1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Atheros AR71XX/9XXX USB PHY driver
4  *
5  * Copyright (C) 2015-2018 Alban Bedel <albeu@free.fr>
6  */
7 
8 #include <linux/module.h>
9 #include <linux/platform_device.h>
10 #include <linux/phy/phy.h>
11 #include <linux/reset.h>
12 
13 struct ath79_usb_phy {
14 	struct reset_control *reset;
15 	/* The suspend override logic is inverted, hence the no prefix
16 	 * to make the code a bit easier to understand.
17 	 */
18 	struct reset_control *no_suspend_override;
19 };
20 
21 static int ath79_usb_phy_power_on(struct phy *phy)
22 {
23 	struct ath79_usb_phy *priv = phy_get_drvdata(phy);
24 	int err = 0;
25 
26 	if (priv->no_suspend_override) {
27 		err = reset_control_assert(priv->no_suspend_override);
28 		if (err)
29 			return err;
30 	}
31 
32 	err = reset_control_deassert(priv->reset);
33 	if (err && priv->no_suspend_override)
34 		reset_control_deassert(priv->no_suspend_override);
35 
36 	return err;
37 }
38 
39 static int ath79_usb_phy_power_off(struct phy *phy)
40 {
41 	struct ath79_usb_phy *priv = phy_get_drvdata(phy);
42 	int err = 0;
43 
44 	err = reset_control_assert(priv->reset);
45 	if (err)
46 		return err;
47 
48 	if (priv->no_suspend_override) {
49 		err = reset_control_deassert(priv->no_suspend_override);
50 		if (err)
51 			reset_control_deassert(priv->reset);
52 	}
53 
54 	return err;
55 }
56 
57 static const struct phy_ops ath79_usb_phy_ops = {
58 	.power_on	= ath79_usb_phy_power_on,
59 	.power_off	= ath79_usb_phy_power_off,
60 	.owner		= THIS_MODULE,
61 };
62 
63 static int ath79_usb_phy_probe(struct platform_device *pdev)
64 {
65 	struct ath79_usb_phy *priv;
66 	struct phy *phy;
67 
68 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
69 	if (!priv)
70 		return -ENOMEM;
71 
72 	priv->reset = devm_reset_control_get(&pdev->dev, "phy");
73 	if (IS_ERR(priv->reset))
74 		return PTR_ERR(priv->reset);
75 
76 	priv->no_suspend_override = devm_reset_control_get_optional(
77 		&pdev->dev, "usb-suspend-override");
78 	if (IS_ERR(priv->no_suspend_override))
79 		return PTR_ERR(priv->no_suspend_override);
80 
81 	phy = devm_phy_create(&pdev->dev, NULL, &ath79_usb_phy_ops);
82 	if (IS_ERR(phy))
83 		return PTR_ERR(phy);
84 
85 	phy_set_drvdata(phy, priv);
86 
87 	return PTR_ERR_OR_ZERO(devm_of_phy_provider_register(
88 				&pdev->dev, of_phy_simple_xlate));
89 }
90 
91 static const struct of_device_id ath79_usb_phy_of_match[] = {
92 	{ .compatible = "qca,ar7100-usb-phy" },
93 	{}
94 };
95 MODULE_DEVICE_TABLE(of, ath79_usb_phy_of_match);
96 
97 static struct platform_driver ath79_usb_phy_driver = {
98 	.probe	= ath79_usb_phy_probe,
99 	.driver = {
100 		.of_match_table	= ath79_usb_phy_of_match,
101 		.name		= "ath79-usb-phy",
102 	}
103 };
104 module_platform_driver(ath79_usb_phy_driver);
105 
106 MODULE_DESCRIPTION("ATH79 USB PHY driver");
107 MODULE_AUTHOR("Alban Bedel <albeu@free.fr>");
108 MODULE_LICENSE("GPL");
109