drivers/phy/intel/phy-intel-keembay-usb.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Intel Keem Bay USB PHY driver
   4  * Copyright (C) 2020 Intel Corporation
   5  */
   6
   7 #include <linux/bitfield.h>
   8 #include <linux/bits.h>
   9 #include <linux/clk.h>
  10 #include <linux/delay.h>
  11 #include <linux/mod_devicetable.h>
  12 #include <linux/module.h>
  13 #include <linux/phy/phy.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/regmap.h>
  16
  17 /* USS (USB Subsystem) clock control registers */
  18 #define USS_CPR_CLK_EN          0x00
  19 #define USS_CPR_CLK_SET         0x04
  20 #define USS_CPR_CLK_CLR         0x08
  21 #define USS_CPR_RST_EN          0x10
  22 #define USS_CPR_RST_SET         0x14
  23 #define USS_CPR_RST_CLR         0x18
  24
  25 /* USS clock/reset bit fields */
  26 #define USS_CPR_PHY_TST         BIT(6)
  27 #define USS_CPR_LOW_JIT         BIT(5)
  28 #define USS_CPR_CORE            BIT(4)
  29 #define USS_CPR_SUSPEND         BIT(3)
  30 #define USS_CPR_ALT_REF         BIT(2)
  31 #define USS_CPR_REF             BIT(1)
  32 #define USS_CPR_SYS             BIT(0)
  33 #define USS_CPR_MASK            GENMASK(6, 0)
  34
  35 /* USS APB slave registers */
  36 #define USS_USB_CTRL_CFG0               0x10
  37 #define  VCC_RESET_N_MASK               BIT(31)
  38
  39 #define USS_USB_PHY_CFG0                0x30
  40 #define  POR_MASK                       BIT(15)
  41 #define  PHY_RESET_MASK                 BIT(14)
  42 #define  PHY_REF_USE_PAD_MASK           BIT(5)
  43
  44 #define USS_USB_PHY_CFG6                0x64
  45 #define  PHY0_SRAM_EXT_LD_DONE_MASK     BIT(23)
  46
  47 #define USS_USB_PARALLEL_IF_CTRL        0xa0
  48 #define  USB_PHY_CR_PARA_SEL_MASK       BIT(2)
  49
  50 #define USS_USB_TSET_SIGNALS_AND_GLOB   0xac
  51 #define  USB_PHY_CR_PARA_CLK_EN_MASK    BIT(7)
  52
  53 #define USS_USB_STATUS_REG              0xb8
  54 #define  PHY0_SRAM_INIT_DONE_MASK       BIT(3)
  55
  56 #define USS_USB_TIEOFFS_CONSTANTS_REG1  0xc0
  57 #define  IDDQ_ENABLE_MASK               BIT(10)
  58
  59 struct keembay_usb_phy {
  60         struct device *dev;
  61         struct regmap *regmap_cpr;
  62         struct regmap *regmap_slv;
  63 };
  64
  65 static const struct regmap_config keembay_regmap_config = {
  66         .reg_bits = 32,
  67         .val_bits = 32,
  68         .reg_stride = 4,
  69         .max_register = USS_USB_TIEOFFS_CONSTANTS_REG1,
  70 };
  71
  72 static int keembay_usb_clocks_on(struct keembay_usb_phy *priv)
  73 {
  74         int ret;
  75
  76         ret = regmap_update_bits(priv->regmap_cpr, USS_CPR_CLK_SET,
  77                                  USS_CPR_MASK, USS_CPR_MASK);
  78         if (ret) {
  79                 dev_err(priv->dev, "error clock set: %d\n", ret);
  80                 return ret;
  81         }
  82
  83         ret = regmap_update_bits(priv->regmap_cpr, USS_CPR_RST_SET,
  84                                  USS_CPR_MASK, USS_CPR_MASK);
  85         if (ret) {
  86                 dev_err(priv->dev, "error reset set: %d\n", ret);
  87                 return ret;
  88         }
  89
  90         ret = regmap_update_bits(priv->regmap_slv,
  91                                  USS_USB_TIEOFFS_CONSTANTS_REG1,
