xref: /linux/drivers/usb/common/common.c (revision 80d443e8876602be2c130f79c4de81e12e2a700d)
1 /*
2  * Provides code common for host and device side USB.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License as
6  * published by the Free Software Foundation, version 2.
7  *
8  * If either host side (ie. CONFIG_USB=y) or device side USB stack
9  * (ie. CONFIG_USB_GADGET=y) is compiled in the kernel, this module is
10  * compiled-in as well.  Otherwise, if either of the two stacks is
11  * compiled as module, this file is compiled as module as well.
12  */
13 
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/of.h>
17 #include <linux/usb/ch9.h>
18 #include <linux/usb/of.h>
19 #include <linux/usb/otg.h>
20 #include <linux/of_platform.h>
21 
22 const char *usb_otg_state_string(enum usb_otg_state state)
23 {
24 	static const char *const names[] = {
25 		[OTG_STATE_A_IDLE] = "a_idle",
26 		[OTG_STATE_A_WAIT_VRISE] = "a_wait_vrise",
27 		[OTG_STATE_A_WAIT_BCON] = "a_wait_bcon",
28 		[OTG_STATE_A_HOST] = "a_host",
29 		[OTG_STATE_A_SUSPEND] = "a_suspend",
30 		[OTG_STATE_A_PERIPHERAL] = "a_peripheral",
31 		[OTG_STATE_A_WAIT_VFALL] = "a_wait_vfall",
32 		[OTG_STATE_A_VBUS_ERR] = "a_vbus_err",
33 		[OTG_STATE_B_IDLE] = "b_idle",
34 		[OTG_STATE_B_SRP_INIT] = "b_srp_init",
35 		[OTG_STATE_B_PERIPHERAL] = "b_peripheral",
36 		[OTG_STATE_B_WAIT_ACON] = "b_wait_acon",
37 		[OTG_STATE_B_HOST] = "b_host",
38 	};
39 
40 	if (state < 0 || state >= ARRAY_SIZE(names))
41 		return "UNDEFINED";
42 
43 	return names[state];
44 }
45 EXPORT_SYMBOL_GPL(usb_otg_state_string);
46 
47 static const char *const speed_names[] = {
48 	[USB_SPEED_UNKNOWN] = "UNKNOWN",
49 	[USB_SPEED_LOW] = "low-speed",
50 	[USB_SPEED_FULL] = "full-speed",
51 	[USB_SPEED_HIGH] = "high-speed",
52 	[USB_SPEED_WIRELESS] = "wireless",
53 	[USB_SPEED_SUPER] = "super-speed",
54 	[USB_SPEED_SUPER_PLUS] = "super-speed-plus",
55 };
56 
57 const char *usb_speed_string(enum usb_device_speed speed)
58 {
59 	if (speed < 0 || speed >= ARRAY_SIZE(speed_names))
60 		speed = USB_SPEED_UNKNOWN;
61 	return speed_names[speed];
62 }
63 EXPORT_SYMBOL_GPL(usb_speed_string);
64 
65 enum usb_device_speed usb_get_maximum_speed(struct device *dev)
66 {
67 	const char *maximum_speed;
68 	int ret;
69 
70 	ret = device_property_read_string(dev, "maximum-speed", &maximum_speed);
71 	if (ret < 0)
72 		return USB_SPEED_UNKNOWN;
73 
74 	ret = match_string(speed_names, ARRAY_SIZE(speed_names), maximum_speed);
75 
76 	return (ret < 0) ? USB_SPEED_UNKNOWN : ret;
77 }
78 EXPORT_SYMBOL_GPL(usb_get_maximum_speed);
79 
80 const char *usb_state_string(enum usb_device_state state)
81 {
82 	static const char *const names[] = {
83 		[USB_STATE_NOTATTACHED] = "not attached",
84 		[USB_STATE_ATTACHED] = "attached",
85 		[USB_STATE_POWERED] = "powered",
86 		[USB_STATE_RECONNECTING] = "reconnecting",
87 		[USB_STATE_UNAUTHENTICATED] = "unauthenticated",
88 		[USB_STATE_DEFAULT] = "default",
89 		[USB_STATE_ADDRESS] = "addressed",
90 		[USB_STATE_CONFIGURED] = "configured",
91 		[USB_STATE_SUSPENDED] = "suspended",
92 	};
93 
94 	if (state < 0 || state >= ARRAY_SIZE(names))
95 		return "UNKNOWN";
96 
97 	return names[state];
98 }
99 EXPORT_SYMBOL_GPL(usb_state_string);
100 
101 static const char *const usb_dr_modes[] = {
102 	[USB_DR_MODE_UNKNOWN]		= "",
103 	[USB_DR_MODE_HOST]		= "host",
104 	[USB_DR_MODE_PERIPHERAL]	= "peripheral",
105 	[USB_DR_MODE_OTG]		= "otg",
106 };
107 
108 static enum usb_dr_mode usb_get_dr_mode_from_string(const char *str)
109 {
110 	int ret;
111 
112 	ret = match_string(usb_dr_modes, ARRAY_SIZE(usb_dr_modes), str);
113 	return (ret < 0) ? USB_DR_MODE_UNKNOWN : ret;
114 }
115 
116 enum usb_dr_mode usb_get_dr_mode(struct device *dev)
117 {
118 	const char *dr_mode;
119 	int err;
120 
121 	err = device_property_read_string(dev, "dr_mode", &dr_mode);
122 	if (err < 0)
123 		return USB_DR_MODE_UNKNOWN;
124 
125 	return usb_get_dr_mode_from_string(dr_mode);
126 }
127 EXPORT_SYMBOL_GPL(usb_get_dr_mode);
128 
129 #ifdef CONFIG_OF
130 /**
131  * of_usb_get_dr_mode_by_phy - Get dual role mode for the controller device
132  * which is associated with the given phy device_node
133  * @np:	Pointer to the given phy device_node
134  * @arg0: phandle args[0] for phy's with #phy-cells >= 1, or -1 for
135  *        phys which do not have phy-cells
136  *
137  * In dts a usb controller associates with phy devices.  The function gets
138  * the string from property 'dr_mode' of the controller associated with the
139  * given phy device node, and returns the correspondig enum usb_dr_mode.
