xref: /openbmc/linux/drivers/usb/core/phy.c (revision be709d48)
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_power_on(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_power_on(roothub_entry->phy);
167 		if (err)
168 			goto err_out;
169 	}
170 
171 	return 0;
172 
173 err_out:
174 	list_for_each_entry_continue_reverse(roothub_entry, head, list)
175 		phy_power_off(roothub_entry->phy);
176 
177 	return err;
178 }
179 EXPORT_SYMBOL_GPL(usb_phy_roothub_power_on);
180 
181 void usb_phy_roothub_power_off(struct usb_phy_roothub *phy_roothub)
182 {
183 	struct usb_phy_roothub *roothub_entry;
184 
185 	if (!phy_roothub)
186 		return;
187 
188 	list_for_each_entry_reverse(roothub_entry, &phy_roothub->list, list)
189 		phy_power_off(roothub_entry->phy);
190 }
191 EXPORT_SYMBOL_GPL(usb_phy_roothub_power_off);
192 
193 int usb_phy_roothub_suspend(struct device *controller_dev,
194 			    struct usb_phy_roothub *phy_roothub)
195 {
196 	usb_phy_roothub_power_off(phy_roothub);
197 
198 	/* keep the PHYs initialized so the device can wake up the system */
199 	if (device_may_wakeup(controller_dev))
200 		return 0;
201 
202 	return usb_phy_roothub_exit(phy_roothub);
203 }
204 EXPORT_SYMBOL_GPL(usb_phy_roothub_suspend);
205 
206 int usb_phy_roothub_resume(struct device *controller_dev,
207 			   struct usb_phy_roothub *phy_roothub)
208 {
209 	int err;
210 
211 	/* if the device can't wake up the system _exit was called */
212 	if (!device_may_wakeup(controller_dev)) {
213 		err = usb_phy_roothub_init(phy_roothub);
214 		if (err)
215 			return err;
216 	}
217 
218 	err = usb_phy_roothub_power_on(phy_roothub);
219 
220 	/* undo _init if _power_on failed */
221 	if (err && !device_may_wakeup(controller_dev))
222 		usb_phy_roothub_exit(phy_roothub);
223 
224 	return err;
225 }
226 EXPORT_SYMBOL_GPL(usb_phy_roothub_resume);
227