drivers/staging/greybus/gbphy.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Greybus Bridged-Phy Bus driver
   4  *
   5  * Copyright 2014 Google Inc.
   6  * Copyright 2014 Linaro Ltd.
   7  */
   8
   9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  10
  11 #include <linux/types.h>
  12 #include <linux/module.h>
  13 #include <linux/kernel.h>
  14 #include <linux/slab.h>
  15 #include <linux/device.h>
  16 #include <linux/greybus.h>
  17
  18 #include "gbphy.h"
  19
  20 #define GB_GBPHY_AUTOSUSPEND_MS 3000
  21
  22 struct gbphy_host {
  23         struct gb_bundle *bundle;
  24         struct list_head devices;
  25 };
  26
  27 static DEFINE_IDA(gbphy_id);
  28
  29 static ssize_t protocol_id_show(struct device *dev,
  30                                 struct device_attribute *attr, char *buf)
  31 {
  32         struct gbphy_device *gbphy_dev = to_gbphy_dev(dev);
  33
  34         return sprintf(buf, "0x%02x\n", gbphy_dev->cport_desc->protocol_id);
  35 }
  36 static DEVICE_ATTR_RO(protocol_id);
  37
  38 static struct attribute *gbphy_dev_attrs[] = {
  39         &dev_attr_protocol_id.attr,
  40         NULL,
  41 };
  42
  43 ATTRIBUTE_GROUPS(gbphy_dev);
  44
  45 static void gbphy_dev_release(struct device *dev)
  46 {
  47         struct gbphy_device *gbphy_dev = to_gbphy_dev(dev);
  48
  49         ida_free(&gbphy_id, gbphy_dev->id);
  50         kfree(gbphy_dev);
  51 }
  52
  53 #ifdef CONFIG_PM
  54 static int gb_gbphy_idle(struct device *dev)
  55 {
  56         pm_runtime_mark_last_busy(dev);
  57         pm_request_autosuspend(dev);
  58         return 0;
  59 }
  60 #endif
  61
  62 static const struct dev_pm_ops gb_gbphy_pm_ops = {
  63         SET_RUNTIME_PM_OPS(pm_generic_runtime_suspend,
  64                            pm_generic_runtime_resume,
  65                            gb_gbphy_idle)
  66 };
  67
  68 static const struct device_type greybus_gbphy_dev_type = {
  69         .name    =      "gbphy_device",
  70         .release =      gbphy_dev_release,
  71         .pm     =       &gb_gbphy_pm_ops,
  72 };
  73
  74 static int gbphy_dev_uevent(const struct device *dev, struct kobj_uevent_env *env)
  75 {
  76         const struct gbphy_device *gbphy_dev = to_gbphy_dev(dev);
  77         const struct greybus_descriptor_cport *cport_desc = gbphy_dev->cport_desc;
  78         const struct gb_bundle *bundle = gbphy_dev->bundle;
  79         const struct gb_interface *intf = bundle->intf;
  80         const struct gb_module *module = intf->module;
  81         const struct gb_host_device *hd = intf->hd;
  82
  83         if (add_uevent_var(env, "BUS=%u", hd->bus_id))
  84                 return -ENOMEM;
  85         if (add_uevent_var(env, "MODULE=%u", module->module_id))
  86                 return -ENOMEM;
  87         if (add_uevent_var(env, "INTERFACE=%u", intf->interface_id))
  88                 return -ENOMEM;
  89         if (add_uevent_var(env, "GREYBUS_ID=%08x/%08x",
  90                            intf->vendor_id, intf->product_id))
  91                 return -ENOMEM;
  92         if (add_uevent_var(env, "BUNDLE=%u", gbphy_dev->bundle->id))
  93                 return -ENOMEM;
  94         if (add_uevent_var(env, "BUNDLE_CLASS=%02x", bundle->class))
  95                 return -ENOMEM;
  96         if (add_uevent_var(env, "GBPHY=%u", gbphy_dev->id))
  97                 return -ENOMEM;
  98         if (add_uevent_var(env, "PROTOCOL_ID=%02x", cport_desc->protocol_id))
  99                 return -ENOMEM;
 100
 101         return 0;
 102 }
 103
 104 static const struct gbphy_device_id *
 105 gbphy_dev_match_id(struct gbphy_device *gbphy_dev,
 106                    struct gbphy_driver *gbphy_drv)
 107 {
 108         const struct gbphy_device_id *id = gbphy_drv->id_table;
 109
 110         if (!id)
 111                 return NULL;
 112
 113         for (; id->protocol_id; id++)
 114                 if (id->protocol_id == gbphy_dev->cport_desc->protocol_id)
 115                         return id;
 116
 117         return NULL;
 118 }
 119
