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.h> 22 #include <linux/seqlock.h> 23 #include <linux/idr.h> 24 #include <linux/netdevice.h> 25 26 #include "swphy.h" 27 28 struct fixed_mdio_bus { 29 struct mii_bus *mii_bus; 30 struct list_head phys; 31 }; 32 33 struct fixed_phy { 34 int addr; 35 struct phy_device *phydev; 36 seqcount_t seqcount; 37 struct fixed_phy_status status; 38 bool no_carrier; 39 int (*link_update)(struct net_device *, struct fixed_phy_status *); 40 struct list_head node; 41 int link_gpio; 42 }; 43 44 static struct platform_device *pdev; 45 static struct fixed_mdio_bus platform_fmb = { 46 .phys = LIST_HEAD_INIT(platform_fmb.phys), 47 }; 48 49 int fixed_phy_change_carrier(struct net_device *dev, bool new_carrier) 50 { 51 struct fixed_mdio_bus *fmb = &platform_fmb; 52 struct phy_device *phydev = dev->phydev; 53 struct fixed_phy *fp; 54 55 if (!phydev || !phydev->mdio.bus) 56 return -EINVAL; 57 58 list_for_each_entry(fp, &fmb->phys, node) { 59 if (fp->addr == phydev->mdio.addr) { 60 fp->no_carrier = !new_carrier; 61 return 0; 62 } 63 } 64 return -EINVAL; 65 } 66 EXPORT_SYMBOL_GPL(fixed_phy_change_carrier); 67 68 static void fixed_phy_update(struct fixed_phy *fp) 69 { 70 if (!fp->no_carrier && gpio_is_valid(fp->link_gpio)) 71 fp->status.link = !!gpio_get_value_cansleep(fp->link_gpio); 72 } 73 74 static int fixed_mdio_read(struct mii_bus *bus, int phy_addr, int reg_num) 75 { 76 struct fixed_mdio_bus *fmb = bus->priv; 77 struct fixed_phy *fp; 78 79 list_for_each_entry(fp, &fmb->phys, node) { 80 if (fp->addr == phy_addr) { 81 struct fixed_phy_status state; 82 int s; 83 84 do { 85 s = read_seqcount_begin(&fp->seqcount); 86 fp->status.link = !fp->no_carrier; 87 /* Issue callback if user registered it. */ 88 if (fp->link_update) { 89 fp->link_update(fp->phydev->attached_dev, 90 &fp->status); 91 fixed_phy_update(fp); 92 } 93 state = fp->status; 94 } while (read_seqcount_retry(&fp->seqcount, s)); 95 96 return swphy_read_reg(reg_num, &state); 97 } 98 } 99 100 return 0xFFFF; 101 } 102 103 static int fixed_mdio_write(struct mii_bus *bus, int phy_addr, int reg_num, 104 u16 val) 105 { 106 return 0; 107 } 108 109 /* 110 * If something weird is required to be done with link/speed, 111 * network driver is able to assign a function to implement this. 112 * May be useful for PHY's that need to be software-driven. 113 */ 114 int fixed_phy_set_link_update(struct phy_device *phydev, 115 int (*link_update)(struct net_device *, 116 struct fixed_phy_status *)) 117 { 118 struct fixed_mdio_bus *fmb = &platform_fmb; 119 struct fixed_phy *fp; 120 121 if (!phydev || !phydev->mdio.bus) 122 return -EINVAL; 123 124 list_for_each_entry(fp, &fmb->phys, node) { 125 if (fp->addr == phydev->mdio.addr) { 126 fp->link_update = link_update; 127 fp->phydev = phydev; 128 return 0; 129 } 130 } 131 132 return -ENOENT; 133 } 134 EXPORT_SYMBOL_GPL(fixed_phy_set_link_update); 135 136 int fixed_phy_add(unsigned int irq, int phy_addr, 137 struct fixed_phy_status *status, 138 int link_gpio) 139 { 140 int ret; 141 struct fixed_mdio_bus *fmb = &platform_fmb; 142 struct fixed_phy *fp; 143 144 ret = swphy_validate_state(status); 145 if (ret < 0) 146 return ret; 147 148 fp = kzalloc(sizeof(*fp), GFP_KERNEL); 149 if (!fp) 150 return -ENOMEM; 151 152 seqcount_init(&fp->seqcount); 153 154 if (irq != PHY_POLL) 155 fmb->mii_bus->irq[phy_addr] = irq; 156 157 fp->addr = phy_addr; 158 fp->status = *status; 159 fp->link_gpio = link_gpio; 160 161 if (gpio_is_valid(fp->link_gpio)) { 162 ret = gpio_request_one(fp->link_gpio, GPIOF_DIR_IN, 163 "fixed-link-gpio-link"); 164 if (ret) 165 goto err_regs; 166 } 167 168 fixed_phy_update(fp); 169 170 list_add_tail(&fp->node, &fmb->phys); 171 172 return 0; 173 174 err_regs: 175 kfree(fp); 176 return ret; 177 } 178 EXPORT_SYMBOL_GPL(fixed_phy_add); 179 180 static DEFINE_IDA(phy_fixed_ida); 181 182 static void fixed_phy_del(int phy_addr) 183 { 184 struct fixed_mdio_bus *fmb = &platform_fmb; 185 struct fixed_phy *fp, *tmp; 186 187 list_for_each_entry_safe(fp, tmp, &fmb->phys, node) { 