xref: /linux/drivers/phy/starfive/phy-jh7110-pcie.c (revision 906fd46a65383cd639e5eec72a047efc33045d86)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * StarFive JH7110 PCIe 2.0 PHY driver
4  *
5  * Copyright (C) 2023 StarFive Technology Co., Ltd.
6  * Author: Minda Chen <minda.chen@starfivetech.com>
7  */
8 
9 #include <linux/bits.h>
10 #include <linux/clk.h>
11 #include <linux/err.h>
12 #include <linux/io.h>
13 #include <linux/module.h>
14 #include <linux/mfd/syscon.h>
15 #include <linux/phy/phy.h>
16 #include <linux/platform_device.h>
17 #include <linux/regmap.h>
18 
19 #define PCIE_KVCO_LEVEL_OFF		0x28
20 #define PCIE_USB3_PHY_PLL_CTL_OFF	0x7c
21 #define PCIE_KVCO_TUNE_SIGNAL_OFF	0x80
22 #define PCIE_USB3_PHY_ENABLE		BIT(4)
23 #define PHY_KVCO_FINE_TUNE_LEVEL	0x91
24 #define PHY_KVCO_FINE_TUNE_SIGNALS	0xc
25 
26 #define USB_PDRSTN_SPLIT		BIT(17)
27 
28 #define PCIE_PHY_MODE			BIT(20)
29 #define PCIE_PHY_MODE_MASK		GENMASK(21, 20)
30 #define PCIE_USB3_BUS_WIDTH_MASK	GENMASK(3, 2)
31 #define PCIE_USB3_BUS_WIDTH		BIT(3)
32 #define PCIE_USB3_RATE_MASK		GENMASK(6, 5)
33 #define PCIE_USB3_RX_STANDBY_MASK	BIT(7)
34 #define PCIE_USB3_PHY_ENABLE		BIT(4)
35 
36 struct jh7110_pcie_phy {
37 	struct phy *phy;
38 	struct regmap *stg_syscon;
39 	struct regmap *sys_syscon;
40 	void __iomem *regs;
41 	u32 sys_phy_connect;
42 	u32 stg_pcie_mode;
43 	u32 stg_pcie_usb;
44 	enum phy_mode mode;
45 };
46 
47 static int phy_usb3_mode_set(struct jh7110_pcie_phy *data)
48 {
49 	if (!data->stg_syscon || !data->sys_syscon) {
50 		dev_err(&data->phy->dev, "doesn't support usb3 mode\n");
51 		return -EINVAL;
52 	}
53 
54 	regmap_update_bits(data->stg_syscon, data->stg_pcie_mode,
55 			   PCIE_PHY_MODE_MASK, PCIE_PHY_MODE);
56 	regmap_update_bits(data->stg_syscon, data->stg_pcie_usb,
57 			   PCIE_USB3_BUS_WIDTH_MASK, 0);
58 	regmap_update_bits(data->stg_syscon, data->stg_pcie_usb,
59 			   PCIE_USB3_PHY_ENABLE, PCIE_USB3_PHY_ENABLE);
60 
61 	/* Connect usb 3.0 phy mode */
62 	regmap_update_bits(data->sys_syscon, data->sys_phy_connect,
63 			   USB_PDRSTN_SPLIT, 0);
64 
65 	/* Configuare spread-spectrum mode: down-spread-spectrum */
66 	writel(PCIE_USB3_PHY_ENABLE, data->regs + PCIE_USB3_PHY_PLL_CTL_OFF);
67 
68 	return 0;
69 }
70 
71 static void phy_pcie_mode_set(struct jh7110_pcie_phy *data)
72 {
73 	u32 val;
74 
75 	/* default is PCIe mode */
76 	if (!data->stg_syscon || !data->sys_syscon)
77 		return;
78 
79 	regmap_update_bits(data->stg_syscon, data->stg_pcie_mode,
80 			   PCIE_PHY_MODE_MASK, 0);
81 	regmap_update_bits(data->stg_syscon, data->stg_pcie_usb,
82 			   PCIE_USB3_BUS_WIDTH_MASK,
83 			   PCIE_USB3_BUS_WIDTH);
84 	regmap_update_bits(data->stg_syscon, data->stg_pcie_usb,
85 			   PCIE_USB3_PHY_ENABLE, 0);
86 
87 	regmap_update_bits(data->sys_syscon, data->sys_phy_connect,
88 			   USB_PDRSTN_SPLIT, 0);
89 
90 	val = readl(data->regs + PCIE_USB3_PHY_PLL_CTL_OFF);
91 	val &= ~PCIE_USB3_PHY_ENABLE;
92 	writel(val, data->regs + PCIE_USB3_PHY_PLL_CTL_OFF);
93 }
94 
95 static void phy_kvco_gain_set(struct jh7110_pcie_phy *phy)
