xref: /openbmc/linux/drivers/usb/common/common.c (revision 6c33a6f4)
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 const char *usb_ep_type_string(int ep_type)
29 {
30 	if (ep_type < 0 || ep_type >= ARRAY_SIZE(ep_type_names))
31 		return "unknown";
32 
33 	return ep_type_names[ep_type];
34 }
35 EXPORT_SYMBOL_GPL(usb_ep_type_string);
36 
37 const char *usb_otg_state_string(enum usb_otg_state state)
38 {
39 	static const char *const names[] = {
40 		[OTG_STATE_A_IDLE] = "a_idle",
41 		[OTG_STATE_A_WAIT_VRISE] = "a_wait_vrise",
42 		[OTG_STATE_A_WAIT_BCON] = "a_wait_bcon",
43 		[OTG_STATE_A_HOST] = "a_host",
44 		[OTG_STATE_A_SUSPEND] = "a_suspend",
45 		[OTG_STATE_A_PERIPHERAL] = "a_peripheral",
46 		[OTG_STATE_A_WAIT_VFALL] = "a_wait_vfall",
47 		[OTG_STATE_A_VBUS_ERR] = "a_vbus_err",
48 		[OTG_STATE_B_IDLE] = "b_idle",
49 		[OTG_STATE_B_SRP_INIT] = "b_srp_init",
50 		[OTG_STATE_B_PERIPHERAL] = "b_peripheral",
51 		[OTG_STATE_B_WAIT_ACON] = "b_wait_acon",
52 		[OTG_STATE_B_HOST] = "b_host",
53 	};
54 
55 	if (state < 0 || state >= ARRAY_SIZE(names))
56 		return "UNDEFINED";
57 
58 	return names[state];
59 }
60 EXPORT_SYMBOL_GPL(usb_otg_state_string);
61 
62 static const char *const speed_names[] = {
63 	[USB_SPEED_UNKNOWN] = "UNKNOWN",
64 	[USB_SPEED_LOW] = "low-speed",
65 	[USB_SPEED_FULL] = "full-speed",
66 	[USB_SPEED_HIGH] = "high-speed",
67 	[USB_SPEED_WIRELESS] = "wireless",
68 	[USB_SPEED_SUPER] = "super-speed",
69 	[USB_SPEED_SUPER_PLUS] = "super-speed-plus",
70 };
71 
72 const char *usb_speed_string(enum usb_device_speed speed)
73 {
74 	if (speed < 0 || speed >= ARRAY_SIZE(speed_names))
75 		speed = USB_SPEED_UNKNOWN;
76 	return speed_names[speed];
77 }
78 EXPORT_SYMBOL_GPL(usb_speed_string);
79 
80 enum usb_device_speed usb_get_maximum_speed(struct device *dev)
81 {
82 	const char *maximum_speed;
83 	int ret;
84 
85 	ret = device_property_read_string(dev, "maximum-speed", &maximum_speed);
86 	if (ret < 0)
87 		return USB_SPEED_UNKNOWN;
88 
89 	ret = match_string(speed_names, ARRAY_SIZE(speed_names), maximum_speed);
90 
91 	return (ret < 0) ? USB_SPEED_UNKNOWN : ret;
92 }
93 EXPORT_SYMBOL_GPL(usb_get_maximum_speed);
94 
95 const char *usb_state_string(enum usb_device_state state)
96 {
97 	static const char *const names[] = {
98 		[USB_STATE_NOTATTACHED] = "not attached",
99 		[USB_STATE_ATTACHED] = "attached",
100 		[USB_STATE_POWERED] = "powered",
101 		[USB_STATE_RECONNECTING] = "reconnecting",
102 		[USB_STATE_UNAUTHENTICATED] = "unauthenticated",
103 		[USB_STATE_DEFAULT] = "default",
104 		[USB_STATE_ADDRESS] = "addressed",
105 		[USB_STATE_CONFIGURED] = "configured",
106 		[USB_STATE_SUSPENDED] = "suspended",
107 	};
108 
109 	if (state < 0 || state >= ARRAY_SIZE(names))
110 		return "UNKNOWN";
111 
112 	return names[state];
113 }
114 EXPORT_SYMBOL_GPL(usb_state_string);
115 
116 static const char *const usb_dr_modes[] = {
117 	[USB_DR_MODE_UNKNOWN]		= "",
118 	[USB_DR_MODE_HOST]		= "host",
119 	[USB_DR_MODE_PERIPHERAL]	= "peripheral",
120 	[USB_DR_MODE_OTG]		= "otg",
121 };
122 
123 static enum usb_dr_mode usb_get_dr_mode_from_string(const char *str)
124 {
125 	int ret;
126 
127 	ret = match_string(usb_dr_modes, ARRAY_SIZE(usb_dr_modes), str);
128 	return (ret < 0) ? USB_DR_MODE_UNKNOWN : ret;
129 }
130 
131 enum usb_dr_mode usb_get_dr_mode(struct device *dev)
132 {
133 	const char *dr_mode;
134 	int err;
135 
136 	err = device_property_read_string(dev, "dr_mode", &dr_mode);
137 	if (err < 0)
138 		return USB_DR_MODE_UNKNOWN;
139 
140 	return usb_get_dr_mode_from_string(dr_mode);
141 }
142 EXPORT_SYMBOL_GPL(usb_get_dr_mode);
143 
144 #ifdef CONFIG_OF
145 /**
146  * of_usb_get_dr_mode_by_phy - Get dual role mode for the controller device
147  * which is associated with the given phy device_node
148  * @np:	Pointer to the given phy device_node
149  * @arg0: phandle args[0] for phy's with #phy-cells >= 1, or -1 for
150  *        phys which do not have phy-cells
151  *
152  * In dts a usb controller associates with phy devices.  The function gets
153  * the string from property 'dr_mode' of the controller associated with the
154  * given phy device node, and returns the correspondig enum usb_dr_mode.
