev, "maximum-speed", &maximum_speed);
140 	if (ret < 0)
141 		return USB_SSP_GEN_UNKNOWN;
142 
143 	ret = match_string(ssp_rate, ARRAY_SIZE(ssp_rate), maximum_speed);
144 	return (ret < 0) ? USB_SSP_GEN_UNKNOWN : ret;
145 }
146 EXPORT_SYMBOL_GPL(usb_get_maximum_ssp_rate);
147 
148 /**
149  * usb_state_string - Returns human readable name for the state.
150  * @state: The state to return a human-readable name for. If it's not
151  *	any of the states devices in usb_device_state_string enum,
152  *	the string UNKNOWN will be returned.
153  */
154 const char *usb_state_string(enum usb_device_state state)
155 {
156 	static const char *const names[] = {
157 		[USB_STATE_NOTATTACHED] = "not attached",
158 		[USB_STATE_ATTACHED] = "attached",
159 		[USB_STATE_POWERED] = "powered",
160 		[USB_STATE_RECONNECTING] = "reconnecting",
161 		[USB_STATE_UNAUTHENTICATED] = "unauthenticated",
162 		[USB_STATE_DEFAULT] = "default",
163 		[USB_STATE_ADDRESS] = "addressed",
164 		[USB_STATE_CONFIGURED] = "configured",
165 		[USB_STATE_SUSPENDED] = "suspended",
166 	};
167 
168 	if (state < 0 || state >= ARRAY_SIZE(names))
169 		return "UNKNOWN";
170 
171 	return names[state];
172 }
173 EXPORT_SYMBOL_GPL(usb_state_string);
174 
175 static const char *const usb_dr_modes[] = {
176 	[USB_DR_MODE_UNKNOWN]		= "",
177 	[USB_DR_MODE_HOST]		= "host",
178 	[USB_DR_MODE_PERIPHERAL]	= "peripheral",
179 	[USB_DR_MODE_OTG]		= "otg",
180 };
181 
182 static enum usb_dr_mode usb_get_dr_mode_from_string(const char *str)
183 {
184 	int ret;
185 
186 	ret = match_string(usb_dr_modes, ARRAY_SIZE(usb_dr_modes), str);
187 	return (ret < 0) ? USB_DR_MODE_UNKNOWN : ret;
188 }
189 
190 enum usb_dr_mode usb_get_dr_mode(struct device *dev)
191 {
192 	const char *dr_mode;
193 	int err;
194 
195 	err = device_property_read_string(dev, "dr_mode", &dr_mode);
196 	if (err < 0)
197 		return USB_DR_MODE_UNKNOWN;
198 
199 	return usb_get_dr_mode_from_string(dr_mode);
200 }
201 EXPORT_SYMBOL_GPL(usb_get_dr_mode);
202 
203 /**
204  * usb_get_role_switch_default_mode - Get default mode for given device
205  * @dev: Pointer to the given device
206  *
207  * The function gets string from property 'role-switch-default-mode',
208  * and returns the corresponding enum usb_dr_mode.
209  */
210 enum usb_dr_mode usb_get_role_switch_default_mode(struct device *dev)
211 {
212 	const char *str;
213 	int ret;
214 
215 	ret = device_property_read_string(dev, "role-switch-default-mode", &str);
216 	if (ret < 0)
217 		return USB_DR_MODE_UNKNOWN;
218 
219 	return usb_get_dr_mode_from_string(str);
220 }
221 EXPORT_SYMBOL_GPL(usb_get_role_switch_default_mode);
222 
223 /**
224  * usb_decode_interval - Decode bInterval into the time expressed in 1us unit
225  * @epd: The descriptor of the endpoint
226  * @speed: The speed that the endpoint works as
227  *
228  * Function returns the interval expressed in 1us unit for servicing
229  * endpoint for data transfers.
230  */
231 unsigned int usb_decode_interval(const struct usb_endpoint_descriptor *epd,
232 				 enum usb_device_speed speed)
233 {
234 	unsigned int interval = 0;
235 
236 	switch (usb_endpoint_type(epd)) {
237 	case USB_ENDPOINT_XFER_CONTROL:
238 		/* uframes per NAK */
239 		if (speed == USB_SPEED_HIGH)
240 			interval = epd->bInterval;
241 		break;
242 	case USB_ENDPOINT_XFER_ISOC:
243 		interval = 1 << (epd->bInterval - 1);
244 		break;
245 	case USB_ENDPOINT_XFER_BULK:
246 		/* uframes per NAK */
247 		if (speed == USB_SPEED_HIGH && usb_endpoint_dir_out(epd))
248 			interval = epd->bInterval;
249 		break;
250 	case USB_ENDPOINT_XFER_INT:
251 		if (speed >= USB_SPEED_HIGH)
252 			interval = 1 << (epd->bInterval - 1);
253 		else
254 			interval = epd->bInterval;
255 		break;
256 	}
257 
258 	interval *= (speed >= USB_SPEED_HIGH) ? 125 : 1000;
259 
260 	return interval;
261 }
262 EXPORT_SYMBOL_GPL(usb_decode_interval);
263 
264 #ifdef CONFIG_OF
265 /**
266  * of_usb_get_dr_mode_by_phy - Get dual role mode for the controller device
267  * which is associated with the given phy device_node
268  * @np:	Pointer to the given phy device_node
269  * @arg0: phandle args[0] for phy's with #phy-cells >= 1, or -1 for
270  *        phys which do not have phy-cells
271  *
272  * In dts a usb controller associates with phy devices.  The function gets
273  * the string from property 'dr_mode' of the controller associated with the
274  * given phy device node, and returns the correspondig enum usb_dr_mode.
