common.c

  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
 44/**
 45 * usb_otg_state_string() - returns human readable name of OTG state.
 46 * @state: the OTG state to return the human readable name of. If it's not
 47 *    any of the states defined in usb_otg_state enum, 'UNDEFINED' will be
 48 *    returned.
 49 */
 50const char *usb_otg_state_string(enum usb_otg_state state)
 51{
 52	static const char *const names[] = {
 53		[OTG_STATE_A_IDLE] = "a_idle",
 54		[OTG_STATE_A_WAIT_VRISE] = "a_wait_vrise",
 55		[OTG_STATE_A_WAIT_BCON] = "a_wait_bcon",
 56		[OTG_STATE_A_HOST] = "a_host",
 57		[OTG_STATE_A_SUSPEND] = "a_suspend",
 58		[OTG_STATE_A_PERIPHERAL] = "a_peripheral",
 59		[OTG_STATE_A_WAIT_VFALL] = "a_wait_vfall",
 60		[OTG_STATE_A_VBUS_ERR] = "a_vbus_err",
 61		[OTG_STATE_B_IDLE] = "b_idle",
 62		[OTG_STATE_B_SRP_INIT] = "b_srp_init",
 63		[OTG_STATE_B_PERIPHERAL] = "b_peripheral",
 64		[OTG_STATE_B_WAIT_ACON] = "b_wait_acon",
 65		[OTG_STATE_B_HOST] = "b_host",
 66	};
 67
 68	if (state < 0 || state >= ARRAY_SIZE(names))
 69		return "UNDEFINED";
 70
 71	return names[state];
 72}
 73EXPORT_SYMBOL_GPL(usb_otg_state_string);
 74
 75static const char *const speed_names[] = {
 76	[USB_SPEED_UNKNOWN] = "UNKNOWN",
 77	[USB_SPEED_LOW] = "low-speed",
 78	[USB_SPEED_FULL] = "full-speed",
 79	[USB_SPEED_HIGH] = "high-speed",
 80	[USB_SPEED_WIRELESS] = "wireless",
 81	[USB_SPEED_SUPER] = "super-speed",
 82	[USB_SPEED_SUPER_PLUS] = "super-speed-plus",
 83};
 84
 85static const char *const ssp_rate[] = {
 86	[USB_SSP_GEN_UNKNOWN] = "UNKNOWN",
 87	[USB_SSP_GEN_2x1] = "super-speed-plus-gen2x1",
 88	[USB_SSP_GEN_1x2] = "super-speed-plus-gen1x2",
 89	[USB_SSP_GEN_2x2] = "super-speed-plus-gen2x2",
 90};
 91
 92/**
 93 * usb_speed_string() - Returns human readable-name of the speed.
 94 * @speed: The speed to return human-readable name for.  If it's not
 95 *   any of the speeds defined in usb_device_speed enum, string for
 96 *   USB_SPEED_UNKNOWN will be returned.
 97 */
 98const char *usb_speed_string(enum usb_device_speed speed)
 99{
100	if (speed < 0 || speed >= ARRAY_SIZE(speed_names))
101		speed = USB_SPEED_UNKNOWN;
102	return speed_names[speed];
103}
104EXPORT_SYMBOL_GPL(usb_speed_string);
105
106/**
107 * usb_get_maximum_speed - Get maximum requested speed for a given USB
108 * controller.
109 * @dev: Pointer to the given USB controller device
110 *
111 * The function gets the maximum speed string from property "maximum-speed",
112 * and returns the corresponding enum usb_device_speed.
113 */
114enum usb_device_speed usb_get_maximum_speed(struct device *dev)
115{
116	const char *p = "maximum-speed";
117	int ret;
118
119	ret = device_property_match_property_string(dev, p, ssp_rate, ARRAY_SIZE(ssp_rate));
120	if (ret > 0)
121		return USB_SPEED_SUPER_PLUS;
122
123	ret = device_property_match_property_string(dev, p, speed_names, ARRAY_SIZE(speed_names));
124	if (ret > 0)
125		return ret;
126
127	return USB_SPEED_UNKNOWN;
128}
129EXPORT_SYMBOL_GPL(usb_get_maximum_speed);
130
131/**
132 * usb_get_maximum_ssp_rate - Get the signaling rate generation and lane count
133 *	of a SuperSpeed Plus capable device.
