drivers/staging/greybus/core.c

   1 /*
   2  * Greybus "Core"
   3  *
   4  * Copyright 2014-2015 Google Inc.
   5  * Copyright 2014-2015 Linaro Ltd.
   6  *
   7  * Released under the GPLv2 only.
   8  */
   9
  10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  11
  12 #define CREATE_TRACE_POINTS
  13 #include "greybus.h"
  14 #include "greybus_trace.h"
  15
  16 #define GB_BUNDLE_AUTOSUSPEND_MS        3000
  17
  18 /* Allow greybus to be disabled at boot if needed */
  19 static bool nogreybus;
  20 #ifdef MODULE
  21 module_param(nogreybus, bool, 0444);
  22 #else
  23 core_param(nogreybus, nogreybus, bool, 0444);
  24 #endif
  25 int greybus_disabled(void)
  26 {
  27         return nogreybus;
  28 }
  29 EXPORT_SYMBOL_GPL(greybus_disabled);
  30
  31 static bool greybus_match_one_id(struct gb_bundle *bundle,
  32                                      const struct greybus_bundle_id *id)
  33 {
  34         if ((id->match_flags & GREYBUS_ID_MATCH_VENDOR) &&
  35             (id->vendor != bundle->intf->vendor_id))
  36                 return false;
  37
  38         if ((id->match_flags & GREYBUS_ID_MATCH_PRODUCT) &&
  39             (id->product != bundle->intf->product_id))
  40                 return false;
  41
  42         if ((id->match_flags & GREYBUS_ID_MATCH_CLASS) &&
  43             (id->class != bundle->class))
  44                 return false;
  45
  46         return true;
  47 }
  48
  49 static const struct greybus_bundle_id *
  50 greybus_match_id(struct gb_bundle *bundle, const struct greybus_bundle_id *id)
  51 {
  52         if (id == NULL)
  53                 return NULL;
  54
  55         for (; id->vendor || id->product || id->class || id->driver_info;
  56                                                                         id++) {
  57                 if (greybus_match_one_id(bundle, id))
  58                         return id;
  59         }
  60
  61         return NULL;
  62 }
  63
  64 static int greybus_match_device(struct device *dev, struct device_driver *drv)
  65 {
  66         struct greybus_driver *driver = to_greybus_driver(drv);
  67         struct gb_bundle *bundle;
  68         const struct greybus_bundle_id *id;
  69
  70         if (!is_gb_bundle(dev))
  71                 return 0;
  72
  73         bundle = to_gb_bundle(dev);
  74
  75         id = greybus_match_id(bundle, driver->id_table);
  76         if (id)
  77                 return 1;
  78         /* FIXME - Dynamic ids? */
  79         return 0;
  80 }
  81
  82 static int greybus_uevent(struct device *dev, struct kobj_uevent_env *env)
  83 {
  84         struct gb_host_device *hd;
  85         struct gb_module *module = NULL;
  86         struct gb_interface *intf = NULL;
  87         struct gb_control *control = NULL;
  88         struct gb_bundle *bundle = NULL;
  89         struct gb_svc *svc = NULL;
  90
  91         if (is_gb_host_device(dev)) {
  92                 hd = to_gb_host_device(dev);
  93         } else if (is_gb_module(dev)) {
  94                 module = to_gb_module(dev);
  95                 hd = module->hd;
  96         } else if (is_gb_interface(dev)) {
  97                 intf = to_gb_interface(dev);
  98                 module = intf->module;
  99                 hd = intf->hd;
 100         } else if (is_gb_control(dev)) {
 101                 control = to_gb_control(dev);
 102                 intf = control->intf;
 103                 module = intf->module;
 104                 hd = intf->hd;
 105         } else if (is_gb_bundle(dev)) {
 106                 bundle = to_gb_bundle(dev);
 107                 intf = bundle->intf;
 108                 module = intf->module;
 109                 hd = intf->hd;
 110         } else if (is_gb_svc(dev)) {
 111                 svc = to_gb_svc(dev);
 112                 hd = svc->hd;
 113         } else {
 114                 dev_WARN(dev, "uevent for unknown greybus device \"type\"!\n");
 115                 return -EINVAL;
 116         }
 117
 118         if (add_uevent_var(env, "BUS=%u", hd->bus_id))
 119                 return -ENOMEM;
 120
 121         if (module) {
 122                 if (add_uevent_var(env, "MODULE=%u", module->module_id))
 123                         return -ENOMEM;
 124         }
 125
 126         if (intf) {
