drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*******************************************************************************
   3   STMMAC Ethernet Driver -- MDIO bus implementation
   4   Provides Bus interface for MII registers
   5
   6   Copyright (C) 2007-2009  STMicroelectronics Ltd
   7
   8
   9   Author: Carl Shaw <carl.shaw@st.com>
  10   Maintainer: Giuseppe Cavallaro <peppe.cavallaro@st.com>
  11 *******************************************************************************/
  12
  13 #include <linux/gpio/consumer.h>
  14 #include <linux/io.h>
  15 #include <linux/iopoll.h>
  16 #include <linux/mii.h>
  17 #include <linux/of_mdio.h>
  18 #include <linux/phy.h>
  19 #include <linux/property.h>
  20 #include <linux/slab.h>
  21
  22 #include "dwxgmac2.h"
  23 #include "stmmac.h"
  24
  25 #define MII_BUSY 0x00000001
  26 #define MII_WRITE 0x00000002
  27 #define MII_DATA_MASK GENMASK(15, 0)
  28
  29 /* GMAC4 defines */
  30 #define MII_GMAC4_GOC_SHIFT             2
  31 #define MII_GMAC4_REG_ADDR_SHIFT        16
  32 #define MII_GMAC4_WRITE                 (1 << MII_GMAC4_GOC_SHIFT)
  33 #define MII_GMAC4_READ                  (3 << MII_GMAC4_GOC_SHIFT)
  34 #define MII_GMAC4_C45E                  BIT(1)
  35
  36 /* XGMAC defines */
  37 #define MII_XGMAC_SADDR                 BIT(18)
  38 #define MII_XGMAC_CMD_SHIFT             16
  39 #define MII_XGMAC_WRITE                 (1 << MII_XGMAC_CMD_SHIFT)
  40 #define MII_XGMAC_READ                  (3 << MII_XGMAC_CMD_SHIFT)
  41 #define MII_XGMAC_BUSY                  BIT(22)
  42 #define MII_XGMAC_MAX_C22ADDR           3
  43 #define MII_XGMAC_C22P_MASK             GENMASK(MII_XGMAC_MAX_C22ADDR, 0)
  44 #define MII_XGMAC_PA_SHIFT              16
  45 #define MII_XGMAC_DA_SHIFT              21
  46
  47 static int stmmac_xgmac2_c45_format(struct stmmac_priv *priv, int phyaddr,
  48                                     int phyreg, u32 *hw_addr)
  49 {
  50         u32 tmp;
  51
  52         /* Set port as Clause 45 */
  53         tmp = readl(priv->ioaddr + XGMAC_MDIO_C22P);
  54         tmp &= ~BIT(phyaddr);
  55         writel(tmp, priv->ioaddr + XGMAC_MDIO_C22P);
  56
  57         *hw_addr = (phyaddr << MII_XGMAC_PA_SHIFT) | (phyreg & 0xffff);
  58         *hw_addr |= (phyreg >> MII_DEVADDR_C45_SHIFT) << MII_XGMAC_DA_SHIFT;
  59         return 0;
  60 }
  61
  62 static int stmmac_xgmac2_c22_format(struct stmmac_priv *priv, int phyaddr,
  63                                     int phyreg, u32 *hw_addr)
  64 {
  65         u32 tmp;
  66
  67         /* HW does not support C22 addr >= 4 */
  68         if (phyaddr > MII_XGMAC_MAX_C22ADDR)
  69                 return -ENODEV;
  70
  71         /* Set port as Clause 22 */
  72         tmp = readl(priv->ioaddr + XGMAC_MDIO_C22P);
  73         tmp &= ~MII_XGMAC_C22P_MASK;
  74         tmp |= BIT(phyaddr);
  75         writel(tmp, priv->ioaddr + XGMAC_MDIO_C22P);
  76
  77         *hw_addr = (phyaddr << MII_XGMAC_PA_SHIFT) | (phyreg & 0x1f);
  78         return 0;
  79 }
  80
  81 static int stmmac_xgmac2_mdio_read(struct mii_bus *bus, int phyaddr, int phyreg)
  82 {
  83         struct net_device *ndev = bus->priv;
  84         struct stmmac_priv *priv = netdev_priv(ndev);
  85         unsigned int mii_address = priv->hw->mii.addr;
  86         unsigned int mii_data = priv->hw->mii.data;
  87         u32 tmp, addr, value = MII_XGMAC_BUSY;
  88         int ret;
  89
  90         /* Wait until any existing MII operation is complete */
  91         if (readl_poll_timeout(priv->ioaddr + mii_data, tmp,
  92                                !(tmp & MII_XGMAC_BUSY), 100, 10000))
  93                 return -EBUSY;
  94
