1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * MDIO controller for RTL9300 switches with integrated SoC. 4 * 5 * The MDIO communication is abstracted by the switch. At the software level 6 * communication uses the switch port to address the PHY. We work out the 7 * mapping based on the MDIO bus described in device tree and phandles on the 8 * ethernet-ports property. 9 */ 10 11 #include <linux/bitfield.h> 12 #include <linux/bitmap.h> 13 #include <linux/bits.h> 14 #include <linux/find.h> 15 #include <linux/mdio.h> 16 #include <linux/mfd/syscon.h> 17 #include <linux/mod_devicetable.h> 18 #include <linux/mutex.h> 19 #include <linux/of_mdio.h> 20 #include <linux/phy.h> 21 #include <linux/platform_device.h> 22 #include <linux/property.h> 23 #include <linux/regmap.h> 24 25 #define SMI_GLB_CTRL 0xca00 26 #define GLB_CTRL_INTF_SEL(intf) BIT(16 + (intf)) 27 #define SMI_PORT0_15_POLLING_SEL 0xca08 28 #define SMI_ACCESS_PHY_CTRL_0 0xcb70 29 #define SMI_ACCESS_PHY_CTRL_1 0xcb74 30 #define PHY_CTRL_REG_ADDR GENMASK(24, 20) 31 #define PHY_CTRL_PARK_PAGE GENMASK(19, 15) 32 #define PHY_CTRL_MAIN_PAGE GENMASK(14, 3) 33 #define PHY_CTRL_WRITE BIT(2) 34 #define PHY_CTRL_READ 0 35 #define PHY_CTRL_TYPE_C45 BIT(1) 36 #define PHY_CTRL_TYPE_C22 0 37 #define PHY_CTRL_CMD BIT(0) 38 #define PHY_CTRL_FAIL BIT(25) 39 #define SMI_ACCESS_PHY_CTRL_2 0xcb78 40 #define PHY_CTRL_INDATA GENMASK(31, 16) 41 #define PHY_CTRL_DATA GENMASK(15, 0) 42 #define SMI_ACCESS_PHY_CTRL_3 0xcb7c 43 #define PHY_CTRL_MMD_DEVAD GENMASK(20, 16) 44 #define PHY_CTRL_MMD_REG GENMASK(15, 0) 45 #define SMI_PORT0_5_ADDR_CTRL 0xcb80 46 47 #define MAX_PORTS 28 48 #define MAX_SMI_BUSSES 4 49 #define MAX_SMI_ADDR 0x1f 50 51 struct rtl9300_mdio_priv { 52 struct regmap *regmap; 53 struct mutex lock; /* protect HW access */ 54 DECLARE_BITMAP(valid_ports, MAX_PORTS); 55 u8 smi_bus[MAX_PORTS]; 56 u8 smi_addr[MAX_PORTS]; 57 bool smi_bus_is_c45[MAX_SMI_BUSSES]; 58 struct mii_bus *bus[MAX_SMI_BUSSES]; 59 }; 60 61 struct rtl9300_mdio_chan { 62 struct rtl9300_mdio_priv *priv; 63 u8 mdio_bus; 64 }; 65 66 static int rtl9300_mdio_phy_to_port(struct mii_bus *bus, int phy_id) 67 { 68 struct rtl9300_mdio_chan *chan = bus->priv; 69 struct rtl9300_mdio_priv *priv; 70 int i; 71 72 priv = chan->priv; 73 74 for_each_set_bit(i, priv->valid_ports, MAX_PORTS) 75 if (priv->smi_bus[i] == chan->mdio_bus && 76 priv->smi_addr[i] == phy_id) 77 return i; 78 79 return -ENOENT; 80 } 81 82 static int rtl9300_mdio_wait_ready(struct rtl9300_mdio_priv *priv) 83 { 84 struct regmap *regmap = priv->regmap; 85 u32 val; 86 87 lockdep_assert_held(&priv->lock); 88 89 return regmap_read_poll_timeout(regmap, SMI_ACCESS_PHY_CTRL_1, 90 val, !