  92                                  IDDQ_ENABLE_MASK,
  93                                  FIELD_PREP(IDDQ_ENABLE_MASK, 0));
  94         if (ret) {
  95                 dev_err(priv->dev, "error iddq disable: %d\n", ret);
  96                 return ret;
  97         }
  98
  99         /* Wait 30us to ensure all analog blocks are powered up. */
 100         usleep_range(30, 60);
 101
 102         ret = regmap_update_bits(priv->regmap_slv, USS_USB_PHY_CFG0,
 103                                  PHY_REF_USE_PAD_MASK,
 104                                  FIELD_PREP(PHY_REF_USE_PAD_MASK, 1));
 105         if (ret)
 106                 dev_err(priv->dev, "error ref clock select: %d\n", ret);
 107
 108         return ret;
 109 }
 110
 111 static int keembay_usb_core_off(struct keembay_usb_phy *priv)
 112 {
 113         int ret;
 114
 115         ret = regmap_update_bits(priv->regmap_slv, USS_USB_CTRL_CFG0,
 116                                  VCC_RESET_N_MASK,
 117                                  FIELD_PREP(VCC_RESET_N_MASK, 0));
 118         if (ret)
 119                 dev_err(priv->dev, "error core reset: %d\n", ret);
 120
 121         return ret;
 122 }
 123
 124 static int keembay_usb_core_on(struct keembay_usb_phy *priv)
 125 {
 126         int ret;
 127
 128         ret = regmap_update_bits(priv->regmap_slv, USS_USB_CTRL_CFG0,
 129                                  VCC_RESET_N_MASK,
 130                                  FIELD_PREP(VCC_RESET_N_MASK, 1));
 131         if (ret)
 132                 dev_err(priv->dev, "error core on: %d\n", ret);
 133
 134         return ret;
 135 }
 136
 137 static int keembay_usb_phys_on(struct keembay_usb_phy *priv)
 138 {
 139         int ret;
 140
 141         ret = regmap_update_bits(priv->regmap_slv, USS_USB_PHY_CFG0,
 142                                  POR_MASK | PHY_RESET_MASK,
 143                                  FIELD_PREP(POR_MASK | PHY_RESET_MASK, 0));
 144         if (ret)
 145                 dev_err(priv->dev, "error phys on: %d\n", ret);
 146
 147         return ret;
 148 }
 149
 150 static int keembay_usb_phy_init(struct phy *phy)
 151 {
 152         struct keembay_usb_phy *priv = phy_get_drvdata(phy);
 153         u32 val;
 154         int ret;
 155
 156         ret = keembay_usb_core_off(priv);
 157         if (ret)
 158                 return ret;
 159
 160         /*
 161          * According to Keem Bay datasheet, wait minimum 20us after clock
 162          * enable before bringing PHYs out of reset.
 163          */
 164         usleep_range(20, 40);
 165
 166         ret = keembay_usb_phys_on(priv);
 167         if (ret)
 168                 return ret;
 169
 170         ret = regmap_update_bits(priv->regmap_slv,
 171                                  USS_USB_TSET_SIGNALS_AND_GLOB,
 172                                  USB_PHY_CR_PARA_CLK_EN_MASK,
 173                                  FIELD_PREP(USB_PHY_CR_PARA_CLK_EN_MASK, 0));
 174         if (ret) {
 175                 dev_err(priv->dev, "error cr clock disable: %d\n", ret);
 176                 return ret;
 177         }
 178
 179         /*
 180          * According to Keem Bay datasheet, wait 2us after disabling the
 181          * clock into the USB 3.x parallel interface.