  95         if (phyreg & MII_ADDR_C45) {
  96                 phyreg &= ~MII_ADDR_C45;
  97
  98                 ret = stmmac_xgmac2_c45_format(priv, phyaddr, phyreg, &addr);
  99                 if (ret)
 100                         return ret;
 101         } else {
 102                 ret = stmmac_xgmac2_c22_format(priv, phyaddr, phyreg, &addr);
 103                 if (ret)
 104                         return ret;
 105
 106                 value |= MII_XGMAC_SADDR;
 107         }
 108
 109         value |= (priv->clk_csr << priv->hw->mii.clk_csr_shift)
 110                 & priv->hw->mii.clk_csr_mask;
 111         value |= MII_XGMAC_READ;
 112
 113         /* Wait until any existing MII operation is complete */
 114         if (readl_poll_timeout(priv->ioaddr + mii_data, tmp,
 115                                !(tmp & MII_XGMAC_BUSY), 100, 10000))
 116                 return -EBUSY;
 117
 118         /* Set the MII address register to read */
 119         writel(addr, priv->ioaddr + mii_address);
 120         writel(value, priv->ioaddr + mii_data);
 121
 122         /* Wait until any existing MII operation is complete */
 123         if (readl_poll_timeout(priv->ioaddr + mii_data, tmp,
 124                                !(tmp & MII_XGMAC_BUSY), 100, 10000))
 125                 return -EBUSY;
 126
 127         /* Read the data from the MII data register */
 128         return readl(priv->ioaddr + mii_data) & GENMASK(15, 0);
 129 }
 130
 131 static int stmmac_xgmac2_mdio_write(struct mii_bus *bus, int phyaddr,
 132                                     int phyreg, u16 phydata)
 133 {
 134         struct net_device *ndev = bus->priv;
 135         struct stmmac_priv *priv = netdev_priv(ndev);
 136         unsigned int mii_address = priv->hw->mii.addr;
 137         unsigned int mii_data = priv->hw->mii.data;
 138         u32 addr, tmp, value = MII_XGMAC_BUSY;
 139         int ret;
 140
 141         /* Wait until any existing MII operation is complete */
 142         if (readl_poll_timeout(priv->ioaddr + mii_data, tmp,
 143                                !(tmp & MII_XGMAC_BUSY), 100, 10000))
 144                 return -EBUSY;
 145
 146         if (phyreg & MII_ADDR_C45) {
 147                 phyreg &= ~MII_ADDR_C45;
 148
 149                 ret = stmmac_xgmac2_c45_format(priv, phyaddr, phyreg, &addr);
 150                 if (ret)
 151                         return ret;
 152         } else {
 153                 ret = stmmac_xgmac2_c22_format(priv, phyaddr, phyreg, &addr);
 154                 if (ret)
 155                         return ret;
 156
 157                 value |= MII_XGMAC_SADDR;
 158         }
 159
 160         value |= (priv->clk_csr << priv->hw->mii.clk_csr_shift)
 161                 & priv->hw->mii.clk_csr_mask;
 162         value |= phydata;
 163         value |= MII_XGMAC_WRITE;
 164
 165         /* Wait until any existing MII operation is complete */
 166         if (readl_poll_timeout(priv->ioaddr + mii_data, tmp,
 167                                !(tmp & MII_XGMAC_BUSY), 100, 10000))
 168                 return -EBUSY;
 169
 170         /* Set the MII address register to write */
 171         writel(addr, priv->ioaddr + mii_address);
 172         writel(value, priv->ioaddr + mii_data);
 173
 174         /* Wait until any existing MII operation is complete */
 175         return readl_poll_timeout(priv->ioaddr + mii_data, tmp,
 176                                   !(tmp & MII_XGMAC_BUSY), 100, 10000);
 177 }
 178
 179 /**
 180  * stmmac_mdio_read
 181  * @bus: points to the mii_bus structure
 182  * @phyaddr: MII addr
 183  * @phyreg: MII reg
 184  * Description: it reads data from the MII register from within the phy device.