(val & PHY_CTRL_CMD), 10, 1000); 91 } 92 93 static int rtl9300_mdio_read_c22(struct mii_bus *bus, int phy_id, int regnum) 94 { 95 struct rtl9300_mdio_chan *chan = bus->priv; 96 struct rtl9300_mdio_priv *priv; 97 struct regmap *regmap; 98 int port; 99 u32 val; 100 int err; 101 102 priv = chan->priv; 103 regmap = priv->regmap; 104 105 port = rtl9300_mdio_phy_to_port(bus, phy_id); 106 if (port < 0) 107 return port; 108 109 mutex_lock(&priv->lock); 110 err = rtl9300_mdio_wait_ready(priv); 111 if (err) 112 goto out_err; 113 114 err = regmap_write(regmap, SMI_ACCESS_PHY_CTRL_2, FIELD_PREP(PHY_CTRL_INDATA, port)); 115 if (err) 116 goto out_err; 117 118 val = FIELD_PREP(PHY_CTRL_REG_ADDR, regnum) | 119 FIELD_PREP(PHY_CTRL_PARK_PAGE, 0x1f) | 120 FIELD_PREP(PHY_CTRL_MAIN_PAGE, 0xfff) | 121 PHY_CTRL_READ | PHY_CTRL_TYPE_C22 | PHY_CTRL_CMD; 122 err = regmap_write(regmap, SMI_ACCESS_PHY_CTRL_1, val); 123 if (err) 124 goto out_err; 125 126 err = rtl9300_mdio_wait_ready(priv); 127 if (err) 128 goto out_err; 129 130 err = regmap_read(regmap, SMI_ACCESS_PHY_CTRL_2, &val); 131 if (err) 132 goto out_err; 133 134 mutex_unlock(&priv->lock); 135 return FIELD_GET(PHY_CTRL_DATA, val); 136 137 out_err: 138 mutex_unlock(&priv->lock); 139 return err; 140 } 141 142 static int rtl9300_mdio_write_c22(struct mii_bus *bus, int phy_id, int regnum, u16 value) 143 { 144 struct rtl9300_mdio_chan *chan = bus->priv; 145 struct rtl9300_mdio_priv *priv; 146 struct regmap *regmap; 147 int port; 148 u32 val; 149 int err; 150 151 priv = chan->priv; 152 regmap = priv->regmap; 153 154 port = rtl9300_mdio_phy_to_port(bus, phy_id); 155 if (port < 0) 156 return port; 157 158 mutex_lock(&priv->lock); 159 err = rtl9300_mdio_wait_ready(priv); 160 if (err) 161 goto out_err; 162 163 err = regmap_write(regmap, SMI_ACCESS_PHY_CTRL_0, BIT(port)); 164 if (err) 165 goto out_err; 166 167 err = regmap_write(regmap, SMI_ACCESS_PHY_CTRL_2, FIELD_PREP(PHY_CTRL_INDATA, value)); 168 if (err) 169 goto out_err; 170 171 val = FIELD_PREP(PHY_CTRL_REG_ADDR, regnum) | 172 FIELD_PREP(PHY_CTRL_PARK_PAGE, 0x1f) | 173 FIELD_PREP(PHY_CTRL_MAIN_PAGE, 0xfff) | 174 PHY_CTRL_WRITE | PHY_CTRL_TYPE_C22 | PHY_CTRL_CMD; 175 err = regmap_write(regmap, SMI_ACCESS_PHY_CTRL_1, val); 176 if (err) 177 goto out_err; 178 179 err = regmap_read_poll_timeout(regmap, SMI_ACCESS_PHY_CTRL_1, 180 val, !(val & PHY_CTRL_CMD), 10, 100); 181 if (err) 182 goto out_err; 183 184 if (val & PHY_CTRL_FAIL) { 185 err = -ENXIO; 186 goto out_err; 187 } 188 189 mutex_unlock(&priv->lock); 190 return 0; 191 192 out_err: 193 mutex_unlock(&priv->lock); 194 return err; 195 } 196 197 static int rtl9300_mdio_read_c45(struct mii_bus *bus, int phy_id, int dev_addr, int regnum) 198 { 199 struct rtl9300_mdio_chan *chan = bus->priv; 200 struct rtl9300_mdio_priv *priv; 201 struct regmap *regmap; 202 int port; 203 u32 val; 204 int err; 205 206 priv = chan->priv; 207 regmap = priv->regmap; 