1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * P2U (PIPE to UPHY) driver for Tegra T194 SoC
4 *
5 * Copyright (C) 2019-2022 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/phy/phy.h>
15#include <linux/platform_device.h>
16
17#define P2U_CONTROL_CMN 0x74
18#define P2U_CONTROL_CMN_ENABLE_L2_EXIT_RATE_CHANGE BIT(13)
19#define P2U_CONTROL_CMN_SKP_SIZE_PROTECTION_EN BIT(20)
20
21#define P2U_PERIODIC_EQ_CTRL_GEN3 0xc0
22#define P2U_PERIODIC_EQ_CTRL_GEN3_PERIODIC_EQ_EN BIT(0)
23#define P2U_PERIODIC_EQ_CTRL_GEN3_INIT_PRESET_EQ_TRAIN_EN BIT(1)
24#define P2U_PERIODIC_EQ_CTRL_GEN4 0xc4
25#define P2U_PERIODIC_EQ_CTRL_GEN4_INIT_PRESET_EQ_TRAIN_EN BIT(1)
26
27#define P2U_RX_DEBOUNCE_TIME 0xa4
28#define P2U_RX_DEBOUNCE_TIME_DEBOUNCE_TIMER_MASK 0xffff
29#define P2U_RX_DEBOUNCE_TIME_DEBOUNCE_TIMER_VAL 160
30
31#define P2U_DIR_SEARCH_CTRL 0xd4
32#define P2U_DIR_SEARCH_CTRL_GEN4_FINE_GRAIN_SEARCH_TWICE BIT(18)
33
34struct tegra_p2u_of_data {
35 bool one_dir_search;
36};
37
38struct tegra_p2u {
39 void __iomem *base;
40 bool skip_sz_protection_en; /* Needed to support two retimers */
41 struct tegra_p2u_of_data *of_data;
42};
43
44static inline void p2u_writel(struct tegra_p2u *phy, const u32 value,
45 const u32 reg)
46{
47 writel_relaxed(value, phy->base + reg);
48}
49
50static inline u32 p2u_readl(struct tegra_p2u *phy, const u32 reg)
51{
52 return readl_relaxed(phy->base + reg);
53}
54
55static int tegra_p2u_power_on(struct phy *x)
56{
57 struct tegra_p2u *phy = phy_get_drvdata(phy: x);
58 u32 val;
59
60 if (phy->skip_sz_protection_en) {
61 val = p2u_readl(phy, P2U_CONTROL_CMN);
62 val |= P2U_CONTROL_CMN_SKP_SIZE_PROTECTION_EN;
63 p2u_writel(phy, value: val, P2U_CONTROL_CMN);
64 }
65
66 val = p2u_readl(phy, P2U_PERIODIC_EQ_CTRL_GEN3);
67 val &= ~P2U_PERIODIC_EQ_CTRL_GEN3_PERIODIC_EQ_EN;
68 val |= P2U_PERIODIC_EQ_CTRL_GEN3_INIT_PRESET_EQ_TRAIN_EN;
69 p2u_writel(phy, value: val, P2U_PERIODIC_EQ_CTRL_GEN3);
70
71 val = p2u_readl(phy, P2U_PERIODIC_EQ_CTRL_GEN4);
72 val |= P2U_PERIODIC_EQ_CTRL_GEN4_INIT_PRESET_EQ_TRAIN_EN;
73 p2u_writel(phy, value: val, P2U_PERIODIC_EQ_CTRL_GEN4);
74
75 val = p2u_readl(phy, P2U_RX_DEBOUNCE_TIME);
76 val &= ~P2U_RX_DEBOUNCE_TIME_DEBOUNCE_TIMER_MASK;
77 val |= P2U_RX_DEBOUNCE_TIME_DEBOUNCE_TIMER_VAL;
78 p2u_writel(phy, value: val, P2U_RX_DEBOUNCE_TIME);
79
80 if (phy->of_data->one_dir_search) {
81 val = p2u_readl(phy, P2U_DIR_SEARCH_CTRL);
82 val &= ~P2U_DIR_SEARCH_CTRL_GEN4_FINE_GRAIN_SEARCH_TWICE;
83 p2u_writel(phy, value: val, P2U_DIR_SEARCH_CTRL);
84 }
85
86 return 0;
87}
88
89static int tegra_p2u_calibrate(struct phy *x)
90{
91 struct tegra_p2u *phy = phy_get_drvdata(phy: x);
92 u32 val;
93
94 val = p2u_readl(phy, P2U_CONTROL_CMN);
95 val |= P2U_CONTROL_CMN_ENABLE_L2_EXIT_RATE_CHANGE;
96 p2u_writel(phy, value: val, P2U_CONTROL_CMN);
97
98 return 0;
99}
100
101static const struct phy_ops ops = {
102 .power_on = tegra_p2u_power_on,
103 .calibrate = tegra_p2u_calibrate,
104 .owner = THIS_MODULE,
105};
106
107static int tegra_p2u_probe(struct platform_device *pdev)
108{
109 struct phy_provider *phy_provider;
110 struct device *dev = &pdev->dev;
111 struct phy *generic_phy;
112 struct tegra_p2u *phy;
113
114 phy = devm_kzalloc(dev, size: sizeof(*phy), GFP_KERNEL);
115 if (!phy)
116 return -ENOMEM;
117
118 phy->of_data =
119 (struct tegra_p2u_of_data *)of_device_get_match_data(dev);
120 if (!phy->of_data)
121 return -EINVAL;
122
123 phy->base = devm_platform_ioremap_resource_byname(pdev, name: "ctl");
124 if (IS_ERR(ptr: phy->base))
125 return PTR_ERR(ptr: phy->base);
126
127 phy->skip_sz_protection_en =
128 of_property_read_bool(np: dev->of_node,
129 propname: "nvidia,skip-sz-protect-en");
130
131 platform_set_drvdata(pdev, data: phy);
132
133 generic_phy = devm_phy_create(dev, NULL, ops: &ops);
134 if (IS_ERR(ptr: generic_phy))
135 return PTR_ERR(ptr: generic_phy);
136
137 phy_set_drvdata(phy: generic_phy, data: phy);
138
139 phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
140 if (IS_ERR(ptr: phy_provider))
141 return PTR_ERR(ptr: phy_provider);
142
143 return 0;
144}
145
146static const struct tegra_p2u_of_data tegra194_p2u_of_data = {
147 .one_dir_search = false,
148};
149
150static const struct tegra_p2u_of_data tegra234_p2u_of_data = {
151 .one_dir_search = true,
152};
153
154static const struct of_device_id tegra_p2u_id_table[] = {
155 {
156 .compatible = "nvidia,tegra194-p2u",
157 .data = &tegra194_p2u_of_data,
158 },
159 {
160 .compatible = "nvidia,tegra234-p2u",
161 .data = &tegra234_p2u_of_data,
162 },
163 {}
164};
165MODULE_DEVICE_TABLE(of, tegra_p2u_id_table);
166
167static struct platform_driver tegra_p2u_driver = {
168 .probe = tegra_p2u_probe,
169 .driver = {
170 .name = "tegra194-p2u",
171 .of_match_table = tegra_p2u_id_table,
172 },
173};
174module_platform_driver(tegra_p2u_driver);
175
176MODULE_AUTHOR("Vidya Sagar <vidyas@nvidia.com>");
177MODULE_DESCRIPTION("NVIDIA Tegra194 PIPE2UPHY PHY driver");
178MODULE_LICENSE("GPL v2");
179

source code of linux/drivers/phy/tegra/phy-tegra194-p2u.c