xref: /openbmc/linux/drivers/usb/common/common.c (revision 249592bf)
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_decode_interval - Decode bInterval into the time expressed in 1us unit
205  * @epd: The descriptor of the endpoint
206  * @speed: The speed that the endpoint works as
207  *
208  * Function returns the interval expressed in 1us unit for servicing
209  * endpoint for data transfers.
210  */
211 unsigned int usb_decode_interval(const struct usb_endpoint_descriptor *epd,
212 				 enum usb_device_speed speed)
213 {
214 	unsigned int interval = 0;
215 
216 	switch (usb_endpoint_type(epd)) {
217 	case USB_ENDPOINT_XFER_CONTROL:
218 		/* uframes per NAK */
219 		if (speed == USB_SPEED_HIGH)
220 			interval = epd->bInterval;
221 		break;
222 	case USB_ENDPOINT_XFER_ISOC:
223 		interval = 1 << (epd->bInterval - 1);
224 		break;
225 	case USB_ENDPOINT_XFER_BULK:
226 		/* uframes per NAK */
227 		if (speed == USB_SPEED_HIGH && usb_endpoint_dir_out(epd))
228 			interval = epd->bInterval;
229 		break;
230 	case USB_ENDPOINT_XFER_INT:
231 		if (speed >= USB_SPEED_HIGH)
232 			interval = 1 << (epd->bInterval - 1);
233 		else
234 			interval = epd->bInterval;
235 		break;
236 	}
237 
238 	interval *= (speed >= USB_SPEED_HIGH) ? 125 : 1000;
239 
240 	return interval;
241 }
242 EXPORT_SYMBOL_GPL(usb_decode_interval);
243 
244 #ifdef CONFIG_OF
245 /**
246  * of_usb_get_dr_mode_by_phy - Get dual role mode for the controller device
247  * which is associated with the given phy device_node
248  * @np:	Pointer to the given phy device_node
249  * @arg0: phandle args[0] for phy's with #phy-cells >= 1, or -1 for
250  *        phys which do not have phy-cells
251  *
252  * In dts a usb controller associates with phy devices.  The function gets
253  * the string from property 'dr_mode' of the controller associated with the
254  * given phy device node, and returns the correspondig enum usb_dr_mode.
255  */
256 enum usb_dr_mode of_usb_get_dr_mode_by_phy(struct device_node *np, int arg0)
257 {
258 	struct device_node *controller = NULL;
259 	struct of_phandle_args args;
260 	const char *dr_mode;
261 	int index;
262 	int err;
263 
264 	do {
265 		controller = of_find_node_with_property(controller, "phys");
266 		if (!of_device_is_available(controller))
267 			continue;
268 		index = 0;
269 		do {
270 			if (arg0 == -1) {
271 				args.np = of_parse_phandle(controller, "phys",
272 							index);
273 				args.args_count = 0;
274 			} else {
275 				err = of_parse_phandle_with_args(controller,
276 							"phys", "#phy-cells",
277 							index, &args);
278 				if (err)
279 					break;
280 			}
281 
282 			of_node_put(args.np);
283 			if (args.np == np && (args.args_count == 0 ||
284 					      args.args[0] == arg0))
285 				goto finish;
286 			index++;
287 		} while (args.np);
288 	} while (controller);
289 
290 finish:
291 	err = of_property_read_string(controller, "dr_mode", &dr_mode);
292 	of_node_put(controller);
293 
294 	if (err < 0)
295 		return USB_DR_MODE_UNKNOWN;
296 
297 	return usb_get_dr_mode_from_string(dr_mode);
298 }
299 EXPORT_SYMBOL_GPL(of_usb_get_dr_mode_by_phy);
300 
301 /**
302  * of_usb_host_tpl_support - to get if Targeted Peripheral List is supported
303  * for given targeted hosts (non-PC hosts)
304  * @np: Pointer to the given device_node
305  *
306  * The function gets if the targeted hosts support TPL or not
307  */
308 bool of_usb_host_tpl_support(struct device_node *np)
309 {
310 	return of_property_read_bool(np, "tpl-support");
311 }
312 EXPORT_SYMBOL_GPL(of_usb_host_tpl_support);
313 
314 /**
315  * of_usb_update_otg_caps - to update usb otg capabilities according to
316  * the passed properties in DT.
317  * @np: Pointer to the given device_node
318  * @otg_caps: Pointer to the target usb_otg_caps to be set
319  *
320  * The function updates the otg capabilities
321  */
322 int of_usb_update_otg_caps(struct device_node *np,
323 			struct usb_otg_caps *otg_caps)
324 {
325 	u32 otg_rev;
326 
327 	if (!otg_caps)
328 		return -EINVAL;
329 
330 	if (!of_property_read_u32(np, "otg-rev", &otg_rev)) {
331 		switch (otg_rev) {
332 		case 0x0100:
333 		case 0x0120:
334 		case 0x0130:
335 		case 0x0200:
336 			/* Choose the lesser one if it's already been set */
337 			if (otg_caps->otg_rev)
338 				otg_caps->otg_rev = min_t(u16, otg_rev,
339 							otg_caps->otg_rev);
340 			else
341 				otg_caps->otg_rev = otg_rev;
342 			break;
343 		default:
344 			pr_err("%pOF: unsupported otg-rev: 0x%x\n",
345 						np, otg_rev);
346 			return -EINVAL;
347 		}
348 	} else {
349 		/*
350 		 * otg-rev is mandatory for otg properties, if not passed
351 		 * we set it to be 0 and assume it's a legacy otg device.
352 		 * Non-dt platform can set it afterwards.
353 		 */
354 		otg_caps->otg_rev = 0;
355 	}
356 
357 	if (of_property_read_bool(np, "hnp-disable"))
358 		otg_caps->hnp_support = false;
359 	if (of_property_read_bool(np, "srp-disable"))
360 		otg_caps->srp_support = false;
361 	if (of_property_read_bool(np, "adp-disable") ||
362 				(otg_caps->otg_rev < 0x0200))
363 		otg_caps->adp_support = false;
364 
365 	return 0;
366 }
367 EXPORT_SYMBOL_GPL(of_usb_update_otg_caps);
368 
369 /**
370  * usb_of_get_companion_dev - Find the companion device
371  * @dev: the device pointer to find a companion
372  *
373  * Find the companion device from platform bus.
374  *
375  * Takes a reference to the returned struct device which needs to be dropped
376  * after use.
377  *
378  * Return: On success, a pointer to the companion device, %NULL on failure.
379  */
380 struct device *usb_of_get_companion_dev(struct device *dev)
381 {
382 	struct device_node *node;
383 	struct platform_device *pdev = NULL;
384 
385 	node = of_parse_phandle(dev->of_node, "companion", 0);
386 	if (node)
387 		pdev = of_find_device_by_node(node);
388 
389 	of_node_put(node);
390 
391 	return pdev ? &pdev->dev : NULL;
392 }
393 EXPORT_SYMBOL_GPL(usb_of_get_companion_dev);
394 #endif
395 
396 struct dentry *usb_debug_root;
397 EXPORT_SYMBOL_GPL(usb_debug_root);
398 
399 static int __init usb_common_init(void)
400 {
401 	usb_debug_root = debugfs_create_dir("usb", NULL);
402 	ledtrig_usb_init();
403 	return 0;
404 }
405 
406 static void __exit usb_common_exit(void)
407 {
408 	ledtrig_usb_exit();
409 	debugfs_remove_recursive(usb_debug_root);
410 }
411 
412 subsys_initcall(usb_common_init);
413 module_exit(usb_common_exit);
414 
415 MODULE_LICENSE("GPL");
416