kernel/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
  20 /* -------------------------------------------------------------------------- */
  21
  22 int ulpi_read(struct ulpi *ulpi, u8 addr)
  23 {
  24         return ulpi->ops->read(ulpi->ops, 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->ops, 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         for (id = drv->id_table; id->vendor; id++)
  43                 if (id->vendor == ulpi->id.vendor &&
  44                     id->product == ulpi->id.product)
  45                         return 1;
  46
  47         return 0;
  48 }
  49
  50 static int ulpi_uevent(struct device *dev, struct kobj_uevent_env *env)
  51 {
  52         struct ulpi *ulpi = to_ulpi_dev(dev);
  53
  54         if (add_uevent_var(env, "MODALIAS=ulpi:v%04xp%04x",
  55                            ulpi->id.vendor, ulpi->id.product))
  56                 return -ENOMEM;
  57         return 0;
  58 }
  59
  60 static int ulpi_probe(struct device *dev)
  61 {
  62         struct ulpi_driver *drv = to_ulpi_driver(dev->driver);
  63
  64         return drv->probe(to_ulpi_dev(dev));
  65 }
  66
  67 static int ulpi_remove(struct device *dev)
  68 {
  69         struct ulpi_driver *drv = to_ulpi_driver(dev->driver);
  70
  71         if (drv->remove)
  72                 drv->remove(to_ulpi_dev(dev));
  73
  74         return 0;
  75 }
  76
  77 static struct bus_type ulpi_bus = {
  78         .name = "ulpi",
  79         .match = ulpi_match,
  80         .uevent = ulpi_uevent,
  81         .probe = ulpi_probe,
  82         .remove = ulpi_remove,
  83 };
  84
  85 /* -------------------------------------------------------------------------- */
  86
  87 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
  88                              char *buf)
  89 {
  90         struct ulpi *ulpi = to_ulpi_dev(dev);
  91
  92         return sprintf(buf, "ulpi:v%04xp%04x\n",
  93                        ulpi->id.vendor, ulpi->id.product);
  94 }
  95 static DEVICE_ATTR_RO(modalias);
  96
  97 static struct attribute *ulpi_dev_attrs[] = {
  98         &dev_attr_modalias.attr,
  99         NULL
 100 };
 101
 102 static struct attribute_group ulpi_dev_attr_group = {
 103         .attrs = ulpi_dev_attrs,
 104 };
 105
 106 static const struct attribute_group *ulpi_dev_attr_groups[] = {
 107         &ulpi_dev_attr_group,
 108         NULL
 109 };
 110
 111 static void ulpi_dev_release(struct device *dev)
 112 {
 113         kfree(to_ulpi_dev(dev));
 114 }
 115
 116 static struct device_type ulpi_dev_type = {
 117         .name = "ulpi_device",
 118         .groups = ulpi_dev_attr_groups,
 119         .release = ulpi_dev_release,
 120 };
 121
 122 /* -------------------------------------------------------------------------- */
 123
 124 /**
 125  * ulpi_register_driver - register a driver with the ULPI bus
 126  * @drv: driver being registered
 127  *
 128  * Registers a driver with the ULPI bus.
 129  */
 130 int ulpi_register_driver(struct ulpi_driver *drv)
 131 {
 132         if (!drv->probe)
 133                 return -EINVAL;
 134
 135         drv->driver.bus = &ulpi_bus;
 136
 137         return driver_register(&drv->driver);
 138 }
 139 EXPORT_SYMBOL_GPL(ulpi_register_driver);
 140
 141 /**
 142  * ulpi_unregister_driver - unregister a driver with the ULPI bus
 143  * @drv: driver to unregister
 144  *
 145  * Unregisters a driver with the ULPI bus.