134 * @dev: Pointer to the given USB controller device
135 *
136 * If the string from "maximum-speed" property is super-speed-plus-genXxY where
137 * 'X' is the generation number and 'Y' is the number of lanes, then this
138 * function returns the corresponding enum usb_ssp_rate.
139 */
140enum usb_ssp_rate usb_get_maximum_ssp_rate(struct device *dev)
141{
142	const char *maximum_speed;
143	int ret;
144
145	ret = device_property_read_string(dev, "maximum-speed", &maximum_speed);
146	if (ret < 0)
147		return USB_SSP_GEN_UNKNOWN;
148
149	ret = match_string(ssp_rate, ARRAY_SIZE(ssp_rate), maximum_speed);
150	return (ret < 0) ? USB_SSP_GEN_UNKNOWN : ret;
151}
152EXPORT_SYMBOL_GPL(usb_get_maximum_ssp_rate);
153
154/**
155 * usb_state_string - Returns human readable name for the state.
156 * @state: The state to return a human-readable name for. If it's not
157 *	any of the states devices in usb_device_state_string enum,
158 *	the string UNKNOWN will be returned.
159 */
160const char *usb_state_string(enum usb_device_state state)
161{
162	static const char *const names[] = {
163		[USB_STATE_NOTATTACHED] = "not attached",
164		[USB_STATE_ATTACHED] = "attached",
165		[USB_STATE_POWERED] = "powered",
166		[USB_STATE_RECONNECTING] = "reconnecting",
167		[USB_STATE_UNAUTHENTICATED] = "unauthenticated",
168		[USB_STATE_DEFAULT] = "default",
169		[USB_STATE_ADDRESS] = "addressed",
170		[USB_STATE_CONFIGURED] = "configured",
171		[USB_STATE_SUSPENDED] = "suspended",
172	};
173
174	if (state < 0 || state >= ARRAY_SIZE(names))
175		return "UNKNOWN";
176
177	return names[state];
178}
179EXPORT_SYMBOL_GPL(usb_state_string);
180
181static const char *const usb_dr_modes[] = {
182	[USB_DR_MODE_UNKNOWN]		= "",
183	[USB_DR_MODE_HOST]		= "host",
184	[USB_DR_MODE_PERIPHERAL]	= "peripheral",
185	[USB_DR_MODE_OTG]		= "otg",
186};
187
188/**
189 * usb_get_dr_mode_from_string() - Get dual role mode for given string
190 * @str: String to find the corresponding dual role mode for
191 *
192 * This function performs a lookup for the given string and returns the
193 * corresponding enum usb_dr_mode. If no match for the string could be found,
194 * 'USB_DR_MODE_UNKNOWN' is returned.
195 */
196static enum usb_dr_mode usb_get_dr_mode_from_string(const char *str)
197{
198	int ret;
199
200	ret = match_string(usb_dr_modes, ARRAY_SIZE(usb_dr_modes), str);
201	return (ret < 0) ? USB_DR_MODE_UNKNOWN : ret;
202}
203
204enum usb_dr_mode usb_get_dr_mode(struct device *dev)
205{
206	const char *dr_mode;
207	int err;
208
209	err = device_property_read_string(dev, "dr_mode", &dr_mode);
210	if (err < 0)
211		return USB_DR_MODE_UNKNOWN;
212
213	return usb_get_dr_mode_from_string(dr_mode);
214}
215EXPORT_SYMBOL_GPL(usb_get_dr_mode);
216
217/**
218 * usb_get_role_switch_default_mode - Get default mode for given device
219 * @dev: Pointer to the given device
220 *
221 * The function gets string from property 'role-switch-default-mode',
222 * and returns the corresponding enum usb_dr_mode.
