xref: /linux/drivers/usb/common/common.c (revision 484f0a071f8d482649eaf025dee7b76a7202fec9)
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/platform_device.h>
15 #include <linux/usb/ch9.h>
16 #include <linux/usb/of.h>
17 #include <linux/usb/otg.h>
18 #include <linux/of_platform.h>
19 #include <linux/debugfs.h>
20 #include "common.h"
21 
22 static const char *const ep_type_names[] = {
23 	[USB_ENDPOINT_XFER_CONTROL] = "ctrl",
24 	[USB_ENDPOINT_XFER_ISOC] = "isoc",
25 	[USB_ENDPOINT_XFER_BULK] = "bulk",
26 	[USB_ENDPOINT_XFER_INT] = "intr",
27 };
28 
29 /**
30  * usb_ep_type_string() - Returns human readable-name of the endpoint type.
31  * @ep_type: The endpoint type to return human-readable name for.  If it's not
32  *   any of the types: USB_ENDPOINT_XFER_{CONTROL, ISOC, BULK, INT},
33  *   usually got by usb_endpoint_type(), the string 'unknown' will be returned.
34  */
35 const char *usb_ep_type_string(int ep_type)
36 {
37 	if (ep_type < 0 || ep_type >= ARRAY_SIZE(ep_type_names))
38 		return "unknown";
39 
40 	return ep_type_names[ep_type];
41 }
42 EXPORT_SYMBOL_GPL(usb_ep_type_string);
43 
44 const char *usb_otg_state_string(enum usb_otg_state state)
45 {
46 	static const char *const names[] = {
47 		[OTG_STATE_A_IDLE] = "a_idle",
48 		[OTG_STATE_A_WAIT_VRISE] = "a_wait_vrise",
49 		[OTG_STATE_A_WAIT_BCON] = "a_wait_bcon",
50 		[OTG_STATE_A_HOST] = "a_host",
51 		[OTG_STATE_A_SUSPEND] = "a_suspend",
52 		[OTG_STATE_A_PERIPHERAL] = "a_peripheral",
53 		[OTG_STATE_A_WAIT_VFALL] = "a_wait_vfall",
54 		[OTG_STATE_A_VBUS_ERR] = "a_vbus_err",
55 		[OTG_STATE_B_IDLE] = "b_idle",
56 		[OTG_STATE_B_SRP_INIT] = "b_srp_init",
57 		[OTG_STATE_B_PERIPHERAL] = "b_peripheral",
58 		[OTG_STATE_B_WAIT_ACON] = "b_wait_acon",
59 		[OTG_STATE_B_HOST] = "b_host",
60 	};
61 
62 	if (state < 0 || state >= ARRAY_SIZE(names))
63 		return "UNDEFINED";
64 
65 	return names[state];
66 }
67 EXPORT_SYMBOL_GPL(usb_otg_state_string);
68 
69 static const char *const speed_names[] = {
70 	[USB_SPEED_UNKNOWN] = "UNKNOWN",
71 	[USB_SPEED_LOW] = "low-speed",
72 	[USB_SPEED_FULL] = "full-speed",
73 	[USB_SPEED_HIGH] = "high-speed",
74 	[USB_SPEED_WIRELESS] = "wireless",
75 	[USB_SPEED_SUPER] = "super-speed",
76 	[USB_SPEED_SUPER_PLUS] = "super-speed-plus",
77 };
78 
79 static const char *const ssp_rate[] = {
80 	[USB_SSP_GEN_UNKNOWN] = "UNKNOWN",
81 	[USB_SSP_GEN_2x1] = "super-speed-plus-gen2x1",
82 	[USB_SSP_GEN_1x2] = "super-speed-plus-gen1x2",
83 	[USB_SSP_GEN_2x2] = "super-speed-plus-gen2x2",
84 };
85 
86 /**
87  * usb_speed_string() - Returns human readable-name of the speed.
88  * @speed: The speed to return human-readable name for.  If it's not
89  *   any of the speeds defined in usb_device_speed enum, string for
90  *   USB_SPEED_UNKNOWN will be returned.
91  */
92 const char *usb_speed_string(enum usb_device_speed speed)
93 {
94 	if (speed < 0 || speed >= ARRAY_SIZE(speed_names))
95 		speed = USB_SPEED_UNKNOWN;
96 	return speed_names[speed];
97 }
98 EXPORT_SYMBOL_GPL(usb_speed_string);
99 
100 /**
101  * usb_get_maximum_speed - Get maximum requested speed for a given USB
102  * controller.