188 if (fp->addr == phy_addr) { 189 list_del(&fp->node); 190 if (gpio_is_valid(fp->link_gpio)) 191 gpio_free(fp->link_gpio); 192 kfree(fp); 193 ida_simple_remove(&phy_fixed_ida, phy_addr); 194 return; 195 } 196 } 197 } 198 199 struct phy_device *fixed_phy_register(unsigned int irq, 200 struct fixed_phy_status *status, 201 int link_gpio, 202 struct device_node *np) 203 { 204 struct fixed_mdio_bus *fmb = &platform_fmb; 205 struct phy_device *phy; 206 int phy_addr; 207 int ret; 208 209 if (!fmb->mii_bus || fmb->mii_bus->state != MDIOBUS_REGISTERED) 210 return ERR_PTR(-EPROBE_DEFER); 211 212 /* Get the next available PHY address, up to PHY_MAX_ADDR */ 213 phy_addr = ida_simple_get(&phy_fixed_ida, 0, PHY_MAX_ADDR, GFP_KERNEL); 214 if (phy_addr < 0) 215 return ERR_PTR(phy_addr); 216 217 ret = fixed_phy_add(irq, phy_addr, status, link_gpio); 218 if (ret < 0) { 219 ida_simple_remove(&phy_fixed_ida, phy_addr); 220 return ERR_PTR(ret); 221 } 222 223 phy = get_phy_device(fmb->mii_bus, phy_addr, false); 224 if (IS_ERR(phy)) { 225 fixed_phy_del(phy_addr); 226 return ERR_PTR(-EINVAL); 227 } 228 229 /* propagate the fixed link values to struct phy_device */ 230 phy->link = status->link; 231 if (status->link) { 232 phy->speed = status->speed; 233 phy->duplex = status->duplex; 234 phy->pause = status->pause; 235 phy->asym_pause = status->asym_pause; 236 } 237 238 of_node_get(np); 239 phy->mdio.dev.of_node = np; 240 phy->is_pseudo_fixed_link = true; 241 242 switch (status->speed) { 243 case SPEED_1000: 244 linkmode_set_bit(ETHTOOL_LINK_MODE_1000baseT_Half_BIT, 245 phy->supported); 246 linkmode_set_bit(ETHTOOL_LINK_MODE_1000baseT_Full_BIT, 247 phy->supported); 248 /* fall through */ 249 case SPEED_100: 250 linkmode_set_bit(ETHTOOL_LINK_MODE_100baseT_Half_BIT, 251 phy->supported); 252 linkmode_set_bit(ETHTOOL_LINK_MODE_100baseT_Full_BIT, 253 phy->supported); 254 /* fall through */ 255 case SPEED_10: 256 default: 257 linkmode_set_bit(ETHTOOL_LINK_MODE_10baseT_Half_BIT, 258 phy->supported); 259 linkmode_set_bit(ETHTOOL_LINK_MODE_10baseT_Full_BIT, 260 phy->supported); 261 } 262 263 ret = phy_device_register(phy); 264 if (ret) { 265 phy_device_free(phy); 266 of_node_put(np); 267 fixed_phy_del(phy_addr); 268 return ERR_PTR(ret); 269 } 270 271 return phy; 272 } 273 EXPORT_SYMBOL_GPL(fixed_phy_register); 274 275 void fixed_phy_unregister(struct phy_device *phy) 276 { 277 phy_device_remove(phy); 278 of_node_put(phy->mdio.dev.of_node); 279 fixed_phy_del(phy->mdio.addr); 280 } 281 EXPORT_SYMBOL_GPL(fixed_phy_unregister); 282 283 static int __init fixed_mdio_bus_init(void) 284 { 285 struct fixed_mdio_bus *fmb = &platform_fmb; 286 int ret; 287 288 pdev = platform_device_register_simple("Fixed MDIO bus", 0, NULL, 0); 289 if (IS_ERR(pdev)) 290 return PTR_ERR(pdev); 291 292 fmb->mii_bus = mdiobus_alloc(); 293 if (fmb->mii_bus == NULL) { 294 ret = -ENOMEM; 295 goto err_mdiobus_reg; 296 } 297 298 snprintf(fmb->mii_bus->id, MII_BUS_ID_SIZE, "fixed-0"); 299 fmb->mii_bus->name = "Fixed MDIO Bus"; 300 fmb->mii_bus->priv = fmb; 301 fmb->mii_bus->parent = &pdev->dev; 302 fmb->mii_bus->read = &fixed_mdio_read; 303 fmb->mii_bus->write = &fixed_mdio_write; 304 305 ret = mdiobus_register(fmb->mii_bus); 306 if (ret) 307 goto err_mdiobus_alloc; 308 309 return 0; 310 311 err_mdiobus_alloc: 312 mdiobus_free(fmb->mii_bus); 313 err_mdiobus_reg: 314 platform_device_unregister(pdev); 315 return ret; 316 } 317 module_init(fixed_mdio_bus_init); 318 319 static void __exit fixed_mdio_bus_exit(void) 320 { 321 struct fixed_mdio_bus *fmb = &platform_fmb; 322 struct fixed_phy *fp, *tmp; 323 324 mdiobus_unregister(fmb->mii_bus); 325 mdiobus_free(fmb->mii_bus); 326 platform_device_unregister(pdev); 327 328 list_for_each_entry_safe(fp, tmp, &fmb->phys, node) { 329 list_del(&fp->node); 330 kfree(fp); 331 } 332 ida_destroy(&phy_fixed_ida); 333 } 334 module_exit(fixed_mdio_bus_exit); 335 336 MODULE_DESCRIPTION("Fixed MDIO bus (MDIO bus emulation with fixed PHYs)"); 337 MODULE_AUTHOR("Vitaly Bordug"); 338 MODULE_LICENSE("GPL"); 339