1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * ulpi.c - USB ULPI PHY bus 4 * 5 * Copyright (C) 2015 Intel Corporation 6 * 7 * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com> 8 */ 9 10 #include <linux/ulpi/interface.h> 11 #include <linux/ulpi/driver.h> 12 #include <linux/ulpi/regs.h> 13 #include <linux/module.h> 14 #include <linux/slab.h> 15 #include <linux/acpi.h> 16 #include <linux/of.h> 17 #include <linux/of_device.h> 18 #include <linux/clk/clk-conf.h> 19 20 /* -------------------------------------------------------------------------- */ 21 22 int ulpi_read(struct ulpi *ulpi, u8 addr) 23 { 24 return ulpi->ops->read(ulpi->dev.parent, addr); 25 } 26 EXPORT_SYMBOL_GPL(ulpi_read); 27 28 int ulpi_write(struct ulpi *ulpi, u8 addr, u8 val) 29 { 30 return ulpi->ops->write(ulpi->dev.parent, addr, val); 31 } 32 EXPORT_SYMBOL_GPL(ulpi_write); 33 34 /* -------------------------------------------------------------------------- */ 35 36 static int ulpi_match(struct device *dev, struct device_driver *driver) 37 { 38 struct ulpi_driver *drv = to_ulpi_driver(driver); 39 struct ulpi *ulpi = to_ulpi_dev(dev); 40 const struct ulpi_device_id *id; 41 42 /* Some ULPI devices don't have a vendor id so rely on OF match */ 43 if (ulpi->id.vendor == 0) 44 return of_driver_match_device(dev, driver); 45 46 for (id = drv->id_table; id->vendor; id++) 47 if (id->vendor == ulpi->id.vendor && 48 id->product == ulpi->id.product) 49 return 1; 50 51 return 0; 52 } 53 54 static int ulpi_uevent(struct device *dev, struct kobj_uevent_env *env) 55 { 56 struct ulpi *ulpi = to_ulpi_dev(dev); 57 int ret; 58 59 ret = of_device_uevent_modalias(dev, env); 60 if (ret != -ENODEV) 61 return ret; 62 63 if (add_uevent_var(env, "MODALIAS=ulpi:v%04xp%04x", 64 ulpi->id.vendor, ulpi->id.product)) 65 return -ENOMEM; 66 return 0; 67 } 68 69 static int ulpi_probe(struct device *dev) 70 { 71 struct ulpi_driver *drv = to_ulpi_driver(dev->driver); 72 int ret; 73 74 ret = of_clk_set_defaults(dev->of_node, false); 75 if (ret < 0) 76 return ret; 77 78 return drv->probe(to_ulpi_dev(dev)); 79 } 80 81 static int ulpi_remove(struct device *dev) 82 { 83 struct ulpi_driver *drv = to_ulpi_driver(dev->driver); 84 85 if (drv->remove) 86 drv->remove(to_ulpi_dev(dev)); 87 88 return 0; 89 } 90 91 static struct bus_type ulpi_bus = { 92 .name = "ulpi", 93 .match = ulpi_match, 94 .uevent = ulpi_uevent, 95 .probe = ulpi_probe, 96 .remove = ulpi_remove, 97 }; 98 99 /* -------------------------------------------------------------------------- */ 100 101 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, 102 char *buf) 103 { 104 int len; 105 struct ulpi *ulpi = to_ulpi_dev(dev); 106 107 len = of_device_modalias(dev, buf, PAGE_SIZE); 108 if (len != -ENODEV) 109 return len; 110 111 return sprintf(buf, "ulpi:v%04xp%04x\n", 112 ulpi->id.vendor, ulpi->id.product); 113 } 114 static DEVICE_ATTR_RO(modalias); 115 116 static struct attribute *ulpi_dev_attrs[] = { 117 &dev_attr_modalias.attr, 118 NULL 119 }; 120 121 static const struct attribute_group ulpi_dev_attr_group = { 122 .attrs = ulpi_dev_attrs, 123 }; 124 125 static const struct attribute_group *ulpi_dev_attr_groups[] = { 126 &ulpi_dev_attr_group, 127 NULL 128 }; 129 130 static void ulpi_dev_release(struct device *dev) 131 { 132 kfree(to_ulpi_dev(dev)); 133 } 134 135 static const struct device_type ulpi_dev_type = { 136 .name = "ulpi_device", 137 .groups = ulpi_dev_attr_groups, 138 .release = ulpi_dev_release, 139 }; 140 141 /* -------------------------------------------------------------------------- */ 142 143 /** 144 * ulpi_register_driver - register a driver with the ULPI bus 145 * @drv: driver being registered 146 * @module: ends up being THIS_MODULE 147 * 148 * Registers a driver with the ULPI bus. 149 */ 150 int __ulpi_register_driver(struct ulpi_driver *drv, struct module *module) 151 { 152 if (!drv->probe) 153 return -EINVAL; 154 155 drv->driver.owner = module; 156 drv->driver.bus = &ulpi_bus; 157 158 return driver_register(&drv->driver); 159 } 160 EXPORT_SYMBOL_GPL(__ulpi_register_driver); 161 162 /** 163 * ulpi_unregister_driver - unregister