140  */
141 enum usb_dr_mode of_usb_get_dr_mode_by_phy(struct device_node *np, int arg0)
142 {
143 	struct device_node *controller = NULL;
144 	struct of_phandle_args args;
145 	const char *dr_mode;
146 	int index;
147 	int err;
148 
149 	do {
150 		controller = of_find_node_with_property(controller, "phys");
151 		index = 0;
152 		do {
153 			if (arg0 == -1) {
154 				args.np = of_parse_phandle(controller, "phys",
155 							index);
156 				args.args_count = 0;
157 			} else {
158 				err = of_parse_phandle_with_args(controller,
159 							"phys", "#phy-cells",
160 							index, &args);
161 				if (err)
162 					break;
163 			}
164 
165 			of_node_put(args.np);
166 			if (args.np == np && (args.args_count == 0 ||
167 					      args.args[0] == arg0))
168 				goto finish;
169 			index++;
170 		} while (args.np);
171 	} while (controller);
172 
173 finish:
174 	err = of_property_read_string(controller, "dr_mode", &dr_mode);
175 	of_node_put(controller);
176 
177 	if (err < 0)
178 		return USB_DR_MODE_UNKNOWN;
179 
180 	return usb_get_dr_mode_from_string(dr_mode);
181 }
182 EXPORT_SYMBOL_GPL(of_usb_get_dr_mode_by_phy);
183 
184 /**
185  * of_usb_host_tpl_support - to get if Targeted Peripheral List is supported
186  * for given targeted hosts (non-PC hosts)
187  * @np: Pointer to the given device_node
188  *
189  * The function gets if the targeted hosts support TPL or not
190  */
191 bool of_usb_host_tpl_support(struct device_node *np)
192 {
193 	if (of_find_property(np, "tpl-support", NULL))
194 		return true;
195 
196 	return false;
197 }
198 EXPORT_SYMBOL_GPL(of_usb_host_tpl_support);
199 
200 /**
201  * of_usb_update_otg_caps - to update usb otg capabilities according to
202  * the passed properties in DT.
203  * @np: Pointer to the given device_node
204  * @otg_caps: Pointer to the target usb_otg_caps to be set
205  *
206  * The function updates the otg capabilities
207  */
208 int of_usb_update_otg_caps(struct device_node *np,
209 			struct usb_otg_caps *otg_caps)
210 {
211 	u32 otg_rev;
212 
213 	if (!otg_caps)
214 		return -EINVAL;
215 
216 	if (!of_property_read_u32(np, "otg-rev", &otg_rev)) {
217 		switch (otg_rev) {
218 		case 0x0100:
219 		case 0x0120:
220 		case 0x0130:
221 		case 0x0200:
222 			/* Choose the lesser one if it's already been set */
223 			if (otg_caps->otg_rev)
224 				otg_caps->otg_rev = min_t(u16, otg_rev,
225 							otg_caps->otg_rev);
226 			else
227 				otg_caps->otg_rev = otg_rev;
228 			break;
229 		default:
230 			pr_err("%s: unsupported otg-rev: 0x%x\n",
231 						np->full_name, otg_rev);
232 			return -EINVAL;
233 		}
234 	} else {
235 		/*
236 		 * otg-rev is mandatory for otg properties, if not passed
237 		 * we set it to be 0 and assume it's a legacy otg device.
238 		 * Non-dt platform can set it afterwards.
239 		 */
240 		otg_caps->otg_rev = 0;
241 	}
242 
243 	if (of_find_property(np, "hnp-disable", NULL))
244 		otg_caps->hnp_support = false;
245 	if (of_find_property(np, "srp-disable", NULL))
246 		otg_caps->srp_support = false;
247 	if (of_find_property(np, "adp-disable", NULL) ||
248 				(otg_caps->otg_rev < 0x0200))
249 		otg_caps->adp_support = false;
250 
251 	return 0;
252 }
253 EXPORT_SYMBOL_GPL(of_usb_update_otg_caps);
254 
255 #endif
256 
257 MODULE_LICENSE("GPL");
258