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 DIO device id structure
  20  *  @ids: array of DIO device id structures to search in
  21  *  @d: the DIO device structure to match against
  22  *
  23  *  Used by a driver to check whether a DIO device present in the
  24  *  system is in its list of supported devices. Returns the matching
  25  *  dio_device_id structure or %NULL if there is no match.
  26  */
  27
  28 static const struct dio_device_id *
  29 dio_match_device(const struct dio_device_id *ids,
  30                    const struct dio_dev *d)
  31 {
  32         while (ids->id) {
  33                 if (ids->id == DIO_WILDCARD)
  34                         return ids;
  35                 if (DIO_NEEDSSECID(ids->id & 0xff)) {
  36                         if (ids->id == d->id)
  37                                 return ids;
  38                 } else {
  39                         if ((ids->id & 0xff) == (d->id & 0xff))
  40                                 return ids;
  41                 }
  42                 ids++;
  43         }
  44         return NULL;
  45 }
  46
  47 static int dio_device_probe(struct device *dev)
  48 {
  49         int error = 0;
  50         struct dio_driver *drv = to_dio_driver(dev->driver);
  51         struct dio_dev *d = to_dio_dev(dev);
  52
  53         if (!d->driver && drv->probe) {
  54                 const struct dio_device_id *id;
  55
  56                 id = dio_match_device(drv->id_table, d);
  57                 if (id)
  58                         error = drv->probe(d, id);
  59                 if (error >= 0) {
  60                         d->driver = drv;
  61                         error = 0;
  62                 }
  63         }
  64         return error;
  65 }
  66
  67
  68 /**
  69  *  dio_register_driver - register a new DIO driver
  70  *  @drv: the driver structure to register
  71  *
  72  *  Adds the driver structure to the list of registered drivers
  73  *  Returns zero or a negative error value.
  74  */
  75
  76 int dio_register_driver(struct dio_driver *drv)
  77 {
  78         /* initialize common driver fields */
  79         drv->driver.name = drv->name;
  80         drv->driver.bus = &dio_bus_type;
  81
  82         /* register with core */
  83         return driver_register(&drv->driver);
  84 }
  85
  86
  87 /**
  88  *  dio_unregister_driver - unregister a DIO driver
  89  *  @drv: the driver structure to unregister
  90  *
  91  *  Deletes the driver structure from the list of registered DIO drivers,
  92  *  gives it a chance to clean up by calling its remove() function for
  93  *  each device it was responsible for, and marks those devices as
  94  *  driverless.
  95  */
  96
  97 void dio_unregister_driver(struct dio_driver *drv)
  98 {
  99         driver_unregister(&drv->driver);
 100 }
 101
 102
 103 /**
 104  *  dio_bus_match - Tell if a DIO device structure has a matching DIO device id structure
 105  *  @dev: the DIO device structure to match against
 106  *  @drv: the &device_driver that points to the array of DIO device id structures to search
 107  *
 108  *  Used by the driver core to check whether a DIO device present in the
 109  *  system is in a driver's list of supported devices. Returns 1 if supported,
 110  *  and 0 if there is no match.
 111  */
 112
 113 static int dio_bus_match(struct device *dev, struct device_driver *drv)
 114 {
 115         struct dio_dev *d = to_dio_dev(dev);
 116         struct dio_driver *dio_drv = to_dio_driver(drv);
 117         const struct dio_device_id *ids = dio_drv->id_table;
 118
 119         if (!ids)
 120                 return 0;
 121
 122         return dio_match_device(ids, d) ? 1 : 0;
 123 }
 124
 125
 126 struct bus_type dio_bus_type = {
 127         .name   = "dio",
 128         .match  = dio_bus_match,
 129         .probe  = dio_device_probe,
 130 };
 131
 132
 133 static int __init dio_driver_init(void)
 134 {
 135         return bus_register(&dio_bus_type);
 136 }
 137
 138 postcore_initcall(dio_driver_init);
 139
 140 EXPORT_SYMBOL(dio_register_driver);
 141 EXPORT_SYMBOL(dio_unregister_driver);
 142 EXPORT_SYMBOL(dio_bus_type);