drivers/sh/superhyway/superhyway.c

   1 /*
   2  * drivers/sh/superhyway/superhyway.c
   3  *
   4  * SuperHyway Bus Driver
   5  *
   6  * Copyright (C) 2004, 2005  Paul Mundt <lethal@linux-sh.org>
   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 #include <linux/kernel.h>
  13 #include <linux/device.h>
  14 #include <linux/init.h>
  15 #include <linux/module.h>
  16 #include <linux/types.h>
  17 #include <linux/list.h>
  18 #include <linux/superhyway.h>
  19
  20 static int superhyway_devices;
  21
  22 static struct device superhyway_bus_device = {
  23         .bus_id = "superhyway",
  24 };
  25
  26 static void superhyway_device_release(struct device *dev)
  27 {
  28         kfree(to_superhyway_device(dev));
  29 }
  30
  31 /**
  32  * superhyway_add_device - Add a SuperHyway module
  33  * @mod_id: Module ID (taken from MODULE.VCR.MOD_ID).
  34  * @base: Physical address where module is mapped.
  35  * @vcr: VCR value.
  36  *
  37  * This is responsible for adding a new SuperHyway module. This sets up a new
  38  * struct superhyway_device for the module being added. Each one of @mod_id,
  39  * @base, and @vcr are registered with the new device for further use
  40  * elsewhere.
  41  *
  42  * Devices are initially added in the order that they are scanned (from the
  43  * top-down of the memory map), and are assigned an ID based on the order that
  44  * they are added. Any manual addition of a module will thus get the ID after
  45  * the devices already discovered regardless of where it resides in memory.
  46  *
  47  * Further work can and should be done in superhyway_scan_bus(), to be sure
  48  * that any new modules are properly discovered and subsequently registered.
  49  */
  50 int superhyway_add_device(unsigned int mod_id, unsigned long base,
  51                           unsigned long long vcr)
  52 {
  53         struct superhyway_device *dev;
  54
  55         dev = kmalloc(sizeof(struct superhyway_device), GFP_KERNEL);
  56         if (!dev)
  57                 return -ENOMEM;
  58
  59         memset(dev, 0, sizeof(struct superhyway_device));
  60
  61         dev->id.id = mod_id;
  62         sprintf(dev->name, "SuperHyway device %04x", dev->id.id);
  63
  64         dev->vcr                = *((struct vcr_info *)(&vcr));
  65         dev->resource.name      = dev->name;
  66         dev->resource.start     = base;
  67         dev->resource.end       = dev->resource.start + 0x01000000;
  68         dev->dev.parent         = &superhyway_bus_device;
  69         dev->dev.bus            = &superhyway_bus_type;
  70         dev->dev.release        = superhyway_device_release;
  71
  72         sprintf(dev->dev.bus_id, "%02x", superhyway_devices);
  73
  74         superhyway_devices++;
  75
  76         return device_register(&dev->dev);
  77 }
  78
  79 static int __init superhyway_init(void)
  80 {
  81         device_register(&superhyway_bus_device);
  82         return superhyway_scan_bus();
  83 }
  84
  85 postcore_initcall(superhyway_init);
  86
  87 static const struct superhyway_device_id *
  88 superhyway_match_id(const struct superhyway_device_id *ids,
  89                     struct superhyway_device *dev)
  90 {
  91         while (ids->id) {
  92                 if (ids->id == dev->id.id)
  93                         return ids;
  94
  95                 ids++;
  96         }
  97
  98         return NULL;
  99 }
 100
 101 static int superhyway_device_probe(struct device *dev)
 102 {
 103         struct superhyway_device *shyway_dev = to_superhyway_device(dev);
 104         struct superhyway_driver *shyway_drv = to_superhyway_driver(dev->driver);
 105
 106         if (shyway_drv && shyway_drv->probe) {
 107                 const struct superhyway_device_id *id;
 108
 109                 id = superhyway_match_id(shyway_drv->id_table, shyway_dev);
 110                 if (id)
 111                         return shyway_drv->probe(shyway_dev, id);
 112         }
 113
 114         return -ENODEV;
 115 }
 116
 117 static int superhyway_device_remove(struct device *dev)
 118 {
 119         struct superhyway_device *shyway_dev = to_superhyway_device(dev);
 120         struct superhyway_driver *shyway_drv = to_superhyway_driver(dev->driver);
 121
 122         if (shyway_drv && shyway_drv->remove) {
 123                 shyway_drv->remove(shyway_dev);
 124                 return 0;
 125         }
 126
 127         return -ENODEV;
 128 }
 129
 130 /**
 131  * superhyway_register_driver - Register a new SuperHyway driver
 132  * @drv: SuperHyway driver to register.
 133  *
 134  * This registers the passed in @drv. Any devices matching the id table will
 135  * automatically be populated and handed off to the driver's specified probe
 136  * routine.
 137  */
 138 int superhyway_register_driver(struct superhyway_driver *drv)
 139 {
 140         drv->drv.name   = drv->name;
 141         drv->drv.bus    = &superhyway_bus_type;
 142         drv->drv.probe  = superhyway_device_probe;
 143         drv->drv.remove = superhyway_device_remove;
 144
 145         return driver_register(&drv->drv);
 146 }
 147
 148 /**
 149  * superhyway_unregister_driver - Unregister a SuperHyway driver
 150  * @drv: SuperHyway driver to unregister.
 151  *
 152  * This cleans up after superhyway_register_driver(), and should be invoked in
 153  * the exit path of any module drivers.
 154  */
 155 void superhyway_unregister_driver(struct superhyway_driver *drv)
 156 {
 157         driver_unregister(&drv->drv);
 158 }
 159
 160 static int superhyway_bus_match(struct device *dev, struct device_driver *drv)
 161 {
 162         struct superhyway_device *shyway_dev = to_superhyway_device(dev);
 163         struct superhyway_driver *shyway_drv = to_superhyway_driver(drv);
 164         const struct superhyway_device_id *ids = shyway_drv->id_table;
 165
 166         if (!ids)
 167                 return -EINVAL;
 168         if (superhyway_match_id(ids, shyway_dev))
 169                 return 1;
 170
 171         return -ENODEV;
 172 }
 173
 174 struct bus_type superhyway_bus_type = {
 175         .name           = "superhyway",
 176         .match          = superhyway_bus_match,
 177 #ifdef CONFIG_SYSFS
 178         .dev_attrs      = superhyway_dev_attrs,
 179 #endif
 180 };
 181
 182 static int __init superhyway_bus_init(void)
 183 {
 184         return bus_register(&superhyway_bus_type);
 185 }
 186
 187 static void __exit superhyway_bus_exit(void)
 188 {
 189         device_unregister(&superhyway_bus_device);
 190         bus_unregister(&superhyway_bus_type);
 191 }
 192
 193 core_initcall(superhyway_bus_init);
 194 module_exit(superhyway_bus_exit);
 195
 196 EXPORT_SYMBOL(superhyway_bus_type);
 197 EXPORT_SYMBOL(superhyway_add_device);
 198 EXPORT_SYMBOL(superhyway_register_driver);
 199 EXPORT_SYMBOL(superhyway_unregister_driver);
 200
 201 MODULE_LICENSE("GPL");