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
 13struct 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
 21static 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
 39static 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
 57static 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
 63static 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
 91static const struct of_device_id ath79_usb_phy_of_match[] = {
 92	{ .compatible = "qca,ar7100-usb-phy" },
 93	{}
 94};
 95MODULE_DEVICE_TABLE(of, ath79_usb_phy_of_match);
 96
 97static 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};
104module_platform_driver(ath79_usb_phy_driver);
105
106MODULE_DESCRIPTION("ATH79 USB PHY driver");
107MODULE_AUTHOR("Alban Bedel <albeu@free.fr>");
108MODULE_LICENSE("GPL");