1 // SPDX-License-Identifier: GPL-2.0+ 2 /* Framework for MDIO devices, other than PHYs. 3 * 4 * Copyright (c) 2016 Andrew Lunn <andrew@lunn.ch> 5 */ 6 7 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 8 9 #include <linux/delay.h> 10 #include <linux/errno.h> 11 #include <linux/gpio.h> 12 #include <linux/gpio/consumer.h> 13 #include <linux/init.h> 14 #include <linux/interrupt.h> 15 #include <linux/kernel.h> 16 #include <linux/mdio.h> 17 #include <linux/mii.h> 18 #include <linux/module.h> 19 #include <linux/phy.h> 20 #include <linux/reset.h> 21 #include <linux/slab.h> 22 #include <linux/string.h> 23 #include <linux/unistd.h> 24 #include <linux/property.h> 25 #include "mdio-private.h" 26 27 void mdio_device_free(struct mdio_device *mdiodev) 28 { 29 put_device(&mdiodev->dev); 30 } 31 EXPORT_SYMBOL(mdio_device_free); 32 33 static void mdio_device_release(struct device *dev) 34 { 35 fwnode_handle_put(dev->fwnode); 36 kfree(to_mdio_device(dev)); 37 } 38 39 static int mdio_device_bus_match(struct device *dev, 40 const struct device_driver *drv) 41 { 42 struct mdio_device *mdiodev = to_mdio_device(dev); 43 const struct mdio_driver *mdiodrv = to_mdio_driver(drv); 44 45 if (mdiodrv->mdiodrv.flags & MDIO_DEVICE_IS_PHY) 46 return 0; 47 48 return strcmp(mdiodev->modalias, drv->name) == 0; 49 } 50 51 struct mdio_device *mdio_device_create(struct mii_bus *bus, int addr) 52 { 53 struct mdio_device *mdiodev; 54 55 /* We allocate the device, and initialize the default values */ 56 mdiodev = kzalloc(sizeof(*mdiodev), GFP_KERNEL); 57 if (!mdiodev) 58 return ERR_PTR(-ENOMEM); 59 60 mdiodev->dev.release = mdio_device_release; 61 mdiodev->dev.parent = &bus->dev; 62 mdiodev->dev.bus = &mdio_bus_type; 63 mdiodev->bus_match = mdio_device_bus_match; 64 mdiodev->device_free = mdio_device_free; 65 mdiodev->device_remove = mdio_device_remove; 66 mdiodev->bus = bus; 67 mdiodev->addr = addr; 68 mdiodev->reset_state = -1; 69 70 dev_set_name(&mdiodev->dev, PHY_ID_FMT, bus->id, addr); 71 72 device_initialize(&mdiodev->dev); 73 74 return mdiodev; 75 } 76 EXPORT_SYMBOL(mdio_device_create); 77 78 /** 79 * mdio_device_register - Register the mdio device on the MDIO bus 80 * @mdiodev: mdio_device structure to be added to the MDIO bus 81 */ 82 int mdio_device_register(struct mdio_device *mdiodev) 83 { 84 int err; 85 86 dev_dbg(&mdiodev->dev, "%s\n", __func__); 87 88 err = mdiobus_register_device(mdiodev); 89 if (err) 90 return err; 91 92 err = device_add(&mdiodev->dev); 93 if (err) { 94 pr_err("MDIO %d failed to add\n", mdiodev->addr); 95 goto out; 96 } 97 98 return 0; 99 100 out: 101 mdiobus_unregister_device(mdiodev); 102 return err; 103 } 104 EXPORT_SYMBOL(mdio_device_register); 105 106 /** 107 * mdio_device_remove - Remove a previously registered mdio device from the 108 * MDIO bus 109 * @mdiodev: mdio_device structure to remove 110 * 111 * This doesn't free the mdio_device itself, it merely reverses the effects 112 * of mdio_device_register(). Use mdio_device_free() to free the device 113 * after calling this function. 114 */ 115 void mdio_device_remove(struct mdio_device *mdiodev) 116 { 117 device_del(&mdiodev->dev); 118 mdiobus_unregister_device(mdiodev); 119 } 120 EXPORT_SYMBOL(mdio_device_remove); 121 122 /** 123 * mdio_device_register_reset - Read and initialize the reset properties of 124 * an mdio device 125 * @mdiodev: mdio_device structure 126 * 127 * Return: Zero if successful, negative error code on failure 128 */ 129 int mdio_device_register_reset(struct mdio_device *mdiodev) 130 { 131 struct reset_control *reset; 132 133 /* Deassert the optional reset signal */ 134 mdiodev->reset_gpio = gpiod_get_optional(&mdiodev->dev, 135 "reset", GPIOD_OUT_LOW); 136 if (IS_ERR(mdiodev->reset_gpio)) 137 return PTR_ERR(mdiodev->reset_gpio); 138 139 if (mdiodev->reset_gpio) 140 gpiod_set_consumer_name(mdiodev->reset_gpio, "PHY