tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
27struct tegra_p2u {
28 void __iomem *base;
29};
30
31static 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
37static inline u32 p2u_readl(struct tegra_p2u *phy, const u32 reg)
38{
39 return readl_relaxed(phy->base + reg);
40}
41
42static 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
64static const struct phy_ops ops = {
65 .power_on = tegra_p2u_power_on,
66 .owner = THIS_MODULE,
67};
68
69static 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 struct resource *res;
76
77 phy = devm_kzalloc(dev, sizeof(*phy), GFP_KERNEL);
78 if (!phy)
79 return -ENOMEM;
80
81 res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "ctl");
82 phy->base = devm_ioremap_resource(dev, res);
83 if (IS_ERR(phy->base))
84 return PTR_ERR(phy->base);
85
86 platform_set_drvdata(pdev, phy);
87
88 generic_phy = devm_phy_create(dev, NULL, &ops);
89 if (IS_ERR(generic_phy))
90 return PTR_ERR(generic_phy);
91
92 phy_set_drvdata(generic_phy, phy);
93
94 phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
95 if (IS_ERR(phy_provider))
96 return PTR_ERR(phy_provider);
97
98 return 0;
99}
100
101static const struct of_device_id tegra_p2u_id_table[] = {
102 {
103 .compatible = "nvidia,tegra194-p2u",
104 },
105 {}
106};
107MODULE_DEVICE_TABLE(of, tegra_p2u_id_table);
108
109static struct platform_driver tegra_p2u_driver = {
110 .probe = tegra_p2u_probe,
111 .driver = {
112 .name = "tegra194-p2u",
113 .of_match_table = tegra_p2u_id_table,
114 },
115};
116module_platform_driver(tegra_p2u_driver);
117
118MODULE_AUTHOR("Vidya Sagar <vidyas@nvidia.com>");
119MODULE_DESCRIPTION("NVIDIA Tegra194 PIPE2UPHY PHY driver");
120MODULE_LICENSE("GPL v2");