223 */
224enum usb_dr_mode usb_get_role_switch_default_mode(struct device *dev)
225{
226	const char *str;
227	int ret;
228
229	ret = device_property_read_string(dev, "role-switch-default-mode", &str);
230	if (ret < 0)
231		return USB_DR_MODE_UNKNOWN;
232
233	return usb_get_dr_mode_from_string(str);
234}
235EXPORT_SYMBOL_GPL(usb_get_role_switch_default_mode);
236
237/**
238 * usb_decode_interval - Decode bInterval into the time expressed in 1us unit
239 * @epd: The descriptor of the endpoint
240 * @speed: The speed that the endpoint works as
241 *
242 * Function returns the interval expressed in 1us unit for servicing
243 * endpoint for data transfers.
244 */
245unsigned int usb_decode_interval(const struct usb_endpoint_descriptor *epd,
246				 enum usb_device_speed speed)
247{
248	unsigned int interval = 0;
249
250	switch (usb_endpoint_type(epd)) {
251	case USB_ENDPOINT_XFER_CONTROL:
252		/* uframes per NAK */
253		if (speed == USB_SPEED_HIGH)
254			interval = epd->bInterval;
255		break;
256	case USB_ENDPOINT_XFER_ISOC:
257		interval = 1 << (epd->bInterval - 1);
258		break;
259	case USB_ENDPOINT_XFER_BULK:
260		/* uframes per NAK */
261		if (speed == USB_SPEED_HIGH && usb_endpoint_dir_out(epd))
262			interval = epd->bInterval;
263		break;
264	case USB_ENDPOINT_XFER_INT:
265		if (speed >= USB_SPEED_HIGH)
266			interval = 1 << (epd->bInterval - 1);
267		else
268			interval = epd->bInterval;
269		break;
270	}
271
272	interval *= (speed >= USB_SPEED_HIGH) ? 125 : 1000;
273
274	return interval;
275}
276EXPORT_SYMBOL_GPL(usb_decode_interval);
277
278#ifdef CONFIG_OF
279/**
280 * of_usb_get_dr_mode_by_phy - Get dual role mode for the controller device
281 * which is associated with the given phy device_node
282 * @np:	Pointer to the given phy device_node
283 * @arg0: phandle args[0] for phy's with #phy-cells >= 1, or -1 for
284 *        phys which do not have phy-cells
285 *
286 * In dts a usb controller associates with phy devices.  The function gets
287 * the string from property 'dr_mode' of the controller associated with the
288 * given phy device node, and returns the correspondig enum usb_dr_mode.
289 */
290enum usb_dr_mode of_usb_get_dr_mode_by_phy(struct device_node *np, int arg0)
291{
292	struct device_node *controller;
293	struct of_phandle_args args;
294	const char *dr_mode;
295	int index;
296	int err;
297
298	for_each_node_with_property(controller, "phys") {
299		if (!of_device_is_available(controller))
300			continue;
301		index = 0;
302		do {
303			if (arg0 == -1) {
304				args.np = of_parse_phandle(controller, "phys",
305							index);
306				args.args_count = 0;
307			} else {
308				err = of_parse_phandle_with_args(controller,
309							"phys", "#phy-cells",
310							index, &args);
311				if (err)
312					break;
313			}
314
315			of_node_put(args.np);
316			if (args.np == np && (args.args_count == 0 ||
317					      args.args[0] == arg0))
318				goto finish;
319			index++;
320		} while (args.np);
321	}
322
323finish:
324	err = of_property_read_string(controller, "dr_mode", &dr_mode);
325	of_node_put(controller);
326
327	if (err < 0)
328		return USB_DR_MODE_UNKNOWN;
329
330	return usb_get_dr_mode_from_string(dr_mode);
331}
332EXPORT_SYMBOL_GPL(of_usb_get_dr_mode_by_phy);
333
334/**
335 * of_usb_host_tpl_support - to get if Targeted Peripheral List is supported
336 * for given targeted hosts (non-PC hosts)
337 * @np: Pointer to the given device_node
338 *
339 * The function gets if the targeted hosts support TPL or not
340 */
341bool of_usb_host_tpl_support(struct device_node *np)
342{
343	return of_property_read_bool(np, "tpl-support");
344}
345EXPORT_SYMBOL_GPL(of_usb_host_tpl_support);
346
347/**
348 * of_usb_update_otg_caps - to update usb otg capabilities according to
349 * the passed properties in DT.