208 209 port = rtl9300_mdio_phy_to_port(bus, phy_id); 210 if (port < 0) 211 return port; 212 213 mutex_lock(&priv->lock); 214 err = rtl9300_mdio_wait_ready(priv); 215 if (err) 216 goto out_err; 217 218 val = FIELD_PREP(PHY_CTRL_INDATA, port); 219 err = regmap_write(regmap, SMI_ACCESS_PHY_CTRL_2, val); 220 if (err) 221 goto out_err; 222 223 val = FIELD_PREP(PHY_CTRL_MMD_DEVAD, dev_addr) | 224 FIELD_PREP(PHY_CTRL_MMD_REG, regnum); 225 err = regmap_write(regmap, SMI_ACCESS_PHY_CTRL_3, val); 226 if (err) 227 goto out_err; 228 229 err = regmap_write(regmap, SMI_ACCESS_PHY_CTRL_1, 230 PHY_CTRL_READ | PHY_CTRL_TYPE_C45 | PHY_CTRL_CMD); 231 if (err) 232 goto out_err; 233 234 err = rtl9300_mdio_wait_ready(priv); 235 if (err) 236 goto out_err; 237 238 err = regmap_read(regmap, SMI_ACCESS_PHY_CTRL_2, &val); 239 if (err) 240 goto out_err; 241 242 mutex_unlock(&priv->lock); 243 return FIELD_GET(PHY_CTRL_DATA, val); 244 245 out_err: 246 mutex_unlock(&priv->lock); 247 return err; 248 } 249 250 static int rtl9300_mdio_write_c45(struct mii_bus *bus, int phy_id, int dev_addr, 251 int regnum, u16 value) 252 { 253 struct rtl9300_mdio_chan *chan = bus->priv; 254 struct rtl9300_mdio_priv *priv; 255 struct regmap *regmap; 256 int port; 257 u32 val; 258 int err; 259 260 priv = chan->priv; 261 regmap = priv->regmap; 262 263 port = rtl9300_mdio_phy_to_port(bus, phy_id); 264 if (port < 0) 265 return port; 266 267 mutex_lock(&priv->lock); 268 err = rtl9300_mdio_wait_ready(priv); 269 if (err) 270 goto out_err; 271 272 err = regmap_write(regmap, SMI_ACCESS_PHY_CTRL_0, BIT(port)); 273 if (err) 274 goto out_err; 275 276 val = FIELD_PREP(PHY_CTRL_INDATA, value); 277 err = regmap_write(regmap, SMI_ACCESS_PHY_CTRL_2, val); 278 if (err) 279 goto out_err; 280 281 val = FIELD_PREP(PHY_CTRL_MMD_DEVAD, dev_addr) | 282 FIELD_PREP(PHY_CTRL_MMD_REG, regnum); 283 err = regmap_write(regmap, SMI_ACCESS_PHY_CTRL_3, val); 284 if (err) 285 goto out_err; 286 287 err = regmap_write(regmap, SMI_ACCESS_PHY_CTRL_1, 288 PHY_CTRL_TYPE_C45 | PHY_CTRL_WRITE | PHY_CTRL_CMD); 289 if (err) 290 goto out_err; 291 292 err = regmap_read_poll_timeout(regmap, SMI_ACCESS_PHY_CTRL_1, 293 val, !(val & PHY_CTRL_CMD), 10, 100); 294 if (err) 295 goto out_err; 296 297 if (val & PHY_CTRL_FAIL) { 298 err = -ENXIO; 299 goto out_err; 300 } 301 302 mutex_unlock(&priv->lock); 303 return 0; 304 305 out_err: 306 mutex_unlock(&priv->lock); 307 return err; 308 } 309 310 static int rtl9300_mdiobus_init(struct rtl9300_mdio_priv *priv) 311 { 312 u32 glb_ctrl_mask = 0, glb_ctrl_val = 0; 313 struct regmap *regmap = priv->regmap; 314 u32 port_addr[5] = { 0 }; 315 u32 poll_sel[2] = { 0 }; 316 int i, err; 317 318 /* Associate the port with the SMI interface and PHY */ 319 for_each_set_bit(i, priv->valid_ports, MAX_PORTS) { 320 int pos; 