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/mod_devicetable.h>
9 #include <linux/module.h>
10 #include <linux/platform_device.h>
11 #include <linux/phy/phy.h>
12 #include <linux/reset.h>
13
14 struct ath79_usb_phy {
15 struct reset_control *reset;
16 /* The suspend override logic is inverted, hence the no prefix
17 * to make the code a bit easier to understand.
18 */
19 struct reset_control *no_suspend_override;
20 };
21
ath79_usb_phy_power_on(struct phy * phy)22 static int ath79_usb_phy_power_on(struct phy *phy)
23 {
24 struct ath79_usb_phy *priv = phy_get_drvdata(phy);
25 int err = 0;
26
27 if (priv->no_suspend_override) {
28 err = reset_control_assert(priv->no_suspend_override);
29 if (err)
30 return err;
31 }
32
33 err = reset_control_deassert(priv->reset);
34 if (err && priv->no_suspend_override)
35 reset_control_deassert(priv->no_suspend_override);
36
37 return err;
38 }
39
ath79_usb_phy_power_off(struct phy * phy)40 static int ath79_usb_phy_power_off(struct phy *phy)
41 {
42 struct ath79_usb_phy *priv = phy_get_drvdata(phy);
43 int err = 0;
44
45 err = reset_control_assert(priv->reset);
46 if (err)
47 return err;
48
49 if (priv->no_suspend_override) {
50 err = reset_control_deassert(priv->no_suspend_override);
51 if (err)
52 reset_control_deassert(priv->reset);
53 }
54
55 return err;
56 }
57
58 static const struct phy_ops ath79_usb_phy_ops = {
59 .power_on = ath79_usb_phy_power_on,
60 .power_off = ath79_usb_phy_power_off,
61 .owner = THIS_MODULE,
62 };
63
ath79_usb_phy_probe(struct platform_device * pdev)64 static int ath79_usb_phy_probe(struct platform_device *pdev)
65 {
66 struct ath79_usb_phy *priv;
67 struct phy *phy;
68
69 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
70 if (!priv)
71 return -ENOMEM;
72
73 priv->reset = devm_reset_control_get(&pdev->dev, "phy");
74 if (IS_ERR(priv->reset))
75 return PTR_ERR(priv->reset);
76
77 priv->no_suspend_override = devm_reset_control_get_optional(
78 &pdev->dev, "usb-suspend-override");
79 if (IS_ERR(priv->no_suspend_override))
80 return PTR_ERR(priv->no_suspend_override);
81
82 phy = devm_phy_create(&pdev->dev, NULL, &ath79_usb_phy_ops);
83 if (IS_ERR(phy))
84 return PTR_ERR(phy);
85
86 phy_set_drvdata(phy, priv);
87
88 return PTR_ERR_OR_ZERO(devm_of_phy_provider_register(
89 &pdev->dev, of_phy_simple_xlate));
90 }
91
92 static const struct of_device_id ath79_usb_phy_of_match[] = {
93 { .compatible = "qca,ar7100-usb-phy" },
94 {}
95 };
96 MODULE_DEVICE_TABLE(of, ath79_usb_phy_of_match);
97
98 static struct platform_driver ath79_usb_phy_driver = {
99 .probe = ath79_usb_phy_probe,
100 .driver = {
101 .of_match_table = ath79_usb_phy_of_match,
102 .name = "ath79-usb-phy",
103 }
104 };
105 module_platform_driver(ath79_usb_phy_driver);
106
107 MODULE_DESCRIPTION("ATH79 USB PHY driver");
108 MODULE_AUTHOR("Alban Bedel <albeu@free.fr>");
109 MODULE_LICENSE("GPL");
110