drivers/phy/tegra/phy-tegra194-p2u.c

   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");