a driver with the ULPI bus 164 * @drv: driver to unregister 165 * 166 * Unregisters a driver with the ULPI bus. 167 */ 168 void ulpi_unregister_driver(struct ulpi_driver *drv) 169 { 170 driver_unregister(&drv->driver); 171 } 172 EXPORT_SYMBOL_GPL(ulpi_unregister_driver); 173 174 /* -------------------------------------------------------------------------- */ 175 176 static int ulpi_of_register(struct ulpi *ulpi) 177 { 178 struct device_node *np = NULL, *child; 179 struct device *parent; 180 181 /* Find a ulpi bus underneath the parent or the grandparent */ 182 parent = ulpi->dev.parent; 183 if (parent->of_node) 184 np = of_get_child_by_name(parent->of_node, "ulpi"); 185 else if (parent->parent && parent->parent->of_node) 186 np = of_get_child_by_name(parent->parent->of_node, "ulpi"); 187 if (!np) 188 return 0; 189 190 child = of_get_next_available_child(np, NULL); 191 of_node_put(np); 192 if (!child) 193 return -EINVAL; 194 195 ulpi->dev.of_node = child; 196 197 return 0; 198 } 199 200 static int ulpi_read_id(struct ulpi *ulpi) 201 { 202 int ret; 203 204 /* Test the interface */ 205 ret = ulpi_write(ulpi, ULPI_SCRATCH, 0xaa); 206 if (ret < 0) 207 goto err; 208 209 ret = ulpi_read(ulpi, ULPI_SCRATCH); 210 if (ret < 0) 211 return ret; 212 213 if (ret != 0xaa) 214 goto err; 215 216 ulpi->id.vendor = ulpi_read(ulpi, ULPI_VENDOR_ID_LOW); 217 ulpi->id.vendor |= ulpi_read(ulpi, ULPI_VENDOR_ID_HIGH) << 8; 218 219 ulpi->id.product = ulpi_read(ulpi, ULPI_PRODUCT_ID_LOW); 220 ulpi->id.product |= ulpi_read(ulpi, ULPI_PRODUCT_ID_HIGH) << 8; 221 222 /* Some ULPI devices don't have a vendor id so rely on OF match */ 223 if (ulpi->id.vendor == 0) 224 goto err; 225 226 request_module("ulpi:v%04xp%04x", ulpi->id.vendor, ulpi->id.product); 227 return 0; 228 err: 229 of_device_request_module(&ulpi->dev); 230 return 0; 231 } 232 233 static int ulpi_register(struct device *dev, struct ulpi *ulpi) 234 { 235 int ret; 236 237 ulpi->dev.parent = dev; /* needed early for ops */ 238 ulpi->dev.bus = &ulpi_bus; 239 ulpi->dev.type = &ulpi_dev_type; 240 dev_set_name(&ulpi->dev, "%s.ulpi", dev_name(dev)); 241 242 ACPI_COMPANION_SET(&ulpi->dev, ACPI_COMPANION(dev)); 243 244 ret = ulpi_of_register(ulpi); 245 if (ret) 246 return ret; 247 248 ret = ulpi_read_id(ulpi); 249 if (ret) 250 return ret; 251 252 ret = device_register(&ulpi->dev); 253 if (ret) 254 return ret; 255 256 dev_dbg(&ulpi->dev, "registered ULPI PHY: vendor %04x, product %04x\n", 257 ulpi->id.vendor, ulpi->id.product); 258 259 return 0; 260 } 261 262 /** 263 * ulpi_register_interface - instantiate new ULPI device 264 * @dev: USB controller's device interface 265 * @ops: ULPI register access 266 * 267 * Allocates and registers a ULPI device and an interface for it. Called from 268 * the USB controller that provides the ULPI interface. 269 */ 270 struct ulpi *ulpi_register_interface(struct device *dev, 271 const struct ulpi_ops *ops) 272 { 273 struct ulpi *ulpi; 274 int ret; 275 276 ulpi = kzalloc(sizeof(*ulpi), GFP_KERNEL); 277 if (!ulpi) 278 return ERR_PTR(-ENOMEM); 279 280 ulpi->ops = ops; 281 282 ret = ulpi_register(dev, ulpi); 283 if (ret) { 284 kfree(ulpi); 285 return ERR_PTR(ret); 286 } 287 288 return ulpi; 289 } 290 EXPORT_SYMBOL_GPL(ulpi_register_interface); 291 292 /** 293 * ulpi_unregister_interface - unregister ULPI interface 294 * @ulpi: struct ulpi_interface 295 * 296 * Unregisters a ULPI device and it's interface that was created with 297 * ulpi_create_interface(). 298 */ 299 void ulpi_unregister_interface(struct ulpi *ulpi) 300 { 301 of_node_put(ulpi->dev.of_node); 302 device_unregister(&ulpi->dev); 303 } 304 EXPORT_SYMBOL_GPL(ulpi_unregister_interface); 305 306 /* -------------------------------------------------------------------------- */ 307 308 static int __init ulpi_init(void) 309 { 310 return bus_register(&ulpi_bus); 311 } 312 subsys_initcall(ulpi_init); 313 314 static void __exit ulpi_exit(void) 315 { 316 bus_unregister(&ulpi_bus); 317 } 318 module_exit(ulpi_exit); 319 320 MODULE_AUTHOR("Intel Corporation"); 321 MODULE_LICENSE("GPL v2"); 322 MODULE_DESCRIPTION("USB ULPI PHY bus"); 323