1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Renesas R-Car Gen3 for USB3.0 PHY driver
  4 *
  5 * Copyright (C) 2017 Renesas Electronics Corporation
  6 */
  7
  8#include <linux/clk.h>
  9#include <linux/delay.h>
 10#include <linux/io.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/pm_runtime.h>
 16
 17#define USB30_CLKSET0		0x034
 18#define USB30_CLKSET1		0x036
 19#define USB30_SSC_SET		0x038
 20#define USB30_PHY_ENABLE	0x060
 21#define USB30_VBUS_EN		0x064
 22
 23/* USB30_CLKSET0 */
 24#define CLKSET0_PRIVATE			0x05c0
 25#define CLKSET0_USB30_FSEL_USB_EXTAL	0x0002
 26
 27/* USB30_CLKSET1 */
 28#define CLKSET1_USB30_PLL_MULTI_SHIFT		6
 29#define CLKSET1_USB30_PLL_MULTI_USB_EXTAL	(0x64 << \
 30						 CLKSET1_USB30_PLL_MULTI_SHIFT)
 31#define CLKSET1_PHYRESET	BIT(4)	/* 1: reset */
 32#define CLKSET1_REF_CLKDIV	BIT(3)	/* 1: USB_EXTAL */
 33#define CLKSET1_PRIVATE_2_1	BIT(1)	/* Write B'01 */
 34#define CLKSET1_REF_CLK_SEL	BIT(0)	/* 1: USB3S0_CLK_P */
 35
 36/* USB30_SSC_SET */
 37#define SSC_SET_SSC_EN		BIT(12)
 38#define SSC_SET_RANGE_SHIFT	9
 39#define SSC_SET_RANGE_4980	(0x0 << SSC_SET_RANGE_SHIFT)
 40#define SSC_SET_RANGE_4492	(0x1 << SSC_SET_RANGE_SHIFT)
 41#define SSC_SET_RANGE_4003	(0x2 << SSC_SET_RANGE_SHIFT)
 42
 43/* USB30_PHY_ENABLE */
 44#define PHY_ENABLE_RESET_EN	BIT(4)
 45
 46/* USB30_VBUS_EN */
 47#define VBUS_EN_VBUS_EN		BIT(1)
 48
 49struct rcar_gen3_usb3 {
 50	void __iomem *base;
 51	struct phy *phy;
 52	u32 ssc_range;
 53	bool usb3s_clk;
 54	bool usb_extal;
 55};
 56
 57static void write_clkset1_for_usb_extal(struct rcar_gen3_usb3 *r, bool reset)
 58{
 59	u16 val = CLKSET1_USB30_PLL_MULTI_USB_EXTAL |
 60		  CLKSET1_REF_CLKDIV | CLKSET1_PRIVATE_2_1;
 61
 62	if (reset)
 63		val |= CLKSET1_PHYRESET;
 64
 65	writew(val, r->base + USB30_CLKSET1);
 66}
 67
 68static void rcar_gen3_phy_usb3_enable_ssc(struct rcar_gen3_usb3 *r)
 69{
 70	u16 val = SSC_SET_SSC_EN;
 71
 72	switch (r->ssc_range) {
 73	case 4980:
 74		val |= SSC_SET_RANGE_4980;
 75		break;
 76	case 4492:
 77		val |= SSC_SET_RANGE_4492;
 78		break;
 79	case 4003:
 80		val |= SSC_SET_RANGE_4003;
 81		break;
 82	default:
 83		dev_err(&r->phy->dev, "%s: unsupported range (%x)\n", __func__,
 84			r->ssc_range);
 85		return;
 86	}
 87
 88	writew(val, r->base + USB30_SSC_SET);
 89}
 90
 91static void rcar_gen3_phy_usb3_select_usb_extal(struct rcar_gen3_usb3 *r)
 92{
 93	write_clkset1_for_usb_extal(r, false);
 94	if (r->ssc_range)
 95		rcar_gen3_phy_usb3_enable_ssc(r);
 96	writew(CLKSET0_PRIVATE | CLKSET0_USB30_FSEL_USB_EXTAL,
 97	       r->base + USB30_CLKSET0);
 98	writew(PHY_ENABLE_RESET_EN, r->base + USB30_PHY_ENABLE);
 99	write_clkset1_for_usb_extal(r, true);
100	usleep_range(10, 20);
101	write_clkset1_for_usb_extal(r, false);
102}
103
104static int rcar_gen3_phy_usb3_init(struct phy *p)
105{
106	struct rcar_gen3_usb3 *r = phy_get_drvdata(p);
107
108	dev_vdbg(&r->phy->dev, "%s: enter (%d, %d, %d)\n", __func__,
109		 r->usb3s_clk, r->usb_extal, r->ssc_range);
110
111	if (!r->usb3s_clk && r->usb_extal)