 127                 if (add_uevent_var(env, "INTERFACE=%u", intf->interface_id))
 128                         return -ENOMEM;
 129                 if (add_uevent_var(env, "GREYBUS_ID=%08x/%08x",
 130                                    intf->vendor_id, intf->product_id))
 131                         return -ENOMEM;
 132         }
 133
 134         if (bundle) {
 135                 // FIXME
 136                 // add a uevent that can "load" a bundle type
 137                 // This is what we need to bind a driver to so use the info
 138                 // in gmod here as well
 139
 140                 if (add_uevent_var(env, "BUNDLE=%u", bundle->id))
 141                         return -ENOMEM;
 142                 if (add_uevent_var(env, "BUNDLE_CLASS=%02x", bundle->class))
 143                         return -ENOMEM;
 144         }
 145
 146         return 0;
 147 }
 148
 149 static void greybus_shutdown(struct device *dev)
 150 {
 151         if (is_gb_host_device(dev)) {
 152                 struct gb_host_device *hd;
 153
 154                 hd = to_gb_host_device(dev);
 155                 gb_hd_shutdown(hd);
 156         }
 157 }
 158
 159 struct bus_type greybus_bus_type = {
 160         .name =         "greybus",
 161         .match =        greybus_match_device,
 162         .uevent =       greybus_uevent,
 163         .shutdown =     greybus_shutdown,
 164 };
 165
 166 static int greybus_probe(struct device *dev)
 167 {
 168         struct greybus_driver *driver = to_greybus_driver(dev->driver);
 169         struct gb_bundle *bundle = to_gb_bundle(dev);
 170         const struct greybus_bundle_id *id;
 171         int retval;
 172
 173         /* match id */
 174         id = greybus_match_id(bundle, driver->id_table);
 175         if (!id)
 176                 return -ENODEV;
 177
 178         retval = pm_runtime_get_sync(&bundle->intf->dev);
 179         if (retval < 0) {
 180                 pm_runtime_put_noidle(&bundle->intf->dev);
 181                 return retval;
 182         }
 183
 184         retval = gb_control_bundle_activate(bundle->intf->control, bundle->id);
 185         if (retval) {
 186                 pm_runtime_put(&bundle->intf->dev);
 187                 return retval;
 188         }
 189
 190         /*
 191          * Unbound bundle devices are always deactivated. During probe, the
 192          * Runtime PM is set to enabled and active and the usage count is
 193          * incremented. If the driver supports runtime PM, it should call
 194          * pm_runtime_put() in its probe routine and pm_runtime_get_sync()
 195          * in remove routine.
 196          */
 197         pm_runtime_set_autosuspend_delay(dev, GB_BUNDLE_AUTOSUSPEND_MS);
 198         pm_runtime_use_autosuspend(dev);
 199         pm_runtime_get_noresume(dev);
 200         pm_runtime_set_active(dev);
 201         pm_runtime_enable(dev);
 202
 203         retval = driver->probe(bundle, id);
 204         if (retval) {
 205                 /*
 206                  * Catch buggy drivers that fail to destroy their connections.
 207                  */
 208                 WARN_ON(!list_empty(&bundle->connections));
 209
 210                 gb_control_bundle_deactivate(bundle->intf->control, bundle->id);
 211
 212                 pm_runtime_disable(dev);
 213                 pm_runtime_set_suspended(dev);
 214                 pm_runtime_put_noidle(dev);
 215                 pm_runtime_dont_use_autosuspend(dev);
 216                 pm_runtime_put(&bundle->intf->dev);
 217
 218                 return retval;
 219         }
 220
 221         pm_runtime_put(&bundle->intf->dev);
 222
 223         return 0;
 224 }
 225
 226 static int greybus_remove(struct device *dev)
 227 {
 228         struct greybus_driver *driver = to_greybus_driver(dev->driver);
 229         struct gb_bundle *bundle = to_gb_bundle(dev);
 230         struct gb_connection *connection;
 231         int retval;
 232
 233         retval = pm_runtime_get_sync(dev);
 234         if (retval < 0)
 235                 dev_err(dev, "failed to resume bundle: %d\n", retval);
 236
 237         /*
 238          * Disable (non-offloaded) connections early in case the interface is
 239          * already gone to avoid unceccessary operation timeouts during
 240          * driver disconnect. Otherwise, only disable incoming requests.
