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  *  @dev: the RIO device structure to match against
  83  *
  84  * return 0 and set rio_dev->driver when drv claims rio_dev, else error
  85  */
  86 static int rio_device_probe(struct device *dev)
  87 {
  88         struct rio_driver *rdrv = to_rio_driver(dev->driver);
  89         struct rio_dev *rdev = to_rio_dev(dev);
  90         int error = -ENODEV;
  91         const struct rio_device_id *id;
  92
  93         if (!rdev->driver && rdrv->probe) {
  94                 if (!rdrv->id_table)
  95                         return error;
  96                 id = rio_match_device(rdrv->id_table, rdev);
  97                 rio_dev_get(rdev);
  98                 if (id)
  99                         error = rdrv->probe(rdev, id);
 100                 if (error >= 0) {
 101                         rdev->driver = rdrv;
 102                         error = 0;
 103                 } else
 104                         rio_dev_put(rdev);
 105         }
 106         return error;
 107 }
 108
 109 /**
 110  *  rio_device_remove - Remove a RIO device from the system
 111  *
 112  *  @dev: the RIO device structure to match against
 113  *
 114  * Remove a RIO device from the system. If it has an associated
 115  * driver, then run the driver remove() method.  Then update
 116  * the reference count.
 117  */
 118 static int rio_device_remove(struct device *dev)
 119 {
 120         struct rio_dev *rdev = to_rio_dev(dev);
 121         struct rio_driver *rdrv = rdev->driver;
 122
 123         if (rdrv) {
 124                 if (rdrv->remove)
 125                         rdrv->remove(rdev);
 126                 rdev->driver = NULL;
 127         }
 128
 129         rio_dev_put(rdev);
 130
 131         return 0;
 132 }
 133
 134 /**
 135  *  rio_register_driver - register a new RIO driver
 136  *  @rdrv: the RIO driver structure to register
 137  *
 138  *  Adds a &struct rio_driver to the list of registered drivers.
 139  *  Returns a negative value on error, otherwise 0. If no error
 140  *  occurred, the driver remains registered even if no device
 141  *  was claimed during registration.
 142  */
 143 int rio_register_driver(struct rio_driver *rdrv)
 144 {
 145         /* initialize common driver fields */
 146         rdrv->driver.name = rdrv->name;
 147         rdrv->driver.bus = &rio_bus_type;
 148
 149         /* register with core */
 150         return driver_register(&rdrv->driver);
 151 }
 152
 153 /**
 154  *  rio_unregister_driver - unregister a RIO driver
 155  *  @rdrv: the RIO driver structure to unregister
 156  *
 157  *  Deletes the &struct rio_driver from the list of registered RIO
 158  *  drivers, gives it a chance to clean up by calling its remove()
 159  *  function for each device it was responsible for, and marks those
 160  *  devices as driverless.
 161  */
 162 void rio_unregister_driver(struct rio_driver *rdrv)
 163 {
 164         driver_unregister(&rdrv->driver);
 165 }
 166
 167 /**
 168  *  rio_match_bus - Tell if a RIO device structure has a matching RIO driver device id structure
 169  *  @dev: the standard device structure to match against
 170  *  @drv: the standard driver structure containing the ids to match against
 171  *
 172  *  Used by a driver to check whether a RIO device present in the
 173  *  system is in its list of supported devices. Returns 1 if
 174  *  there is a matching &struct rio_device_id or 0 if there is
 175  *  no match.
 176  */
 177 static int rio_match_bus(struct device *dev, struct device_driver *drv)
 178 {
 179         struct rio_dev *rdev = to_rio_dev(dev);
 180         struct rio_driver *rdrv = to_rio_driver(drv);
 181         const struct rio_device_id *id = rdrv->id_table;
 182         const struct rio_device_id *found_id;
 183
 184         if (!id)
 185                 goto out;
 186
 187         found_id = rio_match_device(id, rdev);
 188
 189         if (found_id)
 190                 return 1;
 191
 192       out:return 0;
 193 }
 194
 195 static struct device rio_bus = {
 196         .bus_id = "rapidio",
 197 };
 198
 199 struct bus_type rio_bus_type = {
 200         .name = "rapidio",
 201         .match = rio_match_bus,
 202         .dev_attrs = rio_dev_attrs,
 203         .probe = rio_device_probe,
 204         .remove = rio_device_remove,
 205 };
 206
 207 /**
 208  *  rio_bus_init - Register the RapidIO bus with the device model
 209  *
 210  *  Registers the RIO bus device and RIO bus type with the Linux
 211  *  device model.
 212  */
 213 static int __init rio_bus_init(void)
 214 {
 215         if (device_register(&rio_bus) < 0)
 216                 printk("RIO: failed to register RIO bus device\n");
 217         return bus_register(&rio_bus_type);
 218 }
 219
 220 postcore_initcall(rio_bus_init);
 221
 222 EXPORT_SYMBOL_GPL(rio_register_driver);
 223 EXPORT_SYMBOL_GPL(rio_unregister_driver);
 224 EXPORT_SYMBOL_GPL(rio_bus_type);
 225 EXPORT_SYMBOL_GPL(rio_dev_get);
 226 EXPORT_SYMBOL_GPL(rio_dev_put);