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/debugfs.h>
  17 #include <linux/of.h>
  18 #include <linux/of_device.h>
  19 #include <linux/clk/clk-conf.h>
  20
  21 /* -------------------------------------------------------------------------- */
  22
  23 int ulpi_read(struct ulpi *ulpi, u8 addr)
  24 {
  25         return ulpi->ops->read(ulpi->dev.parent, addr);
  26 }
  27 EXPORT_SYMBOL_GPL(ulpi_read);
  28
  29 int ulpi_write(struct ulpi *ulpi, u8 addr, u8 val)
  30 {
  31         return ulpi->ops->write(ulpi->dev.parent, addr, val);
  32 }
  33 EXPORT_SYMBOL_GPL(ulpi_write);
  34
  35 /* -------------------------------------------------------------------------- */
  36
  37 static int ulpi_match(struct device *dev, const struct device_driver *driver)
  38 {
  39         struct ulpi_driver *drv = to_ulpi_driver(driver);
  40         struct ulpi *ulpi = to_ulpi_dev(dev);
  41         const struct ulpi_device_id *id;
  42
  43         /*
  44          * Some ULPI devices don't have a vendor id
  45          * or provide an id_table so rely on OF match.
  46          */
  47         if (ulpi->id.vendor == 0 || !drv->id_table)
  48                 return of_driver_match_device(dev, driver);
  49
  50         for (id = drv->id_table; id->vendor; id++)
  51                 if (id->vendor == ulpi->id.vendor &&
  52                     id->product == ulpi->id.product)
  53                         return 1;
  54
  55         return 0;
  56 }
  57
  58 static int ulpi_uevent(const struct device *dev, struct kobj_uevent_env *env)
  59 {
  60         const struct ulpi *ulpi = to_ulpi_dev(dev);
  61         int ret;
  62
  63         ret = of_device_uevent_modalias(dev, env);
  64         if (ret != -ENODEV)
  65                 return ret;
  66
  67         if (add_uevent_var(env, "MODALIAS=ulpi:v%04xp%04x",
  68                            ulpi->id.vendor, ulpi->id.product))
  69                 return -ENOMEM;
  70         return 0;
  71 }
  72
  73 static int ulpi_probe(struct device *dev)
  74 {
  75         struct ulpi_driver *drv = to_ulpi_driver(dev->driver);
  76         int ret;
  77
  78         ret = of_clk_set_defaults(dev->of_node, false);
  79         if (ret < 0)
  80                 return ret;
  81
  82         return drv->probe(to_ulpi_dev(dev));
  83 }
  84
  85 static void ulpi_remove(struct device *dev)
  86 {
  87         struct ulpi_driver *drv = to_ulpi_driver(dev->driver);
  88
  89         if (drv->remove)
  90                 drv->remove(to_ulpi_dev(dev));
  91 }
  92
  93 static const struct bus_type ulpi_bus = {
  94         .name = "ulpi",
  95         .match = ulpi_match,
  96         .uevent = ulpi_uevent,
  97         .probe = ulpi_probe,
  98         .remove = ulpi_remove,
  99 };
 100
 101 /* -------------------------------------------------------------------------- */
 102
 103 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 104                              char *buf)
 105 {
 106         int len;
 107         struct ulpi *ulpi = to_ulpi_dev(dev);
 108
 109         len = of_device_modalias(dev, buf, PAGE_SIZE);
 110         if (len != -ENODEV)
 111                 return len;
 112
 113         return sprintf(buf, "ulpi:v%04xp%04x\n",
 114                        ulpi->id.vendor, ulpi->id.product);
 115 }
 116 static DEVICE_ATTR_RO(modalias);
 117
 118 static struct attribute *ulpi_dev_attrs[] = {
 119         &dev_attr_modalias.attr,
 120         NULL
 121 };
 122
 123 static const struct attribute_group ulpi_dev_attr_group = {
 124         .attrs = ulpi_dev_attrs,
 125 };
 126
 127 static const struct attribute_group *ulpi_dev_attr_groups[] = {
 128         &ulpi_dev_attr_group,
 129         NULL
 130 };
 131
 132 static void ulpi_dev_release(struct device *dev)
 133 {
 134         of_node_put(dev->of_node);
 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  * @module: ends up being THIS_MODULE
 150  *
 151  * Registers a driver with the ULPI bus.
 152  */
 153 int __ulpi_register_driver(struct ulpi_driver *drv, struct module *module)
 154 {
 155         if (!drv->probe)
 156                 return -EINVAL;
 157
 158         drv->driver.owner = module;
 159         drv->driver.bus = &ulpi_bus;
 160
 161         return driver_register(&drv->driver);
 162 }
 163 EXPORT_SYMBOL_GPL(__ulpi_register_driver);
 164
 165 /**
 166  * ulpi_unregister_driver - unregister a driver with the ULPI bus
 167  * @drv: driver to unregister
 168  *
 169  * Unregisters a driver with the ULPI bus.
