linux/drivers/usb/common/ulpi.c
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   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
  22int ulpi_read(struct ulpi *ulpi, u8 addr)
  23{
  24        return ulpi->ops->read(ulpi->dev.parent, addr);
  25}
  26EXPORT_SYMBOL_GPL(ulpi_read);
  27
  28int ulpi_write(struct ulpi *ulpi, u8 addr, u8 val)
  29{
  30        return ulpi->ops->write(ulpi->dev.parent, addr, val);
  31}
  32EXPORT_SYMBOL_GPL(ulpi_write);
  33
  34/* -------------------------------------------------------------------------- */
  35
  36static 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
  54static 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
  69static 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
  81static 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
  91static 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
 101static 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}
 114static DEVICE_ATTR_RO(modalias);
 115
 116static struct attribute *ulpi_dev_attrs[] = {
 117        &dev_attr_modalias.attr,
 118        NULL
 119};
 120
 121static struct attribute_group ulpi_dev_attr_group = {
 122        .attrs = ulpi_dev_attrs,
 123};
 124
 125static const struct attribute_group *ulpi_dev_attr_groups[] = {
 126        &ulpi_dev_attr_group,
 127        NULL
 128};
 129
 130static void ulpi_dev_release(struct device *dev)
 131{
 132        kfree(to_ulpi_dev(dev));
 133}
 134
 135static 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 */
 150int __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}
 160EXPORT_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 */
 168void ulpi_unregister_driver(struct ulpi_driver *drv)
 169{
 170        driver_unregister(&drv->driver);
 171}
 172EXPORT_SYMBOL_GPL(ulpi_unregister_driver);
 173
 174/* -------------------------------------------------------------------------- */
 175
 176static 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
 200static 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;
 228err:
 229        of_device_request_module(&ulpi->dev);
 230        return 0;
 231}
 232
 233static 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 */
 270struct 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}
 290EXPORT_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 */
 299void ulpi_unregister_interface(struct ulpi *ulpi)
 300{
 301        of_node_put(ulpi->dev.of_node);
 302        device_unregister(&ulpi->dev);
 303}
 304EXPORT_SYMBOL_GPL(ulpi_unregister_interface);
 305
 306/* -------------------------------------------------------------------------- */
 307
 308static int __init ulpi_init(void)
 309{
 310        return bus_register(&ulpi_bus);
 311}
 312subsys_initcall(ulpi_init);
 313
 314static void __exit ulpi_exit(void)
 315{
 316        bus_unregister(&ulpi_bus);
 317}
 318module_exit(ulpi_exit);
 319
 320MODULE_AUTHOR("Intel Corporation");
 321MODULE_LICENSE("GPL v2");
 322MODULE_DESCRIPTION("USB ULPI PHY bus");
 323