1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * P2U (PIPE to UPHY) driver for Tegra T194 SoC
4  *
5  * Copyright (C) 2019 NVIDIA Corporation.
6  *
7  * Author: Vidya Sagar <vidyas@nvidia.com>
8  */
9 
10 #include <linux/err.h>
11 #include <linux/io.h>
12 #include <linux/module.h>
13 #include <linux/of.h>
14 #include <linux/of_platform.h>
15 #include <linux/phy/phy.h>
16 
17 #define P2U_PERIODIC_EQ_CTRL_GEN3	0xc0
18 #define P2U_PERIODIC_EQ_CTRL_GEN3_PERIODIC_EQ_EN		BIT(0)
19 #define P2U_PERIODIC_EQ_CTRL_GEN3_INIT_PRESET_EQ_TRAIN_EN	BIT(1)
20 #define P2U_PERIODIC_EQ_CTRL_GEN4	0xc4
21 #define P2U_PERIODIC_EQ_CTRL_GEN4_INIT_PRESET_EQ_TRAIN_EN	BIT(1)
22 
23 #define P2U_RX_DEBOUNCE_TIME				0xa4
24 #define P2U_RX_DEBOUNCE_TIME_DEBOUNCE_TIMER_MASK	0xffff
25 #define P2U_RX_DEBOUNCE_TIME_DEBOUNCE_TIMER_VAL		160
26 
27 struct tegra_p2u {
28 	void __iomem *base;
29 };
30 
31 static inline void p2u_writel(struct tegra_p2u *phy, const u32 value,
32 			      const u32 reg)
33 {
34 	writel_relaxed(value, phy->base + reg);
35 }
36 
37 static inline u32 p2u_readl(struct tegra_p2u *phy, const u32 reg)
38 {
39 	return readl_relaxed(phy->base + reg);
40 }
41 
42 static int tegra_p2u_power_on(struct phy *x)
43 {
44 	struct tegra_p2u *phy = phy_get_drvdata(x);
45 	u32 val;
46 
47 	val = p2u_readl(phy, P2U_PERIODIC_EQ_CTRL_GEN3);
48 	val &= ~P2U_PERIODIC_EQ_CTRL_GEN3_PERIODIC_EQ_EN;
49 	val |= P2U_PERIODIC_EQ_CTRL_GEN3_INIT_PRESET_EQ_TRAIN_EN;
50 	p2u_writel(phy, val, P2U_PERIODIC_EQ_CTRL_GEN3);
51 
52 	val = p2u_readl(phy, P2U_PERIODIC_EQ_CTRL_GEN4);
53 	val |= P2U_PERIODIC_EQ_CTRL_GEN4_INIT_PRESET_EQ_TRAIN_EN;
54 	p2u_writel(phy, val, P2U_PERIODIC_EQ_CTRL_GEN4);
55 
56 	val = p2u_readl(phy, P2U_RX_DEBOUNCE_TIME);
57 	val &= ~P2U_RX_DEBOUNCE_TIME_DEBOUNCE_TIMER_MASK;
58 	val |= P2U_RX_DEBOUNCE_TIME_DEBOUNCE_TIMER_VAL;
59 	p2u_writel(phy, val, P2U_RX_DEBOUNCE_TIME);
60 
61 	return 0;
62 }
63 
64 static const struct phy_ops ops = {
65 	.power_on = tegra_p2u_power_on,
66 	.owner = THIS_MODULE,
67 };
68 
69 static int tegra_p2u_probe(struct platform_device *pdev)
70 {
71 	struct phy_provider *phy_provider;
72 	struct device *dev = &pdev->dev;
73 	struct phy *generic_phy;
74 	struct tegra_p2u *phy;
75 
76 	phy = devm_kzalloc(dev, sizeof(*phy), GFP_KERNEL);
77 	if (!phy)
78 		return -ENOMEM;
79 
80 	phy->base = devm_platform_ioremap_resource_byname(pdev, "ctl");
81 	if (IS_ERR(phy->base))
82 		return PTR_ERR(phy->base);
83 
84 	platform_set_drvdata(pdev, phy);
85 
86 	generic_phy = devm_phy_create(dev, NULL, &ops);
87 	if (IS_ERR(generic_phy))
88 		return PTR_ERR(generic_phy);
89 
90 	phy_set_drvdata(generic_phy, phy);
91 
92 	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
93 	if (IS_ERR(phy_provider))
94 		return PTR_ERR(phy_provider);
95 
96 	return 0;
97 }
98 
99 static const struct of_device_id tegra_p2u_id_table[] = {
100 	{
101 		.compatible = "nvidia,tegra194-p2u",
102 	},
103 	{}
104 };
105 MODULE_DEVICE_TABLE(of, tegra_p2u_id_table);
106 
107 static struct platform_driver tegra_p2u_driver = {
108 	.probe = tegra_p2u_probe,
109 	.driver = {
110 		.name = "tegra194-p2u",
111 		.of_match_table = tegra_p2u_id_table,
112 	},
113 };
114 module_platform_driver(tegra_p2u_driver);
115 
116 MODULE_AUTHOR("Vidya Sagar <vidyas@nvidia.com>");
117 MODULE_DESCRIPTION("NVIDIA Tegra194 PIPE2UPHY PHY driver");
118 MODULE_LICENSE("GPL v2");
119