 185  * For the 7111 GMAC, we must set the bit 0 in the MII address register while
 186  * accessing the PHY registers.
 187  * Fortunately, it seems this has no drawback for the 7109 MAC.
 188  */
 189 static int stmmac_mdio_read(struct mii_bus *bus, int phyaddr, int phyreg)
 190 {
 191         struct net_device *ndev = bus->priv;
 192         struct stmmac_priv *priv = netdev_priv(ndev);
 193         unsigned int mii_address = priv->hw->mii.addr;
 194         unsigned int mii_data = priv->hw->mii.data;
 195         u32 value = MII_BUSY;
 196         int data = 0;
 197         u32 v;
 198
 199         value |= (phyaddr << priv->hw->mii.addr_shift)
 200                 & priv->hw->mii.addr_mask;
 201         value |= (phyreg << priv->hw->mii.reg_shift) & priv->hw->mii.reg_mask;
 202         value |= (priv->clk_csr << priv->hw->mii.clk_csr_shift)
 203                 & priv->hw->mii.clk_csr_mask;
 204         if (priv->plat->has_gmac4) {
 205                 value |= MII_GMAC4_READ;
 206                 if (phyreg & MII_ADDR_C45) {
 207                         value |= MII_GMAC4_C45E;
 208                         value &= ~priv->hw->mii.reg_mask;
 209                         value |= ((phyreg >> MII_DEVADDR_C45_SHIFT) <<
 210                                priv->hw->mii.reg_shift) &
 211                                priv->hw->mii.reg_mask;
 212
 213                         data |= (phyreg & MII_REGADDR_C45_MASK) <<
 214                                 MII_GMAC4_REG_ADDR_SHIFT;
 215                 }
 216         }
 217
 218         if (readl_poll_timeout(priv->ioaddr + mii_address, v, !(v & MII_BUSY),
 219                                100, 10000))
 220                 return -EBUSY;
 221
 222         writel(data, priv->ioaddr + mii_data);
 223         writel(value, priv->ioaddr + mii_address);
 224
 225         if (readl_poll_timeout(priv->ioaddr + mii_address, v, !(v & MII_BUSY),
 226                                100, 10000))
 227                 return -EBUSY;
 228
 229         /* Read the data from the MII data register */
 230         data = (int)readl(priv->ioaddr + mii_data) & MII_DATA_MASK;
 231
 232         return data;
 233 }
 234
 235 /**
 236  * stmmac_mdio_write
 237  * @bus: points to the mii_bus structure
 238  * @phyaddr: MII addr
 239  * @phyreg: MII reg
 240  * @phydata: phy data
 241  * Description: it writes the data into the MII register from within the device.
