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