xref: /openbmc/linux/drivers/usb/core/phy.c (revision c4e78957)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * A wrapper for multiple PHYs which passes all phy_* function calls to
4  * multiple (actual) PHY devices. This is comes handy when initializing
5  * all PHYs on a HCD and to keep them all in the same state.
6  *
7  * Copyright (C) 2018 Martin Blumenstingl <martin.blumenstingl@googlemail.com>
8  */
9 
10 #include <linux/device.h>
11 #include <linux/list.h>
12 #include <linux/phy/phy.h>
13 #include <linux/of.h>
14 
15 #include "phy.h"
16 
17 struct usb_phy_roothub {
18 	struct phy		*phy;
19 	struct list_head	list;
20 };
21 
22 static int usb_phy_roothub_add_phy(struct device *dev, int index,
23 				   struct list_head *list)
24 {
25 	struct usb_phy_roothub *roothub_entry;
26 	struct phy *phy;
27 
28 	phy = devm_of_phy_get_by_index(dev, dev->of_node, index);
29 	if (IS_ERR(phy)) {
30 		if (PTR_ERR(phy) == -ENODEV)
31 			return 0;
32 		else
33 			return PTR_ERR(phy);
34 	}
35 
36 	roothub_entry = devm_kzalloc(dev, sizeof(*roothub_entry), GFP_KERNEL);
37 	if (!roothub_entry)
38 		return -ENOMEM;
39 
40 	INIT_LIST_HEAD(&roothub_entry->list);
41 
42 	roothub_entry->phy = phy;
43 
44 	list_add_tail(&roothub_entry->list, list);
45 
46 	return 0;
47 }
48 
49 struct usb_phy_roothub *usb_phy_roothub_alloc(struct device *dev)
50 {
51 	struct usb_phy_roothub *phy_roothub;
52 	int i, num_phys, err;
53 
54 	if (!IS_ENABLED(CONFIG_GENERIC_PHY))
55 		return NULL;
56 
57 	num_phys = of_count_phandle_with_args(dev->of_node, "phys",
58 					      "#phy-cells");
59 	if (num_phys <= 0)
60 		return NULL;
61 
62 	phy_roothub = devm_kzalloc(dev, sizeof(*phy_roothub), GFP_KERNEL);
63 	if (!phy_roothub)
64 		return ERR_PTR(-ENOMEM);
65 
66 	INIT_LIST_HEAD(&phy_roothub->list);
67 
68 	for (i = 0; i < num_phys; i++) {
69 		err = usb_phy_roothub_add_phy(dev, i, &phy_roothub->list);
70 		if (err)
71 			return ERR_PTR(err);
72 	}
73 
74 	return phy_roothub;
75 }
76 EXPORT_SYMBOL_GPL(usb_phy_roothub_alloc);
77 
78 int usb_phy_roothub_init(struct usb_phy_roothub *phy_roothub)
79 {
80 	struct usb_phy_roothub *roothub_entry;
81 	struct list_head *head;
82 	int err;
83 
84 	if (!phy_roothub)
85 		return 0;
86 
87 	head = &phy_roothub->list;
88 
89 	list_for_each_entry(roothub_entry, head, list) {
90 		err = phy_init(roothub_entry->phy);
91 		if (err)
92 			goto err_exit_phys;
93 	}
94 
95 	return 0;
96 
97 err_exit_phys:
98 	list_for_each_entry_continue_reverse(roothub_entry, head, list)
99 		phy_exit(roothub_entry->phy);
100 
101 	return err;
102 }
103 EXPORT_SYMBOL_GPL(usb_phy_roothub_init);
104 
105 int usb_phy_roothub_exit(struct usb_phy_roothub *phy_roothub)
106 {
107 	struct usb_phy_roothub *roothub_entry;
108 	struct list_head *head;
109 	int err, ret = 0;
110 
111 	if (!phy_roothub)
112 		return 0;
113 
114 	head = &phy_roothub->list;
115 
116 	list_for_each_entry(roothub_entry, head, list) {
117 		err = phy_exit(roothub_entry->phy);
118 		if (err)
119 			ret = err;
120 	}
121 
122 	return ret;
123 }
124 EXPORT_SYMBOL_GPL(usb_phy_roothub_exit);
125 