103  * @dev: Pointer to the given USB controller device
104  *
105  * The function gets the maximum speed string from property "maximum-speed",
106  * and returns the corresponding enum usb_device_speed.
107  */
108 enum usb_device_speed usb_get_maximum_speed(struct device *dev)
109 {
110 	const char *maximum_speed;
111 	int ret;
112 
113 	ret = device_property_read_string(dev, "maximum-speed", &maximum_speed);
114 	if (ret < 0)
115 		return USB_SPEED_UNKNOWN;
116 
117 	ret = match_string(ssp_rate, ARRAY_SIZE(ssp_rate), maximum_speed);
118 	if (ret > 0)
119 		return USB_SPEED_SUPER_PLUS;
120 
121 	ret = match_string(speed_names, ARRAY_SIZE(speed_names), maximum_speed);
122 	return (ret < 0) ? USB_SPEED_UNKNOWN : ret;
123 }
124 EXPORT_SYMBOL_GPL(usb_get_maximum_speed);
125 
126 /**
127  * usb_get_maximum_ssp_rate - Get the signaling rate generation and lane count
128  *	of a SuperSpeed Plus capable device.
129  * @dev: Pointer to the given USB controller device
130  *
131  * If the string from "maximum-speed" property is super-speed-plus-genXxY where
132  * 'X' is the generation number and 'Y' is the number of lanes, then this
133  * function returns the corresponding enum usb_ssp_rate.
134  */
135 enum usb_ssp_rate usb_get_maximum_ssp_rate(struct device *dev)
136 {
137 	const char *maximum_speed;
138 	int ret;
139 
140 	ret = device_property_read_string(dev, "maximum-speed", &maximum_speed);
141 	if (ret < 0)
142 		return USB_SSP_GEN_UNKNOWN;
143 
144 	ret = match_string(ssp_rate, ARRAY_SIZE(ssp_rate), maximum_speed);
145 	return (ret < 0) ? USB_SSP_GEN_UNKNOWN : ret;
146 }
147 EXPORT_SYMBOL_GPL(usb_get_maximum_ssp_rate);
148 
149 /**
150  * usb_state_string - Returns human readable name for the state.
151  * @state: The state to return a human-readable name for. If it's not
152  *	any of the states devices in usb_device_state_string enum,
153  *	the string UNKNOWN will be returned.
154  */
155 const char *usb_state_string(enum usb_device_state state)
156 {
157 	static const char *const names[] = {
158 		[USB_STATE_NOTATTACHED] = "not attached",
159 		[USB_STATE_ATTACHED] = "attached",
160 		[USB_STATE_POWERED] = "powered",
161 		[USB_STATE_RECONNECTING] = "reconnecting",
162 		[USB_STATE_UNAUTHENTICATED] = "unauthenticated",
163 		[USB_STATE_DEFAULT] = "default",
164 		[USB_STATE_ADDRESS] = "addressed",
165 		[USB_STATE_CONFIGURED] = "configured",
166 		[USB_STATE_SUSPENDED] = "suspended",
167 	};
168 
169 	if (state < 0 || state >= ARRAY_SIZE(names))
170 		return "UNKNOWN";
171 
172 	return names[state];
173 }
174 EXPORT_SYMBOL_GPL(usb_state_string);
175 
176 static const char *const usb_dr_modes[] = {
177 	[USB_DR_MODE_UNKNOWN]		= "",
178 	[USB_DR_MODE_HOST]		= "host",
179 	[USB_DR_MODE_PERIPHERAL]	= "peripheral",
180 	[USB_DR_MODE_OTG]		= "otg",
181 };
182 
183 static enum usb_dr_mode usb_get_dr_mode_from_string(const char *str)
184 {
185 	int ret;
186 
187 	ret = match_string(usb_dr_modes, ARRAY_SIZE(usb_dr_modes), str);
188 	return (ret < 0) ? USB_DR_MODE_UNKNOWN : ret;
189 }
190 
191 enum usb_dr_mode usb_get_dr_mode(struct device *dev)
192 {
193 	const char *dr_mode;
194 	int err;
195 
196 	err = device_property_read_string(dev, "dr_mode", &dr_mode);
197 	if (err < 0)
198 		return USB_DR_MODE_UNKNOWN;
199 
200 	return usb_get_dr_mode_from_string(dr_mode);
201 }
202 EXPORT_SYMBOL_GPL(usb_get_dr_mode);
203 
204 /**
205  * usb_get_role_switch_default_mode - Get default mode for given device
206  * @dev: Pointer to the given device
207  *
208  * The function gets string from property 'role-switch-default-mode',
209  * and returns the corresponding enum usb_dr_mode.
