drivers/rapidio/rio-driver.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * RapidIO driver support
   4  *
   5  * Copyright 2005 MontaVista Software, Inc.
   6  * Matt Porter <mporter@kernel.crashing.org>
   7  */
   8
   9 #include <linux/init.h>
  10 #include <linux/module.h>
  11 #include <linux/rio.h>
  12 #include <linux/rio_ids.h>
  13 #include <linux/rio_drv.h>
  14
  15 #include "rio.h"
  16
  17 /**
  18  *  rio_match_device - Tell if a RIO device has a matching RIO device id structure
  19  *  @id: the RIO device id structure to match against
  20  *  @rdev: the RIO device structure to match against
  21  *
  22  *  Used from driver probe and bus matching to check whether a RIO device
  23  *  matches a device id structure provided by a RIO driver. Returns the
  24  *  matching &struct rio_device_id or %NULL if there is no match.
  25  */
  26 static const struct rio_device_id *rio_match_device(const struct rio_device_id
  27                                                     *id,
  28                                                     const struct rio_dev *rdev)
  29 {
  30         while (id->vid || id->asm_vid) {
  31                 if (((id->vid == RIO_ANY_ID) || (id->vid == rdev->vid)) &&
  32                     ((id->did == RIO_ANY_ID) || (id->did == rdev->did)) &&
  33                     ((id->asm_vid == RIO_ANY_ID)
  34                      || (id->asm_vid == rdev->asm_vid))
  35                     && ((id->asm_did == RIO_ANY_ID)
  36                         || (id->asm_did == rdev->asm_did)))
  37                         return id;
  38                 id++;
  39         }
  40         return NULL;
  41 }
  42
  43 /**
  44  * rio_dev_get - Increments the reference count of the RIO device structure
  45  *
  46  * @rdev: RIO device being referenced
  47  *
  48  * Each live reference to a device should be refcounted.
  49  *
  50  * Drivers for RIO devices should normally record such references in
  51  * their probe() methods, when they bind to a device, and release
  52  * them by calling rio_dev_put(), in their disconnect() methods.
  53  */
  54 struct rio_dev *rio_dev_get(struct rio_dev *rdev)
  55 {
  56         if (rdev)
  57                 get_device(&rdev->dev);
  58
  59         return rdev;
  60 }
  61
  62 /**
  63  * rio_dev_put - Release a use of the RIO device structure
  64  *
  65  * @rdev: RIO device being disconnected
  66  *
  67  * Must be called when a user of a device is finished with it.
  68  * When the last user of the device calls this function, the
  69  * memory of the device is freed.
  70  */
  71 void rio_dev_put(struct rio_dev *rdev)
  72 {
  73         if (rdev)
  74                 put_device(&rdev->dev);
  75 }
  76
  77 /**
  78  *  rio_device_probe - Tell if a RIO device structure has a matching RIO device id structure
  79  *  @dev: the RIO device structure to match against
  80  *
  81  * return 0 and set rio_dev->driver when drv claims rio_dev, else error
  82  */
  83 static int rio_device_probe(struct device *dev)
  84 {
  85         struct rio_driver *rdrv = to_rio_driver(dev->driver);
  86         struct rio_dev *rdev = to_rio_dev(dev);
  87         int error = -ENODEV;
  88         const struct rio_device_id *id;
  89
  90         if (!rdev->driver && rdrv->probe) {
  91                 if (!rdrv->id_table)
  92                         return error;
  93                 id = rio_match_device(rdrv->id_table, rdev);
  94                 rio_dev_get(rdev);
  95                 if (id)
  96                         error = rdrv->probe(rdev, id);
  97                 if (error >= 0) {
  98                         rdev->driver = rdrv;
  99                         error = 0;
 100                 } else
 101                         rio_dev_put(rdev);
 102         }
 103         return error;
 104 }
 105
 106 /**
 107  *  rio_device_remove - Remove a RIO device from the system
 108  *
 109  *  @dev: the RIO device structure to match against
 110  *
 111  * Remove a RIO device from the system. If it has an associated
 112  * driver, then run the driver remove() method.  Then update
 113  * the reference count.
 114  */
 115 static void rio_device_remove(struct device *dev)
 116 {
 117         struct rio_dev *rdev = to_rio_dev(dev);
 118         struct rio_driver *rdrv = rdev->driver;
 119
 120         if (rdrv) {
 121                 if (rdrv->remove)
 122                         rdrv->remove(rdev);
 123                 rdev->driver = NULL;
 124         }
 125
 126         rio_dev_put(rdev);
 127 }
 128
 129 static void rio_device_shutdown(struct device *dev)
 130 {
 131         struct rio_dev *rdev = to_rio_dev(dev);
 132         struct rio_driver *rdrv = rdev->driver;
 133
 134         dev_dbg(dev, "RIO: %s\n", __func__);
 135
 136         if (rdrv && rdrv->shutdown)
 137                 rdrv->shutdown(rdev);
 138 }
 139
 140 /**
 141  *  rio_register_driver - register a new RIO driver
 142  *  @rdrv: the RIO driver structure to register
 143  *
 144  *  Adds a &struct rio_driver to the list of registered drivers.