 170  */
 171 void ulpi_unregister_driver(struct ulpi_driver *drv)
 172 {
 173         driver_unregister(&drv->driver);
 174 }
 175 EXPORT_SYMBOL_GPL(ulpi_unregister_driver);
 176
 177 /* -------------------------------------------------------------------------- */
 178
 179 static int ulpi_of_register(struct ulpi *ulpi)
 180 {
 181         struct device_node *np = NULL, *child;
 182         struct device *parent;
 183
 184         /* Find a ulpi bus underneath the parent or the grandparent */
 185         parent = ulpi->dev.parent;
 186         if (parent->of_node)
 187                 np = of_get_child_by_name(parent->of_node, "ulpi");
 188         else if (parent->parent && parent->parent->of_node)
 189                 np = of_get_child_by_name(parent->parent->of_node, "ulpi");
 190         if (!np)
 191                 return 0;
 192
 193         child = of_get_next_available_child(np, NULL);
 194         of_node_put(np);
 195         if (!child)
 196                 return -EINVAL;
 197
 198         ulpi->dev.of_node = child;
 199
 200         return 0;
 201 }
 202
 203 static int ulpi_read_id(struct ulpi *ulpi)
 204 {
 205         int ret;
 206
 207         /* Test the interface */
 208         ret = ulpi_write(ulpi, ULPI_SCRATCH, 0xaa);
 209         if (ret < 0)
 210                 goto err;
 211
 212         ret = ulpi_read(ulpi, ULPI_SCRATCH);
 213         if (ret < 0)
 214                 return ret;
 215
 216         if (ret != 0xaa)
 217                 goto err;
 218
 219         ulpi->id.vendor = ulpi_read(ulpi, ULPI_VENDOR_ID_LOW);
 220         ulpi->id.vendor |= ulpi_read(ulpi, ULPI_VENDOR_ID_HIGH) << 8;
 221
 222         ulpi->id.product = ulpi_read(ulpi, ULPI_PRODUCT_ID_LOW);
 223         ulpi->id.product |= ulpi_read(ulpi, ULPI_PRODUCT_ID_HIGH) << 8;
 224
 225         /* Some ULPI devices don't have a vendor id so rely on OF match */
 226         if (ulpi->id.vendor == 0)
 227                 goto err;
 228
 229         request_module("ulpi:v%04xp%04x", ulpi->id.vendor, ulpi->id.product);
 230         return 0;
 231 err:
 232         of_request_module(ulpi->dev.of_node);
 233         return 0;
 234 }
 235
 236 static int ulpi_regs_show(struct seq_file *seq, void *data)
 237 {
 238         struct ulpi *ulpi = seq->private;
 239
 240 #define ulpi_print(name, reg) do { \
 241         int ret = ulpi_read(ulpi, reg); \
 242         if (ret < 0) \
 243                 return ret; \
 244         seq_printf(seq, name " %.02x\n", ret); \
 245 } while (0)
 246
 247         ulpi_print("Vendor ID Low               ", ULPI_VENDOR_ID_LOW);
 248         ulpi_print("Vendor ID High              ", ULPI_VENDOR_ID_HIGH);
 249         ulpi_print("Product ID Low              ", ULPI_PRODUCT_ID_LOW);
 250         ulpi_print("Product ID High             ", ULPI_PRODUCT_ID_HIGH);
 251         ulpi_print("Function Control            ", ULPI_FUNC_CTRL);
 252         ulpi_print("Interface Control           ", ULPI_IFC_CTRL);
 253         ulpi_print("OTG Control                 ", ULPI_OTG_CTRL);
 254         ulpi_print("USB Interrupt Enable Rising ", ULPI_USB_INT_EN_RISE);
 255         ulpi_print("USB Interrupt Enable Falling", ULPI_USB_INT_EN_FALL);
 256         ulpi_print("USB Interrupt Status        ", ULPI_USB_INT_STS);
 257         ulpi_print("USB Interrupt Latch         ", ULPI_USB_INT_LATCH);
 258         ulpi_print("Debug                       ", ULPI_DEBUG);
 259         ulpi_print("Scratch Register            ", ULPI_SCRATCH);
 260         ulpi_print("Carkit Control              ", ULPI_CARKIT_CTRL);
 261         ulpi_print("Carkit Interrupt Delay      ", ULPI_CARKIT_INT_DELAY);
 262         ulpi_print("Carkit Interrupt Enable     ", ULPI_CARKIT_INT_EN);
 263         ulpi_print("Carkit Interrupt Status     ", ULPI_CARKIT_INT_STS);
