1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Fixed MDIO bus (MDIO bus emulation with fixed PHYs) 4 * 5 * Author: Vitaly Bordug <vbordug@ru.mvista.com> 6 * Anton Vorontsov <avorontsov@ru.mvista.com> 7 * 8 * Copyright (c) 2006-2007 MontaVista Software, Inc. 9 */ 10 11 #include <linux/kernel.h> 12 #include <linux/module.h> 13 #include <linux/platform_device.h> 14 #include <linux/list.h> 15 #include <linux/mii.h> 16 #include <linux/phy.h> 17 #include <linux/phy_fixed.h> 18 #include <linux/err.h> 19 #include <linux/slab.h> 20 #include <linux/of.h> 21 #include <linux/gpio/consumer.h> 22 #include <linux/seqlock.h> 23 #include <linux/idr.h> 24 #include <linux/netdevice.h> 25 #include <linux/linkmode.h> 26 27 #include "swphy.h" 28 29 struct fixed_mdio_bus { 30 struct mii_bus *mii_bus; 31 struct list_head phys; 32 }; 33 34 struct fixed_phy { 35 int addr; 36 struct phy_device *phydev; 37 seqcount_t seqcount; 38 struct fixed_phy_status status; 39 bool no_carrier; 40 int (*link_update)(struct net_device *, struct fixed_phy_status *); 41 struct list_head node; 42 struct gpio_desc *link_gpiod; 43 }; 44 45 static struct platform_device *pdev; 46 static struct fixed_mdio_bus platform_fmb = { 47 .phys = LIST_HEAD_INIT(platform_fmb.phys), 48 }; 49 50 int fixed_phy_change_carrier(struct net_device *dev, bool new_carrier) 51 { 52 struct fixed_mdio_bus *fmb = &platform_fmb; 53 struct phy_device *phydev = dev->phydev; 54 struct fixed_phy *fp; 55 56 if (!phydev || !phydev->mdio.bus) 57 return -EINVAL; 58 59 list_for_each_entry(fp, &fmb->phys, node) { 60 if (fp->addr == phydev->mdio.addr) { 61 fp->no_carrier = !new_carrier; 62 return 0; 63 } 64 } 65 return -EINVAL; 66 } 67 EXPORT_SYMBOL_GPL(fixed_phy_change_carrier); 68 69 static void fixed_phy_update(struct fixed_phy *fp) 70 { 71 if (!fp->no_carrier && fp->link_gpiod) 72 fp->status.link = !!gpiod_get_value_cansleep(fp->link_gpiod); 73 } 74 75 static int fixed_mdio_read(struct mii_bus *bus, int phy_addr, int reg_num) 76 { 77 struct fixed_mdio_bus *fmb = bus->priv; 78 struct fixed_phy *fp; 79 80 list_for_each_entry(fp, &fmb->phys, node) { 81 if (fp->addr == phy_addr) { 82 struct fixed_phy_status state; 83 int s; 84 85 do { 86 s = read_seqcount_begin(&fp->seqcount); 87 fp->status.link = !fp->no_carrier; 88 /* Issue callback if user registered it. */ 89 if (fp->link_update) 90 fp->link_update(fp->phydev->attached_dev, 91 &fp->status); 92 /* Check the GPIO for change in status */ 93 fixed_phy_update(fp); 94 state = fp->status; 95 } while (read_seqcount_retry(&fp->seqcount, s)); 96 97 return swphy_read_reg(reg_num, &state); 98 } 99 } 100 101 return 0xFFFF; 102 } 103 104 static int fixed_mdio_write(struct mii_bus *bus, int phy_addr, int reg_num, 105 u16 val) 106 { 107 return 0; 108 } 109 110 /* 111 * If something weird is required to be done with link/speed, 112 * network driver is able to assign a function to implement this. 113 * May be useful for PHY's that need to be software-driven. 