1 /** 2 * ulpi.c - USB ULPI PHY bus 3 * 4 * Copyright (C) 2015 Intel Corporation 5 * 6 * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com> 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License version 2 as 10 * published by the Free Software Foundation. 11 */ 12 13 #include <linux/ulpi/interface.h> 14 #include <linux/ulpi/driver.h> 15 #include <linux/ulpi/regs.h> 16 #include <linux/module.h> 17 #include <linux/slab.h> 18 #include <linux/acpi.h> 19 #include <linux/of.h> 20 #include <linux/of_device.h> 21 #include <linux/clk/clk-conf.h> 22 23 /* -------------------------------------------------------------------------- */ 24 25 int ulpi_read(struct ulpi *ulpi, u8 addr) 26 { 27 return ulpi->ops->read(ulpi->dev.parent, addr); 28 } 29 EXPORT_SYMBOL_GPL(ulpi_read); 30 31 int ulpi_write(struct ulpi *ulpi, u8 addr, u8 val) 32 { 33 return ulpi->ops->write(ulpi->dev.parent, addr, val); 34 } 35 EXPORT_SYMBOL_GPL(ulpi_write); 36 37 /* -------------------------------------------------------------------------- */ 38 39 static int ulpi_match(struct device *dev, struct device_driver *driver) 40 { 41 struct ulpi_driver *drv = to_ulpi_driver(driver); 42 struct ulpi *ulpi = to_ulpi_dev(dev); 43 const struct ulpi_device_id *id; 44 45 /* Some ULPI devices don't have a vendor id so rely on OF match */ 46 if (ulpi->id.vendor == 0) 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 int 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 return 0; 92 } 93 94 static struct bus_type ulpi_bus = { 95 .name = "ulpi", 96 .match = ulpi_match, 97 .uevent = ulpi_uevent, 98 .probe = ulpi_probe, 99 .remove = ulpi_remove, 100 }; 101 102 /* -------------------------------------------------------------------------- */ 103 104 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, 105 char *buf) 106 { 107 int len; 108 struct ulpi *ulpi = to_ulpi_dev(dev); 109 110 len = of_device_modalias(dev, buf, PAGE_SIZE); 111 if (len != -ENODEV) 112 return len; 113 114 return sprintf(buf, "ulpi:v%04xp%04x\n", 115 ulpi->id.vendor, ulpi->id.product); 116 } 117 static DEVICE_ATTR_RO(modalias); 118 119 static struct attribute *ulpi_dev_attrs[] = { 120 &dev_attr_modalias.attr, 121 NULL 122 }; 123 124 static struct attribute_group ulpi_dev_attr_group = { 125 .attrs = ulpi_dev_attrs, 126 }; 127 128 static const struct attribute_group *ulpi_dev_attr_groups[] = { 129 &ulpi_dev_attr_group, 130 NULL 131 }; 132 133 static void ulpi_dev_release(struct device *dev) 134 { 135 kfree(to_ulpi_dev(dev)); 136 } 137 138 static const struct device_type ulpi_dev_type = { 139 .name = "ulpi_device", 140 .groups = ulpi_dev_attr_groups, 141 .release = ulpi_dev_release, 142 }; 143 144 /* -------------------------------------------------------------------------- */ 145 146 /** 147 * ulpi_register_driver - register a driver with the ULPI bus 148 * @drv: driver being registered 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_find_node_by_name(parent->of_node, "ulpi"); 187 else if (parent->parent && parent->parent->of_node) 188 np = of_find_node_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 return ret; 253 254 ret = device_register(&ulpi->dev); 255 if (ret) 256 return ret; 257 258 dev_dbg(&ulpi->dev, "registered ULPI PHY: vendor %04x, product %04x\n", 259 ulpi->id.vendor, ulpi->id.product); 260 261 return 0; 262 } 263 264 /** 265 * ulpi_register_interface - instantiate new ULPI device 266 * @dev: USB controller's device interface 267 * @ops: ULPI register access 268 * 269 * Allocates and registers a ULPI device and an interface for it. Called from 270 * the USB controller that provides the ULPI interface. 271 */ 272 struct ulpi *ulpi_register_interface(struct device *dev, 273 const struct ulpi_ops *ops) 274 { 275 struct ulpi *ulpi; 276 int ret; 277 278 ulpi = kzalloc(sizeof(*ulpi), GFP_KERNEL); 279 if (!ulpi) 280 return ERR_PTR(-ENOMEM); 281 282 ulpi->ops = ops; 283 284 ret = ulpi_register(dev, ulpi); 285 if (ret) { 286 kfree(ulpi); 287 return ERR_PTR(ret); 288 } 289 290 return ulpi; 291 } 292 EXPORT_SYMBOL_GPL(ulpi_register_interface); 293 294 /** 295 * ulpi_unregister_interface - unregister ULPI interface 296 * @intrf: struct ulpi_interface 297 * 298 * Unregisters a ULPI device and it's interface that was created with 299 * ulpi_create_interface(). 300 */ 301 void ulpi_unregister_interface(struct ulpi *ulpi) 302 { 303 of_node_put(ulpi->dev.of_node); 304 device_unregister(&ulpi->dev); 305 } 306 EXPORT_SYMBOL_GPL(ulpi_unregister_interface); 307 308 /* -------------------------------------------------------------------------- */ 309 310 static int __init ulpi_init(void) 311 { 312 return bus_register(&ulpi_bus); 313 } 314 subsys_initcall(ulpi_init); 315 316 static void __exit ulpi_exit(void) 317 { 318 bus_unregister(&ulpi_bus); 319 } 320 module_exit(ulpi_exit); 321 322 MODULE_AUTHOR("Intel Corporation"); 323 MODULE_LICENSE("GPL v2"); 324 MODULE_DESCRIPTION("USB ULPI PHY bus"); 325