 120 static int gbphy_dev_match(struct device *dev, const struct device_driver *drv)
 121 {
 122         struct gbphy_driver *gbphy_drv = to_gbphy_driver(drv);
 123         struct gbphy_device *gbphy_dev = to_gbphy_dev(dev);
 124         const struct gbphy_device_id *id;
 125
 126         id = gbphy_dev_match_id(gbphy_dev, gbphy_drv);
 127         if (id)
 128                 return 1;
 129
 130         return 0;
 131 }
 132
 133 static int gbphy_dev_probe(struct device *dev)
 134 {
 135         struct gbphy_driver *gbphy_drv = to_gbphy_driver(dev->driver);
 136         struct gbphy_device *gbphy_dev = to_gbphy_dev(dev);
 137         const struct gbphy_device_id *id;
 138         int ret;
 139
 140         id = gbphy_dev_match_id(gbphy_dev, gbphy_drv);
 141         if (!id)
 142                 return -ENODEV;
 143
 144         /* for old kernels we need get_sync to resume parent devices */
 145         ret = gb_pm_runtime_get_sync(gbphy_dev->bundle);
 146         if (ret < 0)
 147                 return ret;
 148
 149         pm_runtime_set_autosuspend_delay(dev, GB_GBPHY_AUTOSUSPEND_MS);
 150         pm_runtime_use_autosuspend(dev);
 151         pm_runtime_get_noresume(dev);
 152         pm_runtime_set_active(dev);
 153         pm_runtime_enable(dev);
 154
 155         /*
 156          * Drivers should call put on the gbphy dev before returning
 157          * from probe if they support runtime pm.
 158          */
 159         ret = gbphy_drv->probe(gbphy_dev, id);
 160         if (ret) {
 161                 pm_runtime_disable(dev);
 162                 pm_runtime_set_suspended(dev);
 163                 pm_runtime_put_noidle(dev);
 164                 pm_runtime_dont_use_autosuspend(dev);
 165         }
 166
 167         gb_pm_runtime_put_autosuspend(gbphy_dev->bundle);
 168
 169         return ret;
 170 }
 171
 172 static void gbphy_dev_remove(struct device *dev)
 173 {
 174         struct gbphy_driver *gbphy_drv = to_gbphy_driver(dev->driver);
 175         struct gbphy_device *gbphy_dev = to_gbphy_dev(dev);
 176
 177         gbphy_drv->remove(gbphy_dev);
 178
 179         pm_runtime_disable(dev);
 180         pm_runtime_set_suspended(dev);
 181         pm_runtime_put_noidle(dev);
 182         pm_runtime_dont_use_autosuspend(dev);
 183 }
 184
 185 static const struct bus_type gbphy_bus_type = {
 186         .name =         "gbphy",
 187         .match =        gbphy_dev_match,
 188         .probe =        gbphy_dev_probe,
 189         .remove =       gbphy_dev_remove,
 190         .uevent =       gbphy_dev_uevent,
 191 };
 192
 193 int gb_gbphy_register_driver(struct gbphy_driver *driver,
 194                              struct module *owner, const char *mod_name)
 195 {
 196         int retval;
 197
 198         if (greybus_disabled())
 199                 return -ENODEV;
 200
 201         driver->driver.bus = &gbphy_bus_type;
 202         driver->driver.name = driver->name;
 203         driver->driver.owner = owner;
 204         driver->driver.mod_name = mod_name;
 205
 206         retval = driver_register(&driver->driver);
 207         if (retval)
 208                 return retval;
 209
 210         pr_info("registered new driver %s\n", driver->name);
 211         return 0;
 212 }
 213 EXPORT_SYMBOL_GPL(gb_gbphy_register_driver);
 214
 215 void gb_gbphy_deregister_driver(struct gbphy_driver *driver)
 216 {
 217         driver_unregister(&driver->driver);
 218 }
 219 EXPORT_SYMBOL_GPL(gb_gbphy_deregister_driver);
 220
 221 static struct gbphy_device *gb_gbphy_create_dev(struct gb_bundle *bundle,
 222                                                 struct greybus_descriptor_cport *cport_desc)
 223 {
 224         struct gbphy_device *gbphy_dev;
 225         int retval;
 226         int id;
 227
 228         id = ida_alloc_min(&gbphy_id, 1, GFP_KERNEL);
 229         if (id < 0)
 230                 return ERR_PTR(id);
 231
 232         gbphy_dev = kzalloc(sizeof(*gbphy_dev), GFP_KERNEL);
 233         if (!gbphy_dev) {
 234                 ida_free(&gbphy_id, id);
 235                 return ERR_PTR(-ENOMEM);
 236         }
 237