275  */
276 enum usb_dr_mode of_usb_get_dr_mode_by_phy(struct device_node *np, int arg0)
277 {
278 	struct device_node *controller = NULL;
279 	struct of_phandle_args args;
280 	const char *dr_mode;
281 	int index;
282 	int err;
283 
284 	do {
285 		controller = of_find_node_with_property(controller, "phys");
286 		if (!of_device_is_available(controller))
287 			continue;
288 		index = 0;
289 		do {
290 			if (arg0 == -1) {
291 				args.np = of_parse_phandle(controller, "phys",
292 							index);
293 				args.args_count = 0;
294 			} else {
295 				err = of_parse_phandle_with_args(controller,
296 							"phys", "#phy-cells",
297 							index, &args);
298 				if (err)
299 					break;
300 			}
301 
302 			of_node_put(args.np);
303 			if (args.np == np && (args.args_count == 0 ||
304 					      args.args[0] == arg0))
305 				goto finish;
306 			index++;
307 		} while (args.np);
308 	} while (controller);
309 
310 finish:
311 	err = of_property_read_string(controller, "dr_mode", &dr_mode);
312 	of_node_put(controller);
313 
314 	if (err < 0)
315 		return USB_DR_MODE_UNKNOWN;
316 
317 	return usb_get_dr_mode_from_string(dr_mode);
318 }
319 EXPORT_SYMBOL_GPL(of_usb_get_dr_mode_by_phy);
320 
321 /**
322  * of_usb_host_tpl_support - to get if Targeted Peripheral List is supported
323  * for given targeted hosts (non-PC hosts)
324  * @np: Pointer to the given device_node
325  *
326  * The function gets if the targeted hosts support TPL or not
327  */
328 bool of_usb_host_tpl_support(struct device_node *np)
329 {
330 	return of_property_read_bool(np, "tpl-support");
331 }
332 EXPORT_SYMBOL_GPL(of_usb_host_tpl_support);
333 
334 /**
335  * of_usb_update_otg_caps - to update usb otg capabilities according to
336  * the passed properties in DT.
337  * @np: Pointer to the given device_node
338  * @otg_caps: Pointer to the target usb_otg_caps to be set
339  *
340  * The function updates the otg capabilities
341  */
342 int of_usb_update_otg_caps(struct device_node *np,
343 			struct usb_otg_caps *otg_caps)
344 {
345 	u32 otg_rev;
346 
347 	if (!otg_caps)
348 		return -EINVAL;
349 
350 	if (!of_property_read_u32(np, "otg-rev", &otg_rev)) {
351 		switch (otg_rev) {
352 		case 0x0100:
353 		case 0x0120:
354 		case 0x0130:
355 		case 0x0200:
356 			/* Choose the lesser one if it's already been set */
357 			if (otg_caps->otg_rev)
358 				otg_caps->otg_rev = min_t(u16, otg_rev,
359 							otg_caps->otg_rev);
360 			else
361 				otg_caps->otg_rev = otg_rev;
362 			break;
363 		default:
364 			pr_err("%pOF: unsupported otg-rev: 0x%x\n",
365 						np, otg_rev);
366 			return -EINVAL;
367 		}
368 	} else {
369 		/*
370 		 * otg-rev is mandatory for otg properties, if not passed
371 		 * we set it to be 0 and assume it's a legacy otg device.
372 		 * Non-dt platform can set it afterwards.
373 		 */
374 		otg_caps->otg_rev = 0;
375 	}
376 
377 	if (of_property_read_bool(np, "hnp-disable"))
378 		otg_caps->hnp_support = false;
379 	if (of_property_read_bool(np, "srp-disable"))
380 		otg_caps->srp_support = false;
381 	if (of_property_read_bool(np, "adp-disable") ||
382 				(otg_caps->otg_rev < 0x0200))
383 		otg_caps->adp_support = false;
384 
385 	return 0;
386 }
387 EXPORT_SYMBOL_GPL(of_usb_update_otg_caps);
388 
389 /**
390  * usb_of_get_companion_dev - Find the companion device
391  * @dev: the device pointer to find a companion
392  *
393  * Find the companion device from platform bus.
394  *
395  * Takes a reference to the returned struct device which needs to be dropped
396  * after use.
397  *
398  * Return: On success, a pointer to the companion device, %NULL on failure.
399  */
400 struct device *usb_of_get_companion_dev(struct device *dev)
401 {
402 	struct device_node *node;
403 	struct platform_device *pdev = NULL;
404 
405 	node = of_parse_phandle(dev->of_node, "companion", 0);
406 	if (node)
407 		pdev = of_find_device_by_node(node);
408 
409 	of_node_put(node);
410 
411 	return pdev ? &pdev->dev : NULL;
412 }
413 EXPORT_SYMBOL_GPL(usb_of_get_companion_dev);
414 #endif
415 
416 struct dentry *usb_debug_root;
417 EXPORT_SYMBOL_GPL(usb_debug_root);
418 
419 static int __init usb_common_init(void)
420 {
421 	usb_debug_root = debugfs_create_dir("usb", NULL);
422 	ledtrig_usb_init();
423 	return 0;
424 }
425 
426 static void __exit usb_common_exit(void)
427 {
428 	ledtrig_usb_exit();
429 	debugfs_remove_recursive(usb_debug_root);
430 }
431 
432 subsys_initcall(usb_common_init);
433 module_exit(usb_common_exit);
434 
435 MODULE_LICENSE("GPL");
436