xref: /openbmc/linux/drivers/sh/superhyway/superhyway.c (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
1 /*
2  * drivers/sh/superhyway/superhyway.c
3  *
4  * SuperHyway Bus Driver
5  *
6  * Copyright (C) 2004, 2005  Paul Mundt <lethal@linux-sh.org>
7  *
8  * This file is subject to the terms and conditions of the GNU General Public
9  * License.  See the file "COPYING" in the main directory of this archive
10  * for more details.
11  */
12 #include <linux/kernel.h>
13 #include <linux/device.h>
14 #include <linux/init.h>
15 #include <linux/module.h>
16 #include <linux/types.h>
17 #include <linux/list.h>
18 #include <linux/superhyway.h>
19 
20 static int superhyway_devices;
21 
22 static struct device superhyway_bus_device = {
23 	.bus_id = "superhyway",
24 };
25 
26 static void superhyway_device_release(struct device *dev)
27 {
28 	kfree(to_superhyway_device(dev));
29 }
30 
31 /**
32  * superhyway_add_device - Add a SuperHyway module
33  * @mod_id: Module ID (taken from MODULE.VCR.MOD_ID).
34  * @base: Physical address where module is mapped.
35  * @vcr: VCR value.
36  *
37  * This is responsible for adding a new SuperHyway module. This sets up a new
38  * struct superhyway_device for the module being added. Each one of @mod_id,
39  * @base, and @vcr are registered with the new device for further use
40  * elsewhere.
41  *
42  * Devices are initially added in the order that they are scanned (from the
43  * top-down of the memory map), and are assigned an ID based on the order that
44  * they are added. Any manual addition of a module will thus get the ID after
45  * the devices already discovered regardless of where it resides in memory.
46  *
47  * Further work can and should be done in superhyway_scan_bus(), to be sure
48  * that any new modules are properly discovered and subsequently registered.
49  */
50 int superhyway_add_device(unsigned int mod_id, unsigned long base,
51 			  unsigned long long vcr)
52 {
53 	struct superhyway_device *dev;
54 
55 	dev = kmalloc(sizeof(struct superhyway_device), GFP_KERNEL);
56 	if (!dev)
57 		return -ENOMEM;
58 
59 	memset(dev, 0, sizeof(struct superhyway_device));
60 
61 	dev->id.id = mod_id;
62 	sprintf(dev->name, "SuperHyway device %04x", dev->id.id);
63 
64 	dev->vcr		= *((struct vcr_info *)(&vcr));
65 	dev->resource.name	= dev->name;
66 	dev->resource.start	= base;
67 	dev->resource.end	= dev->resource.start + 0x01000000;
68 	dev->dev.parent		= &superhyway_bus_device;
69 	dev->dev.bus		= &superhyway_bus_type;
70 	dev->dev.release	= superhyway_device_release;
71 
72 	sprintf(dev->dev.bus_id, "%02x", superhyway_devices);
73 
74 	superhyway_devices++;
75 
76 	return device_register(&dev->dev);
77 }
78 
79 static int __init superhyway_init(void)
80 {
81 	device_register(&superhyway_bus_device);
82 	return superhyway_scan_bus();
83 }
84 
85 postcore_initcall(superhyway_init);
86 
87 static const struct superhyway_device_id *
88 superhyway_match_id(const struct superhyway_device_id *ids,
89 		    struct superhyway_device *dev)
90 {
91 	while (ids->id) {
92 		if (ids->id == dev->id.id)
93 			return ids;
94 
95 		ids++;
96 	}
97 
98 	return NULL;
99 }
100 
101 static int superhyway_device_probe(struct device *dev)
102 {
103 	struct superhyway_device *shyway_dev = to_superhyway_device(dev);
104 	struct superhyway_driver *shyway_drv = to_superhyway_driver(dev->driver);
105 
106 	if (shyway_drv && shyway_drv->probe) {
107 		const struct superhyway_device_id *id;
108 
109 		id = superhyway_match_id(shyway_drv->id_table, shyway_dev);
110 		if (id)
111 			return shyway_drv->probe(shyway_dev, id);
112 	}
113 
114 	return -ENODEV;
115 }
116 
117 static int superhyway_device_remove(struct device *dev)
118 {
119 	struct superhyway_device *shyway_dev = to_superhyway_device(dev);
120 	struct superhyway_driver *shyway_drv = to_superhyway_driver(dev->driver);
121 
122 	if (shyway_drv && shyway_drv->remove) {
123 		shyway_drv->remove(shyway_dev);
124 		return 0;
125 	}
126 
127 	return -ENODEV;
128 }
129 
130 /**
131  * superhyway_register_driver - Register a new SuperHyway driver
132  * @drv: SuperHyway driver to register.
133  *
134  * This registers the passed in @drv. Any devices matching the id table will
135  * automatically be populated and handed off to the driver's specified probe
136  * routine.
137  */
138 int superhyway_register_driver(struct superhyway_driver *drv)
139 {
140 	drv->drv.name	= drv->name;
141 	drv->drv.bus	= &superhyway_bus_type;
142 	drv->drv.probe	= superhyway_device_probe;
143 	drv->drv.remove	= superhyway_device_remove;
144 
145 	return driver_register(&drv->drv);
146 }
147 
148 /**
149  * superhyway_unregister_driver - Unregister a SuperHyway driver
150  * @drv: SuperHyway driver to unregister.
151  *
152  * This cleans up after superhyway_register_driver(), and should be invoked in
153  * the exit path of any module drivers.
154  */
155 void superhyway_unregister_driver(struct superhyway_driver *drv)
156 {
157 	driver_unregister(&drv->drv);
158 }
159 
160 static int superhyway_bus_match(struct device *dev, struct device_driver *drv)
161 {
162 	struct superhyway_device *shyway_dev = to_superhyway_device(dev);
163 	struct superhyway_driver *shyway_drv = to_superhyway_driver(drv);
164 	const struct superhyway_device_id *ids = shyway_drv->id_table;
165 
166 	if (!ids)
167 		return -EINVAL;
168 	if (superhyway_match_id(ids, shyway_dev))
169 		return 1;
170 
171 	return -ENODEV;
172 }
173 
174 struct bus_type superhyway_bus_type = {
175 	.name		= "superhyway",
176 	.match		= superhyway_bus_match,
177 #ifdef CONFIG_SYSFS
178 	.dev_attrs	= superhyway_dev_attrs,
179 #endif
180 };
181 
182 static int __init superhyway_bus_init(void)
183 {
184 	return bus_register(&superhyway_bus_type);
185 }
186 
187 static void __exit superhyway_bus_exit(void)
188 {
189 	device_unregister(&superhyway_bus_device);
190 	bus_unregister(&superhyway_bus_type);
191 }
192 
193 core_initcall(superhyway_bus_init);
194 module_exit(superhyway_bus_exit);
195 
196 EXPORT_SYMBOL(superhyway_bus_type);
197 EXPORT_SYMBOL(superhyway_add_device);
198 EXPORT_SYMBOL(superhyway_register_driver);
199 EXPORT_SYMBOL(superhyway_unregister_driver);
200 
201 MODULE_LICENSE("GPL");
202