210  */
211 enum usb_dr_mode usb_get_role_switch_default_mode(struct device *dev)
212 {
213 	const char *str;
214 	int ret;
215 
216 	ret = device_property_read_string(dev, "role-switch-default-mode", &str);
217 	if (ret < 0)
218 		return USB_DR_MODE_UNKNOWN;
219 
220 	return usb_get_dr_mode_from_string(str);
221 }
222 EXPORT_SYMBOL_GPL(usb_get_role_switch_default_mode);
223 
224 /**
225  * usb_decode_interval - Decode bInterval into the time expressed in 1us unit
226  * @epd: The descriptor of the endpoint
227  * @speed: The speed that the endpoint works as
228  *
229  * Function returns the interval expressed in 1us unit for servicing
230  * endpoint for data transfers.
231  */
232 unsigned int usb_decode_interval(const struct usb_endpoint_descriptor *epd,
233 				 enum usb_device_speed speed)
234 {
235 	unsigned int interval = 0;
236 
237 	switch (usb_endpoint_type(epd)) {
238 	case USB_ENDPOINT_XFER_CONTROL:
239 		/* uframes per NAK */
240 		if (speed == USB_SPEED_HIGH)
241 			interval = epd->bInterval;
242 		break;
243 	case USB_ENDPOINT_XFER_ISOC:
244 		interval = 1 << (epd->bInterval - 1);
245 		break;
246 	case USB_ENDPOINT_XFER_BULK:
247 		/* uframes per NAK */
248 		if (speed == USB_SPEED_HIGH && usb_endpoint_dir_out(epd))
249 			interval = epd->bInterval;
250 		break;
251 	case USB_ENDPOINT_XFER_INT:
252 		if (speed >= USB_SPEED_HIGH)
253 			interval = 1 << (epd->bInterval - 1);
254 		else
255 			interval = epd->bInterval;
256 		break;
257 	}
258 
259 	interval *= (speed >= USB_SPEED_HIGH) ? 125 : 1000;
260 
261 	return interval;
262 }
263 EXPORT_SYMBOL_GPL(usb_decode_interval);
264 
265 #ifdef CONFIG_OF
266 /**
267  * of_usb_get_dr_mode_by_phy - Get dual role mode for the controller device
268  * which is associated with the given phy device_node
269  * @np:	Pointer to the given phy device_node
270  * @arg0: phandle args[0] for phy's with #phy-cells >= 1, or -1 for
271  *        phys which do not have phy-cells
272  *
273  * In dts a usb controller associates with phy devices.  The function gets
274  * the string from property 'dr_mode' of the controller associated with the
275  * given phy device node, and returns the correspondig enum usb_dr_mode.
276  */
277 enum usb_dr_mode of_usb_get_dr_mode_by_phy(struct device_node *np, int arg0)
278 {
279 	struct device_node *controller = NULL;
280 	struct of_phandle_args args;
281 	const char *dr_mode;
282 	int index;
283 	int err;
284 
285 	do {
286 		controller = of_find_node_with_property(controller, "phys");
287 		if (!of_device_is_available(controller))
288 			continue;
289 		index = 0;
290 		do {
291 			if (arg0 == -1) {
292 				args.np = of_parse_phandle(controller, "phys",
293 							index);
294 				args.args_count = 0;
295 			} else {
296 				err = of_parse_phandle_with_args(controller,
297 							"phys", "#phy-cells",
298 							index, &args);
299 				if (err)
300 					break;
301 			}
302 
303 			of_node_put(args.np);
304 			if (args.np == np && (args.args_count == 0 ||
305 					      args.args[0] == arg0))
306 				goto finish;
307 			index++;
308 		} while (args.np);
309 	} while (controller);
310 
311 finish:
312 	err = of_property_read_string(controller, "dr_mode", &dr_mode);
313 	of_node_put(controller);
314 
315 	if (err < 0)
316 		return USB_DR_MODE_UNKNOWN;
317 
318 	return usb_get_dr_mode_from_string(dr_mode);
319 }
320 EXPORT_SYMBOL_GPL(of_usb_get_dr_mode_by_phy);
321 
322 /**
323  * of_usb_host_tpl_support - to get if Targeted Peripheral List is supported
324  * for given targeted hosts (non-PC hosts)
325  * @np: Pointer to the given device_node
326  *
327  * The function gets if the targeted hosts support TPL or not
328  */
329 bool of_usb_host_tpl_support(struct device_node *np)
330 {
331 	return of_property_read_bool(np, "tpl-support");
332 }
333 EXPORT_SYMBOL_GPL(of_usb_host_tpl_support);
334 
335 /**
336  * of_usb_update_otg_caps - to update usb otg capabilities according to
337  * the passed properties in DT.
