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