114 */ 115 int fixed_phy_set_link_update(struct phy_device *phydev, 116 int (*link_update)(struct net_device *, 117 struct fixed_phy_status *)) 118 { 119 struct fixed_mdio_bus *fmb = &platform_fmb; 120 struct fixed_phy *fp; 121 122 if (!phydev || !phydev->mdio.bus) 123 return -EINVAL; 124 125 list_for_each_entry(fp, &fmb->phys, node) { 126 if (fp->addr == phydev->mdio.addr) { 127 fp->link_update = link_update; 128 fp->phydev = phydev; 129 return 0; 130 } 131 } 132 133 return -ENOENT; 134 } 135 EXPORT_SYMBOL_GPL(fixed_phy_set_link_update); 136 137 static int fixed_phy_add_gpiod(unsigned int irq, int phy_addr, 138 struct fixed_phy_status *status, 139 struct gpio_desc *gpiod) 140 { 141 int ret; 142 struct fixed_mdio_bus *fmb = &platform_fmb; 143 struct fixed_phy *fp; 144 145 ret = swphy_validate_state(status); 146 if (ret < 0) 147 return ret; 148 149 fp = kzalloc(sizeof(*fp), GFP_KERNEL); 150 if (!fp) 151 return -ENOMEM; 152 153 seqcount_init(&fp->seqcount); 154 155 if (irq != PHY_POLL) 156 fmb->mii_bus->irq[phy_addr] = irq; 157 158 fp->addr = phy_addr; 159 fp->status = *status; 160 fp->link_gpiod = gpiod; 161 162 fixed_phy_update(fp); 163 164 list_add_tail(&fp->node, &fmb->phys); 165 166 return 0; 167 } 168 169 int fixed_phy_add(unsigned int irq, int phy_addr, 170 struct fixed_phy_status *status) { 171 172 return fixed_phy_add_gpiod(irq, phy_addr, status, NULL); 173 } 174 EXPORT_SYMBOL_GPL(fixed_phy_add); 175 176 static DEFINE_IDA(phy_fixed_ida); 177 178 static void fixed_phy_del(int phy_addr) 179 { 180 struct fixed_mdio_bus *fmb = &platform_fmb; 181 struct fixed_phy *fp, *tmp; 182 183 list_for_each_entry_safe(fp, tmp, &fmb->phys, node) { 184 if (fp->addr == phy_addr) { 185 list_del(&fp->node); 186 if (fp->link_gpiod) 187 gpiod_put(fp->link_gpiod); 188 kfree(fp); 189 ida_simple_remove(&phy_fixed_ida, phy_addr); 190 return; 191 } 192 } 193 } 194 195 #ifdef CONFIG_OF_GPIO 196 static struct gpio_desc *fixed_phy_get_gpiod(struct device_node *np) 197 { 198 struct device_node *fixed_link_node; 199 struct gpio_desc *gpiod; 200 201 if (!np) 202 return NULL; 203 204 fixed_link_node = of_get_child_by_name(np, "fixed-link"); 205 if (!fixed_link_node) 206 return NULL; 207 208 /* 209 * As the fixed link is just a device tree node without any 210 * Linux device associated with it, we simply have obtain 211 * the GPIO descriptor from the device tree like this. 212 */ 213 gpiod = gpiod_get_from_of_node(fixed_link_node, "link-gpios", 0, 214 GPIOD_IN, "mdio"); 215 of_node_put(fixed_link_node); 216 if (IS_ERR(gpiod)) { 217 if (PTR_ERR(gpiod) == -EPROBE_DEFER) 218 return gpiod; 219 pr_err("error getting GPIO for fixed link %pOF, proceed without\n", 220 fixed_link_node); 221 gpiod = NULL; 222 } 223 224 return gpiod; 225 } 226 #else 227 static struct gpio_desc *fixed_phy_get_gpiod(struct device_node *np) 228 { 229 return NULL; 230 } 231 #endif 232 233 static struct phy_device *__fixed_phy_register(unsigned int irq, 234 struct fixed_phy_status *status, 235 struct device_node *np, 236 struct gpio_desc *gpiod) 237 { 238 struct fixed_mdio_bus *fmb = &platform_fmb; 239 struct phy_device *phy; 240 int phy_addr; 241 int ret; 242 243 if (!fmb->mii_bus || fmb->mii_bus->state != MDIOBUS_REGISTERED) 244 return ERR_PTR(-EPROBE_DEFER); 245 246 /* Check if we have a GPIO associated with this fixed phy */ 247 if (!gpiod) { 248 gpiod = fixed_phy_get_gpiod(np); 249 if (IS_ERR(gpiod)) 250 return ERR_CAST(gpiod); 251 } 252 253 /* Get the next available PHY address, up to PHY_MAX_ADDR */ 254 phy_addr = ida_simple_get(&phy_fixed_ida, 0, PHY_MAX_ADDR, GFP_KERNEL); 255 if (phy_addr < 0) 256 return ERR_PTR(phy_addr); 257 258 ret = fixed_phy_add_gpiod(irq, phy_addr, status, gpiod); 259 if (ret < 0) { 260 ida_simple_remove(&phy_fixed_ida, phy_addr); 261 return ERR_PTR(ret); 262 } 263 264 phy = get_phy_device(fmb->mii_bus, phy_addr, false); 265 if (IS_ERR(phy)) { 266 fixed_phy_del(phy_addr); 267 return ERR_PTR(-EINVAL); 