xref: /openbmc/linux/drivers/usb/common/common.c (revision a06c488d)
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 };
55 
56 const char *usb_speed_string(enum usb_device_speed speed)
57 {
58 	if (speed < 0 || speed >= ARRAY_SIZE(speed_names))
59 		speed = USB_SPEED_UNKNOWN;
60 	return speed_names[speed];
61 }
62 EXPORT_SYMBOL_GPL(usb_speed_string);
63 
64 enum usb_device_speed usb_get_maximum_speed(struct device *dev)
65 {
66 	const char *maximum_speed;
67 	int err;
68 	int i;
69 
70 	err = device_property_read_string(dev, "maximum-speed", &maximum_speed);
71 	if (err < 0)
72 		return USB_SPEED_UNKNOWN;
73 
74 	for (i = 0; i < ARRAY_SIZE(speed_names); i++)
75 		if (strcmp(maximum_speed, speed_names[i]) == 0)
76 			return i;
77 
78 	return USB_SPEED_UNKNOWN;
79 }
80 EXPORT_SYMBOL_GPL(usb_get_maximum_speed);
81 
82 const char *usb_state_string(enum usb_device_state state)
83 {
84 	static const char *const names[] = {
85 		[USB_STATE_NOTATTACHED] = "not attached",
86 		[USB_STATE_ATTACHED] = "attached",
87 		[USB_STATE_POWERED] = "powered",
88 		[USB_STATE_RECONNECTING] = "reconnecting",
89 		[USB_STATE_UNAUTHENTICATED] = "unauthenticated",
90 		[USB_STATE_DEFAULT] = "default",
91 		[USB_STATE_ADDRESS] = "addressed",
92 		[USB_STATE_CONFIGURED] = "configured",
93 		[USB_STATE_SUSPENDED] = "suspended",
94 	};
95 
96 	if (state < 0 || state >= ARRAY_SIZE(names))
97 		return "UNKNOWN";
98 
99 	return names[state];
100 }
101 EXPORT_SYMBOL_GPL(usb_state_string);
102 
103 static const char *const usb_dr_modes[] = {
104 	[USB_DR_MODE_UNKNOWN]		= "",
105 	[USB_DR_MODE_HOST]		= "host",
106 	[USB_DR_MODE_PERIPHERAL]	= "peripheral",
107 	[USB_DR_MODE_OTG]		= "otg",
108 };
109 
110 static enum usb_dr_mode usb_get_dr_mode_from_string(const char *str)
111 {
112 	int i;
113 
114 	for (i = 0; i < ARRAY_SIZE(usb_dr_modes); i++)
115 		if (!strcmp(usb_dr_modes[i], str))
116 			return i;
117 
118 	return USB_DR_MODE_UNKNOWN;
119 }
120 
121 enum usb_dr_mode usb_get_dr_mode(struct device *dev)
122 {
123 	const char *dr_mode;
124 	int err;
125 
126 	err = device_property_read_string(dev, "dr_mode", &dr_mode);
127 	if (err < 0)
128 		return USB_DR_MODE_UNKNOWN;
129 
130 	return usb_get_dr_mode_from_string(dr_mode);
131 }
132 EXPORT_SYMBOL_GPL(usb_get_dr_mode);
133 
134 #ifdef CONFIG_OF
135 /**
136  * of_usb_get_dr_mode_by_phy - Get dual role mode for the controller device
137  * which is associated with the given phy device_node
138  * @np:	Pointer to the given phy device_node
139  *
140  * In dts a usb controller associates with phy devices.  The function gets
141  * the string from property 'dr_mode' of the controller associated with the
142  * given phy device node, and returns the correspondig enum usb_dr_mode.
143  */
144 enum usb_dr_mode of_usb_get_dr_mode_by_phy(struct device_node *phy_np)
145 {
146 	struct device_node *controller = NULL;
147 	struct device_node *phy;
148 	const char *dr_mode;
149 	int index;
150 	int err;
151 
152 	do {
153 		controller = of_find_node_with_property(controller, "phys");
154 		index = 0;
155 		do {
156 			phy = of_parse_phandle(controller, "phys", index);
157 			of_node_put(phy);
158 			if (phy == phy_np)
159 				goto finish;
160 			index++;
161 		} while (phy);
162 	} while (controller);
163 
164 finish:
165 	err = of_property_read_string(controller, "dr_mode", &dr_mode);
166 	of_node_put(controller);
167 
168 	if (err < 0)
169 		return USB_DR_MODE_UNKNOWN;
170 
171 	return usb_get_dr_mode_from_string(dr_mode);
172 }
173 EXPORT_SYMBOL_GPL(of_usb_get_dr_mode_by_phy);
174 
175 /**
176  * of_usb_host_tpl_support - to get if Targeted Peripheral List is supported
177  * for given targeted hosts (non-PC hosts)
178  * @np: Pointer to the given device_node
179  *
180  * The function gets if the targeted hosts support TPL or not
181  */
182 bool of_usb_host_tpl_support(struct device_node *np)
183 {
184 	if (of_find_property(np, "tpl-support", NULL))
185 		return true;
186 
187 	return false;
188 }
189 EXPORT_SYMBOL_GPL(of_usb_host_tpl_support);
190 
191 /**
192  * of_usb_update_otg_caps - to update usb otg capabilities according to
193  * the passed properties in DT.
194  * @np: Pointer to the given device_node
195  * @otg_caps: Pointer to the target usb_otg_caps to be set
196  *
197  * The function updates the otg capabilities
198  */
199 int of_usb_update_otg_caps(struct device_node *np,
200 			struct usb_otg_caps *otg_caps)
201 {
202 	u32 otg_rev;
203 
204 	if (!otg_caps)
205 		return -EINVAL;
206 
207 	if (!of_property_read_u32(np, "otg-rev", &otg_rev)) {
208 		switch (otg_rev) {
209 		case 0x0100:
210 		case 0x0120:
211 		case 0x0130:
212 		case 0x0200:
213 			/* Choose the lesser one if it's already been set */
214 			if (otg_caps->otg_rev)
215 				otg_caps->otg_rev = min_t(u16, otg_rev,
216 							otg_caps->otg_rev);
217 			else
218 				otg_caps->otg_rev = otg_rev;
219 			break;
220 		default:
221 			pr_err("%s: unsupported otg-rev: 0x%x\n",
222 						np->full_name, otg_rev);
223 			return -EINVAL;
224 		}
225 	} else {
226 		/*
227 		 * otg-rev is mandatory for otg properties, if not passed
228 		 * we set it to be 0 and assume it's a legacy otg device.
229 		 * Non-dt platform can set it afterwards.
230 		 */
231 		otg_caps->otg_rev = 0;
232 	}
233 
234 	if (of_find_property(np, "hnp-disable", NULL))
235 		otg_caps->hnp_support = false;
236 	if (of_find_property(np, "srp-disable", NULL))
237 		otg_caps->srp_support = false;
238 	if (of_find_property(np, "adp-disable", NULL) ||
239 				(otg_caps->otg_rev < 0x0200))
240 		otg_caps->adp_support = false;
241 
242 	return 0;
243 }
244 EXPORT_SYMBOL_GPL(of_usb_update_otg_caps);
245 
246 #endif
247 
248 MODULE_LICENSE("GPL");
249