xref: /openbmc/linux/drivers/usb/common/common.c (revision 7587eb18)
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  *
135  * In dts a usb controller associates with phy devices.  The function gets
136  * the string from property 'dr_mode' of the controller associated with the
137  * given phy device node, and returns the correspondig enum usb_dr_mode.
138  */
139 enum usb_dr_mode of_usb_get_dr_mode_by_phy(struct device_node *phy_np)
140 {
141 	struct device_node *controller = NULL;
142 	struct device_node *phy;
143 	const char *dr_mode;
144 	int index;
145 	int err;
146 
147 	do {
148 		controller = of_find_node_with_property(controller, "phys");
149 		index = 0;
150 		do {
151 			phy = of_parse_phandle(controller, "phys", index);
152 			of_node_put(phy);
153 			if (phy == phy_np)
154 				goto finish;
155 			index++;
156 		} while (phy);
157 	} while (controller);
158 
159 finish:
160 	err = of_property_read_string(controller, "dr_mode", &dr_mode);
161 	of_node_put(controller);
162 
163 	if (err < 0)
164 		return USB_DR_MODE_UNKNOWN;
165 
166 	return usb_get_dr_mode_from_string(dr_mode);
167 }
168 EXPORT_SYMBOL_GPL(of_usb_get_dr_mode_by_phy);
169 
170 /**
171  * of_usb_host_tpl_support - to get if Targeted Peripheral List is supported
172  * for given targeted hosts (non-PC hosts)
173  * @np: Pointer to the given device_node
174  *
175  * The function gets if the targeted hosts support TPL or not
176  */
177 bool of_usb_host_tpl_support(struct device_node *np)
178 {
179 	if (of_find_property(np, "tpl-support", NULL))
180 		return true;
181 
182 	return false;
183 }
184 EXPORT_SYMBOL_GPL(of_usb_host_tpl_support);
185 
186 /**
187  * of_usb_update_otg_caps - to update usb otg capabilities according to
188  * the passed properties in DT.
189  * @np: Pointer to the given device_node
190  * @otg_caps: Pointer to the target usb_otg_caps to be set
191  *
192  * The function updates the otg capabilities
193  */
194 int of_usb_update_otg_caps(struct device_node *np,
195 			struct usb_otg_caps *otg_caps)
196 {
197 	u32 otg_rev;
198 
199 	if (!otg_caps)
200 		return -EINVAL;
201 
202 	if (!of_property_read_u32(np, "otg-rev", &otg_rev)) {
203 		switch (otg_rev) {
204 		case 0x0100:
205 		case 0x0120:
206 		case 0x0130:
207 		case 0x0200:
208 			/* Choose the lesser one if it's already been set */
209 			if (otg_caps->otg_rev)
210 				otg_caps->otg_rev = min_t(u16, otg_rev,
211 							otg_caps->otg_rev);
212 			else
213 				otg_caps->otg_rev = otg_rev;
214 			break;
215 		default:
216 			pr_err("%s: unsupported otg-rev: 0x%x\n",
217 						np->full_name, otg_rev);
218 			return -EINVAL;
219 		}
220 	} else {
221 		/*
222 		 * otg-rev is mandatory for otg properties, if not passed
223 		 * we set it to be 0 and assume it's a legacy otg device.
224 		 * Non-dt platform can set it afterwards.
225 		 */
226 		otg_caps->otg_rev = 0;
227 	}
228 
229 	if (of_find_property(np, "hnp-disable", NULL))
230 		otg_caps->hnp_support = false;
231 	if (of_find_property(np, "srp-disable", NULL))
232 		otg_caps->srp_support = false;
233 	if (of_find_property(np, "adp-disable", NULL) ||
234 				(otg_caps->otg_rev < 0x0200))
235 		otg_caps->adp_support = false;
236 
237 	return 0;
238 }
239 EXPORT_SYMBOL_GPL(of_usb_update_otg_caps);
240 
241 #endif
242 
243 MODULE_LICENSE("GPL");
244