reset"); 141 142 reset = reset_control_get_optional_exclusive(&mdiodev->dev, "phy"); 143 if (IS_ERR(reset)) { 144 gpiod_put(mdiodev->reset_gpio); 145 mdiodev->reset_gpio = NULL; 146 return PTR_ERR(reset); 147 } 148 149 mdiodev->reset_ctrl = reset; 150 151 /* Read optional firmware properties */ 152 fwnode_property_read_u32(dev_fwnode(&mdiodev->dev), "reset-assert-us", 153 &mdiodev->reset_assert_delay); 154 fwnode_property_read_u32(dev_fwnode(&mdiodev->dev), "reset-deassert-us", 155 &mdiodev->reset_deassert_delay); 156 157 return 0; 158 } 159 160 /** 161 * mdio_device_unregister_reset - uninitialize the reset properties of 162 * an mdio device 163 * @mdiodev: mdio_device structure 164 */ 165 void mdio_device_unregister_reset(struct mdio_device *mdiodev) 166 { 167 gpiod_put(mdiodev->reset_gpio); 168 reset_control_put(mdiodev->reset_ctrl); 169 } 170 171 void mdio_device_reset(struct mdio_device *mdiodev, int value) 172 { 173 unsigned int d; 174 175 if (!mdiodev->reset_gpio && !mdiodev->reset_ctrl) 176 return; 177 178 if (mdiodev->reset_state == value) 179 return; 180 181 if (mdiodev->reset_gpio) 182 gpiod_set_value_cansleep(mdiodev->reset_gpio, value); 183 184 if (mdiodev->reset_ctrl) { 185 if (value) 186 reset_control_assert(mdiodev->reset_ctrl); 187 else 188 reset_control_deassert(mdiodev->reset_ctrl); 189 } 190 191 d = value ? mdiodev->reset_assert_delay : mdiodev->reset_deassert_delay; 192 if (d) 193 fsleep(d); 194 195 mdiodev->reset_state = value; 196 } 197 EXPORT_SYMBOL(mdio_device_reset); 198 199 /** 200 * mdio_probe - probe an MDIO device 201 * @dev: device to probe 202 * 203 * Description: Take care of setting up the mdio_device structure 204 * and calling the driver to probe the device. 205 */ 206 static int mdio_probe(struct device *dev) 207 { 208 struct mdio_device *mdiodev = to_mdio_device(dev); 209 struct device_driver *drv = mdiodev->dev.driver; 210 struct mdio_driver *mdiodrv = to_mdio_driver(drv); 211 int err = 0; 212 213 /* Deassert the reset signal */ 214 mdio_device_reset(mdiodev, 0); 215 216 if (mdiodrv->probe) { 217 err = mdiodrv->probe(mdiodev); 218 if (err) { 219 /* Assert the reset signal */ 220 mdio_device_reset(mdiodev, 1); 221 } 222 } 223 224 return err; 225 } 226 227 static int mdio_remove(struct device *dev) 228 { 229 struct mdio_device *mdiodev = to_mdio_device(dev); 230 struct device_driver *drv = mdiodev->dev.driver; 231 struct mdio_driver *mdiodrv = to_mdio_driver(drv); 232 233 if (mdiodrv->remove) 234 mdiodrv->remove(mdiodev); 235 236 /* Assert the reset signal */ 237 mdio_device_reset(mdiodev, 1); 238 239 return 0; 240 } 241 242 static void mdio_shutdown(struct device *dev) 243 { 244 struct mdio_device *mdiodev = to_mdio_device(dev); 245 struct device_driver *drv = mdiodev->dev.driver; 246 struct mdio_driver *mdiodrv = to_mdio_driver(drv); 247 248 if (mdiodrv->shutdown) 249 mdiodrv->shutdown(mdiodev); 250 } 251 252 /** 253 * mdio_driver_register - register an mdio_driver with the MDIO layer 254 * @drv: new mdio_driver to register 255 */ 256 int mdio_driver_register(struct mdio_driver *drv) 257 { 258 struct mdio_driver_common *mdiodrv = &drv->mdiodrv; 259 int retval; 260 261 pr_debug("%s: %s\n", __func__, mdiodrv->driver.name); 262 263 mdiodrv->driver.bus = &mdio_bus_type; 264 mdiodrv->driver.probe = mdio_probe; 265 mdiodrv->driver.remove = mdio_remove; 266 mdiodrv->driver.shutdown = mdio_shutdown; 267 268 retval = driver_register(&mdiodrv->driver); 269 if (retval) { 270 pr_err("%s: Error %d in registering driver\n", 271 mdiodrv->driver.name, retval); 272 273 return retval; 274 } 275 276 return 0; 277 } 278 EXPORT_SYMBOL(mdio_driver_register); 279 280 void mdio_driver_unregister(struct mdio_driver *drv) 281 { 282 struct mdio_driver_common *mdiodrv = &drv->mdiodrv; 283 284 driver_unregister(&mdiodrv->driver); 285 } 286 EXPORT_SYMBOL(mdio_driver_unregister); 287