drivers/staging/greybus/gbphy.c

   1 /*
   2  * Greybus Bridged-Phy Bus driver
   3  *
   4  * Copyright 2014 Google Inc.
   5  * Copyright 2014 Linaro Ltd.
   6  *
   7  * Released under the GPLv2 only.
   8  */
   9
  10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  11
  12 #include <linux/types.h>
  13 #include <linux/module.h>
  14 #include <linux/moduleparam.h>
  15 #include <linux/kernel.h>
  16 #include <linux/slab.h>
  17 #include <linux/device.h>
  18
  19 #include "greybus.h"
  20 #include "gbphy.h"
  21
  22 #define GB_GBPHY_AUTOSUSPEND_MS 3000
  23
  24 struct gbphy_host {
  25         struct gb_bundle *bundle;
  26         struct list_head devices;
  27 };
  28
  29 static DEFINE_IDA(gbphy_id);
  30
  31 static ssize_t protocol_id_show(struct device *dev,
  32                                  struct device_attribute *attr, char *buf)
  33 {
  34         struct gbphy_device *gbphy_dev = to_gbphy_dev(dev);
  35
  36         return sprintf(buf, "0x%02x\n", gbphy_dev->cport_desc->protocol_id);
  37 }
  38 static DEVICE_ATTR_RO(protocol_id);
  39
  40 static struct attribute *gbphy_dev_attrs[] = {
  41         &dev_attr_protocol_id.attr,
  42         NULL,
  43 };
  44
  45 ATTRIBUTE_GROUPS(gbphy_dev);
  46
  47 static void gbphy_dev_release(struct device *dev)
  48 {
  49         struct gbphy_device *gbphy_dev = to_gbphy_dev(dev);
  50
  51         ida_simple_remove(&gbphy_id, gbphy_dev->id);
  52         kfree(gbphy_dev);
  53 }
  54
  55 #ifdef CONFIG_PM
  56 static int gb_gbphy_idle(struct device *dev)
  57 {
  58         pm_runtime_mark_last_busy(dev);
  59         pm_request_autosuspend(dev);
  60         return 0;
  61 }
  62 #endif
  63
  64 static const struct dev_pm_ops gb_gbphy_pm_ops = {
  65         SET_RUNTIME_PM_OPS(pm_generic_runtime_suspend,
  66                            pm_generic_runtime_resume,
  67                            gb_gbphy_idle)
  68 };
  69
  70 static struct device_type greybus_gbphy_dev_type = {
  71         .name    =      "gbphy_device",
  72         .release =      gbphy_dev_release,
  73         .pm     =       &gb_gbphy_pm_ops,
  74 };
  75
  76 static int gbphy_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
  77 {
  78         struct gbphy_device *gbphy_dev = to_gbphy_dev(dev);
  79         struct greybus_descriptor_cport *cport_desc = gbphy_dev->cport_desc;
  80         struct gb_bundle *bundle = gbphy_dev->bundle;
  81         struct gb_interface *intf = bundle->intf;
  82         struct gb_module *module = intf->module;
  83         struct gb_host_device *hd = intf->hd;
  84
  85         if (add_uevent_var(env, "BUS=%u", hd->bus_id))
  86                 return -ENOMEM;
  87         if (add_uevent_var(env, "MODULE=%u", module->module_id))
  88                 return -ENOMEM;
  89         if (add_uevent_var(env, "INTERFACE=%u", intf->interface_id))
  90                 return -ENOMEM;
  91         if (add_uevent_var(env, "GREYBUS_ID=%08x/%08x",
  92                            intf->vendor_id, intf->product_id))
  93                 return -ENOMEM;
  94         if (add_uevent_var(env, "BUNDLE=%u", gbphy_dev->bundle->id))
  95                 return -ENOMEM;
  96         if (add_uevent_var(env, "BUNDLE_CLASS=%02x", bundle->class))
  97                 return -ENOMEM;
  98         if (add_uevent_var(env, "GBPHY=%u", gbphy_dev->id))
  99                 return -ENOMEM;
 100         if (add_uevent_var(env, "PROTOCOL_ID=%02x", cport_desc->protocol_id))
 101                 return -ENOMEM;
 102
 103         return 0;
 104 }
 105
 106 static const struct gbphy_device_id *
 107 gbphy_dev_match_id(struct gbphy_device *gbphy_dev, struct gbphy_driver *gbphy_drv)
 108 {
 109         const struct gbphy_device_id *id = gbphy_drv->id_table;
 110
 111         if (!id)
 112                 return NULL;
 113
 114         for (; id->protocol_id; id++)
 115                 if (id->protocol_id == gbphy_dev->cport_desc->protocol_id)
 116                         return id;
 117
 118         return NULL;
 119 }
 120
