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 /* 43 * Some ULPI devices don't have a vendor id 44 * or provide an id_table so rely on OF match. 45 */ 46 if (ulpi->id.vendor == 0 || !drv->id_table) 47 return of_driver_match_device(dev, driver); 48 49 for (id = drv->id_table; id->vendor; id++) 50 if (id->vendor == ulpi->id.vendor && 51 id->product == ulpi->id.product) 52 return 1; 53 54 return 0; 55 } 56 57 static int ulpi_uevent(struct device *dev, struct kobj_uevent_env *env) 58 { 59 struct ulpi *ulpi = to_ulpi_dev(dev); 60 int ret; 61 62 ret = of_device_uevent_modalias(dev, env); 63 if (ret != -ENODEV) 64 return ret; 65 66 if (add_uevent_var(env, "MODALIAS=ulpi:v%04xp%04x", 67 ulpi->id.vendor, ulpi->id.product)) 68 return -ENOMEM; 69 return 0; 70 } 71 72 static int ulpi_probe(struct device *dev) 73 { 74 struct ulpi_driver *drv = to_ulpi_driver(dev->driver); 75 int ret; 76 77 ret = of_clk_set_defaults(dev->of_node, false); 78 if (ret < 0) 79 return ret; 80 81 return drv->probe(to_ulpi_dev(dev)); 82 } 83 84 static void ulpi_remove(struct device *dev) 85 { 86 struct ulpi_driver *drv = to_ulpi_driver(dev->driver); 87 88 if (drv->remove) 89 drv->remove(to_ulpi_dev(dev)); 90 } 91 92 static struct bus_type ulpi_bus = { 93 .name = "ulpi", 94 .match = ulpi_match, 95 .uevent = ulpi_uevent, 96 .probe = ulpi_probe, 97 .remove = ulpi_remove, 98 }; 99 100 /* -------------------------------------------------------------------------- */ 101 102 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, 103 char *buf) 104 { 105 int len; 106 struct ulpi *ulpi = to_ulpi_dev(dev); 107 108 len = of_device_modalias(dev, buf, PAGE_SIZE); 109 if (len != -ENODEV) 110 return len; 111 112 return sprintf(buf, "ulpi:v%04xp%04x\n", 113 ulpi->id.vendor, ulpi->id.product); 114 } 115 static DEVICE_ATTR_RO(modalias); 116 117 static struct attribute *ulpi_dev_attrs[] = { 118 &dev_attr_modalias.attr, 119 NULL 120 }; 121 122 static const struct attribute_group ulpi_dev_attr_group = { 123 .attrs = ulpi_dev_attrs, 124 }; 125 126 static const struct attribute_group *ulpi_dev_attr_groups[] = { 127 &ulpi_dev_attr_group, 128 NULL 129 }; 130 131 static void ulpi_dev_release(struct device *dev) 132 { 133 of_node_put(dev->of_node); 134 kfree(to_ulpi_dev(dev)); 135 } 136 137 static const struct device_type ulpi_dev_type = { 138 .name = "ulpi_device", 139 .groups = ulpi_dev_attr_groups, 140 .release = ulpi_dev_release, 141 }; 142 143 /* -------------------------------------------------------------------------- */ 144 145 /** 146 * __ulpi_register_driver - register a driver with the ULPI bus 147 * @drv: driver being registered 148 * @module: ends up being THIS_MODULE 149 * 150 * Registers a driver with the ULPI bus. 151 */ 152 int __ulpi_register_driver(struct ulpi_driver *drv, struct module *module) 153 { 154 if (!drv->probe) 155 return -EINVAL; 156 157 drv->driver.owner = module; 158 drv->driver.bus = &ulpi_bus; 159 160 return driver_register(&drv->driver); 161 } 162 EXPORT_SYMBOL_GPL(__ulpi_register_driver); 163 164 /** 165 * ulpi_unregister_driver - unregister a driver with the ULPI bus 166 * @drv: driver to unregister 167 * 168 * Unregisters a driver with the ULPI bus. 169 */ 170 void ulpi_unregister_driver(struct ulpi_driver *drv) 171 { 172 driver_unregister(&drv->driver); 173 } 174 EXPORT_SYMBOL_GPL(ulpi_unregister_driver); 175 176 /* -------------------------------------------------------------------------- */ 177 178 static int ulpi_of_register(struct ulpi *ulpi) 179 { 180 struct device_node *np = NULL, *child; 181 struct device *parent; 182 183 /* Find a ulpi bus underneath the parent