1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * ISA bus.
4  */
5 
6 #include <linux/device.h>
7 #include <linux/kernel.h>
8 #include <linux/slab.h>
9 #include <linux/module.h>
10 #include <linux/init.h>
11 #include <linux/dma-mapping.h>
12 #include <linux/isa.h>
13 
14 static struct device isa_bus = {
15 	.init_name	= "isa"
16 };
17 
18 struct isa_dev {
19 	struct device dev;
20 	struct device *next;
21 	unsigned int id;
22 };
23 
24 #define to_isa_dev(x) container_of((x), struct isa_dev, dev)
25 
isa_bus_match(struct device * dev,struct device_driver * driver)26 static int isa_bus_match(struct device *dev, struct device_driver *driver)
27 {
28 	struct isa_driver *isa_driver = to_isa_driver(driver);
29 
30 	if (dev->platform_data == isa_driver) {
31 		if (!isa_driver->match ||
32 			isa_driver->match(dev, to_isa_dev(dev)->id))
33 			return 1;
34 		dev->platform_data = NULL;
35 	}
36 	return 0;
37 }
38 
isa_bus_probe(struct device * dev)39 static int isa_bus_probe(struct device *dev)
40 {
41 	struct isa_driver *isa_driver = dev->platform_data;
42 
43 	if (isa_driver && isa_driver->probe)
44 		return isa_driver->probe(dev, to_isa_dev(dev)->id);
45 
46 	return 0;
47 }
48 
isa_bus_remove(struct device * dev)49 static int isa_bus_remove(struct device *dev)
50 {
51 	struct isa_driver *isa_driver = dev->platform_data;
52 
53 	if (isa_driver && isa_driver->remove)
54 		return isa_driver->remove(dev, to_isa_dev(dev)->id);
55 
56 	return 0;
57 }
58 
isa_bus_shutdown(struct device * dev)59 static void isa_bus_shutdown(struct device *dev)
60 {
61 	struct isa_driver *isa_driver = dev->platform_data;
62 
63 	if (isa_driver && isa_driver->shutdown)
64 		isa_driver->shutdown(dev, to_isa_dev(dev)->id);
65 }
66 
isa_bus_suspend(struct device * dev,pm_message_t state)67 static int isa_bus_suspend(struct device *dev, pm_message_t state)
68 {
69 	struct isa_driver *isa_driver = dev->platform_data;
70 
71 	if (isa_driver && isa_driver->suspend)
72 		return isa_driver->suspend(dev, to_isa_dev(dev)->id, state);
73 
74 	return 0;
75 }
76 
isa_bus_resume(struct device * dev)77 static int isa_bus_resume(struct device *dev)
78 {
79 	struct isa_driver *isa_driver = dev->platform_data;
80 
81 	if (isa_driver && isa_driver->resume)
82 		return isa_driver->resume(dev, to_isa_dev(dev)->id);
83 
84 	return 0;
85 }
86 
87 static struct bus_type isa_bus_type = {
88 	.name		= "isa",
89 	.match		= isa_bus_match,
90 	.probe		= isa_bus_probe,
91 	.remove		= isa_bus_remove,
92 	.shutdown	= isa_bus_shutdown,
93 	.suspend	= isa_bus_suspend,
94 	.resume		= isa_bus_resume
95 };
96 
isa_dev_release(struct device * dev)97 static void isa_dev_release(struct device *dev)
98 {
99 	kfree(to_isa_dev(dev));
100 }
101 
isa_unregister_driver(struct isa_driver * isa_driver)102 void isa_unregister_driver(struct isa_driver *isa_driver)
103 {
104 	struct device *dev = isa_driver->devices;
105 
106 	while (dev) {
107 		struct device *tmp = to_isa_dev(dev)->next;
108 		device_unregister(dev);
109 		dev = tmp;
110 	}
111 	driver_unregister(&isa_driver->driver);
112 }
113 EXPORT_SYMBOL_GPL(isa_unregister_driver);
114 
isa_register_driver(struct isa_driver * isa_driver,unsigned int ndev)115 int isa_register_driver(struct isa_driver *isa_driver, unsigned int ndev)
116 {
117 	int error;
118 	unsigned int id;
119 
120 	isa_driver->driver.bus	= &isa_bus_type;
121 	isa_driver->devices	= NULL;
122 
123 	error = driver_register(&isa_driver->driver);
124 	if (error)
125 		return error;
126 
127 	for (id = 0; id < ndev; id++) {
128 		struct isa_dev *isa_dev;
129 
130 		isa_dev = kzalloc(sizeof *isa_dev, GFP_KERNEL);
131 		if (!isa_dev) {
132 			error = -ENOMEM;
133 			break;
134 		}
135 
136 		isa_dev->dev.parent	= &isa_bus;
137 		isa_dev->dev.bus	= &isa_bus_type;
138 
139 		dev_set_name(&isa_dev->dev, "%s.%u",
140 			     isa_driver->driver.name, id);
141 		isa_dev->dev.platform_data	= isa_driver;
142 		isa_dev->dev.release		= isa_dev_release;
143 		isa_dev->id			= id;
144 
145 		isa_dev->dev.coherent_dma_mask = DMA_BIT_MASK(24);
146 		isa_dev->dev.dma_mask = &isa_dev->dev.coherent_dma_mask;
147 
148 		error = device_register(&isa_dev->dev);
149 		if (error) {
150 			put_device(&isa_dev->dev);
151 			break;
152 		}
153 
154 		if (isa_dev->dev.platform_data) {
155 			isa_dev->next = isa_driver->devices;
156 			isa_driver->devices = &isa_dev->dev;
157 		} else
158 			device_unregister(&isa_dev->dev);
159 	}
160 
161 	if (!error && !isa_driver->devices)
162 		error = -ENODEV;
163 
164 	if (error)
165 		isa_unregister_driver(isa_driver);
166 
167 	return error;
168 }
169 EXPORT_SYMBOL_GPL(isa_register_driver);
170 
isa_bus_init(void)171 static int __init isa_bus_init(void)
172 {
173 	int error;
174 
175 	error = bus_register(&isa_bus_type);
176 	if (!error) {
177 		error = device_register(&isa_bus);
178 		if (error)
179 			bus_unregister(&isa_bus_type);
180 	}
181 	return error;
182 }
183 
184 postcore_initcall(isa_bus_init);
185