126 int usb_phy_roothub_set_mode(struct usb_phy_roothub *phy_roothub,
127 			     enum phy_mode mode)
128 {
129 	struct usb_phy_roothub *roothub_entry;
130 	struct list_head *head;
131 	int err;
132 
133 	if (!phy_roothub)
134 		return 0;
135 
136 	head = &phy_roothub->list;
137 
138 	list_for_each_entry(roothub_entry, head, list) {
139 		err = phy_set_mode(roothub_entry->phy, mode);
140 		if (err)
141 			goto err_out;
142 	}
143 
144 	return 0;
145 
146 err_out:
147 	list_for_each_entry_continue_reverse(roothub_entry, head, list)
148 		phy_power_off(roothub_entry->phy);
149 
150 	return err;
151 }
152 EXPORT_SYMBOL_GPL(usb_phy_roothub_set_mode);
153 
154 int usb_phy_roothub_calibrate(struct usb_phy_roothub *phy_roothub)
155 {
156 	struct usb_phy_roothub *roothub_entry;
157 	struct list_head *head;
158 	int err;
159 
160 	if (!phy_roothub)
161 		return 0;
162 
163 	head = &phy_roothub->list;
164 
165 	list_for_each_entry(roothub_entry, head, list) {
166 		err = phy_calibrate(roothub_entry->phy);
167 		if (err)
168 			return err;
169 	}
170 
171 	return 0;
172 }
173 EXPORT_SYMBOL_GPL(usb_phy_roothub_calibrate);
174 
175 int usb_phy_roothub_power_on(struct usb_phy_roothub *phy_roothub)
176 {
177 	struct usb_phy_roothub *roothub_entry;
178 	struct list_head *head;
179 	int err;
180 
181 	if (!phy_roothub)
182 		return 0;
183 
184 	head = &phy_roothub->list;
185 
186 	list_for_each_entry(roothub_entry, head, list) {
187 		err = phy_power_on(roothub_entry->phy);
188 		if (err)
189 			goto err_out;
190 	}
191 
192 	return 0;
193 
194 err_out:
195 	list_for_each_entry_continue_reverse(roothub_entry, head, list)
196 		phy_power_off(roothub_entry->phy);
197 
198 	return err;
199 }
200 EXPORT_SYMBOL_GPL(usb_phy_roothub_power_on);
201 
202 void usb_phy_roothub_power_off(struct usb_phy_roothub *phy_roothub)
203 {
204 	struct usb_phy_roothub *roothub_entry;
205 
206 	if (!phy_roothub)
207 		return;
208 
209 	list_for_each_entry_reverse(roothub_entry, &phy_roothub->list, list)
210 		phy_power_off(roothub_entry->phy);
211 }
212 EXPORT_SYMBOL_GPL(usb_phy_roothub_power_off);
213 
214 int usb_phy_roothub_suspend(struct device *controller_dev,
215 			    struct usb_phy_roothub *phy_roothub)
216 {
217 	usb_phy_roothub_power_off(phy_roothub);
218 
219 	/* keep the PHYs initialized so the device can wake up the system */
220 	if (device_may_wakeup(controller_dev))
221 		return 0;
222 
223 	return usb_phy_roothub_exit(phy_roothub);
224 }
225 EXPORT_SYMBOL_GPL(usb_phy_roothub_suspend);
226 
227 int usb_phy_roothub_resume(struct device *controller_dev,
228 			   struct usb_phy_roothub *phy_roothub)
229 {
230 	int err;
231 
232 	/* if the device can't wake up the system _exit was called */
233 	if (!device_may_wakeup(controller_dev)) {
234 		err = usb_phy_roothub_init(phy_roothub);
235 		if (err)
236 			return err;
237 	}
238 
239 	err = usb_phy_roothub_power_on(phy_roothub);
240 
241 	/* undo _init if _power_on failed */
242 	if (err && !device_may_wakeup(controller_dev))
243 		usb_phy_roothub_exit(phy_roothub);
244 
245 	return err;
246 }
247 EXPORT_SYMBOL_GPL(usb_phy_roothub_resume);
248