 242  */
 243 static int stmmac_mdio_write(struct mii_bus *bus, int phyaddr, int phyreg,
 244                              u16 phydata)
 245 {
 246         struct net_device *ndev = bus->priv;
 247         struct stmmac_priv *priv = netdev_priv(ndev);
 248         unsigned int mii_address = priv->hw->mii.addr;
 249         unsigned int mii_data = priv->hw->mii.data;
 250         u32 value = MII_BUSY;
 251         int data = phydata;
 252         u32 v;
 253
 254         value |= (phyaddr << priv->hw->mii.addr_shift)
 255                 & priv->hw->mii.addr_mask;
 256         value |= (phyreg << priv->hw->mii.reg_shift) & priv->hw->mii.reg_mask;
 257
 258         value |= (priv->clk_csr << priv->hw->mii.clk_csr_shift)
 259                 & priv->hw->mii.clk_csr_mask;
 260         if (priv->plat->has_gmac4) {
 261                 value |= MII_GMAC4_WRITE;
 262                 if (phyreg & MII_ADDR_C45) {
 263                         value |= MII_GMAC4_C45E;
 264                         value &= ~priv->hw->mii.reg_mask;
 265                         value |= ((phyreg >> MII_DEVADDR_C45_SHIFT) <<
 266                                priv->hw->mii.reg_shift) &
 267                                priv->hw->mii.reg_mask;
 268
 269                         data |= (phyreg & MII_REGADDR_C45_MASK) <<
 270                                 MII_GMAC4_REG_ADDR_SHIFT;
 271                 }
 272         } else {
 273                 value |= MII_WRITE;
 274         }
 275
 276         /* Wait until any existing MII operation is complete */
 277         if (readl_poll_timeout(priv->ioaddr + mii_address, v, !(v & MII_BUSY),
 278                                100, 10000))
 279                 return -EBUSY;
 280
 281         /* Set the MII address register to write */
 282         writel(data, priv->ioaddr + mii_data);
 283         writel(value, priv->ioaddr + mii_address);
 284
 285         /* Wait until any existing MII operation is complete */
 286         return readl_poll_timeout(priv->ioaddr + mii_address, v, !(v & MII_BUSY),
 287                                   100, 10000);
 288 }
 289
 290 /**
 291  * stmmac_mdio_reset
 292  * @bus: points to the mii_bus structure
 293  * Description: reset the MII bus
 294  */
 295 int stmmac_mdio_reset(struct mii_bus *bus)
 296 {
 297 #if IS_ENABLED(CONFIG_STMMAC_PLATFORM)
 298         struct net_device *ndev = bus->priv;
 299         struct stmmac_priv *priv = netdev_priv(ndev);
 300         unsigned int mii_address = priv->hw->mii.addr;
 301
 302 #ifdef CONFIG_OF
 303         if (priv->device->of_node) {
 304                 struct gpio_desc *reset_gpio;
 305                 u32 delays[3] = { 0, 0, 0 };
 306
 307                 reset_gpio = devm_gpiod_get_optional(priv->device,
 308                                                      "snps,reset",
 309                                                      GPIOD_OUT_LOW);
 310                 if (IS_ERR(reset_gpio))
 311                         return PTR_ERR(reset_gpio);
 312
 313                 device_property_read_u32_array(priv->device,
 314                                                "snps,reset-delays-us",
 315                                                delays, ARRAY_SIZE(delays));
 316
 317                 if (delays[0])
 318                         msleep(DIV_ROUND_UP(delays[0], 1000));
 319
 320                 gpiod_set_value_cansleep(reset_gpio, 1);
 321                 if (delays[1])
 322                         msleep(DIV_ROUND_UP(delays[1], 1000));
 323
 324                 gpiod_set_value_cansleep(reset_gpio, 0);
 325                 if (delays[2])
 326                         msleep(DIV_ROUND_UP(delays[2], 1000));
 327         }
 328 #endif
 329
 330         /* This is a workaround for problems with the STE101P PHY.
 331          * It doesn't complete its reset until at least one clock cycle
 332          * on MDC, so perform a dummy mdio read. To be updated for GMAC4
 333          * if needed.