112		rcar_gen3_phy_usb3_select_usb_extal(r);
113
114	/* Enables VBUS detection anyway */
115	writew(VBUS_EN_VBUS_EN, r->base + USB30_VBUS_EN);
116
117	return 0;
118}
119
120static const struct phy_ops rcar_gen3_phy_usb3_ops = {
121	.init		= rcar_gen3_phy_usb3_init,
122	.owner		= THIS_MODULE,
123};
124
125static const struct of_device_id rcar_gen3_phy_usb3_match_table[] = {
126	{ .compatible = "renesas,rcar-gen3-usb3-phy" },
127	{ }
128};
129MODULE_DEVICE_TABLE(of, rcar_gen3_phy_usb3_match_table);
130
131static int rcar_gen3_phy_usb3_probe(struct platform_device *pdev)
132{
133	struct device *dev = &pdev->dev;
134	struct rcar_gen3_usb3 *r;
135	struct phy_provider *provider;
136	struct resource *res;
137	int ret = 0;
138	struct clk *clk;
139
140	if (!dev->of_node) {
141		dev_err(dev, "This driver needs device tree\n");
142		return -EINVAL;
143	}
144
145	r = devm_kzalloc(dev, sizeof(*r), GFP_KERNEL);
146	if (!r)
147		return -ENOMEM;
148
149	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
150	r->base = devm_ioremap_resource(dev, res);
151	if (IS_ERR(r->base))
152		return PTR_ERR(r->base);
153
154	clk = devm_clk_get(dev, "usb3s_clk");
155	if (!IS_ERR(clk) && !clk_prepare_enable(clk)) {
156		r->usb3s_clk = !!clk_get_rate(clk);
157		clk_disable_unprepare(clk);
158	}
159	clk = devm_clk_get(dev, "usb_extal");
160	if (!IS_ERR(clk) && !clk_prepare_enable(clk)) {
161		r->usb_extal = !!clk_get_rate(clk);
162		clk_disable_unprepare(clk);
163	}
164
165	if (!r->usb3s_clk && !r->usb_extal) {
166		dev_err(dev, "This driver needs usb3s_clk and/or usb_extal\n");
167		ret = -EINVAL;
168		goto error;
169	}
170
171	/*
172	 * devm_phy_create() will call pm_runtime_enable(&phy->dev);
173	 * And then, phy-core will manage runtime pm for this device.
174	 */
175	pm_runtime_enable(dev);
176
177	r->phy = devm_phy_create(dev, NULL, &rcar_gen3_phy_usb3_ops);
178	if (IS_ERR(r->phy)) {
179		dev_err(dev, "Failed to create USB3 PHY\n");
180		ret = PTR_ERR(r->phy);
181		goto error;
182	}
183
184	of_property_read_u32(dev->of_node, "renesas,ssc-range", &r->ssc_range);
185
186	platform_set_drvdata(pdev, r);
187	phy_set_drvdata(r->phy, r);
188
189	provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
190	if (IS_ERR(provider)) {
191		dev_err(dev, "Failed to register PHY provider\n");
192		ret = PTR_ERR(provider);
193		goto error;
194	}
195
196	return 0;
197
198error:
199	pm_runtime_disable(dev);
200
201	return ret;
202}
203
204static int rcar_gen3_phy_usb3_remove(struct platform_device *pdev)
205{
206	pm_runtime_disable(&pdev->dev);
207
208	return 0;
209};
210
211static struct platform_driver rcar_gen3_phy_usb3_driver = {
212	.driver = {
213		.name		= "phy_rcar_gen3_usb3",
214		.of_match_table	= rcar_gen3_phy_usb3_match_table,
215	},
216	.probe	= rcar_gen3_phy_usb3_probe,
217	.remove = rcar_gen3_phy_usb3_remove,
218};
219module_platform_driver(rcar_gen3_phy_usb3_driver);
220
221MODULE_LICENSE("GPL v2");
222MODULE_DESCRIPTION("Renesas R-Car Gen3 USB 3.0 PHY");
223MODULE_AUTHOR("Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>");