phy-ma35d1-usb2.c

  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Copyright (C) 2024 Nuvoton Technology Corp.
  4 */
  5#include <linux/bitfield.h>
  6#include <linux/clk.h>
  7#include <linux/delay.h>
  8#include <linux/io.h>
  9#include <linux/kernel.h>
 10#include <linux/mfd/syscon.h>
 11#include <linux/module.h>
 12#include <linux/of.h>
 13#include <linux/phy/phy.h>
 14#include <linux/platform_device.h>
 15#include <linux/regmap.h>
 16
 17/* USB PHY Miscellaneous Control Register */
 18#define MA35_SYS_REG_USBPMISCR	0x60
 19#define PHY0POR			BIT(0)  /* PHY Power-On Reset Control Bit */
 20#define PHY0SUSPEND			BIT(1)  /* PHY Suspend; 0: suspend, 1: operaion */
 21#define PHY0COMN			BIT(2)  /* PHY Common Block Power-Down Control */
 22#define PHY0DEVCKSTB			BIT(10) /* PHY 60 MHz UTMI clock stable bit */
 23
 24struct ma35_usb_phy {
 25	struct clk *clk;
 26	struct device *dev;
 27	struct regmap *sysreg;
 28};
 29
 30static int ma35_usb_phy_power_on(struct phy *phy)
 31{
 32	struct ma35_usb_phy *p_phy = phy_get_drvdata(phy);
 33	unsigned int val;
 34	int ret;
 35
 36	ret = clk_prepare_enable(p_phy->clk);
 37	if (ret < 0) {
 38		dev_err(p_phy->dev, "Failed to enable PHY clock: %d\n", ret);
 39		return ret;
 40	}
 41
 42	regmap_read(p_phy->sysreg, MA35_SYS_REG_USBPMISCR, &val);
 43	if (val & PHY0SUSPEND) {
 44		/*
 45		 * USB PHY0 is in operation mode already
 46		 * make sure USB PHY 60 MHz UTMI Interface Clock ready
 47		 */
 48		ret = regmap_read_poll_timeout(p_phy->sysreg, MA35_SYS_REG_USBPMISCR, val,
 49						val & PHY0DEVCKSTB, 10, 1000);
 50		if (ret == 0)
 51			return 0;
 52	}
 53
 54	/*
 55	 * reset USB PHY0.
 56	 * wait until USB PHY0 60 MHz UTMI Interface Clock ready
 57	 */
 58	regmap_update_bits(p_phy->sysreg, MA35_SYS_REG_USBPMISCR, 0x7, (PHY0POR | PHY0SUSPEND));
 59	udelay(20);
 60
 61	/* make USB PHY0 enter operation mode */
 62	regmap_update_bits(p_phy->sysreg, MA35_SYS_REG_USBPMISCR, 0x7, PHY0SUSPEND);
 63
 64	/* make sure USB PHY 60 MHz UTMI Interface Clock ready */
 65	ret = regmap_read_poll_timeout(p_phy->sysreg, MA35_SYS_REG_USBPMISCR, val,
 66					val & PHY0DEVCKSTB, 10, 1000);
 67	if (ret == -ETIMEDOUT) {
 68		dev_err(p_phy->dev, "Check PHY clock, Timeout: %d\n", ret);
 69		clk_disable_unprepare(p_phy->clk);
 70		return ret;
 71	}
 72
 73	return 0;
 74}
 75
 76static int ma35_usb_phy_power_off(struct phy *phy)
 77{
 78	struct ma35_usb_phy *p_phy = phy_get_drvdata(phy);
 79
 80	clk_disable_unprepare(p_phy->clk);
 81	return 0;
 82}
 83
 84static const struct phy_ops ma35_usb_phy_ops = {
 85	.power_on = ma35_usb_phy_power_on,
 86	.power_off = ma35_usb_phy_power_off,
 87	.owner = THIS_MODULE,
 88};
 89
 90static int ma35_usb_phy_probe(struct platform_device *pdev)
 91{
 92	struct phy_provider *provider;
 93	struct ma35_usb_phy *p_phy;
 94	struct phy *phy;
 95
 96	p_phy = devm_kzalloc(&pdev->dev, sizeof(*p_phy), GFP_KERNEL);
 97	if (!p_phy)
 98		return -ENOMEM;
 99
100	p_phy->dev = &pdev->dev;
101	platform_set_drvdata(pdev, p_phy);
102
103	p_phy->sysreg = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "nuvoton,sys");
104	if (IS_ERR(p_phy->sysreg))
105		return dev_err_probe(&pdev->dev, PTR_ERR(p_phy->sysreg),
106				     "Failed to get SYS registers\n");
107
108	p_phy->clk = of_clk_get(pdev->dev.of_node, 0);
109	if (IS_ERR(p_phy->clk))
110		return dev_err_probe(&pdev->dev, PTR_ERR(p_phy->clk),
111				     "failed to find usb_phy clock\n");
112
113	phy = devm_phy_create(&pdev->dev, NULL, &ma35_usb_phy_ops);
114	if (IS_ERR(phy))
115		return dev_err_probe(&pdev->dev, PTR_ERR(phy), "Failed to create PHY\n");
116
117	phy_set_drvdata(phy, p_phy);
118
119	provider = devm_of_phy_provider_register(&pdev->dev, of_phy_simple_xlate);
120	if (IS_ERR(provider))
121		return dev_err_probe(&pdev->dev, PTR_ERR(provider),
122				     "Failed to register PHY provider\n");
123	return 0;
124}
125
126static const struct of_device_id ma35_usb_phy_of_match[] = {
127	{ .compatible = "nuvoton,ma35d1-usb2-phy", },
128	{ },
129};
130MODULE_DEVICE_TABLE(of, ma35_usb_phy_of_match);
131
132static struct platform_driver ma35_usb_phy_driver = {
133	.probe		= ma35_usb_phy_probe,
134	.driver	= {
135		.name	= "ma35d1-usb2-phy",
136		.of_match_table = ma35_usb_phy_of_match,
137	},
138};
139module_platform_driver(ma35_usb_phy_driver);
140
141MODULE_DESCRIPTION("Nuvoton ma35d1 USB2.0 PHY driver");
142MODULE_AUTHOR("Hui-Ping Chen <hpchen0nvt@gmail.com>");
143MODULE_LICENSE("GPL");