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 = fwnode_gpiod_get_index(of_fwnode_handle(fixed_link_node), 214 "link", 0, GPIOD_IN, "mdio"); 215 if (IS_ERR(gpiod) && PTR_ERR(gpiod) != -EPROBE_DEFER) { 216 if (PTR_ERR(gpiod) != -ENOENT) 217 pr_err("error getting GPIO for fixed link %pOF, proceed without\n", 218 fixed_link_node); 219 gpiod = NULL; 220 } 221 of_node_put(fixed_link_node); 222 223 return gpiod; 224 } 225 #else 226 static struct gpio_desc *fixed_phy_get_gpiod(struct device_node *np) 227 { 228 return NULL; 229 } 230 #endif 231 232 static struct phy_device *__fixed_phy_register(unsigned int irq, 233 struct fixed_phy_status *status, 234 struct device_node *np, 235 struct gpio_desc *gpiod) 236 { 237 struct fixed_mdio_bus *fmb = &platform_fmb; 238 struct phy_device *phy; 239 int phy_addr; 240 int ret; 241 242 if (!fmb->mii_bus || fmb->mii_bus->state != MDIOBUS_REGISTERED) 243 return ERR_PTR(-EPROBE_DEFER); 244 245 /* Check if we have a GPIO associated with this fixed phy */ 246 if (!gpiod) { 247 gpiod = fixed_phy_get_gpiod(np); 248 if (IS_ERR(gpiod)) 249 return ERR_CAST(gpiod); 250 } 251 252 /* Get the next available PHY address, up to PHY_MAX_ADDR */ 253 phy_addr = ida_simple_get(&phy_fixed_ida, 0, PHY_MAX_ADDR, GFP_KERNEL); 254 if (phy_addr < 0) 255 return ERR_PTR(phy_addr); 256 257 ret = fixed_phy_add_gpiod(irq, phy_addr, status, gpiod); 258 if (ret < 0) { 259 ida_simple_remove(&phy_fixed_ida, phy_addr); 260 return ERR_PTR(ret); 261 } 262 263 phy = get_phy_device(fmb->mii_bus, phy_addr, false); 264 if (IS_ERR(phy)) { 265 fixed_phy_del(phy_addr); 266 return ERR_PTR(-EINVAL); 267 } 268 269 /* propagate the fixed link values to struct phy_device */ 270 phy->link = status->link; 271 if (status->link) { 272 phy->speed = status->speed; 273 phy->duplex = status->duplex; 274 phy->pause = status->pause; 275 phy->asym_pause = status->asym_pause; 276 } 277 278 of_node_get(np); 279 phy->mdio.dev.of_node = np; 280 phy->is_pseudo_fixed_link = true; 281 282 switch (status->speed) { 283 case SPEED_1000: 284 linkmode_set_bit(ETHTOOL_LINK_MODE_1000baseT_Half_BIT, 285 phy->supported); 286 linkmode_set_bit(ETHTOOL_LINK_MODE_1000baseT_Full_BIT, 287 phy->supported); 288 /* fall through */ 289 case SPEED_100: 290 linkmode_set_bit(ETHTOOL_LINK_MODE_100baseT_Half_BIT, 291 phy->supported); 292 linkmode_set_bit(ETHTOOL_LINK_MODE_100baseT_Full_BIT, 293 phy->supported); 294 /* fall through */ 295 case SPEED_10: 296 default: 297 linkmode_set_bit(ETHTOOL_LINK_MODE_10baseT_Half_BIT, 298 phy->supported); 299 linkmode_set_bit(ETHTOOL_LINK_MODE_10baseT_Full_BIT, 300 phy->supported); 301 } 302 303 phy_advertise_supported(phy); 304 305 ret = phy_device_register(phy); 306 if (ret) { 307 phy_device_free(phy); 308 of_node_put(np); 309 fixed_phy_del(phy_addr); 310 return ERR_PTR(ret); 311 } 312 313 return phy; 314 } 315 316 struct phy_device *fixed_phy_register(unsigned int irq, 317 struct fixed_phy_status *status, 318 struct device_node *np) 319 { 320 return __fixed_phy_register(irq, status, np, NULL); 321 } 322 EXPORT_SYMBOL_GPL(fixed_phy_register); 323 324 struct phy_device * 325 fixed_phy_register_with_gpiod(unsigned int irq, 326 struct fixed_phy_status *status, 327 struct gpio_desc *gpiod) 328 { 329 return __fixed_phy_register(irq, status, NULL, gpiod); 330 } 331 EXPORT_SYMBOL_GPL(fixed_phy_register_with_gpiod); 332 333 void fixed_phy_unregister(struct phy_device *phy) 334 { 335 phy_device_remove(phy); 336 of_node_put(phy->mdio.dev.of_node); 337 fixed_phy_del(phy->mdio.addr); 338 } 339 EXPORT_SYMBOL_GPL(fixed_phy_unregister); 340 341 static int __init fixed_mdio_bus_init(void) 342 { 343 struct fixed_mdio_bus *fmb = &platform_fmb; 344 int ret; 345 346 pdev = platform_device_register_simple("Fixed MDIO bus", 0, NULL, 0); 347 if (IS_ERR(pdev)) 348 return PTR_ERR(pdev); 349 350 fmb->mii_bus = mdiobus_alloc(); 351 if (fmb->mii_bus == NULL) { 352 ret = -ENOMEM; 353 goto err_mdiobus_reg; 354 } 355 356 snprintf(fmb->mii_bus->id, MII_BUS_ID_SIZE, "fixed-0"); 357 fmb->mii_bus->name = "Fixed MDIO Bus"; 358 fmb->mii_bus->priv = fmb; 359 fmb->mii_bus->parent = &pdev->dev; 360 fmb->mii_bus->read = &fixed_mdio_read; 361 fmb->mii_bus->write = &fixed_mdio_write; 362 363 ret = mdiobus_register(fmb->mii_bus); 364 if (ret) 365 goto err_mdiobus_alloc; 366 367 return 0; 368 369 err_mdiobus_alloc: 370 mdiobus_free(fmb->mii_bus); 371 err_mdiobus_reg: 372 platform_device_unregister(pdev); 373 return ret; 374 } 375 module_init(fixed_mdio_bus_init); 376 377 static void __exit fixed_mdio_bus_exit(void) 378 { 379 struct fixed_mdio_bus *fmb = &platform_fmb; 380 struct fixed_phy *fp, *tmp; 381 382 mdiobus_unregister(fmb->mii_bus); 383 mdiobus_free(fmb->mii_bus); 384 platform_device_unregister(pdev); 385 386 list_for_each_entry_safe(fp, tmp, &fmb->phys, node) { 387 list_del(&fp->node); 388 kfree(fp); 389 } 390 ida_destroy(&phy_fixed_ida); 391 } 392 module_exit(fixed_mdio_bus_exit); 393 394 MODULE_DESCRIPTION("Fixed MDIO bus (MDIO bus emulation with fixed PHYs)"); 395 MODULE_AUTHOR("Vitaly Bordug"); 396 MODULE_LICENSE("GPL"); 397