drivers/usb/common/ulpi.c

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