268 } 269 270 /* propagate the fixed link values to struct phy_device */ 271 phy->link = status->link; 272 if (status->link) { 273 phy->speed = status->speed; 274 phy->duplex = status->duplex; 275 phy->pause = status->pause; 276 phy->asym_pause = status->asym_pause; 277 } 278 279 of_node_get(np); 280 phy->mdio.dev.of_node = np; 281 phy->is_pseudo_fixed_link = true; 282 283 switch (status->speed) { 284 case SPEED_1000: 285 linkmode_set_bit(ETHTOOL_LINK_MODE_1000baseT_Half_BIT, 286 phy->supported); 287 linkmode_set_bit(ETHTOOL_LINK_MODE_1000baseT_Full_BIT, 288 phy->supported); 289 /* fall through */ 290 case SPEED_100: 291 linkmode_set_bit(ETHTOOL_LINK_MODE_100baseT_Half_BIT, 292 phy->supported); 293 linkmode_set_bit(ETHTOOL_LINK_MODE_100baseT_Full_BIT, 294 phy->supported); 295 /* fall through */ 296 case SPEED_10: 297 default: 298 linkmode_set_bit(ETHTOOL_LINK_MODE_10baseT_Half_BIT, 299 phy->supported); 300 linkmode_set_bit(ETHTOOL_LINK_MODE_10baseT_Full_BIT, 301 phy->supported); 302 } 303 304 phy_advertise_supported(phy); 305 306 ret = phy_device_register(phy); 307 if (ret) { 308 phy_device_free(phy); 309 of_node_put(np); 310 fixed_phy_del(phy_addr); 311 return ERR_PTR(ret); 312 } 313 314 return phy; 315 } 316 317 struct phy_device *fixed_phy_register(unsigned int irq, 318 struct fixed_phy_status *status, 319 struct device_node *np) 320 { 321 return __fixed_phy_register(irq, status, np, NULL); 322 } 323 EXPORT_SYMBOL_GPL(fixed_phy_register); 324 325 struct phy_device * 326 fixed_phy_register_with_gpiod(unsigned int irq, 327 struct fixed_phy_status *status, 328 struct gpio_desc *gpiod) 329 { 330 return __fixed_phy_register(irq, status, NULL, gpiod); 331 } 332 EXPORT_SYMBOL_GPL(fixed_phy_register_with_gpiod); 333 334 void fixed_phy_unregister(struct phy_device *phy) 335 { 336 phy_device_remove(phy); 337 of_node_put(phy->mdio.dev.of_node); 338 fixed_phy_del(phy->mdio.addr); 339 } 340 EXPORT_SYMBOL_GPL(fixed_phy_unregister); 341 342 static int __init fixed_mdio_bus_init(void) 343 { 344 struct fixed_mdio_bus *fmb = &platform_fmb; 345 int ret; 346 347 pdev = platform_device_register_simple("Fixed MDIO bus", 0, NULL, 0); 348 if (IS_ERR(pdev)) 349 return PTR_ERR(pdev); 350 351 fmb->mii_bus = mdiobus_alloc(); 352 if (fmb->mii_bus == NULL) { 353 ret = -ENOMEM; 354 goto err_mdiobus_reg; 355 } 356 357 snprintf(fmb->mii_bus->id, MII_BUS_ID_SIZE, "fixed-0"); 358 fmb->mii_bus->name = "Fixed MDIO Bus"; 359 fmb->mii_bus->priv = fmb; 360 fmb->mii_bus->parent = &pdev->dev; 361 fmb->mii_bus->read = &fixed_mdio_read; 362 fmb->mii_bus->write = &fixed_mdio_write; 363 364 ret = mdiobus_register(fmb->mii_bus); 365 if (ret) 366 goto err_mdiobus_alloc; 367 368 return 0; 369 370 err_mdiobus_alloc: 371 mdiobus_free(fmb->mii_bus); 372 err_mdiobus_reg: 373 platform_device_unregister(pdev); 374 return ret; 375 } 376 module_init(fixed_mdio_bus_init); 377 378 static void __exit fixed_mdio_bus_exit(void) 379 { 380 struct fixed_mdio_bus *fmb = &platform_fmb; 381 struct fixed_phy *fp, *tmp; 382 383 mdiobus_unregister(fmb->mii_bus); 384 mdiobus_free(fmb->mii_bus); 385 platform_device_unregister(pdev); 386 387 list_for_each_entry_safe(fp, tmp, &fmb->phys, node) { 388 list_del(&fp->node); 389 kfree(fp); 390 } 391 ida_destroy(&phy_fixed_ida); 392 } 393 module_exit(fixed_mdio_bus_exit); 394 395 MODULE_DESCRIPTION("Fixed MDIO bus (MDIO bus emulation with fixed PHYs)"); 396 MODULE_AUTHOR("Vitaly Bordug"); 397 MODULE_LICENSE("GPL"); 398