 146  */
 147 void ulpi_unregister_driver(struct ulpi_driver *drv)
 148 {
 149         driver_unregister(&drv->driver);
 150 }
 151 EXPORT_SYMBOL_GPL(ulpi_unregister_driver);
 152
 153 /* -------------------------------------------------------------------------- */
 154
 155 static int ulpi_register(struct device *dev, struct ulpi *ulpi)
 156 {
 157         int ret;
 158
 159         /* Test the interface */
 160         ret = ulpi_write(ulpi, ULPI_SCRATCH, 0xaa);
 161         if (ret < 0)
 162                 return ret;
 163
 164         ret = ulpi_read(ulpi, ULPI_SCRATCH);
 165         if (ret < 0)
 166                 return ret;
 167
 168         if (ret != 0xaa)
 169                 return -ENODEV;
 170
 171         ulpi->id.vendor = ulpi_read(ulpi, ULPI_VENDOR_ID_LOW);
 172         ulpi->id.vendor |= ulpi_read(ulpi, ULPI_VENDOR_ID_HIGH) << 8;
 173
 174         ulpi->id.product = ulpi_read(ulpi, ULPI_PRODUCT_ID_LOW);
 175         ulpi->id.product |= ulpi_read(ulpi, ULPI_PRODUCT_ID_HIGH) << 8;
 176
 177         ulpi->dev.parent = dev;
 178         ulpi->dev.bus = &ulpi_bus;
 179         ulpi->dev.type = &ulpi_dev_type;
 180         dev_set_name(&ulpi->dev, "%s.ulpi", dev_name(dev));
 181
 182         ACPI_COMPANION_SET(&ulpi->dev, ACPI_COMPANION(dev));
 183
 184         request_module("ulpi:v%04xp%04x", ulpi->id.vendor, ulpi->id.product);
 185
 186         ret = device_register(&ulpi->dev);
 187         if (ret)
 188                 return ret;
 189
 190         dev_dbg(&ulpi->dev, "registered ULPI PHY: vendor %04x, product %04x\n",
 191                 ulpi->id.vendor, ulpi->id.product);
 192
 193         return 0;
 194 }
 195
 196 /**
 197  * ulpi_register_interface - instantiate new ULPI device
 198  * @dev: USB controller's device interface
 199  * @ops: ULPI register access
 200  *
 201  * Allocates and registers a ULPI device and an interface for it. Called from
 202  * the USB controller that provides the ULPI interface.
 203  */
 204 struct ulpi *ulpi_register_interface(struct device *dev, struct ulpi_ops *ops)
 205 {
 206         struct ulpi *ulpi;
 207         int ret;
 208
 209         ulpi = kzalloc(sizeof(*ulpi), GFP_KERNEL);
 210         if (!ulpi)
 211                 return ERR_PTR(-ENOMEM);
 212
 213         ulpi->ops = ops;
 214         ops->dev = dev;
 215
 216         ret = ulpi_register(dev, ulpi);
 217         if (ret) {
 218                 kfree(ulpi);
 219                 return ERR_PTR(ret);
 220         }
 221
 222         return ulpi;
 223 }
 224 EXPORT_SYMBOL_GPL(ulpi_register_interface);
 225
 226 /**
 227  * ulpi_unregister_interface - unregister ULPI interface
 228  * @intrf: struct ulpi_interface
 229  *
 230  * Unregisters a ULPI device and it's interface that was created with
 231  * ulpi_create_interface().
 232  */
 233 void ulpi_unregister_interface(struct ulpi *ulpi)
 234 {
 235         device_unregister(&ulpi->dev);
 236 }
 237 EXPORT_SYMBOL_GPL(ulpi_unregister_interface);
 238
 239 /* -------------------------------------------------------------------------- */
 240
 241 static int __init ulpi_init(void)
 242 {
 243         return bus_register(&ulpi_bus);
 244 }
 245 subsys_initcall(ulpi_init);
 246
 247 static void __exit ulpi_exit(void)
 248 {
 249         bus_unregister(&ulpi_bus);
 250 }
 251 module_exit(ulpi_exit);
 252
 253 MODULE_AUTHOR("Intel Corporation");
 254 MODULE_LICENSE("GPL v2");
 255 MODULE_DESCRIPTION("USB ULPI PHY bus");