 121 static int gbphy_dev_match(struct device *dev, struct device_driver *drv)
 122 {
 123         struct gbphy_driver *gbphy_drv = to_gbphy_driver(drv);
 124         struct gbphy_device *gbphy_dev = to_gbphy_dev(dev);
 125         const struct gbphy_device_id *id;
 126
 127         id = gbphy_dev_match_id(gbphy_dev, gbphy_drv);
 128         if (id)
 129                 return 1;
 130
 131         return 0;
 132 }
 133
 134 static int gbphy_dev_probe(struct device *dev)
 135 {
 136         struct gbphy_driver *gbphy_drv = to_gbphy_driver(dev->driver);
 137         struct gbphy_device *gbphy_dev = to_gbphy_dev(dev);
 138         const struct gbphy_device_id *id;
 139         int ret;
 140
 141         id = gbphy_dev_match_id(gbphy_dev, gbphy_drv);
 142         if (!id)
 143                 return -ENODEV;
 144
 145         /* for old kernels we need get_sync to resume parent devices */
 146         ret = gb_pm_runtime_get_sync(gbphy_dev->bundle);
 147         if (ret < 0)
 148                 return ret;
 149
 150         pm_runtime_set_autosuspend_delay(dev, GB_GBPHY_AUTOSUSPEND_MS);
 151         pm_runtime_use_autosuspend(dev);
 152         pm_runtime_get_noresume(dev);
 153         pm_runtime_set_active(dev);
 154         pm_runtime_enable(dev);
 155
 156         /*
 157          * Drivers should call put on the gbphy dev before returning
 158          * from probe if they support runtime pm.
 159          */
 160         ret = gbphy_drv->probe(gbphy_dev, id);
 161         if (ret) {
 162                 pm_runtime_disable(dev);
 163                 pm_runtime_set_suspended(dev);
 164                 pm_runtime_put_noidle(dev);
 165                 pm_runtime_dont_use_autosuspend(dev);
 166         }
 167
 168         gb_pm_runtime_put_autosuspend(gbphy_dev->bundle);
 169
 170         return ret;
 171 }
 172
 173 static int gbphy_dev_remove(struct device *dev)
 174 {
 175         struct gbphy_driver *gbphy_drv = to_gbphy_driver(dev->driver);
 176         struct gbphy_device *gbphy_dev = to_gbphy_dev(dev);
 177
 178         gbphy_drv->remove(gbphy_dev);
 179
 180         pm_runtime_disable(dev);
 181         pm_runtime_set_suspended(dev);
 182         pm_runtime_put_noidle(dev);
 183         pm_runtime_dont_use_autosuspend(dev);
 184
 185         return 0;
 186 }
 187
 188 static struct bus_type gbphy_bus_type = {
 189         .name =         "gbphy",
 190         .match =        gbphy_dev_match,
 191         .probe =        gbphy_dev_probe,
 192         .remove =       gbphy_dev_remove,
 193         .uevent =       gbphy_dev_uevent,
 194 };
 195
 196 int gb_gbphy_register_driver(struct gbphy_driver *driver,
 197                              struct module *owner, const char *mod_name)
 198 {
 199         int retval;
 200
 201         if (greybus_disabled())
 202                 return -ENODEV;
 203
 204         driver->driver.bus = &gbphy_bus_type;
 205         driver->driver.name = driver->name;
 206         driver->driver.owner = owner;
 207         driver->driver.mod_name = mod_name;
 208
 209         retval = driver_register(&driver->driver);
 210         if (retval)
 211                 return retval;
 212
 213         pr_info("registered new driver %s\n", driver->name);
 214         return 0;
 215 }
 216 EXPORT_SYMBOL_GPL(gb_gbphy_register_driver);
 217
 218 void gb_gbphy_deregister_driver(struct gbphy_driver *driver)
 219 {
 220         driver_unregister(&driver->driver);
 221 }
 222 EXPORT_SYMBOL_GPL(gb_gbphy_deregister_driver);
 223
 224 static struct gbphy_device *gb_gbphy_create_dev(struct gb_bundle *bundle,
 225                                 struct greybus_descriptor_cport *cport_desc)
 226 {
 227         struct gbphy_device *gbphy_dev;
 228         int retval;
 229         int id;
 230
 231         id = ida_simple_get(&gbphy_id, 1, 0, GFP_KERNEL);
 232         if (id < 0)
 233                 return ERR_PTR(id);
 234
 235         gbphy_dev = kzalloc(sizeof(*gbphy_dev), GFP_KERNEL);
 236         if (!gbphy_dev) {
 237                 ida_simple_remove(&gbphy_id, id);
 238                 return ERR_PTR(-ENOMEM);
