xref: /openbmc/linux/drivers/usb/common/common.c (revision eb3fcf00)
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 
21 const char *usb_otg_state_string(enum usb_otg_state state)
22 {
23 	static const char *const names[] = {
24 		[OTG_STATE_A_IDLE] = "a_idle",
25 		[OTG_STATE_A_WAIT_VRISE] = "a_wait_vrise",
26 		[OTG_STATE_A_WAIT_BCON] = "a_wait_bcon",
27 		[OTG_STATE_A_HOST] = "a_host",
28 		[OTG_STATE_A_SUSPEND] = "a_suspend",
29 		[OTG_STATE_A_PERIPHERAL] = "a_peripheral",
30 		[OTG_STATE_A_WAIT_VFALL] = "a_wait_vfall",
31 		[OTG_STATE_A_VBUS_ERR] = "a_vbus_err",
32 		[OTG_STATE_B_IDLE] = "b_idle",
33 		[OTG_STATE_B_SRP_INIT] = "b_srp_init",
34 		[OTG_STATE_B_PERIPHERAL] = "b_peripheral",
35 		[OTG_STATE_B_WAIT_ACON] = "b_wait_acon",
36 		[OTG_STATE_B_HOST] = "b_host",
37 	};
38 
39 	if (state < 0 || state >= ARRAY_SIZE(names))
40 		return "UNDEFINED";
41 
42 	return names[state];
43 }
44 EXPORT_SYMBOL_GPL(usb_otg_state_string);
45 
46 static const char *const speed_names[] = {
47 	[USB_SPEED_UNKNOWN] = "UNKNOWN",
48 	[USB_SPEED_LOW] = "low-speed",
49 	[USB_SPEED_FULL] = "full-speed",
50 	[USB_SPEED_HIGH] = "high-speed",
51 	[USB_SPEED_WIRELESS] = "wireless",
52 	[USB_SPEED_SUPER] = "super-speed",
53 };
54 
55 const char *usb_speed_string(enum usb_device_speed speed)
56 {
57 	if (speed < 0 || speed >= ARRAY_SIZE(speed_names))
58 		speed = USB_SPEED_UNKNOWN;
59 	return speed_names[speed];
60 }
61 EXPORT_SYMBOL_GPL(usb_speed_string);
62 
63 const char *usb_state_string(enum usb_device_state state)
64 {
65 	static const char *const names[] = {
66 		[USB_STATE_NOTATTACHED] = "not attached",
67 		[USB_STATE_ATTACHED] = "attached",
68 		[USB_STATE_POWERED] = "powered",
69 		[USB_STATE_RECONNECTING] = "reconnecting",
70 		[USB_STATE_UNAUTHENTICATED] = "unauthenticated",
71 		[USB_STATE_DEFAULT] = "default",
72 		[USB_STATE_ADDRESS] = "addressed",
73 		[USB_STATE_CONFIGURED] = "configured",
74 		[USB_STATE_SUSPENDED] = "suspended",
75 	};
76 
77 	if (state < 0 || state >= ARRAY_SIZE(names))
78 		return "UNKNOWN";
79 
80 	return names[state];
81 }
82 EXPORT_SYMBOL_GPL(usb_state_string);
83 
84 #ifdef CONFIG_OF
85 static const char *const usb_dr_modes[] = {
86 	[USB_DR_MODE_UNKNOWN]		= "",
87 	[USB_DR_MODE_HOST]		= "host",
88 	[USB_DR_MODE_PERIPHERAL]	= "peripheral",
89 	[USB_DR_MODE_OTG]		= "otg",
90 };
91 
92 /**
93  * of_usb_get_dr_mode - Get dual role mode for given device_node
94  * @np:	Pointer to the given device_node
95  *
96  * The function gets phy interface string from property 'dr_mode',
97  * and returns the correspondig enum usb_dr_mode
98  */
99 enum usb_dr_mode of_usb_get_dr_mode(struct device_node *np)
100 {
101 	const char *dr_mode;
102 	int err, i;
103 
104 	err = of_property_read_string(np, "dr_mode", &dr_mode);
105 	if (err < 0)
106 		return USB_DR_MODE_UNKNOWN;
107 
108 	for (i = 0; i < ARRAY_SIZE(usb_dr_modes); i++)
109 		if (!strcmp(dr_mode, usb_dr_modes[i]))
110 			return i;
111 
112 	return USB_DR_MODE_UNKNOWN;
113 }
114 EXPORT_SYMBOL_GPL(of_usb_get_dr_mode);
115 
116 /**
117  * of_usb_get_maximum_speed - Get maximum requested speed for a given USB
118  * controller.
