drivers/phy/lantiq/phy-lantiq-rcu-usb2.c

   1 /*
   2  * Lantiq XWAY SoC RCU module based USB 1.1/2.0 PHY driver
   3  *
   4  * Copyright (C) 2016 Martin Blumenstingl <martin.blumenstingl@googlemail.com>
   5  * Copyright (C) 2017 Hauke Mehrtens <hauke@hauke-m.de>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/clk.h>
  13 #include <linux/delay.h>
  14 #include <linux/mfd/syscon.h>
  15 #include <linux/module.h>
  16 #include <linux/of.h>
  17 #include <linux/of_address.h>
  18 #include <linux/of_device.h>
  19 #include <linux/phy/phy.h>
  20 #include <linux/platform_device.h>
  21 #include <linux/property.h>
  22 #include <linux/regmap.h>
  23 #include <linux/reset.h>
  24
  25 /* Transmitter HS Pre-Emphasis Enable */
  26 #define RCU_CFG1_TX_PEE         BIT(0)
  27 /* Disconnect Threshold */
  28 #define RCU_CFG1_DIS_THR_MASK   0x00038000
  29 #define RCU_CFG1_DIS_THR_SHIFT  15
  30
  31 struct ltq_rcu_usb2_bits {
  32         u8 hostmode;
  33         u8 slave_endianness;
  34         u8 host_endianness;
  35         bool have_ana_cfg;
  36 };
  37
  38 struct ltq_rcu_usb2_priv {
  39         struct regmap                   *regmap;
  40         unsigned int                    phy_reg_offset;
  41         unsigned int                    ana_cfg1_reg_offset;
  42         const struct ltq_rcu_usb2_bits  *reg_bits;
  43         struct device                   *dev;
  44         struct phy                      *phy;
  45         struct clk                      *phy_gate_clk;
  46         struct reset_control            *ctrl_reset;
  47         struct reset_control            *phy_reset;
  48 };
  49
  50 static const struct ltq_rcu_usb2_bits xway_rcu_usb2_reg_bits = {
  51         .hostmode = 11,
  52         .slave_endianness = 9,
  53         .host_endianness = 10,
  54         .have_ana_cfg = false,
  55 };
  56
  57 static const struct ltq_rcu_usb2_bits xrx100_rcu_usb2_reg_bits = {
  58         .hostmode = 11,
  59         .slave_endianness = 17,
  60         .host_endianness = 10,
  61         .have_ana_cfg = false,
  62 };
  63
  64 static const struct ltq_rcu_usb2_bits xrx200_rcu_usb2_reg_bits = {
  65         .hostmode = 11,
  66         .slave_endianness = 9,
  67         .host_endianness = 10,
  68         .have_ana_cfg = true,
  69 };
  70
  71 static const struct of_device_id ltq_rcu_usb2_phy_of_match[] = {
  72         {
  73                 .compatible = "lantiq,ase-usb2-phy",
  74                 .data = &xway_rcu_usb2_reg_bits,
  75         },
  76         {
  77                 .compatible = "lantiq,danube-usb2-phy",
  78                 .data = &xway_rcu_usb2_reg_bits,
  79         },
  80         {
  81                 .compatible = "lantiq,xrx100-usb2-phy",
  82                 .data = &xrx100_rcu_usb2_reg_bits,
  83         },
  84         {
  85                 .compatible = "lantiq,xrx200-usb2-phy",
  86                 .data = &xrx200_rcu_usb2_reg_bits,
  87         },
  88         {
  89                 .compatible = "lantiq,xrx300-usb2-phy",
  90                 .data = &xrx200_rcu_usb2_reg_bits,
  91         },
  92         { },
  93 };
  94 MODULE_DEVICE_TABLE(of, ltq_rcu_usb2_phy_of_match);
  95
  96 static int ltq_rcu_usb2_phy_init(struct phy *phy)
  97 {
  98         struct ltq_rcu_usb2_priv *priv = phy_get_drvdata(phy);
  99
 100         if (priv->reg_bits->have_ana_cfg) {
 101                 regmap_update_bits(priv->regmap, priv->ana_cfg1_reg_offset,
 102                         RCU_CFG1_TX_PEE, RCU_CFG1_TX_PEE);
 103                 regmap_update_bits(priv->regmap, priv->ana_cfg1_reg_offset,
 104                         RCU_CFG1_DIS_THR_MASK, 7 << RCU_CFG1_DIS_THR_SHIFT);
 105         }
 106
 107         /* Configure core to host mode */
 108         regmap_update_bits(priv->regmap, priv->phy_reg_offset,
 109                            BIT(priv->reg_bits->hostmode), 0);
 110
 111         /* Select DMA endianness (Host-endian: big-endian) */
 112         regmap_update_bits(priv->regmap, priv->phy_reg_offset,
 113                 BIT(priv->reg_bits->slave_endianness), 0);
 114         regmap_update_bits(priv->regmap, priv->phy_reg_offset,
 115                 BIT(priv->reg_bits->host_endianness),
 116                 BIT(priv->reg_bits->host_endianness));
 117
 118         return 0;
 119 }
 120
 121 static int ltq_rcu_usb2_phy_power_on(struct phy *phy)
 122 {
 123         struct ltq_rcu_usb2_priv *priv = phy_get_drvdata(phy);
 124         struct device *dev = priv->dev;
 125         int ret;
 126
 127         reset_control_deassert(priv->phy_reset);
