drivers/phy/allwinner/phy-sun50i-usb3.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Allwinner sun50i(H6) USB 3.0 phy driver
   4  *
   5  * Copyright (C) 2017 Icenowy Zheng <icenowy@aosc.io>
   6  *
   7  * Based on phy-sun9i-usb.c, which is:
   8  *
   9  * Copyright (C) 2014-2015 Chen-Yu Tsai <wens@csie.org>
  10  *
  11  * Based on code from Allwinner BSP, which is:
  12  *
  13  * Copyright (c) 2010-2015 Allwinner Technology Co., Ltd.
  14  */
  15
  16 #include <linux/clk.h>
  17 #include <linux/err.h>
  18 #include <linux/io.h>
  19 #include <linux/module.h>
  20 #include <linux/phy/phy.h>
  21 #include <linux/platform_device.h>
  22 #include <linux/reset.h>
  23
  24 /* Interface Status and Control Registers */
  25 #define SUNXI_ISCR                      0x00
  26 #define SUNXI_PIPE_CLOCK_CONTROL        0x14
  27 #define SUNXI_PHY_TUNE_LOW              0x18
  28 #define SUNXI_PHY_TUNE_HIGH             0x1c
  29 #define SUNXI_PHY_EXTERNAL_CONTROL      0x20
  30
  31 /* USB2.0 Interface Status and Control Register */
  32 #define SUNXI_ISCR_FORCE_VBUS           (3 << 12)
  33
  34 /* PIPE Clock Control Register */
  35 #define SUNXI_PCC_PIPE_CLK_OPEN         (1 << 6)
  36
  37 /* PHY External Control Register */
  38 #define SUNXI_PEC_EXTERN_VBUS           (3 << 1)
  39 #define SUNXI_PEC_SSC_EN                (1 << 24)
  40 #define SUNXI_PEC_REF_SSP_EN            (1 << 26)
  41
  42 /* PHY Tune High Register */
  43 #define SUNXI_TX_DEEMPH_3P5DB(n)        ((n) << 19)
  44 #define SUNXI_TX_DEEMPH_3P5DB_MASK      GENMASK(24, 19)
  45 #define SUNXI_TX_DEEMPH_6DB(n)          ((n) << 13)
  46 #define SUNXI_TX_DEEMPH_6GB_MASK        GENMASK(18, 13)
  47 #define SUNXI_TX_SWING_FULL(n)          ((n) << 6)
  48 #define SUNXI_TX_SWING_FULL_MASK        GENMASK(12, 6)
  49 #define SUNXI_LOS_BIAS(n)               ((n) << 3)
  50 #define SUNXI_LOS_BIAS_MASK             GENMASK(5, 3)
  51 #define SUNXI_TXVBOOSTLVL(n)            ((n) << 0)
  52 #define SUNXI_TXVBOOSTLVL_MASK          GENMASK(0, 2)
  53
  54 struct sun50i_usb3_phy {
  55         struct phy *phy;
  56         void __iomem *regs;
  57         struct reset_control *reset;
  58         struct clk *clk;
  59 };
  60
  61 static void sun50i_usb3_phy_open(struct sun50i_usb3_phy *phy)
  62 {
  63         u32 val;
  64
  65         val = readl(phy->regs + SUNXI_PHY_EXTERNAL_CONTROL);
  66         val |= SUNXI_PEC_EXTERN_VBUS;
  67         val |= SUNXI_PEC_SSC_EN | SUNXI_PEC_REF_SSP_EN;
  68         writel(val, phy->regs + SUNXI_PHY_EXTERNAL_CONTROL);
  69
  70         val = readl(phy->regs + SUNXI_PIPE_CLOCK_CONTROL);
  71         val |= SUNXI_PCC_PIPE_CLK_OPEN;
  72         writel(val, phy->regs + SUNXI_PIPE_CLOCK_CONTROL);
  73
  74         val = readl(phy->regs + SUNXI_ISCR);
  75         val |= SUNXI_ISCR_FORCE_VBUS;
  76         writel(val, phy->regs + SUNXI_ISCR);
  77
  78         /*
  79          * All the magic numbers written to the PHY_TUNE_{LOW_HIGH}
  80          * registers are directly taken from the BSP USB3 driver from
  81          * Allwiner.