or the grandparent */ 184 parent = ulpi->dev.parent; 185 if (parent->of_node) 186 np = of_get_child_by_name(parent->of_node, "ulpi"); 187 else if (parent->parent && parent->parent->of_node) 188 np = of_get_child_by_name(parent->parent->of_node, "ulpi"); 189 if (!np) 190 return 0; 191 192 child = of_get_next_available_child(np, NULL); 193 of_node_put(np); 194 if (!child) 195 return -EINVAL; 196 197 ulpi->dev.of_node = child; 198 199 return 0; 200 } 201 202 static int ulpi_read_id(struct ulpi *ulpi) 203 { 204 int ret; 205 206 /* Test the interface */ 207 ret = ulpi_write(ulpi, ULPI_SCRATCH, 0xaa); 208 if (ret < 0) 209 goto err; 210 211 ret = ulpi_read(ulpi, ULPI_SCRATCH); 212 if (ret < 0) 213 return ret; 214 215 if (ret != 0xaa) 216 goto err; 217 218 ulpi->id.vendor = ulpi_read(ulpi, ULPI_VENDOR_ID_LOW); 219 ulpi->id.vendor |= ulpi_read(ulpi, ULPI_VENDOR_ID_HIGH) << 8; 220 221 ulpi->id.product = ulpi_read(ulpi, ULPI_PRODUCT_ID_LOW); 222 ulpi->id.product |= ulpi_read(ulpi, ULPI_PRODUCT_ID_HIGH) << 8; 223 224 /* Some ULPI devices don't have a vendor id so rely on OF match */ 225 if (ulpi->id.vendor == 0) 226 goto err; 227 228 request_module("ulpi:v%04xp%04x", ulpi->id.vendor, ulpi->id.product); 229 return 0; 230 err: 231 of_device_request_module(&ulpi->dev); 232 return 0; 233 } 234 235 static int ulpi_register(struct device *dev, struct ulpi *ulpi) 236 { 237 int ret; 238 239 ulpi->dev.parent = dev; /* needed early for ops */ 240 ulpi->dev.bus = &ulpi_bus; 241 ulpi->dev.type = &ulpi_dev_type; 242 dev_set_name(&ulpi->dev, "%s.ulpi", dev_name(dev)); 243 244 ACPI_COMPANION_SET(&ulpi->dev, ACPI_COMPANION(dev)); 245 246 ret = ulpi_of_register(ulpi); 247 if (ret) 248 return ret; 249 250 ret = ulpi_read_id(ulpi); 251 if (ret) { 252 of_node_put(ulpi->dev.of_node); 253 return ret; 254 } 255 256 ret = device_register(&ulpi->dev); 257 if (ret) { 258 put_device(&ulpi->dev); 259 return ret; 260 } 261 262 dev_dbg(&ulpi->dev, "registered ULPI PHY: vendor %04x, product %04x\n", 263 ulpi->id.vendor, ulpi->id.product); 264 265 return 0; 266 } 267 268 /** 269 * ulpi_register_interface - instantiate new ULPI device 270 * @dev: USB controller's device interface 271 * @ops: ULPI register access 272 * 273 * Allocates and registers a ULPI device and an interface for it. Called from 274 * the USB controller that provides the ULPI interface. 275 */ 276 struct ulpi *ulpi_register_interface(struct device *dev, 277 const struct ulpi_ops *ops) 278 { 279 struct ulpi *ulpi; 280 int ret; 281 282 ulpi = kzalloc(sizeof(*ulpi), GFP_KERNEL); 283 if (!ulpi) 284 return ERR_PTR(-ENOMEM); 285 286 ulpi->ops = ops; 287 288 ret = ulpi_register(dev, ulpi); 289 if (ret) { 290 kfree(ulpi); 291 return ERR_PTR(ret); 292 } 293 294 return ulpi; 295 } 296 EXPORT_SYMBOL_GPL(ulpi_register_interface); 297 298 /** 299 * ulpi_unregister_interface - unregister ULPI interface 300 * @ulpi: struct ulpi_interface 301 * 302 * Unregisters a ULPI device and it's interface that was created with 303 * ulpi_create_interface(). 304 */ 305 void ulpi_unregister_interface(struct ulpi *ulpi) 306 { 307 device_unregister(&ulpi->dev); 308 } 309 EXPORT_SYMBOL_GPL(ulpi_unregister_interface); 310 311 /* -------------------------------------------------------------------------- */ 312 313 static int __init ulpi_init(void) 314 { 315 return bus_register(&ulpi_bus); 316 } 317 subsys_initcall(ulpi_init); 318 319 static void __exit ulpi_exit(void) 320 { 321 bus_unregister(&ulpi_bus); 322 } 323 module_exit(ulpi_exit); 324 325 MODULE_AUTHOR("Intel Corporation"); 326 MODULE_LICENSE("GPL v2"); 327 MODULE_DESCRIPTION("USB ULPI PHY bus"); 328