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/pm_runtime.h> 19 #include <linux/phy.h> 20 #include <linux/property.h> 21 #include <linux/slab.h> 22 23 #include "dwxgmac2.h" 24 #include "stmmac.h" 25 26 #define MII_BUSY 0x00000001 27 #define MII_WRITE 0x00000002 28 #define MII_DATA_MASK GENMASK(15, 0) 29 30 /* GMAC4 defines */ 31 #define MII_GMAC4_GOC_SHIFT 2 32 #define MII_GMAC4_REG_ADDR_SHIFT 16 33 #define MII_GMAC4_WRITE (1 << MII_GMAC4_GOC_SHIFT) 34 #define MII_GMAC4_READ (3 << MII_GMAC4_GOC_SHIFT) 35 #define MII_GMAC4_C45E BIT(1) 36 37 /* XGMAC defines */ 38 #define MII_XGMAC_SADDR BIT(18) 39 #define MII_XGMAC_CMD_SHIFT 16 40 #define MII_XGMAC_WRITE (1 << MII_XGMAC_CMD_SHIFT) 41 #define MII_XGMAC_READ (3 << MII_XGMAC_CMD_SHIFT) 42 #define MII_XGMAC_BUSY BIT(22) 43 #define MII_XGMAC_MAX_C22ADDR 3 44 #define MII_XGMAC_C22P_MASK GENMASK(MII_XGMAC_MAX_C22ADDR, 0) 45 #define MII_XGMAC_PA_SHIFT 16 46 #define MII_XGMAC_DA_SHIFT 21 47 48 static void stmmac_xgmac2_c45_format(struct stmmac_priv *priv, int phyaddr, 49 int devad, int phyreg, u32 *hw_addr) 50 { 51 u32 tmp; 52 53 /* Set port as Clause 45 */ 54 tmp = readl(priv->ioaddr + XGMAC_MDIO_C22P); 55 tmp &= ~BIT(phyaddr); 56 writel(tmp, priv->ioaddr + XGMAC_MDIO_C22P); 57 58 *hw_addr = (phyaddr << MII_XGMAC_PA_SHIFT) | (phyreg & 0xffff); 59 *hw_addr |= devad << MII_XGMAC_DA_SHIFT; 60 } 61 62 static void stmmac_xgmac2_c22_format(struct stmmac_priv *priv, int phyaddr, 63 int phyreg, u32 *hw_addr) 64 { 65 u32 tmp; 66 67 /* Set port as Clause 22 */ 68 tmp = readl(priv->ioaddr + XGMAC_MDIO_C22P); 69 tmp &= ~MII_XGMAC_C22P_MASK; 70 tmp |= BIT(phyaddr); 71 writel(tmp, priv->ioaddr + XGMAC_MDIO_C22P); 72 73 *hw_addr = (phyaddr << MII_XGMAC_PA_SHIFT) | (phyreg & 0x1f); 74 } 75 76 static int stmmac_xgmac2_mdio_read(struct stmmac_priv *priv, u32 addr, 77 u32 value) 78 { 79 unsigned int mii_address = priv->hw->mii.addr; 80 unsigned int mii_data = priv->hw->mii.data; 81 u32 tmp; 82 int ret; 83 84 ret = pm_runtime_resume_and_get(priv->device); 85 if (ret < 0) 86 return ret; 87 88 /* Wait until any existing MII operation is complete */ 89 if (readl_poll_timeout(priv->ioaddr + mii_data, tmp, 90 !(tmp & MII_XGMAC_BUSY), 100, 10000)) { 91 ret = -EBUSY; 92 goto err_disable_clks; 93 } 94 95 value |= (priv->clk_csr << priv->hw->mii.clk_csr_shift) 96 & priv->hw->mii.clk_csr_mask; 97 value |= MII_XGMAC_READ; 98 99 /* Wait until any existing MII operation is complete */ 100 if (readl_poll_timeout(priv->ioaddr + mii_data, tmp, 101 !(tmp & MII_XGMAC_BUSY), 100, 10000)) { 102 ret = -EBUSY; 103 goto err_disable_clks; 104 } 105 106 /* Set the MII address register to read */ 107 writel(addr, priv->ioaddr + mii_address); 108 writel(value, priv->ioaddr + mii_data); 109 110 /* Wait until any existing MII operation is complete */ 111 if (readl_poll_timeout(priv->ioaddr + mii_data, tmp, 112 !