drivers/rapidio/rio-driver.c

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