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 void 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 		isa_driver->remove(dev, to_isa_dev(dev)->id);
55 }
56 
isa_bus_shutdown(struct device * dev)57 static void isa_bus_shutdown(struct device *dev)
58 {
59 	struct isa_driver *isa_driver = dev->platform_data;
60 
61 	if (isa_driver && isa_driver->shutdown)
62 		isa_driver->shutdown(dev, to_isa_dev(dev)->id);
63 }
64 
isa_bus_suspend(struct device * dev,pm_message_t state)65 static int isa_bus_suspend(struct device *dev, pm_message_t state)
66 {
67 	struct isa_driver *isa_driver = dev->platform_data;
68 
69 	if (isa_driver && isa_driver->suspend)
70 		return isa_driver->suspend(dev, to_isa_dev(dev)->id, state);
71 
72 	return 0;
73 }
74 
isa_bus_resume(struct device * dev)75 static int isa_bus_resume(struct device *dev)
76 {
77 	struct isa_driver *isa_driver = dev->platform_data;
78 
79 	if (isa_driver && isa_driver->resume)
80 		return isa_driver->resume(dev, to_isa_dev(dev)->id);
81 
82 	return 0;
83 }
84 
85 static struct bus_type isa_bus_type = {
86 	.name		= "isa",
87 	.match		= isa_bus_match,
88 	.probe		= isa_bus_probe,
89 	.remove		= isa_bus_remove,
90 	.shutdown	= isa_bus_shutdown,
91 	.suspend	= isa_bus_suspend,
92 	.resume		= isa_bus_resume
93 };
94 
isa_dev_release(struct device * dev)95 static void isa_dev_release(struct device *dev)
96 {
97 	kfree(to_isa_dev(dev));
98 }
99 
isa_unregister_driver(struct isa_driver * isa_driver)100 void isa_unregister_driver(struct isa_driver *isa_driver)
101 {
102 	struct device *dev = isa_driver->devices;
103 
104 	while (dev) {
105 		struct device *tmp = to_isa_dev(dev)->next;
106 		device_unregister(dev);
107 		dev = tmp;
108 	}
109 	driver_unregister(&isa_driver->driver);
110 }
111 EXPORT_SYMBOL_GPL(isa_unregister_driver);
112 
isa_register_driver(struct isa_driver * isa_driver,unsigned int ndev)113 int isa_register_driver(struct isa_driver *isa_driver, unsigned int ndev)
114 {
115 	int error;
116 	unsigned int id;
117 
118 	isa_driver->driver.bus	= &isa_bus_type;
119 	isa_driver->devices	= NULL;
120 
121 	error = driver_register(&isa_driver->driver);
122 	if (error)
123 		return error;
124 
125 	for (id = 0; id < ndev; id++) {
126 		struct isa_dev *isa_dev;
127 
128 		isa_dev = kzalloc(sizeof *isa_dev, GFP_KERNEL);
129 		if (!isa_dev) {
130 			error = -ENOMEM;
131 			break;
132 		}
133 
134 		isa_dev->dev.parent	= &isa_bus;
135 		isa_dev->dev.bus	= &isa_bus_type;
136 
137 		dev_set_name(&isa_dev->dev, "%s.%u",
138 			     isa_driver->driver.name, id);
139 		isa_dev->dev.platform_data	= isa_driver;
140 		isa_dev->dev.release		= isa_dev_release;
141 		isa_dev->id			= id;
142 
143 		isa_dev->dev.coherent_dma_mask = DMA_BIT_MASK(24);
144 		isa_dev->dev.dma_mask = &isa_dev->dev.coherent_dma_mask;
145 
146 		error = device_register(&isa_dev->dev);
147 		if (error) {
148 			put_device(&isa_dev->dev);
149 			break;
150 		}
151 
152 		if (isa_dev->dev.platform_data) {
153 			isa_dev->next = isa_driver->devices;
154 			isa_driver->devices = &isa_dev->dev;
155 		} else
156 			device_unregister(&isa_dev->dev);
157 	}
158 
159 	if (!error && !isa_driver->devices)
160 		error = -ENODEV;
161 
162 	if (error)
163 		isa_unregister_driver(isa_driver);
164 
165 	return error;
166 }
167 EXPORT_SYMBOL_GPL(isa_register_driver);
168 
isa_bus_init(void)169 static int __init isa_bus_init(void)
170 {
171 	int error;
172 
173 	error = bus_register(&isa_bus_type);
174 	if (!error) {
175 		error = device_register(&isa_bus);
176 		if (error)
177 			bus_unregister(&isa_bus_type);
178 	}
179 	return error;
180 }
181 
182 postcore_initcall(isa_bus_init);
183