 241          */
 242         list_for_each_entry(connection, &bundle->connections, bundle_links) {
 243                 if (gb_connection_is_offloaded(connection))
 244                         continue;
 245
 246                 if (bundle->intf->disconnected)
 247                         gb_connection_disable_forced(connection);
 248                 else
 249                         gb_connection_disable_rx(connection);
 250         }
 251
 252         driver->disconnect(bundle);
 253
 254         /* Catch buggy drivers that fail to destroy their connections. */
 255         WARN_ON(!list_empty(&bundle->connections));
 256
 257         if (!bundle->intf->disconnected)
 258                 gb_control_bundle_deactivate(bundle->intf->control, bundle->id);
 259
 260         pm_runtime_put_noidle(dev);
 261         pm_runtime_disable(dev);
 262         pm_runtime_set_suspended(dev);
 263         pm_runtime_dont_use_autosuspend(dev);
 264         pm_runtime_put_noidle(dev);
 265
 266         return 0;
 267 }
 268
 269 int greybus_register_driver(struct greybus_driver *driver, struct module *owner,
 270                 const char *mod_name)
 271 {
 272         int retval;
 273
 274         if (greybus_disabled())
 275                 return -ENODEV;
 276
 277         driver->driver.bus = &greybus_bus_type;
 278         driver->driver.name = driver->name;
 279         driver->driver.probe = greybus_probe;
 280         driver->driver.remove = greybus_remove;
 281         driver->driver.owner = owner;
 282         driver->driver.mod_name = mod_name;
 283
 284         retval = driver_register(&driver->driver);
 285         if (retval)
 286                 return retval;
 287
 288         pr_info("registered new driver %s\n", driver->name);
 289         return 0;
 290 }
 291 EXPORT_SYMBOL_GPL(greybus_register_driver);
 292
 293 void greybus_deregister_driver(struct greybus_driver *driver)
 294 {
 295         driver_unregister(&driver->driver);
 296 }
 297 EXPORT_SYMBOL_GPL(greybus_deregister_driver);
 298
 299 static int __init gb_init(void)
 300 {
 301         int retval;
 302
 303         if (greybus_disabled())
 304                 return -ENODEV;
 305
 306         BUILD_BUG_ON(CPORT_ID_MAX >= (long)CPORT_ID_BAD);
 307
 308         gb_debugfs_init();
 309
 310         retval = bus_register(&greybus_bus_type);
 311         if (retval) {
 312                 pr_err("bus_register failed (%d)\n", retval);
 313                 goto error_bus;
 314         }
 315
 316         retval = gb_hd_init();
 317         if (retval) {
 318                 pr_err("gb_hd_init failed (%d)\n", retval);
 319                 goto error_hd;
 320         }
 321
 322         retval = gb_operation_init();
 323         if (retval) {
 324                 pr_err("gb_operation_init failed (%d)\n", retval);
 325                 goto error_operation;
 326         }
 327         return 0;       /* Success */
 328
 329 error_operation:
 330         gb_hd_exit();
 331 error_hd:
 332         bus_unregister(&greybus_bus_type);
 333 error_bus:
 334         gb_debugfs_cleanup();
 335
 336         return retval;
 337 }
 338 module_init(gb_init);
 339
 340 static void __exit gb_exit(void)
 341 {
 342         gb_operation_exit();
 343         gb_hd_exit();
 344         bus_unregister(&greybus_bus_type);
 345         gb_debugfs_cleanup();
 346         tracepoint_synchronize_unregister();
 347 }
 348 module_exit(gb_exit);
 349 MODULE_LICENSE("GPL v2");
 350 MODULE_AUTHOR("Greg Kroah-Hartman <gregkh@linuxfoundation.org>");