155  */
156 enum usb_dr_mode of_usb_get_dr_mode_by_phy(struct device_node *np, int arg0)
157 {
158 	struct device_node *controller = NULL;
159 	struct of_phandle_args args;
160 	const char *dr_mode;
161 	int index;
162 	int err;
163 
164 	do {
165 		controller = of_find_node_with_property(controller, "phys");
166 		if (!of_device_is_available(controller))
167 			continue;
168 		index = 0;
169 		do {
170 			if (arg0 == -1) {
171 				args.np = of_parse_phandle(controller, "phys",
172 							index);
173 				args.args_count = 0;
174 			} else {
175 				err = of_parse_phandle_with_args(controller,
176 							"phys", "#phy-cells",
177 							index, &args);
178 				if (err)
179 					break;
180 			}
181 
182 			of_node_put(args.np);
183 			if (args.np == np && (args.args_count == 0 ||
184 					      args.args[0] == arg0))
185 				goto finish;
186 			index++;
187 		} while (args.np);
188 	} while (controller);
189 
190 finish:
191 	err = of_property_read_string(controller, "dr_mode", &dr_mode);
192 	of_node_put(controller);
193 
194 	if (err < 0)
195 		return USB_DR_MODE_UNKNOWN;
196 
197 	return usb_get_dr_mode_from_string(dr_mode);
198 }
199 EXPORT_SYMBOL_GPL(of_usb_get_dr_mode_by_phy);
200 
201 /**
202  * of_usb_host_tpl_support - to get if Targeted Peripheral List is supported
203  * for given targeted hosts (non-PC hosts)
204  * @np: Pointer to the given device_node
205  *
206  * The function gets if the targeted hosts support TPL or not
207  */
208 bool of_usb_host_tpl_support(struct device_node *np)
209 {
210 	return of_property_read_bool(np, "tpl-support");
211 }
212 EXPORT_SYMBOL_GPL(of_usb_host_tpl_support);
213 
214 /**
215  * of_usb_update_otg_caps - to update usb otg capabilities according to
216  * the passed properties in DT.
217  * @np: Pointer to the given device_node
218  * @otg_caps: Pointer to the target usb_otg_caps to be set
219  *
220  * The function updates the otg capabilities
221  */
222 int of_usb_update_otg_caps(struct device_node *np,
223 			struct usb_otg_caps *otg_caps)
224 {
225 	u32 otg_rev;
226 
227 	if (!otg_caps)
228 		return -EINVAL;
229 
230 	if (!of_property_read_u32(np, "otg-rev", &otg_rev)) {
231 		switch (otg_rev) {
232 		case 0x0100:
233 		case 0x0120:
234 		case 0x0130:
235 		case 0x0200:
236 			/* Choose the lesser one if it's already been set */
237 			if (otg_caps->otg_rev)
238 				otg_caps->otg_rev = min_t(u16, otg_rev,
239 							otg_caps->otg_rev);
240 			else
241 				otg_caps->otg_rev = otg_rev;
242 			break;
243 		default:
244 			pr_err("%pOF: unsupported otg-rev: 0x%x\n",
245 						np, otg_rev);
246 			return -EINVAL;
247 		}
248 	} else {
249 		/*
250 		 * otg-rev is mandatory for otg properties, if not passed
251 		 * we set it to be 0 and assume it's a legacy otg device.
252 		 * Non-dt platform can set it afterwards.
253 		 */
254 		otg_caps->otg_rev = 0;
255 	}
256 
257 	if (of_property_read_bool(np, "hnp-disable"))
258 		otg_caps->hnp_support = false;
259 	if (of_property_read_bool(np, "srp-disable"))
260 		otg_caps->srp_support = false;
261 	if (of_property_read_bool(np, "adp-disable") ||
262 				(otg_caps->otg_rev < 0x0200))
263 		otg_caps->adp_support = false;
264 
265 	return 0;
266 }
267 EXPORT_SYMBOL_GPL(of_usb_update_otg_caps);
268 
269 /**
270  * usb_of_get_companion_dev - Find the companion device
271  * @dev: the device pointer to find a companion
272  *
273  * Find the companion device from platform bus.
274  *
275  * Takes a reference to the returned struct device which needs to be dropped
276  * after use.
277  *
278  * Return: On success, a pointer to the companion device, %NULL on failure.
279  */
280 struct device *usb_of_get_companion_dev(struct device *dev)
281 {
282 	struct device_node *node;
283 	struct platform_device *pdev = NULL;
284 
285 	node = of_parse_phandle(dev->of_node, "companion", 0);
286 	if (node)
287 		pdev = of_find_device_by_node(node);
288 
289 	of_node_put(node);
290 
291 	return pdev ? &pdev->dev : NULL;
292 }
293 EXPORT_SYMBOL_GPL(usb_of_get_companion_dev);
294 #endif
295 
296 struct dentry *usb_debug_root;
297 EXPORT_SYMBOL_GPL(usb_debug_root);
298 
299 static int __init usb_common_init(void)
300 {
301 	usb_debug_root = debugfs_create_dir("usb", NULL);
302 	ledtrig_usb_init();
303 	return 0;
304 }
305 
306 static void __exit usb_common_exit(void)
307 {
308 	ledtrig_usb_exit();
309 	debugfs_remove_recursive(usb_debug_root);
310 }
311 
312 subsys_initcall(usb_common_init);
313 module_exit(usb_common_exit);
314 
315 MODULE_LICENSE("GPL");
316