(tmp & MII_XGMAC_BUSY), 100, 10000)) { 113 ret = -EBUSY; 114 goto err_disable_clks; 115 } 116 117 /* Read the data from the MII data register */ 118 ret = (int)readl(priv->ioaddr + mii_data) & GENMASK(15, 0); 119 120 err_disable_clks: 121 pm_runtime_put(priv->device); 122 123 return ret; 124 } 125 126 static int stmmac_xgmac2_mdio_read_c22(struct mii_bus *bus, int phyaddr, 127 int phyreg) 128 { 129 struct net_device *ndev = bus->priv; 130 struct stmmac_priv *priv; 131 u32 addr; 132 133 priv = netdev_priv(ndev); 134 135 /* HW does not support C22 addr >= 4 */ 136 if (phyaddr > MII_XGMAC_MAX_C22ADDR) 137 return -ENODEV; 138 139 stmmac_xgmac2_c22_format(priv, phyaddr, phyreg, &addr); 140 141 return stmmac_xgmac2_mdio_read(priv, addr, MII_XGMAC_BUSY); 142 } 143 144 static int stmmac_xgmac2_mdio_read_c45(struct mii_bus *bus, int phyaddr, 145 int devad, int phyreg) 146 { 147 struct net_device *ndev = bus->priv; 148 struct stmmac_priv *priv; 149 u32 addr; 150 151 priv = netdev_priv(ndev); 152 153 stmmac_xgmac2_c45_format(priv, phyaddr, devad, phyreg, &addr); 154 155 return stmmac_xgmac2_mdio_read(priv, addr, MII_XGMAC_BUSY); 156 } 157 158 static int stmmac_xgmac2_mdio_write(struct stmmac_priv *priv, u32 addr, 159 u32 value, u16 phydata) 160 { 161 unsigned int mii_address = priv->hw->mii.addr; 162 unsigned int mii_data = priv->hw->mii.data; 163 u32 tmp; 164 int ret; 165 166 ret = pm_runtime_resume_and_get(priv->device); 167 if (ret < 0) 168 return ret; 169 170 /* Wait until any existing MII operation is complete */ 171 if (readl_poll_timeout(priv->ioaddr + mii_data, tmp, 172 !(tmp & MII_XGMAC_BUSY), 100, 10000)) { 173 ret = -EBUSY; 174 goto err_disable_clks; 175 } 176 177 value |= (priv->clk_csr << priv->hw->mii.clk_csr_shift) 178 & priv->hw->mii.clk_csr_mask; 179 value |= phydata; 180 value |= MII_XGMAC_WRITE; 181 182 /* Wait until any existing MII operation is complete */ 183 if (readl_poll_timeout(priv->ioaddr + mii_data, tmp, 184 !(tmp & MII_XGMAC_BUSY), 100, 10000)) { 185 ret = -EBUSY; 186 goto err_disable_clks; 187 } 188 189 /* Set the MII address register to write */ 190 writel(addr, priv->ioaddr + mii_address); 191 writel(value, priv->ioaddr + mii_data); 192 193 /* Wait until any existing MII operation is complete */ 194 ret = readl_poll_timeout(priv->ioaddr + mii_data, tmp, 195 !(tmp & MII_XGMAC_BUSY), 100, 10000); 196 197 err_disable_clks: 198 pm_runtime_put(priv->device); 199 200 return ret; 201 } 202 203 static int stmmac_xgmac2_mdio_write_c22(struct mii_bus *bus, int phyaddr, 204 int phyreg, u16 phydata) 205 { 206 struct net_device *ndev = bus->priv; 207 struct stmmac_priv *priv; 208 u32 addr; 209 210 priv = netdev_priv(ndev); 211 212 /* HW does not support C22 addr >= 4 */ 213 if (phyaddr > MII_XGMAC_MAX_C22ADDR) 214 return -ENODEV; 215 216 stmmac_xgmac2_c22_format(priv, phyaddr, phyreg, &addr); 217 218 return stmmac_xgmac2_mdio_write(priv, addr, 219 MII_XGMAC_BUSY | MII_XGMAC_SADDR, phydata); 220 } 221 222 static int stmmac_xgmac2_mdio_write_c45(struct mii_bus *bus, int phyaddr, 223 int devad, int phyreg, u16 phydata) 224 { 225 struct net_device *ndev = bus->priv; 226 struct stmmac_priv *priv; 227 u32 addr; 228 229 priv = netdev_priv(ndev); 230 231 stmmac_xgmac2_c45_format(priv, phyaddr, devad, phyreg, &addr); 232 233 return stmmac_xgmac2_mdio_write(priv, addr, MII_XGMAC_BUSY, 234 phydata); 235 } 236 237 static int stmmac_mdio_read(struct stmmac_priv *priv, int data, u32 value) 238 { 239 unsigned int mii_address = priv->hw->mii.addr; 240 unsigned int mii_data = priv->hw->mii.data; 241 u32 v; 242 243 if (readl_poll_timeout(priv->ioaddr + mii_address, v, !