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 static void pnp_free_ids(struct pnp_dev *dev)
82 {
83 	struct pnp_id *id;
84 	struct pnp_id *next;
85 
86 	id = dev->id;
87 	while (id) {
88 		next = id->next;
89 		kfree(id);
90 		id = next;
91 	}
92 }
93 
94 void pnp_free_resource(struct pnp_resource *pnp_res)
95 {
96 	list_del(&pnp_res->list);
97 	kfree(pnp_res);
98 }
99 
100 void pnp_free_resources(struct pnp_dev *dev)
101 {
102 	struct pnp_resource *pnp_res, *tmp;
103 
104 	list_for_each_entry_safe(pnp_res, tmp, &dev->resources, list) {
105 		pnp_free_resource(pnp_res);
106 	}
107 }
108 
109 static void pnp_release_device(struct device *dmdev)
110 {
111 	struct pnp_dev *dev = to_pnp_dev(dmdev);
112 
113 	pnp_free_ids(dev);
114 	pnp_free_resources(dev);
115 	pnp_free_options(dev);
116 	kfree(dev);
117 }
118 
119 struct pnp_dev *pnp_alloc_dev(struct pnp_protocol *protocol, int id,
120 			      const char *pnpid)
121 {
122 	struct pnp_dev *dev;
123 	struct pnp_id *dev_id;
124 
125 	dev = kzalloc(sizeof(struct pnp_dev), GFP_KERNEL);
126 	if (!dev)
127 		return NULL;
128 
129 	INIT_LIST_HEAD(&dev->resources);
130 	INIT_LIST_HEAD(&dev->options);
131 	dev->protocol = protocol;
132 	dev->number = id;
133 	dev->dma_mask = DMA_BIT_MASK(24);
134 
135 	dev->dev.parent = &dev->protocol->dev;
136 	dev->dev.bus = &pnp_bus_type;
137 	dev->dev.dma_mask = &dev->dma_mask;
138 	dev->dev.coherent_dma_mask = dev->dma_mask;
139 	dev->dev.release = &pnp_release_device;
140 
141 	dev_id = pnp_add_id(dev, pnpid);
142 	if (!dev_id) {
143 		kfree(dev);
144 		return NULL;
145 	}
146 
147 	dev_set_name(&dev->dev, "%02x:%02x", dev->protocol->number, dev->number);
148 
149 	return dev;
150 }
151 
152 static void pnp_delist_device(struct pnp_dev *dev)
153 {
154 	mutex_lock(&pnp_lock);
155 	list_del(&dev->global_list);
156 	list_del(&dev->protocol_list);
157 	mutex_unlock(&pnp_lock);
158 }
159 
160 int __pnp_add_device(struct pnp_dev *dev)
161 {
162 	int ret;
163 
164 	pnp_fixup_device(dev);
165 	dev->status = PNP_READY;
166 
167 	mutex_lock(&pnp_lock);
168 
169 	list_add_tail(&dev->global_list, &pnp_global);
170 	list_add_tail(&dev->protocol_list, &dev->protocol->devices);
171 
172 	mutex_unlock(&pnp_lock);
173 
174 	ret = device_register(&dev->dev);
175 	if (ret)
176 		pnp_delist_device(dev);
177 	else if (dev->protocol->can_wakeup)
178 		device_set_wakeup_capable(&dev->dev,
179 				dev->protocol->can_wakeup(dev));
180 
181 	return ret;
182 }
183 
184 /*
185  * pnp_add_device - adds a pnp device to the pnp layer
186  * @dev: pointer to dev to add
187  *
188  *  adds to driver model, name database, fixups, interface, etc.
189  */
190 int pnp_add_device(struct pnp_dev *dev)
191 {
192 	int ret;
193 	char buf[128];
194 	int len = 0;
195 	struct pnp_id *id;
196 
197 	if (dev->card)
198 		return -EINVAL;
199 
200 	ret = __pnp_add_device(dev);
201 	if (ret)
202 		return ret;
203 
204 	buf[0] = '\0';
205 	for (id = dev->id; id; id = id->next)
206 		len += scnprintf(buf + len, sizeof(buf) - len, " %s", id->id);
207 
208 	dev_dbg(&dev->dev, "%s device, IDs%s (%s)\n", dev->protocol->name, buf,
209 		dev->active ? "active" : "disabled");
210 	return 0;
211 }
212 
213 static int __init pnp_init(void)
214 {
215 	return bus_register(&pnp_bus_type);
216 }
217 
218 subsys_initcall(pnp_init);
219 
220 int pnp_debug;
221 
222 #if defined(CONFIG_PNP_DEBUG_MESSAGES)
223 module_param_named(debug, pnp_debug, int, 0644);
224 #endif
225