 182          */
 183         udelay(2);
 184
 185         ret = regmap_update_bits(priv->regmap_slv,
 186                                  USS_USB_PARALLEL_IF_CTRL,
 187                                  USB_PHY_CR_PARA_SEL_MASK,
 188                                  FIELD_PREP(USB_PHY_CR_PARA_SEL_MASK, 1));
 189         if (ret) {
 190                 dev_err(priv->dev, "error cr select: %d\n", ret);
 191                 return ret;
 192         }
 193
 194         ret = regmap_update_bits(priv->regmap_slv,
 195                                  USS_USB_TSET_SIGNALS_AND_GLOB,
 196                                  USB_PHY_CR_PARA_CLK_EN_MASK,
 197                                  FIELD_PREP(USB_PHY_CR_PARA_CLK_EN_MASK, 1));
 198         if (ret) {
 199                 dev_err(priv->dev, "error cr clock enable: %d\n", ret);
 200                 return ret;
 201         }
 202
 203         ret = regmap_read_poll_timeout(priv->regmap_slv, USS_USB_STATUS_REG,
 204                                        val, val & PHY0_SRAM_INIT_DONE_MASK,
 205                                        USEC_PER_MSEC, 10 * USEC_PER_MSEC);
 206         if (ret) {
 207                 dev_err(priv->dev, "SRAM init not done: %d\n", ret);
 208                 return ret;
 209         }
 210
 211         ret = regmap_update_bits(priv->regmap_slv, USS_USB_PHY_CFG6,
 212                                  PHY0_SRAM_EXT_LD_DONE_MASK,
 213                                  FIELD_PREP(PHY0_SRAM_EXT_LD_DONE_MASK, 1));
 214         if (ret) {
 215                 dev_err(priv->dev, "error SRAM init done set: %d\n", ret);
 216                 return ret;
 217         }
 218
 219         /*
 220          * According to Keem Bay datasheet, wait 20us after setting the
 221          * SRAM load done bit, before releasing the controller reset.
 222          */
 223         usleep_range(20, 40);
 224
 225         return keembay_usb_core_on(priv);
 226 }
 227
 228 static const struct phy_ops ops = {
 229         .init           = keembay_usb_phy_init,
 230         .owner          = THIS_MODULE,
 231 };
 232
 233 static int keembay_usb_phy_probe(struct platform_device *pdev)
 234 {
 235         struct device *dev = &pdev->dev;
 236         struct keembay_usb_phy *priv;
 237         struct phy *generic_phy;
 238         struct phy_provider *phy_provider;
 239         void __iomem *base;
 240         int ret;
 241
 242         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 243         if (!priv)
 244                 return -ENOMEM;
 245
 246         base = devm_platform_ioremap_resource_byname(pdev, "cpr-apb-base");
 247         if (IS_ERR(base))
 248                 return PTR_ERR(base);
 249
 250         priv->regmap_cpr = devm_regmap_init_mmio(dev, base,
 251                                                  &keembay_regmap_config);
 252         if (IS_ERR(priv->regmap_cpr))
 253                 return PTR_ERR(priv->regmap_cpr);
 254
 255         base = devm_platform_ioremap_resource_byname(pdev, "slv-apb-base");
 256         if (IS_ERR(base))
 257                 return PTR_ERR(base);
 258
 259         priv->regmap_slv = devm_regmap_init_mmio(dev, base,
 260                                                  &keembay_regmap_config);
 261         if (IS_ERR(priv->regmap_slv))
 262                 return PTR_ERR(priv->regmap_slv);
 263
 264         generic_phy = devm_phy_create(dev, dev->of_node, &ops);
 265         if (IS_ERR(generic_phy))
 266                 return dev_err_probe(dev, PTR_ERR(generic_phy),
 267                                      "failed to create PHY\n");
 268
 269         phy_set_drvdata(generic_phy, priv);
 270         phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
 271         if (IS_ERR(phy_provider))
 272                 return dev_err_probe(dev, PTR_ERR(phy_provider),
 273                                      "failed to register phy provider\n");
 274
 275         /* Setup USB subsystem clocks */
 276         ret = keembay_usb_clocks_on(priv);
 277         if (ret)
 278                 return ret;
 279
 280         /* and turn on the DWC3 core, prior to DWC3 driver init. */
 281         return keembay_usb_core_on(priv);
 282 }
 283
 284 static const struct of_device_id keembay_usb_phy_dt_ids[] = {
 285         { .compatible = "intel,keembay-usb-phy" },
 286         {}
 287 };
 288 MODULE_DEVICE_TABLE(of, keembay_usb_phy_dt_ids);
 289
 290 static struct platform_driver keembay_usb_phy_driver = {
 291         .probe          = keembay_usb_phy_probe,
 292         .driver         = {
 293                 .name   = "keembay-usb-phy",
 294                 .of_match_table = keembay_usb_phy_dt_ids,
 295         },
 296 };
 297 module_platform_driver(keembay_usb_phy_driver);
 298
 299 MODULE_AUTHOR("Wan Ahmad Zainie <wan.ahmad.zainie.wan.mohamad@intel.com>");
 300 MODULE_DESCRIPTION("Intel Keem Bay USB PHY driver");
 301 MODULE_LICENSE("GPL v2");