(v & MII_BUSY), 244 100, 10000)) 245 return -EBUSY; 246 247 writel(data, priv->ioaddr + mii_data); 248 writel(value, priv->ioaddr + mii_address); 249 250 if (readl_poll_timeout(priv->ioaddr + mii_address, v, !(v & MII_BUSY), 251 100, 10000)) 252 return -EBUSY; 253 254 /* Read the data from the MII data register */ 255 return readl(priv->ioaddr + mii_data) & MII_DATA_MASK; 256 } 257 258 /** 259 * stmmac_mdio_read_c22 260 * @bus: points to the mii_bus structure 261 * @phyaddr: MII addr 262 * @phyreg: MII reg 263 * Description: it reads data from the MII register from within the phy device. 264 * For the 7111 GMAC, we must set the bit 0 in the MII address register while 265 * accessing the PHY registers. 266 * Fortunately, it seems this has no drawback for the 7109 MAC. 267 */ 268 static int stmmac_mdio_read_c22(struct mii_bus *bus, int phyaddr, int phyreg) 269 { 270 struct net_device *ndev = bus->priv; 271 struct stmmac_priv *priv = netdev_priv(ndev); 272 u32 value = MII_BUSY; 273 int data = 0; 274 275 data = pm_runtime_resume_and_get(priv->device); 276 if (data < 0) 277 return data; 278 279 value |= (phyaddr << priv->hw->mii.addr_shift) 280 & priv->hw->mii.addr_mask; 281 value |= (phyreg << priv->hw->mii.reg_shift) & priv->hw->mii.reg_mask; 282 value |= (priv->clk_csr << priv->hw->mii.clk_csr_shift) 283 & priv->hw->mii.clk_csr_mask; 284 if (priv->plat->has_gmac4) 285 value |= MII_GMAC4_READ; 286 287 data = stmmac_mdio_read(priv, data, value); 288 289 pm_runtime_put(priv->device); 290 291 return data; 292 } 293 294 /** 295 * stmmac_mdio_read_c45 296 * @bus: points to the mii_bus structure 297 * @phyaddr: MII addr 298 * @devad: device address to read 299 * @phyreg: MII reg 300 * Description: it reads data from the MII register from within the phy device. 301 * For the 7111 GMAC, we must set the bit 0 in the MII address register while 302 * accessing the PHY registers. 303 * Fortunately, it seems this has no drawback for the 7109 MAC. 304 */ 305 static int stmmac_mdio_read_c45(struct mii_bus *bus, int phyaddr, int devad, 306 int phyreg) 307 { 308 struct net_device *ndev = bus->priv; 309 struct stmmac_priv *priv = netdev_priv(ndev); 310 u32 value = MII_BUSY; 311 int data = 0; 312 313 data = pm_runtime_get_sync(priv->device); 314 if (data < 0) { 315 pm_runtime_put_noidle(priv->device); 316 return data; 317 } 318 319 value |= (phyaddr << priv->hw->mii.addr_shift) 320 & priv->hw->mii.addr_mask; 321 value |= (phyreg << priv->hw->mii.reg_shift) & priv->hw->mii.reg_mask; 322 value |= (priv->clk_csr << priv->hw->mii.clk_csr_shift) 323 & priv->hw->mii.clk_csr_mask; 324 value |= MII_GMAC4_READ; 325 value |= MII_GMAC4_C45E; 326 value &= ~priv->hw->mii.reg_mask; 327 value |= (devad << priv->hw->mii.reg_shift) & priv->hw->mii.reg_mask; 328 329 data |= phyreg << MII_GMAC4_REG_ADDR_SHIFT; 330 331 data = stmmac_mdio_read(priv, data, value); 332 333 pm_runtime_put(priv->device); 334 335 return data; 336 } 337 338 static int stmmac_mdio_write(struct stmmac_priv *priv, int data, u32 value) 339 { 340 unsigned int mii_address = priv->hw->mii.addr; 341 unsigned int mii_data = priv->hw->mii.data; 342 u32 v; 343 344 /* Wait until any existing MII operation is complete */ 345 if (readl_poll_timeout(priv->ioaddr + mii_address, v, !