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
 17struct usb_phy_roothub {
 18	struct phy		*phy;
 19	struct list_head	list;
 20};
 21
 22static 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 = devm_of_phy_get_by_index(dev, dev->of_node, index);
 27
 28	if (IS_ERR_OR_NULL(phy)) {
 29		if (!phy || PTR_ERR(phy) == -ENODEV)
 30			return 0;
 31		else
 32			return PTR_ERR(phy);
 33	}
 34
 35	roothub_entry = devm_kzalloc(dev, sizeof(*roothub_entry), GFP_KERNEL);
 36	if (!roothub_entry)
 37		return -ENOMEM;
 38
 39	INIT_LIST_HEAD(&roothub_entry->list);
 40
 41	roothub_entry->phy = phy;
 42
 43	list_add_tail(&roothub_entry->list, list);
 44
 45	return 0;
 46}
 47
 48struct usb_phy_roothub *usb_phy_roothub_alloc(struct device *dev)
 49{
 50	struct usb_phy_roothub *phy_roothub;
 51	int i, num_phys, err;
 52
 53	if (!IS_ENABLED(CONFIG_GENERIC_PHY))
 54		return NULL;
 55
 56	num_phys = of_count_phandle_with_args(dev->of_node, "phys",
 57					      "#phy-cells");
 58	if (num_phys <= 0)
 59		return NULL;
 60
 61	phy_roothub = devm_kzalloc(dev, sizeof(*phy_roothub), GFP_KERNEL);
 62	if (!phy_roothub)
 63		return ERR_PTR(-ENOMEM);
 64
 65	INIT_LIST_HEAD(&phy_roothub->list);
 66
 67	for (i = 0; i < num_phys; i++) {
 68		err = usb_phy_roothub_add_phy(dev, i, &phy_roothub->list);
 69		if (err)
 70			return ERR_PTR(err);
 71	}
 72
 73	return phy_roothub;
 74}
 75EXPORT_SYMBOL_GPL(usb_phy_roothub_alloc);
 76
 77int usb_phy_roothub_init(struct usb_phy_roothub *phy_roothub)
 78{
 79	struct usb_phy_roothub *roothub_entry;
 80	struct list_head *head;
 81	int err;
 82
 83	if (!phy_roothub)
 84		return 0;
 85
 86	head = &phy_roothub->list;
 87
 88	list_for_each_entry(roothub_entry, head, list) {
 89		err = phy_init(roothub_entry->phy);
 90		if (err)
 91			goto err_exit_phys;
 92	}
 93
 94	return 0;
 95
 96err_exit_phys:
 97	list_for_each_entry_continue_reverse(roothub_entry, head, list)
 98		phy_exit(roothub_entry->phy);
 99
100	return err;
101}
102EXPORT_SYMBOL_GPL(usb_phy_roothub_init);
103
104int usb_phy_roothub_exit(struct usb_phy_roothub *phy_roothub)
105{
106	struct usb_phy_roothub *roothub_entry;
107	struct list_head *head;
108	int err, ret = 0;
109
110	if (!phy_roothub)
111		return 0;
112
113	head = &phy_roothub->list;
114
115	list_for_each_entry(roothub_entry, head, list) {
116		err = phy_exit(roothub_entry->phy);
117		if (err)
118			ret = err;
119	}
120
121	return ret;
122}
123EXPORT_SYMBOL_GPL(usb_phy_roothub_exit);
124
125int usb_phy_roothub_power_on(struct usb_phy_roothub *phy_roothub)
126{
127	struct usb_phy_roothub *roothub_entry;
128	struct list_head *head;
129	int err;
130
131	if (!phy_roothub)
132		return 0;
133
134	head = &phy_roothub->list;
135
136	list_for_each_entry(roothub_entry, head, list) {
137		err = phy_power_on(roothub_entry->phy);
138		if (err)
139			goto err_out;
140	}
141
142	return 0;
143
144err_out:
145	list_for_each_entry_continue_reverse(roothub_entry, head, list)
146		phy_power_off(roothub_entry->phy);
147
148	return err;
149}
150EXPORT_SYMBOL_GPL(usb_phy_roothub_power_on);
151
152void usb_phy_roothub_power_off(struct usb_phy_roothub *phy_roothub)
153{
154	struct usb_phy_roothub *roothub_entry;
155
156	if (!phy_roothub)
157		return;
158
159	list_for_each_entry_reverse(roothub_entry, &phy_roothub->list, list)
160		phy_power_off(roothub_entry->phy);
161}
162EXPORT_SYMBOL_GPL(usb_phy_roothub_power_off);
163
164int usb_phy_roothub_suspend(struct device *controller_dev,
165			    struct usb_phy_roothub *phy_roothub)
166{
167	usb_phy_roothub_power_off(phy_roothub);
168
169	/* keep the PHYs initialized so the device can wake up the system */
170	if (device_may_wakeup(controller_dev))
171		return 0;
172
173	return usb_phy_roothub_exit(phy_roothub);
174}
175EXPORT_SYMBOL_GPL(usb_phy_roothub_suspend);
176
177int usb_phy_roothub_resume(struct device *controller_dev,
178			   struct usb_phy_roothub *phy_roothub)
179{
180	int err;
181
182	/* if the device can't wake up the system _exit was called */
183	if (!device_may_wakeup(controller_dev)) {
184		err = usb_phy_roothub_init(phy_roothub);
185		if (err)
186			return err;
187	}
188
189	err = usb_phy_roothub_power_on(phy_roothub);
190
191	/* undo _init if _power_on failed */
192	if (err && !device_may_wakeup(controller_dev))
193		usb_phy_roothub_exit(phy_roothub);
194
195	return err;
196}
197EXPORT_SYMBOL_GPL(usb_phy_roothub_resume);