119  * @np: Pointer to the given device_node
120  *
121  * The function gets the maximum speed string from property "maximum-speed",
122  * and returns the corresponding enum usb_device_speed.
123  */
124 enum usb_device_speed of_usb_get_maximum_speed(struct device_node *np)
125 {
126 	const char *maximum_speed;
127 	int err;
128 	int i;
129 
130 	err = of_property_read_string(np, "maximum-speed", &maximum_speed);
131 	if (err < 0)
132 		return USB_SPEED_UNKNOWN;
133 
134 	for (i = 0; i < ARRAY_SIZE(speed_names); i++)
135 		if (strcmp(maximum_speed, speed_names[i]) == 0)
136 			return i;
137 
138 	return USB_SPEED_UNKNOWN;
139 }
140 EXPORT_SYMBOL_GPL(of_usb_get_maximum_speed);
141 
142 /**
143  * of_usb_host_tpl_support - to get if Targeted Peripheral List is supported
144  * for given targeted hosts (non-PC hosts)
145  * @np: Pointer to the given device_node
146  *
147  * The function gets if the targeted hosts support TPL or not
148  */
149 bool of_usb_host_tpl_support(struct device_node *np)
150 {
151 	if (of_find_property(np, "tpl-support", NULL))
152 		return true;
153 
154 	return false;
155 }
156 EXPORT_SYMBOL_GPL(of_usb_host_tpl_support);
157 
158 /**
159  * of_usb_update_otg_caps - to update usb otg capabilities according to
160  * the passed properties in DT.
161  * @np: Pointer to the given device_node
162  * @otg_caps: Pointer to the target usb_otg_caps to be set
163  *
164  * The function updates the otg capabilities
165  */
166 int of_usb_update_otg_caps(struct device_node *np,
167 			struct usb_otg_caps *otg_caps)
168 {
169 	u32 otg_rev;
170 
171 	if (!otg_caps)
172 		return -EINVAL;
173 
174 	if (!of_property_read_u32(np, "otg-rev", &otg_rev)) {
175 		switch (otg_rev) {
176 		case 0x0100:
177 		case 0x0120:
178 		case 0x0130:
179 		case 0x0200:
180 			/* Choose the lesser one if it's already been set */
181 			if (otg_caps->otg_rev)
182 				otg_caps->otg_rev = min_t(u16, otg_rev,
183 							otg_caps->otg_rev);
184 			else
185 				otg_caps->otg_rev = otg_rev;
186 			break;
187 		default:
188 			pr_err("%s: unsupported otg-rev: 0x%x\n",
189 						np->full_name, otg_rev);
190 			return -EINVAL;
191 		}
192 	} else {
193 		/*
194 		 * otg-rev is mandatory for otg properties, if not passed
195 		 * we set it to be 0 and assume it's a legacy otg device.
196 		 * Non-dt platform can set it afterwards.
197 		 */
198 		otg_caps->otg_rev = 0;
199 	}
200 
201 	if (of_find_property(np, "hnp-disable", NULL))
202 		otg_caps->hnp_support = false;
203 	if (of_find_property(np, "srp-disable", NULL))
204 		otg_caps->srp_support = false;
205 	if (of_find_property(np, "adp-disable", NULL) ||
206 				(otg_caps->otg_rev < 0x0200))
207 		otg_caps->adp_support = false;
208 
209 	return 0;
210 }
211 EXPORT_SYMBOL_GPL(of_usb_update_otg_caps);
212 
213 #endif
214 
215 MODULE_LICENSE("GPL");
216