321 322 pos = (i % 6) * 5; 323 port_addr[i / 6] |= (priv->smi_addr[i] & 0x1f) << pos; 324 325 pos = (i % 16) * 2; 326 poll_sel[i / 16] |= (priv->smi_bus[i] & 0x3) << pos; 327 } 328 329 /* Put the interfaces into C45 mode if required */ 330 glb_ctrl_mask = GENMASK(19, 16); 331 for (i = 0; i < MAX_SMI_BUSSES; i++) 332 if (priv->smi_bus_is_c45[i]) 333 glb_ctrl_val |= GLB_CTRL_INTF_SEL(i); 334 335 err = regmap_bulk_write(regmap, SMI_PORT0_5_ADDR_CTRL, 336 port_addr, 5); 337 if (err) 338 return err; 339 340 err = regmap_bulk_write(regmap, SMI_PORT0_15_POLLING_SEL, 341 poll_sel, 2); 342 if (err) 343 return err; 344 345 err = regmap_update_bits(regmap, SMI_GLB_CTRL, 346 glb_ctrl_mask, glb_ctrl_val); 347 if (err) 348 return err; 349 350 return 0; 351 } 352 353 static int rtl9300_mdiobus_probe_one(struct device *dev, struct rtl9300_mdio_priv *priv, 354 struct fwnode_handle *node) 355 { 356 struct rtl9300_mdio_chan *chan; 357 struct mii_bus *bus; 358 u32 mdio_bus; 359 int err; 360 361 err = fwnode_property_read_u32(node, "reg", &mdio_bus); 362 if (err) 363 return err; 364 365 /* The MDIO accesses from the kernel work with the PHY polling unit in 366 * the switch. We need to tell the PPU to operate either in GPHY (i.e. 367 * clause 22) or 10GPHY mode (i.e. clause 45). 368 * 369 * We select 10GPHY mode if there is at least one PHY that declares 370 * compatible = "ethernet-phy-ieee802.3-c45". This does mean we can't 371 * support both c45 and c22 on the same MDIO bus. 372 */ 373 fwnode_for_each_child_node_scoped(node, child) 374 if (fwnode_device_is_compatible(child, "ethernet-phy-ieee802.3-c45")) 375 priv->smi_bus_is_c45[mdio_bus] = true; 376 377 bus = devm_mdiobus_alloc_size(dev, sizeof(*chan)); 378 if (!bus) 379 return -ENOMEM; 380 381 bus->name = "Realtek Switch MDIO Bus"; 382 if (priv->smi_bus_is_c45[mdio_bus]) { 383 bus->read_c45 = rtl9300_mdio_read_c45; 384 bus->write_c45 = rtl9300_mdio_write_c45; 385 } else { 386 bus->read = rtl9300_mdio_read_c22; 387 bus->write = rtl9300_mdio_write_c22; 388 } 389 bus->parent = dev; 390 chan = bus->priv; 391 chan->mdio_bus = mdio_bus; 392 chan->priv = priv; 393 394 snprintf(bus->id, MII_BUS_ID_SIZE, "%s-%d", dev_name(dev), mdio_bus); 395 396 err = devm_of_mdiobus_register(dev, bus, to_of_node(node)); 397 if (err) 398 return dev_err_probe(dev, err, "cannot register MDIO bus\n"); 399 400 return 0; 401 } 402 403 /* The mdio-controller is part of a switch block so we parse the sibling 404 * ethernet-ports node and build a mapping of the switch port to MDIO bus/addr 405 * based on the phy-handle. 