 238         gbphy_dev->id = id;
 239         gbphy_dev->bundle = bundle;
 240         gbphy_dev->cport_desc = cport_desc;
 241         gbphy_dev->dev.parent = &bundle->dev;
 242         gbphy_dev->dev.bus = &gbphy_bus_type;
 243         gbphy_dev->dev.type = &greybus_gbphy_dev_type;
 244         gbphy_dev->dev.groups = gbphy_dev_groups;
 245         gbphy_dev->dev.dma_mask = bundle->dev.dma_mask;
 246         dev_set_name(&gbphy_dev->dev, "gbphy%d", id);
 247
 248         retval = device_register(&gbphy_dev->dev);
 249         if (retval) {
 250                 put_device(&gbphy_dev->dev);
 251                 return ERR_PTR(retval);
 252         }
 253
 254         return gbphy_dev;
 255 }
 256
 257 static void gb_gbphy_disconnect(struct gb_bundle *bundle)
 258 {
 259         struct gbphy_host *gbphy_host = greybus_get_drvdata(bundle);
 260         struct gbphy_device *gbphy_dev, *temp;
 261         int ret;
 262
 263         ret = gb_pm_runtime_get_sync(bundle);
 264         if (ret < 0)
 265                 gb_pm_runtime_get_noresume(bundle);
 266
 267         list_for_each_entry_safe(gbphy_dev, temp, &gbphy_host->devices, list) {
 268                 list_del(&gbphy_dev->list);
 269                 device_unregister(&gbphy_dev->dev);
 270         }
 271
 272         kfree(gbphy_host);
 273 }
 274
 275 static int gb_gbphy_probe(struct gb_bundle *bundle,
 276                           const struct greybus_bundle_id *id)
 277 {
 278         struct gbphy_host *gbphy_host;
 279         struct gbphy_device *gbphy_dev;
 280         int i;
 281
 282         if (bundle->num_cports == 0)
 283                 return -ENODEV;
 284
 285         gbphy_host = kzalloc(sizeof(*gbphy_host), GFP_KERNEL);
 286         if (!gbphy_host)
 287                 return -ENOMEM;
 288
 289         gbphy_host->bundle = bundle;
 290         INIT_LIST_HEAD(&gbphy_host->devices);
 291         greybus_set_drvdata(bundle, gbphy_host);
 292
 293         /*
 294          * Create a bunch of children devices, one per cport, and bind the
 295          * bridged phy drivers to them.
 296          */
 297         for (i = 0; i < bundle->num_cports; ++i) {
 298                 gbphy_dev = gb_gbphy_create_dev(bundle, &bundle->cport_desc[i]);
 299                 if (IS_ERR(gbphy_dev)) {
 300                         gb_gbphy_disconnect(bundle);
 301                         return PTR_ERR(gbphy_dev);
 302                 }
 303                 list_add(&gbphy_dev->list, &gbphy_host->devices);
 304         }
 305
 306         gb_pm_runtime_put_autosuspend(bundle);
 307
 308         return 0;
 309 }
 310
 311 static const struct greybus_bundle_id gb_gbphy_id_table[] = {
 312         { GREYBUS_DEVICE_CLASS(GREYBUS_CLASS_BRIDGED_PHY) },
 313         { },
 314 };
 315 MODULE_DEVICE_TABLE(greybus, gb_gbphy_id_table);
 316
 317 static struct greybus_driver gb_gbphy_driver = {
 318         .name           = "gbphy",
 319         .probe          = gb_gbphy_probe,
 320         .disconnect     = gb_gbphy_disconnect,
 321         .id_table       = gb_gbphy_id_table,
 322 };
 323
 324 static int __init gbphy_init(void)
 325 {
 326         int retval;
 327
 328         retval = bus_register(&gbphy_bus_type);
 329         if (retval) {
 330                 pr_err("gbphy bus register failed (%d)\n", retval);
 331                 return retval;
 332         }
 333
 334         retval = greybus_register(&gb_gbphy_driver);
 335         if (retval) {
 336                 pr_err("error registering greybus driver\n");
 337                 goto error_gbphy;
 338         }
 339
 340         return 0;
 341
 342 error_gbphy:
 343         bus_unregister(&gbphy_bus_type);
 344         ida_destroy(&gbphy_id);
 345         return retval;
 346 }
 347 module_init(gbphy_init);
 348
 349 static void __exit gbphy_exit(void)
 350 {
 351         greybus_deregister(&gb_gbphy_driver);
 352         bus_unregister(&gbphy_bus_type);
 353         ida_destroy(&gbphy_id);
 354 }
 355 module_exit(gbphy_exit);
 356
 357 MODULE_DESCRIPTION("Greybus Bridged-Phy Bus driver");
 358 MODULE_LICENSE("GPL v2");