  82          */
  83         writel(0x0047fc87, phy->regs + SUNXI_PHY_TUNE_LOW);
  84
  85         val = readl(phy->regs + SUNXI_PHY_TUNE_HIGH);
  86         val &= ~(SUNXI_TXVBOOSTLVL_MASK | SUNXI_LOS_BIAS_MASK |
  87                  SUNXI_TX_SWING_FULL_MASK | SUNXI_TX_DEEMPH_6GB_MASK |
  88                  SUNXI_TX_DEEMPH_3P5DB_MASK);
  89         val |= SUNXI_TXVBOOSTLVL(0x7);
  90         val |= SUNXI_LOS_BIAS(0x7);
  91         val |= SUNXI_TX_SWING_FULL(0x55);
  92         val |= SUNXI_TX_DEEMPH_6DB(0x20);
  93         val |= SUNXI_TX_DEEMPH_3P5DB(0x15);
  94         writel(val, phy->regs + SUNXI_PHY_TUNE_HIGH);
  95 }
  96
  97 static int sun50i_usb3_phy_init(struct phy *_phy)
  98 {
  99         struct sun50i_usb3_phy *phy = phy_get_drvdata(_phy);
 100         int ret;
 101
 102         ret = clk_prepare_enable(phy->clk);
 103         if (ret)
 104                 return ret;
 105
 106         ret = reset_control_deassert(phy->reset);
 107         if (ret) {
 108                 clk_disable_unprepare(phy->clk);
 109                 return ret;
 110         }
 111
 112         sun50i_usb3_phy_open(phy);
 113         return 0;
 114 }
 115
 116 static int sun50i_usb3_phy_exit(struct phy *_phy)
 117 {
 118         struct sun50i_usb3_phy *phy = phy_get_drvdata(_phy);
 119
 120         reset_control_assert(phy->reset);
 121         clk_disable_unprepare(phy->clk);
 122
 123         return 0;
 124 }
 125
 126 static const struct phy_ops sun50i_usb3_phy_ops = {
 127         .init           = sun50i_usb3_phy_init,
 128         .exit           = sun50i_usb3_phy_exit,
 129         .owner          = THIS_MODULE,
 130 };
 131
 132 static int sun50i_usb3_phy_probe(struct platform_device *pdev)
 133 {
 134         struct sun50i_usb3_phy *phy;
 135         struct device *dev = &pdev->dev;
 136         struct phy_provider *phy_provider;
 137         struct resource *res;
 138
 139         phy = devm_kzalloc(dev, sizeof(*phy), GFP_KERNEL);
 140         if (!phy)
 141                 return -ENOMEM;
 142
 143         phy->clk = devm_clk_get(dev, NULL);
 144         if (IS_ERR(phy->clk)) {
 145                 if (PTR_ERR(phy->clk) != -EPROBE_DEFER)
 146                         dev_err(dev, "failed to get phy clock\n");
 147                 return PTR_ERR(phy->clk);
 148         }
 149
 150         phy->reset = devm_reset_control_get(dev, NULL);
 151         if (IS_ERR(phy->reset)) {
 152                 dev_err(dev, "failed to get reset control\n");
 153                 return PTR_ERR(phy->reset);
 154         }
 155
 156         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 157         phy->regs = devm_ioremap_resource(dev, res);
 158         if (IS_ERR(phy->regs))
 159                 return PTR_ERR(phy->regs);
 160
 161         phy->phy = devm_phy_create(dev, NULL, &sun50i_usb3_phy_ops);
 162         if (IS_ERR(phy->phy)) {
 163                 dev_err(dev, "failed to create PHY\n");
 164                 return PTR_ERR(phy->phy);
 165         }
 166
 167         phy_set_drvdata(phy->phy, phy);
 168         phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
 169
 170         return PTR_ERR_OR_ZERO(phy_provider);
 171 }
 172
 173 static const struct of_device_id sun50i_usb3_phy_of_match[] = {
 174         { .compatible = "allwinner,sun50i-h6-usb3-phy" },
 175         { },
 176 };
 177 MODULE_DEVICE_TABLE(of, sun50i_usb3_phy_of_match);
 178
 179 static struct platform_driver sun50i_usb3_phy_driver = {
 180         .probe  = sun50i_usb3_phy_probe,
 181         .driver = {
 182                 .of_match_table = sun50i_usb3_phy_of_match,
 183                 .name  = "sun50i-usb3-phy",
 184         }
 185 };
 186 module_platform_driver(sun50i_usb3_phy_driver);
 187
 188 MODULE_DESCRIPTION("Allwinner H6 USB 3.0 phy driver");
 189 MODULE_AUTHOR("Icenowy Zheng <icenowy@aosc.io>");
 190 MODULE_LICENSE("GPL");