 239         }
 240
 241         gbphy_dev->id = id;
 242         gbphy_dev->bundle = bundle;
 243         gbphy_dev->cport_desc = cport_desc;
 244         gbphy_dev->dev.parent = &bundle->dev;
 245         gbphy_dev->dev.bus = &gbphy_bus_type;
 246         gbphy_dev->dev.type = &greybus_gbphy_dev_type;
 247         gbphy_dev->dev.groups = gbphy_dev_groups;
 248         gbphy_dev->dev.dma_mask = bundle->dev.dma_mask;
 249         dev_set_name(&gbphy_dev->dev, "gbphy%d", id);
 250
 251         retval = device_register(&gbphy_dev->dev);
 252         if (retval) {
 253                 put_device(&gbphy_dev->dev);
 254                 return ERR_PTR(retval);
 255         }
 256
 257         return gbphy_dev;
 258 }
 259
 260 static void gb_gbphy_disconnect(struct gb_bundle *bundle)
 261 {
 262         struct gbphy_host *gbphy_host = greybus_get_drvdata(bundle);
 263         struct gbphy_device *gbphy_dev, *temp;
 264         int ret;
 265
 266         ret = gb_pm_runtime_get_sync(bundle);
 267         if (ret < 0)
 268                 gb_pm_runtime_get_noresume(bundle);
 269
 270         list_for_each_entry_safe(gbphy_dev, temp, &gbphy_host->devices, list) {
 271                 list_del(&gbphy_dev->list);
 272                 device_unregister(&gbphy_dev->dev);
 273         }
 274
 275         kfree(gbphy_host);
 276 }
 277
 278 static int gb_gbphy_probe(struct gb_bundle *bundle,
 279                           const struct greybus_bundle_id *id)
 280 {
 281         struct gbphy_host *gbphy_host;
 282         struct gbphy_device *gbphy_dev;
 283         int i;
 284
 285         if (bundle->num_cports == 0)
 286                 return -ENODEV;
 287
 288         gbphy_host = kzalloc(sizeof(*gbphy_host), GFP_KERNEL);
 289         if (!gbphy_host)
 290                 return -ENOMEM;
 291
 292         gbphy_host->bundle = bundle;
 293         INIT_LIST_HEAD(&gbphy_host->devices);
 294         greybus_set_drvdata(bundle, gbphy_host);
 295
 296         /*
 297          * Create a bunch of children devices, one per cport, and bind the
 298          * bridged phy drivers to them.
 299          */
 300         for (i = 0; i < bundle->num_cports; ++i) {
 301                 gbphy_dev = gb_gbphy_create_dev(bundle, &bundle->cport_desc[i]);
 302                 if (IS_ERR(gbphy_dev)) {
 303                         gb_gbphy_disconnect(bundle);
 304                         return PTR_ERR(gbphy_dev);
 305                 }
 306                 list_add(&gbphy_dev->list, &gbphy_host->devices);
 307         }
 308
 309         gb_pm_runtime_put_autosuspend(bundle);
 310
 311         return 0;
 312 }
 313
 314 static const struct greybus_bundle_id gb_gbphy_id_table[] = {
 315         { GREYBUS_DEVICE_CLASS(GREYBUS_CLASS_BRIDGED_PHY) },
 316         { },
 317 };
 318 MODULE_DEVICE_TABLE(greybus, gb_gbphy_id_table);
 319
 320 static struct greybus_driver gb_gbphy_driver = {
 321         .name           = "gbphy",
 322         .probe          = gb_gbphy_probe,
 323         .disconnect     = gb_gbphy_disconnect,
 324         .id_table       = gb_gbphy_id_table,
 325 };
 326
 327 static int __init gbphy_init(void)
 328 {
 329         int retval;
 330
 331         retval = bus_register(&gbphy_bus_type);
 332         if (retval) {
 333                 pr_err("gbphy bus register failed (%d)\n", retval);
 334                 return retval;
 335         }
 336
 337         retval = greybus_register(&gb_gbphy_driver);
 338         if (retval) {
 339                 pr_err("error registering greybus driver\n");
 340                 goto error_gbphy;
 341         }
 342
 343         return 0;
 344
 345 error_gbphy:
 346         bus_unregister(&gbphy_bus_type);
 347         ida_destroy(&gbphy_id);
 348         return retval;
 349 }
 350 module_init(gbphy_init);
 351
 352 static void __exit gbphy_exit(void)
 353 {
 354         greybus_deregister(&gb_gbphy_driver);
 355         bus_unregister(&gbphy_bus_type);
 356         ida_destroy(&gbphy_id);
 357 }
 358 module_exit(gbphy_exit);
 359
 360 MODULE_LICENSE("GPL v2");