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
ath79_usb_phy_power_on(struct phy * phy)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_assert(priv->no_suspend_override);
35
36 return err;
37 }
38
ath79_usb_phy_power_off(struct phy * phy)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
ath79_usb_phy_probe(struct platform_device * pdev)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, "usb-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