350 * @np: Pointer to the given device_node
351 * @otg_caps: Pointer to the target usb_otg_caps to be set
352 *
353 * The function updates the otg capabilities
354 */
355int of_usb_update_otg_caps(struct device_node *np,
356			struct usb_otg_caps *otg_caps)
357{
358	u32 otg_rev;
359
360	if (!otg_caps)
361		return -EINVAL;
362
363	if (!of_property_read_u32(np, "otg-rev", &otg_rev)) {
364		switch (otg_rev) {
365		case 0x0100:
366		case 0x0120:
367		case 0x0130:
368		case 0x0200:
369			/* Choose the lesser one if it's already been set */
370			if (otg_caps->otg_rev)
371				otg_caps->otg_rev = min_t(u16, otg_rev,
372							otg_caps->otg_rev);
373			else
374				otg_caps->otg_rev = otg_rev;
375			break;
376		default:
377			pr_err("%pOF: unsupported otg-rev: 0x%x\n",
378						np, otg_rev);
379			return -EINVAL;
380		}
381	} else {
382		/*
383		 * otg-rev is mandatory for otg properties, if not passed
384		 * we set it to be 0 and assume it's a legacy otg device.
385		 * Non-dt platform can set it afterwards.
386		 */
387		otg_caps->otg_rev = 0;
388	}
389
390	if (of_property_read_bool(np, "hnp-disable"))
391		otg_caps->hnp_support = false;
392	if (of_property_read_bool(np, "srp-disable"))
393		otg_caps->srp_support = false;
394	if (of_property_read_bool(np, "adp-disable") ||
395				(otg_caps->otg_rev < 0x0200))
396		otg_caps->adp_support = false;
397
398	return 0;
399}
400EXPORT_SYMBOL_GPL(of_usb_update_otg_caps);
401
402/**
403 * usb_of_get_companion_dev - Find the companion device
404 * @dev: the device pointer to find a companion
405 *
406 * Find the companion device from platform bus.
407 *
408 * Takes a reference to the returned struct device which needs to be dropped
409 * after use.
410 *
411 * Return: On success, a pointer to the companion device, %NULL on failure.
412 */
413struct device *usb_of_get_companion_dev(struct device *dev)
414{
415	struct device_node *node;
416	struct platform_device *pdev = NULL;
417
418	node = of_parse_phandle(dev->of_node, "companion", 0);
419	if (node)
420		pdev = of_find_device_by_node(node);
421
422	of_node_put(node);
423
424	return pdev ? &pdev->dev : NULL;
425}
426EXPORT_SYMBOL_GPL(usb_of_get_companion_dev);
427#endif
428
429struct dentry *usb_debug_root;
430EXPORT_SYMBOL_GPL(usb_debug_root);
431
432DEFINE_MUTEX(usb_dynids_lock);
433EXPORT_SYMBOL_GPL(usb_dynids_lock);
434
435static int __init usb_common_init(void)
436{
437	usb_debug_root = debugfs_create_dir("usb", NULL);
438	ledtrig_usb_init();
439	return 0;
440}
441
442static void __exit usb_common_exit(void)
443{
444	ledtrig_usb_exit();
445	debugfs_remove_recursive(usb_debug_root);
446}
447
448subsys_initcall(usb_common_init);
449module_exit(usb_common_exit);
450
451MODULE_DESCRIPTION("Common code for host and device side USB");
452MODULE_LICENSE("GPL");