xref: /linux/drivers/pnp/core.c (revision 7ae9fb1b7ecbb5d85d07857943f677fd1a559b18)
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 
pnp_remove_protocol(struct pnp_protocol * protocol)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  */
pnp_register_protocol(struct pnp_protocol * protocol)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  */
pnp_unregister_protocol(struct pnp_protocol * protocol)85 void pnp_unregister_protocol(struct pnp_protocol *protocol)
86 {
87 	pnp_remove_protocol(protocol);
88 	device_unregister(&protocol->dev);
89 }
90 
pnp_free_ids(struct pnp_dev * dev)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 
pnp_free_resource(struct pnp_resource * pnp_res)104 void pnp_free_resource(struct pnp_resource *pnp_res)
105 {
106 	list_del(&pnp_res->list);
107 	kfree(pnp_res);
108 }
109 
pnp_free_resources(struct pnp_dev * dev)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 
pnp_release_device(struct device * dmdev)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 
pnp_alloc_dev(struct pnp_protocol * protocol,int id,const char * pnpid)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 
pnp_delist_device(struct pnp_dev * dev)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 
__pnp_add_device(struct pnp_dev * dev)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  */
pnp_add_device(struct pnp_dev * dev)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 
__pnp_remove_device(struct pnp_dev * dev)223 void __pnp_remove_device(struct pnp_dev *dev)
224 {
225 	pnp_delist_device(dev);
226 	device_unregister(&dev->dev);
227 }
228 
pnp_init(void)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
241