(v & MII_BUSY), 346 100, 10000)) 347 return -EBUSY; 348 349 /* Set the MII address register to write */ 350 writel(data, priv->ioaddr + mii_data); 351 writel(value, priv->ioaddr + mii_address); 352 353 /* Wait until any existing MII operation is complete */ 354 return readl_poll_timeout(priv->ioaddr + mii_address, v, 355 !(v & MII_BUSY), 100, 10000); 356 } 357 358 /** 359 * stmmac_mdio_write_c22 360 * @bus: points to the mii_bus structure 361 * @phyaddr: MII addr 362 * @phyreg: MII reg 363 * @phydata: phy data 364 * Description: it writes the data into the MII register from within the device. 365 */ 366 static int stmmac_mdio_write_c22(struct mii_bus *bus, int phyaddr, int phyreg, 367 u16 phydata) 368 { 369 struct net_device *ndev = bus->priv; 370 struct stmmac_priv *priv = netdev_priv(ndev); 371 int ret, data = phydata; 372 u32 value = MII_BUSY; 373 374 ret = pm_runtime_resume_and_get(priv->device); 375 if (ret < 0) 376 return ret; 377 378 value |= (phyaddr << priv->hw->mii.addr_shift) 379 & priv->hw->mii.addr_mask; 380 value |= (phyreg << priv->hw->mii.reg_shift) & priv->hw->mii.reg_mask; 381 382 value |= (priv->clk_csr << priv->hw->mii.clk_csr_shift) 383 & priv->hw->mii.clk_csr_mask; 384 if (priv->plat->has_gmac4) 385 value |= MII_GMAC4_WRITE; 386 else 387 value |= MII_WRITE; 388 389 ret = stmmac_mdio_write(priv, data, value); 390 391 pm_runtime_put(priv->device); 392 393 return ret; 394 } 395 396 /** 397 * stmmac_mdio_write_c45 398 * @bus: points to the mii_bus structure 399 * @phyaddr: MII addr 400 * @phyreg: MII reg 401 * @devad: device address to read 402 * @phydata: phy data 403 * Description: it writes the data into the MII register from within the device. 404 */ 405 static int stmmac_mdio_write_c45(struct mii_bus *bus, int phyaddr, 406 int devad, int phyreg, u16 phydata) 407 { 408 struct net_device *ndev = bus->priv; 409 struct stmmac_priv *priv = netdev_priv(ndev); 410 int ret, data = phydata; 411 u32 value = MII_BUSY; 412 413 ret = pm_runtime_get_sync(priv->device); 414 if (ret < 0) { 415 pm_runtime_put_noidle(priv->device); 416 return ret; 417 } 418 419 value |= (phyaddr << priv->hw->mii.addr_shift) 420 & priv->hw->mii.addr_mask; 421 value |= (phyreg << priv->hw->mii.reg_shift) & priv->hw->mii.reg_mask; 422 423 value |= (priv->clk_csr << priv->hw->mii.clk_csr_shift) 424 & priv->hw->mii.clk_csr_mask; 425 426 value |= MII_GMAC4_WRITE; 427 value |= MII_GMAC4_C45E; 428 value &= ~priv->hw->mii.reg_mask; 429 value |= (devad << priv->hw->mii.reg_shift) & priv->hw->mii.reg_mask; 430 431 data |= phyreg << MII_GMAC4_REG_ADDR_SHIFT; 432 433 ret = stmmac_mdio_write(priv, data, value); 434 435 pm_runtime_put(priv->device); 436 437 return