96 {
97 	/* PCIe Multi-PHY PLL KVCO Gain fine tune settings: */
98 	writel(PHY_KVCO_FINE_TUNE_LEVEL, phy->regs + PCIE_KVCO_LEVEL_OFF);
99 	writel(PHY_KVCO_FINE_TUNE_SIGNALS, phy->regs + PCIE_KVCO_TUNE_SIGNAL_OFF);
100 }
101 
102 static int jh7110_pcie_phy_set_mode(struct phy *_phy,
103 				    enum phy_mode mode, int submode)
104 {
105 	struct jh7110_pcie_phy *phy = phy_get_drvdata(_phy);
106 	int ret;
107 
108 	if (mode == phy->mode)
109 		return 0;
110 
111 	switch (mode) {
112 	case PHY_MODE_USB_HOST:
113 	case PHY_MODE_USB_DEVICE:
114 	case PHY_MODE_USB_OTG:
115 		ret = phy_usb3_mode_set(phy);
116 		if (ret)
117 			return ret;
118 		break;
119 	case PHY_MODE_PCIE:
120 		phy_pcie_mode_set(phy);
121 		break;
122 	default:
123 		return -EINVAL;
124 	}
125 
126 	dev_dbg(&_phy->dev, "Changing phy mode to %d\n", mode);
127 	phy->mode = mode;
128 
129 	return 0;
130 }
131 
132 static const struct phy_ops jh7110_pcie_phy_ops = {
133 	.set_mode	= jh7110_pcie_phy_set_mode,
134 	.owner		= THIS_MODULE,
135 };
136 
137 static int jh7110_pcie_phy_probe(struct platform_device *pdev)
138 {
139 	struct jh7110_pcie_phy *phy;
140 	struct device *dev = &pdev->dev;
141 	struct phy_provider *phy_provider;
142 	u32 args[2];
143 
144 	phy = devm_kzalloc(dev, sizeof(*phy), GFP_KERNEL);
145 	if (!phy)
146 		return -ENOMEM;
147 
148 	phy->regs = devm_platform_ioremap_resource(pdev, 0);
149 	if (IS_ERR(phy->regs))
150 		return PTR_ERR(phy->regs);
151 
152 	phy->phy = devm_phy_create(dev, NULL, &jh7110_pcie_phy_ops);
153 	if (IS_ERR(phy->phy))
154 		return dev_err_probe(dev, PTR_ERR(phy->phy),
155 				     "Failed to map phy base\n");
156 
157 	phy->sys_syscon =
158 		syscon_regmap_lookup_by_phandle_args(pdev->dev.of_node,
159 						     "starfive,sys-syscon",
160 						     1, args);
161 
162 	if (!IS_ERR_OR_NULL(phy->sys_syscon))
163 		phy->sys_phy_connect = args[0];
164 	else
165 		phy->sys_syscon = NULL;
166 
167 	phy->stg_syscon =
168 		syscon_regmap_lookup_by_phandle_args(pdev->dev.of_node,
169 						     "starfive,stg-syscon",
170 						     2, args);
171 
172 	if (!IS_ERR_OR_NULL(phy->stg_syscon)) {
173 		phy->stg_pcie_mode = args[0];
174 		phy->stg_pcie_usb = args[1];
175 	} else {
176 		phy->stg_syscon = NULL;
177 	}
178 
179 	phy_kvco_gain_set(phy);
180 
181 	phy_set_drvdata(phy->phy, phy);
182 	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
183 
184 	return PTR_ERR_OR_ZERO(phy_provider);
185 }
186 
187 static const struct of_device_id jh7110_pcie_phy_of_match[] = {
188 	{ .compatible = "starfive,jh7110-pcie-phy" },
189 	{ /* sentinel */ },
190 };
191 MODULE_DEVICE_TABLE(of, jh7110_pcie_phy_of_match);
192 
193 static struct platform_driver jh7110_pcie_phy_driver = {
194 	.probe	= jh7110_pcie_phy_probe,
195 	.driver = {
196 		.of_match_table	= jh7110_pcie_phy_of_match,
197 		.name  = "jh7110-pcie-phy",
198 	}
199 };
200 module_platform_driver(jh7110_pcie_phy_driver);
201 
202 MODULE_DESCRIPTION("StarFive JH7110 PCIe 2.0 PHY driver");
203 MODULE_AUTHOR("Minda Chen <minda.chen@starfivetech.com>");
204 MODULE_LICENSE("GPL");
205