drivers/phy/qualcomm/phy-ath79-usb.c

   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");