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
 22static 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 */
 35const 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}
 42EXPORT_SYMBOL_GPL(usb_ep_type_string);
 43
 44const 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}
 67EXPORT_SYMBOL_GPL(usb_otg_state_string);
 68
 69static 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
 79static 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 */
 92const 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}
 98EXPORT_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 */
108enum 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}
123EXPORT_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 */
134enum 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}
146EXPORT_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 */
154const 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}
173EXPORT_SYMBOL_GPL(usb_state_string);
174
175static 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
182static 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
190enum 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}
201EXPORT_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 */
210enum 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}
221EXPORT_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 */
231unsigned 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}
262EXPORT_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 */
276enum 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
309finish:
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}
318EXPORT_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 */
327bool of_usb_host_tpl_support(struct device_node *np)
328{
329	return of_property_read_bool(np, "tpl-support");
330}
331EXPORT_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 */
341int 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}
386EXPORT_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 */
399struct 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}
412EXPORT_SYMBOL_GPL(usb_of_get_companion_dev);
413#endif
414
415struct dentry *usb_debug_root;
416EXPORT_SYMBOL_GPL(usb_debug_root);
417
418DEFINE_MUTEX(usb_dynids_lock);
419EXPORT_SYMBOL_GPL(usb_dynids_lock);
420
421static int __init usb_common_init(void)
422{
423	usb_debug_root = debugfs_create_dir("usb", NULL);
424	ledtrig_usb_init();
425	return 0;
426}
427
428static void __exit usb_common_exit(void)
429{
430	ledtrig_usb_exit();
431	debugfs_remove_recursive(usb_debug_root);
432}
433
434subsys_initcall(usb_common_init);
435module_exit(usb_common_exit);
436
437MODULE_DESCRIPTION("Common code for host and device side USB");
438MODULE_LICENSE("GPL");