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
34 struct tegra_p2u_of_data {
35 bool one_dir_search;
36 };
37
38 struct 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
p2u_writel(struct tegra_p2u * phy,const u32 value,const u32 reg)44 static 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
p2u_readl(struct tegra_p2u * phy,const u32 reg)50 static inline u32 p2u_readl(struct tegra_p2u *phy, const u32 reg)
51 {
52 return readl_relaxed(phy->base + reg);
53 }
54
tegra_p2u_power_on(struct phy * x)55 static int tegra_p2u_power_on(struct phy *x)
56 {
57 struct tegra_p2u *phy = phy_get_drvdata(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, 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, 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, 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, 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, val, P2U_DIR_SEARCH_CTRL);
84 }
85
86 return 0;
87 }
88
tegra_p2u_calibrate(struct phy * x)89 static int tegra_p2u_calibrate(struct phy *x)
90 {
91 struct tegra_p2u *phy = phy_get_drvdata(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, val, P2U_CONTROL_CMN);
97
98 return 0;
99 }
100
101 static const struct phy_ops ops = {
102 .power_on = tegra_p2u_power_on,
103 .calibrate = tegra_p2u_calibrate,
104 .owner = THIS_MODULE,
105 };
106
tegra_p2u_probe(struct platform_device * pdev)107 static 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, 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, "ctl");
124 if (IS_ERR(phy->base))
125 return PTR_ERR(phy->base);
126
127 phy->skip_sz_protection_en =
128 of_property_read_bool(dev->of_node,
129 "nvidia,skip-sz-protect-en");
130
131 platform_set_drvdata(pdev, phy);
132
133 generic_phy = devm_phy_create(dev, NULL, &ops);
134 if (IS_ERR(generic_phy))
135 return PTR_ERR(generic_phy);
136
137 phy_set_drvdata(generic_phy, phy);
138
139 phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
140 if (IS_ERR(phy_provider))
141 return PTR_ERR(phy_provider);
142
143 return 0;
144 }
145
146 static const struct tegra_p2u_of_data tegra194_p2u_of_data = {
147 .one_dir_search = false,
148 };
149
150 static const struct tegra_p2u_of_data tegra234_p2u_of_data = {
151 .one_dir_search = true,
152 };
153
154 static 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 };
165 MODULE_DEVICE_TABLE(of, tegra_p2u_id_table);
166
167 static 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 };
174 module_platform_driver(tegra_p2u_driver);
175
176 MODULE_AUTHOR("Vidya Sagar <vidyas@nvidia.com>");
177 MODULE_DESCRIPTION("NVIDIA Tegra194 PIPE2UPHY PHY driver");
178 MODULE_LICENSE("GPL v2");
179