406 */ 407 static int rtl9300_mdiobus_map_ports(struct device *dev) 408 { 409 struct rtl9300_mdio_priv *priv = dev_get_drvdata(dev); 410 struct device *parent = dev->parent; 411 int err; 412 413 struct fwnode_handle *ports __free(fwnode_handle) = 414 device_get_named_child_node(parent, "ethernet-ports"); 415 if (!ports) 416 return dev_err_probe(dev, -EINVAL, "%pfwP missing ethernet-ports\n", 417 dev_fwnode(parent)); 418 419 fwnode_for_each_child_node_scoped(ports, port) { 420 struct device_node *mdio_dn; 421 u32 addr; 422 u32 bus; 423 u32 pn; 424 425 struct device_node *phy_dn __free(device_node) = 426 of_parse_phandle(to_of_node(port), "phy-handle", 0); 427 /* skip ports without phys */ 428 if (!phy_dn) 429 continue; 430 431 mdio_dn = phy_dn->parent; 432 /* only map ports that are connected to this mdio-controller */ 433 if (mdio_dn->parent != dev->of_node) 434 continue; 435 436 err = fwnode_property_read_u32(port, "reg", &pn); 437 if (err) 438 return err; 439 440 if (pn >= MAX_PORTS) 441 return dev_err_probe(dev, -EINVAL, "illegal port number %d\n", pn); 442 443 if (test_bit(pn, priv->valid_ports)) 444 return dev_err_probe(dev, -EINVAL, "duplicated port number %d\n", pn); 445 446 err = of_property_read_u32(mdio_dn, "reg", &bus); 447 if (err) 448 return err; 449 450 if (bus >= MAX_SMI_BUSSES) 451 return dev_err_probe(dev, -EINVAL, "illegal smi bus number %d\n", bus); 452 453 err = of_property_read_u32(phy_dn, "reg", &addr); 454 if (err) 455 return err; 456 457 __set_bit(pn, priv->valid_ports); 458 priv->smi_bus[pn] = bus; 459 priv->smi_addr[pn] = addr; 460 } 461 462 return 0; 463 } 464 465 static int rtl9300_mdiobus_probe(struct platform_device *pdev) 466 { 467 struct device *dev = &pdev->dev; 468 struct rtl9300_mdio_priv *priv; 469 struct fwnode_handle *child; 470 int err; 471 472 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); 473 if (!priv) 474 return -ENOMEM; 475 476 err = devm_mutex_init(dev, &priv->lock); 477 if (err) 478 return err; 479 480 priv->regmap = syscon_node_to_regmap(dev->parent->of_node); 481 if (IS_ERR(priv->regmap)) 482 return PTR_ERR(priv->regmap); 483 484 platform_set_drvdata(pdev, priv); 485 486 err = rtl9300_mdiobus_map_ports(dev); 487 if (err) 488 return err; 489 490 device_for_each_child_node(dev, child) { 491 err = rtl9300_mdiobus_probe_one(dev, priv, child); 492 if (err) 493 return err; 494 } 495 496 err = rtl9300_mdiobus_init(priv); 497 if (err) 498 return dev_err_probe(dev, err, "failed to initialise MDIO bus controller\n"); 499 500 return 0; 501 } 502 503 static const struct of_device_id rtl9300_mdio_ids[] = { 504 { .compatible = "realtek,rtl9301-mdio" }, 505 {} 506 }; 507 MODULE_DEVICE_TABLE(of, rtl9300_mdio_ids); 508 509 static struct platform_driver rtl9300_mdio_driver = { 510 .probe = rtl9300_mdiobus_probe, 511 .driver = { 512 .name = "mdio-rtl9300", 513 .of_match_table = rtl9300_mdio_ids, 514 }, 515 }; 516 517 module_platform_driver(rtl9300_mdio_driver); 518 519 MODULE_DESCRIPTION("RTL9300 MDIO driver"); 520 MODULE_LICENSE("GPL"); 521