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 */
usb_ep_type_string(int ep_type)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
usb_otg_state_string(enum usb_otg_state state)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 */
usb_speed_string(enum usb_device_speed speed)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 */
usb_get_maximum_speed(struct device * dev)108 enum usb_device_speed usb_get_maximum_speed(struct device *dev)
109 {
110 const char *p = "maximum-speed";
111 int ret;
112
113 ret = device_property_match_property_string(dev, p, ssp_rate, ARRAY_SIZE(ssp_rate));
114 if (ret > 0)
115 return USB_SPEED_SUPER_PLUS;
116
117 ret = device_property_match_property_string(dev, p, speed_names, ARRAY_SIZE(speed_names));
118 if (ret > 0)
119 return ret;
120
121 return USB_SPEED_UNKNOWN;
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 */
usb_get_maximum_ssp_rate(struct device * dev)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 */
usb_state_string(enum usb_device_state state)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
usb_get_dr_mode_from_string(const char * str)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
usb_get_dr_mode(struct device * dev)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 */
usb_get_role_switch_default_mode(struct device * dev)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 */
usb_decode_interval(const struct usb_endpoint_descriptor * epd,enum usb_device_speed speed)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 */
of_usb_get_dr_mode_by_phy(struct device_node * np,int arg0)276 enum usb_dr_mode of_usb_get_dr_mode_by_phy(struct device_node *np, int arg0)
277 {
278 struct device_node *controller;
279 struct of_phandle_args args;
280 const char *dr_mode;
281 int index;
282 int err;
283
284 for_each_node_with_property(controller, "phys") {
285 if (!of_device_is_available(controller))
286 continue;
287 index = 0;
288 do {
289 if (arg0 == -1) {
290 args.np = of_parse_phandle(controller, "phys",
291 index);
292 args.args_count = 0;
293 } else {
294 err = of_parse_phandle_with_args(controller,
295 "phys", "#phy-cells",
296 index, &args);
297 if (err)
298 break;
299 }
300
301 of_node_put(args.np);
302 if (args.np == np && (args.args_count == 0 ||
303 args.args[0] == arg0))
304 goto finish;
305 index++;
306 } while (args.np);
307 }
308
309 finish:
310 err = of_property_read_string(controller, "dr_mode", &dr_mode);
311 of_node_put(controller);
312
313 if (err < 0)
314 return USB_DR_MODE_UNKNOWN;
315
316 return usb_get_dr_mode_from_string(dr_mode);
317 }
318 EXPORT_SYMBOL_GPL(of_usb_get_dr_mode_by_phy);
319
320 /**
321 * of_usb_host_tpl_support - to get if Targeted Peripheral List is supported
322 * for given targeted hosts (non-PC hosts)
323 * @np: Pointer to the given device_node
324 *
325 * The function gets if the targeted hosts support TPL or not
326 */
of_usb_host_tpl_support(struct device_node * np)327 bool of_usb_host_tpl_support(struct device_node *np)
328 {
329 return of_property_read_bool(np, "tpl-support");
330 }
331 EXPORT_SYMBOL_GPL(of_usb_host_tpl_support);
332
333 /**
334 * of_usb_update_otg_caps - to update usb otg capabilities according to
335 * the passed properties in DT.
336 * @np: Pointer to the given device_node
337 * @otg_caps: Pointer to the target usb_otg_caps to be set
338 *
339 * The function updates the otg capabilities
340 */
of_usb_update_otg_caps(struct device_node * np,struct usb_otg_caps * otg_caps)341 int of_usb_update_otg_caps(struct device_node *np,
342 struct usb_otg_caps *otg_caps)
343 {
344 u32 otg_rev;
345
346 if (!otg_caps)
347 return -EINVAL;
348
349 if (!of_property_read_u32(np, "otg-rev", &otg_rev)) {
350 switch (otg_rev) {
351 case 0x0100:
352 case 0x0120:
353 case 0x0130:
354 case 0x0200:
355 /* Choose the lesser one if it's already been set */
356 if (otg_caps->otg_rev)
357 otg_caps->otg_rev = min_t(u16, otg_rev,
358 otg_caps->otg_rev);
359 else
360 otg_caps->otg_rev = otg_rev;
361 break;
362 default:
363 pr_err("%pOF: unsupported otg-rev: 0x%x\n",
364 np, otg_rev);
365 return -EINVAL;
366 }
367 } else {
368 /*
369 * otg-rev is mandatory for otg properties, if not passed
370 * we set it to be 0 and assume it's a legacy otg device.
371 * Non-dt platform can set it afterwards.
372 */
373 otg_caps->otg_rev = 0;
374 }
375
376 if (of_property_read_bool(np, "hnp-disable"))
377 otg_caps->hnp_support = false;
378 if (of_property_read_bool(np, "srp-disable"))
379 otg_caps->srp_support = false;
380 if (of_property_read_bool(np, "adp-disable") ||
381 (otg_caps->otg_rev < 0x0200))
382 otg_caps->adp_support = false;
383
384 return 0;
385 }
386 EXPORT_SYMBOL_GPL(of_usb_update_otg_caps);
387
388 /**
389 * usb_of_get_companion_dev - Find the companion device
390 * @dev: the device pointer to find a companion
391 *
392 * Find the companion device from platform bus.
393 *
394 * Takes a reference to the returned struct device which needs to be dropped
395 * after use.
396 *
397 * Return: On success, a pointer to the companion device, %NULL on failure.
398 */
usb_of_get_companion_dev(struct device * dev)399 struct device *usb_of_get_companion_dev(struct device *dev)
400 {
401 struct device_node *node;
402 struct platform_device *pdev = NULL;
403
404 node = of_parse_phandle(dev->of_node, "companion", 0);
405 if (node)
406 pdev = of_find_device_by_node(node);
407
408 of_node_put(node);
409
410 return pdev ? &pdev->dev : NULL;
411 }
412 EXPORT_SYMBOL_GPL(usb_of_get_companion_dev);
413 #endif
414
415 struct dentry *usb_debug_root;
416 EXPORT_SYMBOL_GPL(usb_debug_root);
417
usb_common_init(void)418 static int __init usb_common_init(void)
419 {
420 usb_debug_root = debugfs_create_dir("usb", NULL);
421 ledtrig_usb_init();
422 return 0;
423 }
424
usb_common_exit(void)425 static void __exit usb_common_exit(void)
426 {
427 ledtrig_usb_exit();
428 debugfs_remove_recursive(usb_debug_root);
429 }
430
431 subsys_initcall(usb_common_init);
432 module_exit(usb_common_exit);
433
434 MODULE_DESCRIPTION("Common code for host and device side USB");
435 MODULE_LICENSE("GPL");
436