338  * @np: Pointer to the given device_node
339  * @otg_caps: Pointer to the target usb_otg_caps to be set
340  *
341  * The function updates the otg capabilities
342  */
343 int of_usb_update_otg_caps(struct device_node *np,
344 			struct usb_otg_caps *otg_caps)
345 {
346 	u32 otg_rev;
347 
348 	if (!otg_caps)
349 		return -EINVAL;
350 
351 	if (!of_property_read_u32(np, "otg-rev", &otg_rev)) {
352 		switch (otg_rev) {
353 		case 0x0100:
354 		case 0x0120:
355 		case 0x0130:
356 		case 0x0200:
357 			/* Choose the lesser one if it's already been set */
358 			if (otg_caps->otg_rev)
359 				otg_caps->otg_rev = min_t(u16, otg_rev,
360 							otg_caps->otg_rev);
361 			else
362 				otg_caps->otg_rev = otg_rev;
363 			break;
364 		default:
365 			pr_err("%pOF: unsupported otg-rev: 0x%x\n",
366 						np, otg_rev);
367 			return -EINVAL;
368 		}
369 	} else {
370 		/*
371 		 * otg-rev is mandatory for otg properties, if not passed
372 		 * we set it to be 0 and assume it's a legacy otg device.
373 		 * Non-dt platform can set it afterwards.
374 		 */
375 		otg_caps->otg_rev = 0;
376 	}
377 
378 	if (of_property_read_bool(np, "hnp-disable"))
379 		otg_caps->hnp_support = false;
380 	if (of_property_read_bool(np, "srp-disable"))
381 		otg_caps->srp_support = false;
382 	if (of_property_read_bool(np, "adp-disable") ||
383 				(otg_caps->otg_rev < 0x0200))
384 		otg_caps->adp_support = false;
385 
386 	return 0;
387 }
388 EXPORT_SYMBOL_GPL(of_usb_update_otg_caps);
389 
390 /**
391  * usb_of_get_companion_dev - Find the companion device
392  * @dev: the device pointer to find a companion
393  *
394  * Find the companion device from platform bus.
395  *
396  * Takes a reference to the returned struct device which needs to be dropped
397  * after use.
398  *
399  * Return: On success, a pointer to the companion device, %NULL on failure.
400  */
401 struct device *usb_of_get_companion_dev(struct device *dev)
402 {
403 	struct device_node *node;
404 	struct platform_device *pdev = NULL;
405 
406 	node = of_parse_phandle(dev->of_node, "companion", 0);
407 	if (node)
408 		pdev = of_find_device_by_node(node);
409 
410 	of_node_put(node);
411 
412 	return pdev ? &pdev->dev : NULL;
413 }
414 EXPORT_SYMBOL_GPL(usb_of_get_companion_dev);
415 #endif
416 
417 struct dentry *usb_debug_root;
418 EXPORT_SYMBOL_GPL(usb_debug_root);
419 
420 static int __init usb_common_init(void)
421 {
422 	usb_debug_root = debugfs_create_dir("usb", NULL);
423 	ledtrig_usb_init();
424 	return 0;
425 }
426 
427 static void __exit usb_common_exit(void)
428 {
429 	ledtrig_usb_exit();
430 	debugfs_remove_recursive(usb_debug_root);
431 }
432 
433 subsys_initcall(usb_common_init);
434 module_exit(usb_common_exit);
435 
436 MODULE_LICENSE("GPL");
437