 145  *  Returns a negative value on error, otherwise 0. If no error
 146  *  occurred, the driver remains registered even if no device
 147  *  was claimed during registration.
 148  */
 149 int rio_register_driver(struct rio_driver *rdrv)
 150 {
 151         /* initialize common driver fields */
 152         rdrv->driver.name = rdrv->name;
 153         rdrv->driver.bus = &rio_bus_type;
 154
 155         /* register with core */
 156         return driver_register(&rdrv->driver);
 157 }
 158
 159 /**
 160  *  rio_unregister_driver - unregister a RIO driver
 161  *  @rdrv: the RIO driver structure to unregister
 162  *
 163  *  Deletes the &struct rio_driver from the list of registered RIO
 164  *  drivers, gives it a chance to clean up by calling its remove()
 165  *  function for each device it was responsible for, and marks those
 166  *  devices as driverless.
 167  */
 168 void rio_unregister_driver(struct rio_driver *rdrv)
 169 {
 170         driver_unregister(&rdrv->driver);
 171 }
 172
 173 void rio_attach_device(struct rio_dev *rdev)
 174 {
 175         rdev->dev.bus = &rio_bus_type;
 176 }
 177 EXPORT_SYMBOL_GPL(rio_attach_device);
 178
 179 /**
 180  *  rio_match_bus - Tell if a RIO device structure has a matching RIO driver device id structure
 181  *  @dev: the standard device structure to match against
 182  *  @drv: the standard driver structure containing the ids to match against
 183  *
 184  *  Used by a driver to check whether a RIO device present in the
 185  *  system is in its list of supported devices. Returns 1 if
 186  *  there is a matching &struct rio_device_id or 0 if there is
 187  *  no match.
 188  */
 189 static int rio_match_bus(struct device *dev, const struct device_driver *drv)
 190 {
 191         struct rio_dev *rdev = to_rio_dev(dev);
 192         const struct rio_driver *rdrv = to_rio_driver(drv);
 193         const struct rio_device_id *id = rdrv->id_table;
 194         const struct rio_device_id *found_id;
 195
 196         if (!id)
 197                 goto out;
 198
 199         found_id = rio_match_device(id, rdev);
 200
 201         if (found_id)
 202                 return 1;
 203
 204       out:return 0;
 205 }
 206
 207 static int rio_uevent(const struct device *dev, struct kobj_uevent_env *env)
 208 {
 209         const struct rio_dev *rdev;
 210
 211         if (!dev)
 212                 return -ENODEV;
 213
 214         rdev = to_rio_dev(dev);
 215         if (!rdev)
 216                 return -ENODEV;
 217
 218         if (add_uevent_var(env, "MODALIAS=rapidio:v%04Xd%04Xav%04Xad%04X",
 219                            rdev->vid, rdev->did, rdev->asm_vid, rdev->asm_did))
 220                 return -ENOMEM;
 221         return 0;
 222 }
 223
 224 struct class rio_mport_class = {
 225         .name           = "rapidio_port",
 226         .dev_groups     = rio_mport_groups,
 227 };
 228 EXPORT_SYMBOL_GPL(rio_mport_class);
 229
 230 struct bus_type rio_bus_type = {
 231         .name = "rapidio",
 232         .match = rio_match_bus,
 233         .dev_groups = rio_dev_groups,
 234         .bus_groups = rio_bus_groups,
 235         .probe = rio_device_probe,
 236         .remove = rio_device_remove,
 237         .shutdown = rio_device_shutdown,
 238         .uevent = rio_uevent,
 239 };
 240
 241 /**
 242  *  rio_bus_init - Register the RapidIO bus with the device model
 243  *
 244  *  Registers the RIO mport device class and RIO bus type with the Linux
 245  *  device model.
 246  */
 247 static int __init rio_bus_init(void)
 248 {
 249         int ret;
 250
 251         ret = class_register(&rio_mport_class);
 252         if (!ret) {
 253                 ret = bus_register(&rio_bus_type);
 254                 if (ret)
 255                         class_unregister(&rio_mport_class);
 256         }
 257         return ret;
 258 }
 259
 260 postcore_initcall(rio_bus_init);
 261
 262 EXPORT_SYMBOL_GPL(rio_register_driver);
 263 EXPORT_SYMBOL_GPL(rio_unregister_driver);
 264 EXPORT_SYMBOL_GPL(rio_bus_type);
 265 EXPORT_SYMBOL_GPL(rio_dev_get);
 266 EXPORT_SYMBOL_GPL(rio_dev_put);