 334          */
 335         if (!priv->plat->has_gmac4)
 336                 writel(0, priv->ioaddr + mii_address);
 337 #endif
 338         return 0;
 339 }
 340
 341 /**
 342  * stmmac_mdio_register
 343  * @ndev: net device structure
 344  * Description: it registers the MII bus
 345  */
 346 int stmmac_mdio_register(struct net_device *ndev)
 347 {
 348         int err = 0;
 349         struct mii_bus *new_bus;
 350         struct stmmac_priv *priv = netdev_priv(ndev);
 351         struct stmmac_mdio_bus_data *mdio_bus_data = priv->plat->mdio_bus_data;
 352         struct device_node *mdio_node = priv->plat->mdio_node;
 353         struct device *dev = ndev->dev.parent;
 354         int addr, found, max_addr;
 355
 356         if (!mdio_bus_data)
 357                 return 0;
 358
 359         new_bus = mdiobus_alloc();
 360         if (!new_bus)
 361                 return -ENOMEM;
 362
 363         if (mdio_bus_data->irqs)
 364                 memcpy(new_bus->irq, mdio_bus_data->irqs, sizeof(new_bus->irq));
 365
 366         new_bus->name = "stmmac";
 367
 368         if (priv->plat->has_xgmac) {
 369                 new_bus->read = &stmmac_xgmac2_mdio_read;
 370                 new_bus->write = &stmmac_xgmac2_mdio_write;
 371
 372                 /* Right now only C22 phys are supported */
 373                 max_addr = MII_XGMAC_MAX_C22ADDR + 1;
 374
 375                 /* Check if DT specified an unsupported phy addr */
 376                 if (priv->plat->phy_addr > MII_XGMAC_MAX_C22ADDR)
 377                         dev_err(dev, "Unsupported phy_addr (max=%d)\n",
 378                                         MII_XGMAC_MAX_C22ADDR);
 379         } else {
 380                 new_bus->read = &stmmac_mdio_read;
 381                 new_bus->write = &stmmac_mdio_write;
 382                 max_addr = PHY_MAX_ADDR;
 383         }
 384
 385         if (mdio_bus_data->needs_reset)
 386                 new_bus->reset = &stmmac_mdio_reset;
 387
 388         snprintf(new_bus->id, MII_BUS_ID_SIZE, "%s-%x",
 389                  new_bus->name, priv->plat->bus_id);
 390         new_bus->priv = ndev;
 391         new_bus->phy_mask = mdio_bus_data->phy_mask;
 392         new_bus->parent = priv->device;
 393
 394         err = of_mdiobus_register(new_bus, mdio_node);
 395         if (err != 0) {
 396                 dev_err(dev, "Cannot register the MDIO bus\n");
 397                 goto bus_register_fail;
 398         }
 399
 400         /* Looks like we need a dummy read for XGMAC only and C45 PHYs */
 401         if (priv->plat->has_xgmac)
 402                 stmmac_xgmac2_mdio_read(new_bus, 0, MII_ADDR_C45);
 403
 404         if (priv->plat->phy_node || mdio_node)
 405                 goto bus_register_done;
 406
 407         found = 0;
 408         for (addr = 0; addr < max_addr; addr++) {
 409                 struct phy_device *phydev = mdiobus_get_phy(new_bus, addr);
 410
 411                 if (!phydev)
 412                         continue;
 413
 414                 /*
 415                  * If an IRQ was provided to be assigned after
 416                  * the bus probe, do it here.
 417                  */
 418                 if (!mdio_bus_data->irqs &&
 419                     (mdio_bus_data->probed_phy_irq > 0)) {
 420                         new_bus->irq[addr] = mdio_bus_data->probed_phy_irq;
 421                         phydev->irq = mdio_bus_data->probed_phy_irq;
 422                 }
 423
 424                 /*
 425                  * If we're going to bind the MAC to this PHY bus,
 426                  * and no PHY number was provided to the MAC,
 427                  * use the one probed here.
 428                  */
 429                 if (priv->plat->phy_addr == -1)
 430                         priv->plat->phy_addr = addr;
 431
 432                 phy_attached_info(phydev);
 433                 found = 1;
 434         }
 435
 436         if (!found && !mdio_node) {
 437                 dev_warn(dev, "No PHY found\n");
 438                 mdiobus_unregister(new_bus);
 439                 mdiobus_free(new_bus);
 440                 return -ENODEV;
 441         }
 442
 443 bus_register_done:
 444         priv->mii = new_bus;
 445
 446         return 0;
 447
 448 bus_register_fail:
 449         mdiobus_free(new_bus);
 450         return err;
 451 }
 452
 453 /**
 454  * stmmac_mdio_unregister
 455  * @ndev: net device structure
 456  * Description: it unregisters the MII bus
 457  */
 458 int stmmac_mdio_unregister(struct net_device *ndev)
 459 {
 460         struct stmmac_priv *priv = netdev_priv(ndev);
 461
 462         if (!priv->mii)
 463                 return 0;
 464
 465         mdiobus_unregister(priv->mii);
 466         priv->mii->priv = NULL;
 467         mdiobus_free(priv->mii);
 468         priv->mii = NULL;
 469
 470         return 0;
 471 }