 264         ulpi_print("Carkit Interrupt Latch      ", ULPI_CARKIT_INT_LATCH);
 265         ulpi_print("Carkit Pulse Control        ", ULPI_CARKIT_PLS_CTRL);
 266         ulpi_print("Transmit Positive Width     ", ULPI_TX_POS_WIDTH);
 267         ulpi_print("Transmit Negative Width     ", ULPI_TX_NEG_WIDTH);
 268         ulpi_print("Receive Polarity Recovery   ", ULPI_POLARITY_RECOVERY);
 269
 270         return 0;
 271 }
 272 DEFINE_SHOW_ATTRIBUTE(ulpi_regs);
 273
 274 static struct dentry *ulpi_root;
 275
 276 static int ulpi_register(struct device *dev, struct ulpi *ulpi)
 277 {
 278         int ret;
 279         struct dentry *root;
 280
 281         ulpi->dev.parent = dev; /* needed early for ops */
 282         ulpi->dev.bus = &ulpi_bus;
 283         ulpi->dev.type = &ulpi_dev_type;
 284         dev_set_name(&ulpi->dev, "%s.ulpi", dev_name(dev));
 285
 286         ACPI_COMPANION_SET(&ulpi->dev, ACPI_COMPANION(dev));
 287
 288         ret = ulpi_of_register(ulpi);
 289         if (ret)
 290                 return ret;
 291
 292         ret = ulpi_read_id(ulpi);
 293         if (ret) {
 294                 of_node_put(ulpi->dev.of_node);
 295                 return ret;
 296         }
 297
 298         ret = device_register(&ulpi->dev);
 299         if (ret) {
 300                 put_device(&ulpi->dev);
 301                 return ret;
 302         }
 303
 304         root = debugfs_create_dir(dev_name(&ulpi->dev), ulpi_root);
 305         debugfs_create_file("regs", 0444, root, ulpi, &ulpi_regs_fops);
 306
 307         dev_dbg(&ulpi->dev, "registered ULPI PHY: vendor %04x, product %04x\n",
 308                 ulpi->id.vendor, ulpi->id.product);
 309
 310         return 0;
 311 }
 312
 313 /**
 314  * ulpi_register_interface - instantiate new ULPI device
 315  * @dev: USB controller's device interface
 316  * @ops: ULPI register access
 317  *
 318  * Allocates and registers a ULPI device and an interface for it. Called from
 319  * the USB controller that provides the ULPI interface.
 320  */
 321 struct ulpi *ulpi_register_interface(struct device *dev,
 322                                      const struct ulpi_ops *ops)
 323 {
 324         struct ulpi *ulpi;
 325         int ret;
 326
 327         ulpi = kzalloc(sizeof(*ulpi), GFP_KERNEL);
 328         if (!ulpi)
 329                 return ERR_PTR(-ENOMEM);
 330
 331         ulpi->ops = ops;
 332
 333         ret = ulpi_register(dev, ulpi);
 334         if (ret) {
 335                 kfree(ulpi);
 336                 return ERR_PTR(ret);
 337         }
 338
 339         return ulpi;
 340 }
 341 EXPORT_SYMBOL_GPL(ulpi_register_interface);
 342
 343 /**
 344  * ulpi_unregister_interface - unregister ULPI interface
 345  * @ulpi: struct ulpi_interface
 346  *
 347  * Unregisters a ULPI device and it's interface that was created with
 348  * ulpi_create_interface().
 349  */
 350 void ulpi_unregister_interface(struct ulpi *ulpi)
 351 {
 352         debugfs_lookup_and_remove(dev_name(&ulpi->dev), ulpi_root);
 353         device_unregister(&ulpi->dev);
 354 }
 355 EXPORT_SYMBOL_GPL(ulpi_unregister_interface);
 356
 357 /* -------------------------------------------------------------------------- */
 358
 359 static int __init ulpi_init(void)
 360 {
 361         int ret;
 362
 363         ulpi_root = debugfs_create_dir(KBUILD_MODNAME, NULL);
 364         ret = bus_register(&ulpi_bus);
 365         if (ret)
 366                 debugfs_remove(ulpi_root);
 367         return ret;
 368 }
 369 subsys_initcall(ulpi_init);
 370
 371 static void __exit ulpi_exit(void)
 372 {
 373         bus_unregister(&ulpi_bus);
 374         debugfs_remove(ulpi_root);
 375 }
 376 module_exit(ulpi_exit);
 377
 378 MODULE_AUTHOR("Intel Corporation");
 379 MODULE_LICENSE("GPL v2");
 380 MODULE_DESCRIPTION("USB ULPI PHY bus");