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 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 * 147 * Registers a driver with the ULPI bus. 148 */ 149 int __ulpi_register_driver(struct ulpi_driver *drv, struct module *module) 150 { 151 if (!drv->probe) 152 return -EINVAL; 153 154 drv->driver.owner = module; 155 drv->driver.bus = &ulpi_bus; 156 157 return driver_register(&drv->driver); 158 } 159 EXPORT_SYMBOL_GPL(__ulpi_register_driver); 160 161 /** 162 * ulpi_unregister_driver - unregister a driver with the ULPI bus 163 * @drv: driver to unregister 164 * 165 * Unregisters a driver with the ULPI bus. 166 */ 167 void ulpi_unregister_driver(struct ulpi_driver *drv) 168 { 169 driver_unregister(&drv->driver); 170 } 171 EXPORT_SYMBOL_GPL(ulpi_unregister_driver); 172 173 /* -------------------------------------------------------------------------- */ 174 175 static int ulpi_of_register(struct ulpi *ulpi) 176 { 177 struct device_node *np = NULL, *child; 178 struct device *parent; 179 180 /* Find a ulpi bus underneath the parent or the grandparent */ 181 parent = ulpi->dev.parent; 182 if (parent->of_node) 183 np = of_get_child_by_name(parent->of_node, "ulpi"); 184 else if (parent->parent && parent->parent->of_node) 185 np = of_get_child_by_name(parent->parent->of_node, "ulpi"); 186 if (!np) 187 return 0; 188 189 child = of_get_next_available_child(np, NULL); 190 of_node_put(np); 191 if (!child) 192 return -EINVAL; 193 194 ulpi->dev.of_node = child; 195 196 return 0; 197 } 198 199 static int ulpi_read_id(struct ulpi *ulpi) 200 { 201 int ret; 202 203 /* Test the interface */ 204 ret = ulpi_write(ulpi, ULPI_SCRATCH, 0xaa); 205 if (ret < 0) 206 goto err; 207 208 ret = ulpi_read(ulpi, ULPI_SCRATCH); 209 if (ret < 0) 210 return ret; 211 212 if (ret != 0xaa) 213 goto err; 214 215 ulpi->id.vendor = ulpi_read(ulpi, ULPI_VENDOR_ID_LOW); 216 ulpi->id.vendor |= ulpi_read(ulpi, ULPI_VENDOR_ID_HIGH) << 8; 217 218 ulpi->id.product = ulpi_read(ulpi, ULPI_PRODUCT_ID_LOW); 219 ulpi->id.product |= ulpi_read(ulpi, ULPI_PRODUCT_ID_HIGH) << 8; 220 221 /* Some ULPI devices don't have a vendor id so rely on OF match */ 222 if (ulpi->id.vendor == 0) 223 goto err; 224 225 request_module("ulpi:v%04xp%04x", ulpi->id.vendor, ulpi->id.product); 226 return 0; 227 err: 228 of_device_request_module(&ulpi->dev); 229 return 0; 230 } 231 232 static int ulpi_register(struct device *dev, struct ulpi *ulpi) 233 { 234 int ret; 235 236 ulpi->dev.parent = dev; /* needed early for ops */ 237 ulpi->dev.bus = &ulpi_bus; 238 ulpi->dev.type = &ulpi_dev_type; 239 dev_set_name(&ulpi->dev, "%s.ulpi", dev_name(dev)); 240 241 ACPI_COMPANION_SET(&ulpi->dev, ACPI_COMPANION(dev)); 242 243 ret = ulpi_of_register(ulpi); 244 if (ret) 245 return ret; 246 247 ret = ulpi_read_id(ulpi); 248 if (ret) 249 return ret; 250 251 ret = device_register(&ulpi->dev); 252 if (ret) 253 return ret; 254 255 dev_dbg(&ulpi->dev, "registered ULPI PHY: vendor %04x, product %04x\n", 256 ulpi->id.vendor, ulpi->id.product); 257 258 return 0; 259 } 260 261 /** 262 * ulpi_register_interface - instantiate new ULPI device 263 * @dev: USB controller's device interface 264 * @ops: ULPI register access 265 * 266 * Allocates and registers a ULPI device and an interface for it. Called from 267 * the USB controller that provides the ULPI interface. 268 */ 269 struct ulpi *ulpi_register_interface(struct device *dev, 270 const struct ulpi_ops *ops) 271 { 272 struct ulpi *ulpi; 273 int ret; 274 275 ulpi = kzalloc(sizeof(*ulpi), GFP_KERNEL); 276 if (!ulpi) 277 return ERR_PTR(-ENOMEM); 278 279 ulpi->ops = ops; 280 281 ret = ulpi_register(dev, ulpi); 282 if (ret) { 283 kfree(ulpi); 284 return ERR_PTR(ret); 285 } 286 287 return ulpi; 288 } 289 EXPORT_SYMBOL_GPL(ulpi_register_interface); 290 291 /** 292 * ulpi_unregister_interface - unregister ULPI interface 293 * @intrf: struct ulpi_interface 294 * 295 * Unregisters a ULPI device and it's interface that was created with 296 * ulpi_create_interface(). 297 */ 298 void ulpi_unregister_interface(struct ulpi *ulpi) 299 { 300 of_node_put(ulpi->dev.of_node); 301 device_unregister(&ulpi->dev); 302 } 303 EXPORT_SYMBOL_GPL(ulpi_unregister_interface); 304 305 /* -------------------------------------------------------------------------- */ 306 307 static int __init ulpi_init(void) 308 { 309 return bus_register(&ulpi_bus); 310 } 311 subsys_initcall(ulpi_init); 312 313 static void __exit ulpi_exit(void) 314 { 315 bus_unregister(&ulpi_bus); 316 } 317 module_exit(ulpi_exit); 318 319 MODULE_AUTHOR("Intel Corporation"); 320 MODULE_LICENSE("GPL v2"); 321 MODULE_DESCRIPTION("USB ULPI PHY bus"); 322