drivers/pnp/core.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * core.c - contains all core device and protocol registration functions
   4  *
   5  * Copyright 2002 Adam Belay <ambx1@neo.rr.com>
   6  */
   7
   8 #include <linux/pnp.h>
   9 #include <linux/types.h>
  10 #include <linux/list.h>
  11 #include <linux/device.h>
  12 #include <linux/module.h>
  13 #include <linux/mutex.h>
  14 #include <linux/init.h>
  15 #include <linux/string.h>
  16 #include <linux/slab.h>
  17 #include <linux/errno.h>
  18 #include <linux/dma-mapping.h>
  19
  20 #include "base.h"
  21
  22 static LIST_HEAD(pnp_protocols);
  23 LIST_HEAD(pnp_global);
  24 DEFINE_MUTEX(pnp_lock);
  25
  26 /*
  27  * ACPI or PNPBIOS should tell us about all platform devices, so we can
  28  * skip some blind probes.  ISAPNP typically enumerates only plug-in ISA
  29  * devices, not built-in things like COM ports.
  30  */
  31 int pnp_platform_devices;
  32 EXPORT_SYMBOL(pnp_platform_devices);
  33
  34 static void pnp_remove_protocol(struct pnp_protocol *protocol)
  35 {
  36         mutex_lock(&pnp_lock);
  37         list_del(&protocol->protocol_list);
  38         mutex_unlock(&pnp_lock);
  39 }
  40
  41 /**
  42  * pnp_register_protocol - adds a pnp protocol to the pnp layer
  43  * @protocol: pointer to the corresponding pnp_protocol structure
  44  *
  45  *  Ex protocols: ISAPNP, PNPBIOS, etc
  46  */
  47 int pnp_register_protocol(struct pnp_protocol *protocol)
  48 {
  49         struct list_head *pos;
  50         int nodenum, ret;
  51
  52         INIT_LIST_HEAD(&protocol->devices);
  53         INIT_LIST_HEAD(&protocol->cards);
  54         nodenum = 0;
  55
  56         mutex_lock(&pnp_lock);
  57
  58         /* assign the lowest unused number */
  59         list_for_each(pos, &pnp_protocols) {
  60                 struct pnp_protocol *cur = to_pnp_protocol(pos);
  61                 if (cur->number == nodenum) {
  62                         pos = &pnp_protocols;
  63                         nodenum++;
  64                 }
  65         }
  66
  67         protocol->number = nodenum;
  68         dev_set_name(&protocol->dev, "pnp%d", nodenum);
  69
  70         list_add_tail(&protocol->protocol_list, &pnp_protocols);
  71
  72         mutex_unlock(&pnp_lock);
  73
  74         ret = device_register(&protocol->dev);
  75         if (ret)
  76                 pnp_remove_protocol(protocol);
  77
  78         return ret;
  79 }
  80
  81 /**
  82  * pnp_unregister_protocol - removes a pnp protocol from the pnp layer
  83  * @protocol: pointer to the corresponding pnp_protocol structure
  84  */
  85 void pnp_unregister_protocol(struct pnp_protocol *protocol)
  86 {
  87         pnp_remove_protocol(protocol);
  88         device_unregister(&protocol->dev);
  89 }
  90
  91 static void pnp_free_ids(struct pnp_dev *dev)
  92 {
  93         struct pnp_id *id;
  94         struct pnp_id *next;
  95
  96         id = dev->id;
  97         while (id) {
  98                 next = id->next;
  99                 kfree(id);
 100                 id = next;
 101         }
 102 }
 103
 104 void pnp_free_resource(struct pnp_resource *pnp_res)
 105 {
 106         list_del(&pnp_res->list);
 107         kfree(pnp_res);
 108 }
 109
 110 void pnp_free_resources(struct pnp_dev *dev)
 111 {
 112         struct pnp_resource *pnp_res, *tmp;
 113
 114         list_for_each_entry_safe(pnp_res, tmp, &dev->resources, list) {
 115                 pnp_free_resource(pnp_res);
 116         }
 117 }
 118
 119 static void pnp_release_device(struct device *dmdev)
