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  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
 21static 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 */
 34const 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}
 41EXPORT_SYMBOL_GPL(usb_ep_type_string);
 42
 43const 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}
 66EXPORT_SYMBOL_GPL(usb_otg_state_string);
 67
 68static 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
 78static 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 */
 91const 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}
 97EXPORT_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 */
107enum 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}
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_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 */
211unsigned 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}
242EXPORT_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 */
256enum 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
290finish:
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}
299EXPORT_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 */
308bool of_usb_host_tpl_support(struct device_node *np)
309{
310	return of_property_read_bool(np, "tpl-support");
311}
312EXPORT_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 */
322int 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}
367EXPORT_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 */
380struct 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}
393EXPORT_SYMBOL_GPL(usb_of_get_companion_dev);
394#endif
395
396struct dentry *usb_debug_root;
397EXPORT_SYMBOL_GPL(usb_debug_root);
398
399static 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
406static void __exit usb_common_exit(void)
407{
408	ledtrig_usb_exit();
409	debugfs_remove_recursive(usb_debug_root);
410}
411
412subsys_initcall(usb_common_init);
413module_exit(usb_common_exit);
414
415MODULE_LICENSE("GPL");