xref: /linux/drivers/usb/common/common.c (revision 3b812ecce736432e6b55e77028ea387eb1517d24)
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 err;
69 	int i;
70 
71 	err = device_property_read_string(dev, "maximum-speed", &maximum_speed);
72 	if (err < 0)
73 		return USB_SPEED_UNKNOWN;
74 
75 	for (i = 0; i < ARRAY_SIZE(speed_names); i++)
76 		if (strcmp(maximum_speed, speed_names[i]) == 0)
77 			return i;
78 
79 	return USB_SPEED_UNKNOWN;
80 }
81 EXPORT_SYMBOL_GPL(usb_get_maximum_speed);
82 
83 const char *usb_state_string(enum usb_device_state state)
84 {
85 	static const char *const names[] = {
86 		[USB_STATE_NOTATTACHED] = "not attached",
87 		[USB_STATE_ATTACHED] = "attached",
88 		[USB_STATE_POWERED] = "powered",
89 		[USB_STATE_RECONNECTING] = "reconnecting",
90 		[USB_STATE_UNAUTHENTICATED] = "unauthenticated",
91 		[USB_STATE_DEFAULT] = "default",
92 		[USB_STATE_ADDRESS] = "addressed",
93 		[USB_STATE_CONFIGURED] = "configured",
94 		[USB_STATE_SUSPENDED] = "suspended",
95 	};
96 
97 	if (state < 0 || state >= ARRAY_SIZE(names))
98 		return "UNKNOWN";
99 
100 	return names[state];
101 }
102 EXPORT_SYMBOL_GPL(usb_state_string);
103 
104 static const char *const usb_dr_modes[] = {
105 	[USB_DR_MODE_UNKNOWN]		= "",
106 	[USB_DR_MODE_HOST]		= "host",
107 	[USB_DR_MODE_PERIPHERAL]	= "peripheral",
108 	[USB_DR_MODE_OTG]		= "otg",
109 };
110 
111 static enum usb_dr_mode usb_get_dr_mode_from_string(const char *str)
112 {
113 	int i;
114 
115 	for (i = 0; i < ARRAY_SIZE(usb_dr_modes); i++)
116 		if (!strcmp(usb_dr_modes[i], str))
117 			return i;
118 
119 	return USB_DR_MODE_UNKNOWN;
120 }
121 
122 enum usb_dr_mode usb_get_dr_mode(struct device *dev)
123 {
124 	const char *dr_mode;
125 	int err;
126 
127 	err = device_property_read_string(dev, "dr_mode", &dr_mode);
128 	if (err < 0)
129 		return USB_DR_MODE_UNKNOWN;
130 
131 	return usb_get_dr_mode_from_string(dr_mode);
132 }
133 EXPORT_SYMBOL_GPL(usb_get_dr_mode);
134 
135 #ifdef CONFIG_OF
136 /**
137  * of_usb_get_dr_mode_by_phy - Get dual role mode for the controller device
138  * which is associated with the given phy device_node
139  * @np:	Pointer to the given phy device_node
140  *
141  * In dts a usb controller associates with phy devices.  The function gets
142  * the string from property 'dr_mode' of the controller associated with the
143  * given phy device node, and returns the correspondig enum usb_dr_mode.
144  */
145 enum usb_dr_mode of_usb_get_dr_mode_by_phy(struct device_node *phy_np)
146 {
147 	struct device_node *controller = NULL;
148 	struct device_node *phy;
149 	const char *dr_mode;
150 	int index;
151 	int err;
152 
153 	do {
154 		controller = of_find_node_with_property(controller, "phys");
155 		index = 0;
156 		do {
157 			phy = of_parse_phandle(controller, "phys", index);
158 			of_node_put(phy);
159 			if (phy == phy_np)
160 				goto finish;
161 			index++;
162 		} while (phy);
163 	} while (controller);
164 
165 finish:
166 	err = of_property_read_string(controller, "dr_mode", &dr_mode);
167 	of_node_put(controller);
168 
169 	if (err < 0)
170 		return USB_DR_MODE_UNKNOWN;
171 
172 	return usb_get_dr_mode_from_string(dr_mode);
173 }
174 EXPORT_SYMBOL_GPL(of_usb_get_dr_mode_by_phy);
175 
176 /**
177  * of_usb_host_tpl_support - to get if Targeted Peripheral List is supported
178  * for given targeted hosts (non-PC hosts)
179  * @np: Pointer to the given device_node
180  *
181  * The function gets if the targeted hosts support TPL or not
182  */
183 bool of_usb_host_tpl_support(struct device_node *np)
184 {
185 	if (of_find_property(np, "tpl-support", NULL))
186 		return true;
187 
188 	return false;
189 }
190 EXPORT_SYMBOL_GPL(of_usb_host_tpl_support);
191 
192 /**
193  * of_usb_update_otg_caps - to update usb otg capabilities according to
194  * the passed properties in DT.
195  * @np: Pointer to the given device_node
196  * @otg_caps: Pointer to the target usb_otg_caps to be set
197  *
198  * The function updates the otg capabilities
199  */
200 int of_usb_update_otg_caps(struct device_node *np,
201 			struct usb_otg_caps *otg_caps)
202 {
203 	u32 otg_rev;
204 
205 	if (!otg_caps)
206 		return -EINVAL;
207 
208 	if (!of_property_read_u32(np, "otg-rev", &otg_rev)) {
209 		switch (otg_rev) {
210 		case 0x0100:
211 		case 0x0120:
212 		case 0x0130:
213 		case 0x0200:
214 			/* Choose the lesser one if it's already been set */
215 			if (otg_caps->otg_rev)
216 				otg_caps->otg_rev = min_t(u16, otg_rev,
217 							otg_caps->otg_rev);
218 			else
219 				otg_caps->otg_rev = otg_rev;
220 			break;
221 		default:
222 			pr_err("%s: unsupported otg-rev: 0x%x\n",
223 						np->full_name, otg_rev);
224 			return -EINVAL;
225 		}
226 	} else {
227 		/*
228 		 * otg-rev is mandatory for otg properties, if not passed
229 		 * we set it to be 0 and assume it's a legacy otg device.
230 		 * Non-dt platform can set it afterwards.
231 		 */
232 		otg_caps->otg_rev = 0;
233 	}
234 
235 	if (of_find_property(np, "hnp-disable", NULL))
236 		otg_caps->hnp_support = false;
237 	if (of_find_property(np, "srp-disable", NULL))
238 		otg_caps->srp_support = false;
239 	if (of_find_property(np, "adp-disable", NULL) ||
240 				(otg_caps->otg_rev < 0x0200))
241 		otg_caps->adp_support = false;
242 
243 	return 0;
244 }
245 EXPORT_SYMBOL_GPL(of_usb_update_otg_caps);
246 
247 #endif
248 
249 MODULE_LICENSE("GPL");
250