 128
 129         ret = clk_prepare_enable(priv->phy_gate_clk);
 130         if (ret)
 131                 dev_err(dev, "failed to enable PHY gate\n");
 132
 133         return ret;
 134 }
 135
 136 static int ltq_rcu_usb2_phy_power_off(struct phy *phy)
 137 {
 138         struct ltq_rcu_usb2_priv *priv = phy_get_drvdata(phy);
 139
 140         reset_control_assert(priv->phy_reset);
 141
 142         clk_disable_unprepare(priv->phy_gate_clk);
 143
 144         return 0;
 145 }
 146
 147 static struct phy_ops ltq_rcu_usb2_phy_ops = {
 148         .init           = ltq_rcu_usb2_phy_init,
 149         .power_on       = ltq_rcu_usb2_phy_power_on,
 150         .power_off      = ltq_rcu_usb2_phy_power_off,
 151         .owner          = THIS_MODULE,
 152 };
 153
 154 static int ltq_rcu_usb2_of_parse(struct ltq_rcu_usb2_priv *priv,
 155                                  struct platform_device *pdev)
 156 {
 157         struct device *dev = priv->dev;
 158         const __be32 *offset;
 159         int ret;
 160
 161         priv->reg_bits = of_device_get_match_data(dev);
 162
 163         priv->regmap = syscon_node_to_regmap(dev->of_node->parent);
 164         if (IS_ERR(priv->regmap)) {
 165                 dev_err(dev, "Failed to lookup RCU regmap\n");
 166                 return PTR_ERR(priv->regmap);
 167         }
 168
 169         offset = of_get_address(dev->of_node, 0, NULL, NULL);
 170         if (!offset) {
 171                 dev_err(dev, "Failed to get RCU PHY reg offset\n");
 172                 return -ENOENT;
 173         }
 174         priv->phy_reg_offset = __be32_to_cpu(*offset);
 175
 176         if (priv->reg_bits->have_ana_cfg) {
 177                 offset = of_get_address(dev->of_node, 1, NULL, NULL);
 178                 if (!offset) {
 179                         dev_err(dev, "Failed to get RCU ANA CFG1 reg offset\n");
 180                         return -ENOENT;
 181                 }
 182                 priv->ana_cfg1_reg_offset = __be32_to_cpu(*offset);
 183         }
 184
 185         priv->phy_gate_clk = devm_clk_get(dev, "phy");
 186         if (IS_ERR(priv->phy_gate_clk)) {
 187                 dev_err(dev, "Unable to get USB phy gate clk\n");
 188                 return PTR_ERR(priv->phy_gate_clk);
 189         }
 190
 191         priv->ctrl_reset = devm_reset_control_get_shared(dev, "ctrl");
 192         if (IS_ERR(priv->ctrl_reset)) {
 193                 if (PTR_ERR(priv->ctrl_reset) != -EPROBE_DEFER)
 194                         dev_err(dev, "failed to get 'ctrl' reset\n");
 195                 return PTR_ERR(priv->ctrl_reset);
 196         }
 197
 198         priv->phy_reset = devm_reset_control_get_optional(dev, "phy");
 199         if (IS_ERR(priv->phy_reset))
 200                 return PTR_ERR(priv->phy_reset);
 201
 202         return 0;
 203 }
 204
 205 static int ltq_rcu_usb2_phy_probe(struct platform_device *pdev)
 206 {
 207         struct device *dev = &pdev->dev;
 208         struct ltq_rcu_usb2_priv *priv;
 209         struct phy_provider *provider;
 210         int ret;
 211
 212         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 213         if (!priv)
 214                 return -ENOMEM;
 215
 216         priv->dev = dev;
 217
 218         ret = ltq_rcu_usb2_of_parse(priv, pdev);
 219         if (ret)
 220                 return ret;
 221
 222         /* Reset USB core through reset controller */
 223         reset_control_deassert(priv->ctrl_reset);
 224
 225         reset_control_assert(priv->phy_reset);
 226
 227         priv->phy = devm_phy_create(dev, dev->of_node, &ltq_rcu_usb2_phy_ops);
 228         if (IS_ERR(priv->phy)) {
 229                 dev_err(dev, "failed to create PHY\n");
 230                 return PTR_ERR(priv->phy);
 231         }
 232
 233         phy_set_drvdata(priv->phy, priv);
 234
 235         provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
 236         if (IS_ERR(provider))
 237                 return PTR_ERR(provider);
 238
 239         dev_set_drvdata(priv->dev, priv);
 240         return 0;
 241 }
 242
 243 static struct platform_driver ltq_rcu_usb2_phy_driver = {
 244         .probe  = ltq_rcu_usb2_phy_probe,
 245         .driver = {
 246                 .name   = "lantiq-rcu-usb2-phy",
 247                 .of_match_table = ltq_rcu_usb2_phy_of_match,
 248         }
 249 };
 250 module_platform_driver(ltq_rcu_usb2_phy_driver);
 251
 252 MODULE_AUTHOR("Martin Blumenstingl <martin.blumenstingl@googlemail.com>");
 253 MODULE_DESCRIPTION("Lantiq XWAY USB2 PHY driver");
 254 MODULE_LICENSE("GPL v2");