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

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