 120 {
 121         struct pnp_dev *dev = to_pnp_dev(dmdev);
 122
 123         pnp_free_ids(dev);
 124         pnp_free_resources(dev);
 125         pnp_free_options(dev);
 126         kfree(dev);
 127 }
 128
 129 struct pnp_dev *pnp_alloc_dev(struct pnp_protocol *protocol, int id,
 130                               const char *pnpid)
 131 {
 132         struct pnp_dev *dev;
 133         struct pnp_id *dev_id;
 134
 135         dev = kzalloc(sizeof(struct pnp_dev), GFP_KERNEL);
 136         if (!dev)
 137                 return NULL;
 138
 139         INIT_LIST_HEAD(&dev->resources);
 140         INIT_LIST_HEAD(&dev->options);
 141         dev->protocol = protocol;
 142         dev->number = id;
 143         dev->dma_mask = DMA_BIT_MASK(24);
 144
 145         dev->dev.parent = &dev->protocol->dev;
 146         dev->dev.bus = &pnp_bus_type;
 147         dev->dev.dma_mask = &dev->dma_mask;
 148         dev->dev.coherent_dma_mask = dev->dma_mask;
 149         dev->dev.release = &pnp_release_device;
 150
 151         dev_id = pnp_add_id(dev, pnpid);
 152         if (!dev_id) {
 153                 kfree(dev);
 154                 return NULL;
 155         }
 156
 157         dev_set_name(&dev->dev, "%02x:%02x", dev->protocol->number, dev->number);
 158
 159         return dev;
 160 }
 161
 162 static void pnp_delist_device(struct pnp_dev *dev)
 163 {
 164         mutex_lock(&pnp_lock);
 165         list_del(&dev->global_list);
 166         list_del(&dev->protocol_list);
 167         mutex_unlock(&pnp_lock);
 168 }
 169
 170 int __pnp_add_device(struct pnp_dev *dev)
 171 {
 172         int ret;
 173
 174         pnp_fixup_device(dev);
 175         dev->status = PNP_READY;
 176
 177         mutex_lock(&pnp_lock);
 178
 179         list_add_tail(&dev->global_list, &pnp_global);
 180         list_add_tail(&dev->protocol_list, &dev->protocol->devices);
 181
 182         mutex_unlock(&pnp_lock);
 183
 184         ret = device_register(&dev->dev);
 185         if (ret)
 186                 pnp_delist_device(dev);
 187         else if (dev->protocol->can_wakeup)
 188                 device_set_wakeup_capable(&dev->dev,
 189                                 dev->protocol->can_wakeup(dev));
 190
 191         return ret;
 192 }
 193
 194 /*
 195  * pnp_add_device - adds a pnp device to the pnp layer
 196  * @dev: pointer to dev to add
 197  *
 198  *  adds to driver model, name database, fixups, interface, etc.
 199  */
 200 int pnp_add_device(struct pnp_dev *dev)
 201 {
 202         int ret;
 203         char buf[128];
 204         int len = 0;
 205         struct pnp_id *id;
 206
 207         if (dev->card)
 208                 return -EINVAL;
 209
 210         ret = __pnp_add_device(dev);
 211         if (ret)
 212                 return ret;
 213
 214         buf[0] = '\0';
 215         for (id = dev->id; id; id = id->next)
 216                 len += scnprintf(buf + len, sizeof(buf) - len, " %s", id->id);
 217
 218         dev_dbg(&dev->dev, "%s device, IDs%s (%s)\n", dev->protocol->name, buf,
 219                 dev->active ? "active" : "disabled");
 220         return 0;
 221 }
 222
 223 void __pnp_remove_device(struct pnp_dev *dev)
 224 {
 225         pnp_delist_device(dev);
 226         device_unregister(&dev->dev);
 227 }
 228
 229 static int __init pnp_init(void)
 230 {
 231         return bus_register(&pnp_bus_type);
 232 }
 233
 234 subsys_initcall(pnp_init);
 235
 236 int pnp_debug;
 237
 238 #if defined(CONFIG_PNP_DEBUG_MESSAGES)
 239 module_param_named(debug, pnp_debug, int, 0644);
 240 #endif