drivers/usb/common/ulpi.c

   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");