ret; 438 } 439 440 /** 441 * stmmac_mdio_reset 442 * @bus: points to the mii_bus structure 443 * Description: reset the MII bus 444 */ 445 int stmmac_mdio_reset(struct mii_bus *bus) 446 { 447 #if IS_ENABLED(CONFIG_STMMAC_PLATFORM) 448 struct net_device *ndev = bus->priv; 449 struct stmmac_priv *priv = netdev_priv(ndev); 450 unsigned int mii_address = priv->hw->mii.addr; 451 452 #ifdef CONFIG_OF 453 if (priv->device->of_node) { 454 struct gpio_desc *reset_gpio; 455 u32 delays[3] = { 0, 0, 0 }; 456 457 reset_gpio = devm_gpiod_get_optional(priv->device, 458 "snps,reset", 459 GPIOD_OUT_LOW); 460 if (IS_ERR(reset_gpio)) 461 return PTR_ERR(reset_gpio); 462 463 device_property_read_u32_array(priv->device, 464 "snps,reset-delays-us", 465 delays, ARRAY_SIZE(delays)); 466 467 if (delays[0]) 468 msleep(DIV_ROUND_UP(delays[0], 1000)); 469 470 gpiod_set_value_cansleep(reset_gpio, 1); 471 if (delays[1]) 472 msleep(DIV_ROUND_UP(delays[1], 1000)); 473 474 gpiod_set_value_cansleep(reset_gpio, 0); 475 if (delays[2]) 476 msleep(DIV_ROUND_UP(delays[2], 1000)); 477 } 478 #endif 479 480 /* This is a workaround for problems with the STE101P PHY. 481 * It doesn't complete its reset until at least one clock cycle 482 * on MDC, so perform a dummy mdio read. To be updated for GMAC4 483 * if needed. 484 */ 485 if (!priv->plat->has_gmac4) 486 writel(0, priv->ioaddr + mii_address); 487 #endif 488 return 0; 489 } 490 491 int stmmac_xpcs_setup(struct mii_bus *bus) 492 { 493 struct net_device *ndev = bus->priv; 494 struct stmmac_priv *priv; 495 struct dw_xpcs *xpcs; 496 int mode, addr; 497 498 priv = netdev_priv(ndev); 499 mode = priv->plat->phy_interface; 500 501 /* Try to probe the XPCS by scanning all addresses. */ 502 for (addr = 0; addr < PHY_MAX_ADDR; addr++) { 503 xpcs = xpcs_create_mdiodev(bus, addr, mode); 504 if (IS_ERR(xpcs)) 505 continue; 506 507 priv->hw->xpcs = xpcs; 508 break; 509 } 510 511 if (!priv->hw->xpcs) { 512 dev_warn(priv->device, "No xPCS found\n"); 513 return -ENODEV; 514 } 515 516 return 0; 517 } 518 519 /** 520 * stmmac_mdio_register 521 * @ndev: net device structure 522 * Description: it registers the MII bus 523 */ 524 int stmmac_mdio_register(struct net_device *ndev) 525 { 526 int err = 0; 527 struct mii_bus *new_bus; 528 struct stmmac_priv *priv = netdev_priv(ndev); 529 struct fwnode_handle *fwnode = of_fwnode_handle(priv->plat->phylink_node); 530 struct stmmac_mdio_bus_data *mdio_bus_data = priv->plat->mdio_bus_data; 531 struct device_node *mdio_node = priv->plat->mdio_node; 532 struct device *dev = ndev->dev.parent; 533 struct fwnode_handle *fixed_node; 534 int addr, found, max_addr; 535 536 if (!mdio_bus_data) 537 return 0; 538 539 new_bus = mdiobus_alloc(); 540 if (!new_bus) 541 return -ENOMEM; 542 543 if (mdio_bus_data->irqs) 544 memcpy(new_bus->irq, mdio_bus_data->irqs, sizeof(new_bus->irq)); 545 546 new_bus->name = "stmmac"; 547 548 if (priv->plat->has_xgmac) { 549 new_bus->read = &stmmac_xgmac2_mdio_read_c22; 550 new_bus->write = &stmmac_xgmac2_mdio_write_c22; 551 new_bus->read_c45 = &stmmac_xgmac2_mdio_read_c45; 552 new_bus->write_c45 = &stmmac_xgmac2_mdio_write_c45; 553 554 /* Right now only C22 phys are supported */ 555 max_addr = MII_XGMAC_MAX_C22ADDR + 1; 556 557 /* Check if DT specified an unsupported phy addr */ 558 if (priv->plat->phy_addr > MII_XGMAC_MAX_C22ADDR) 559 dev_err(dev, "Unsupported phy_addr (max=%d)\n", 560 MII_XGMAC_MAX_C22ADDR); 561 } else { 562 new_bus->read = &stmmac_mdio_read_c22; 563 new_bus->write = &stmmac_mdio_write_c22; 564 if (priv->plat->has_gmac4) { 565 new_bus->read_c45 = &stmmac_mdio_read_c45; 566 new_bus->write_c45 = &stmmac_mdio_write_c45; 567 } 568 569 max_addr = PHY_MAX_ADDR; 570 } 571 572 if (mdio_bus_data->needs_reset) 573 new_bus->reset = &stmmac_mdio_reset; 574 575 snprintf(new_bus->id, MII_BUS_ID_SIZE, "%s-%x", 576 new_bus->name, priv->plat->bus_id); 577 new_bus->priv = ndev; 578 new_bus->phy_mask = mdio_bus_data->phy_mask; 579 new_bus->parent = priv->device; 580 581 err = of_mdiobus_register(new_bus, mdio_node); 582 if (err != 0) { 583 dev_err_probe(dev, err, "Cannot register the MDIO bus\n"); 584 goto bus_register_fail; 585 } 586 587 /* Looks like we need a dummy read for XGMAC only and C45 PHYs */ 588 if (priv->plat->has_xgmac) 589 stmmac_xgmac2_mdio_read_c45(new_bus, 0, 0, 0); 590 591 /* If fixed-link is set, skip PHY scanning */ 592 if (!fwnode) 593 fwnode = dev_fwnode(priv->device); 594 595 if (fwnode) { 596 fixed_node = fwnode_get_named_child_node(fwnode, "fixed-link"); 597 if (fixed_node) { 598 fwnode_handle_put(fixed_node); 599 goto bus_register_done; 600 } 601 } 602 603 if (priv->plat->phy_node || mdio_node) 604 goto bus_register_done; 605 606 found = 0; 607 for (addr = 0; addr < max_addr; addr++) { 608 struct phy_device *phydev = mdiobus_get_phy(new_bus, addr); 609 610 if (!phydev) 611 continue; 612 613 /* 614 * If an IRQ was provided to be assigned after 615 * the bus probe, do it here. 616 */ 617 if (!mdio_bus_data->irqs && 618 (mdio_bus_data->probed_phy_irq > 0)) { 619 new_bus->irq[addr] = mdio_bus_data->probed_phy_irq; 620 phydev->irq = mdio_bus_data->probed_phy_irq; 621 } 622 623 /* 624 * If we're going to bind the MAC to this PHY bus, 625 * and no PHY number was provided to the MAC, 626 * use the one probed here. 627 */ 628 if (priv->plat->phy_addr == -1) 629 priv->plat->phy_addr = addr; 630 631 phy_attached_info(phydev); 632 found = 1; 633 } 634 635 if (!found && !mdio_node) { 636 dev_warn(dev, "No PHY found\n"); 637 err = -ENODEV; 638 goto no_phy_found; 639 } 640 641 bus_register_done: 642 priv->mii = new_bus; 643 644 return 0; 645 646 no_phy_found: 647 mdiobus_unregister(new_bus); 648 bus_register_fail: 649 mdiobus_free(new_bus); 650 return err; 651 } 652 653 /** 654 * stmmac_mdio_unregister 655 * @ndev: net device structure 656 * Description: it unregisters the MII bus 657 */ 658 int stmmac_mdio_unregister(struct net_device *ndev) 659 { 660 struct stmmac_priv *priv = netdev_priv(ndev); 661 662 if (!priv->mii) 663 return 0; 664 665 if (priv->hw->xpcs) 666 xpcs_destroy(priv->hw->xpcs); 667 668 mdiobus_unregister(priv->mii); 669 priv->mii->priv = NULL; 670 mdiobus_free(priv->mii); 671 priv->mii = NULL; 672 673 return 0; 674 } 675