drivers/dio/dio-driver.c

   1 /*
   2  *  DIO Driver Services
   3  *
   4  *  Copyright (C) 2004 Jochen Friedrich
   5  *
   6  *  Loosely based on drivers/pci/pci-driver.c and drivers/zorro/zorro-driver.c
   7  *
   8  *  This file is subject to the terms and conditions of the GNU General Public
   9  *  License.  See the file COPYING in the main directory of this archive
  10  *  for more details.
  11  */
  12
  13 #include <linux/init.h>
  14 #include <linux/module.h>
  15 #include <linux/dio.h>
  16
  17
  18         /**
  19          *  dio_match_device - Tell if a DIO device structure has a matching
  20          *                     DIO device id structure
  21          *  @ids: array of DIO device id structures to search in
  22          *  @dev: the DIO device structure to match against
  23          *
  24          *  Used by a driver to check whether a DIO device present in the
  25          *  system is in its list of supported devices. Returns the matching
  26          *  dio_device_id structure or %NULL if there is no match.
  27          */
  28
  29 const struct dio_device_id *
  30 dio_match_device(const struct dio_device_id *ids,
  31                    const struct dio_dev *d)
  32 {
  33         while (ids->id) {
  34                 if (ids->id == DIO_WILDCARD)
  35                         return ids;
  36                 if (DIO_NEEDSSECID(ids->id & 0xff)) {
  37                         if (ids->id == d->id)
  38                                 return ids;
  39                 } else {
  40                         if ((ids->id & 0xff) == (d->id & 0xff))
  41                                 return ids;
  42                 }
  43                 ids++;
  44         }
  45         return NULL;
  46 }
  47
  48 static int dio_device_probe(struct device *dev)
  49 {
  50         int error = 0;
  51         struct dio_driver *drv = to_dio_driver(dev->driver);
  52         struct dio_dev *d = to_dio_dev(dev);
  53
  54         if (!d->driver && drv->probe) {
  55                 const struct dio_device_id *id;
  56
  57                 id = dio_match_device(drv->id_table, d);
  58                 if (id)
  59                         error = drv->probe(d, id);
  60                 if (error >= 0) {
  61                         d->driver = drv;
  62                         error = 0;
  63                 }
  64         }
  65         return error;
  66 }
  67
  68
  69         /**
  70          *  dio_register_driver - register a new DIO driver
  71          *  @drv: the driver structure to register
  72          *
  73          *  Adds the driver structure to the list of registered drivers
  74          *  Returns the number of DIO devices which were claimed by the driver
  75          *  during registration.  The driver remains registered even if the
  76          *  return value is zero.
  77          */
  78
  79 int dio_register_driver(struct dio_driver *drv)
  80 {
  81         int count = 0;
  82
  83         /* initialize common driver fields */
  84         drv->driver.name = drv->name;
  85         drv->driver.bus = &dio_bus_type;
  86
  87         /* register with core */
  88         count = driver_register(&drv->driver);
  89         return count ? count : 1;
  90 }
  91
  92
  93         /**
  94          *  dio_unregister_driver - unregister a DIO driver
  95          *  @drv: the driver structure to unregister
  96          *
  97          *  Deletes the driver structure from the list of registered DIO drivers,
  98          *  gives it a chance to clean up by calling its remove() function for
  99          *  each device it was responsible for, and marks those devices as
 100          *  driverless.
 101          */
 102
 103 void dio_unregister_driver(struct dio_driver *drv)
 104 {
 105         driver_unregister(&drv->driver);
 106 }
 107
 108
 109         /**
 110          *  dio_bus_match - Tell if a DIO device structure has a matching DIO
 111          *                  device id structure
 112          *  @ids: array of DIO device id structures to search in
 113          *  @dev: the DIO device structure to match against
 114          *
 115          *  Used by a driver to check whether a DIO device present in the
 116          *  system is in its list of supported devices. Returns the matching
 117          *  dio_device_id structure or %NULL if there is no match.
 118          */
 119
 120 static int dio_bus_match(struct device *dev, struct device_driver *drv)
 121 {
 122         struct dio_dev *d = to_dio_dev(dev);
 123         struct dio_driver *dio_drv = to_dio_driver(drv);
 124         const struct dio_device_id *ids = dio_drv->id_table;
 125
 126         if (!ids)
 127                 return 0;
 128
 129         while (ids->id) {
 130                 if (ids->id == DIO_WILDCARD)
 131                         return 1;
 132                 if (DIO_NEEDSSECID(ids->id & 0xff)) {
 133                         if (ids->id == d->id)
 134                                 return 1;
 135                 } else {
 136                         if ((ids->id & 0xff) == (d->id & 0xff))
 137                                 return 1;
 138                 }
 139                 ids++;
 140         }
 141         return 0;
 142 }
 143
 144
 145 struct bus_type dio_bus_type = {
 146         .name   = "dio",
 147         .match  = dio_bus_match,
 148         .probe  = dio_device_probe,
 149 };
 150
 151
 152 static int __init dio_driver_init(void)
 153 {
 154         return bus_register(&dio_bus_type);
 155 }
 156
 157 postcore_initcall(dio_driver_init);
 158
 159 EXPORT_SYMBOL(dio_match_device);
 160 EXPORT_SYMBOL(dio_register_driver);
 161 EXPORT_SYMBOL(dio_unregister_driver);
 162 EXPORT_SYMBOL(dio_dev_driver);
 163 EXPORT_SYMBOL(dio_bus_type);