tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Bus for UWB Multi-interface Controller capabilities.
3 *
4 * Copyright (C) 2007 Cambridge Silicon Radio Ltd.
5 *
6 * This file is released under the GNU GPL v2.
7 */
8#include <linux/kernel.h>
9#include <linux/sysfs.h>
10#include <linux/workqueue.h>
11#include <linux/uwb/umc.h>
12#include <linux/pci.h>
13
14static int umc_bus_unbind_helper(struct device *dev, void *data)
15{
16 struct device *parent = data;
17
18 if (dev->parent == parent && dev->driver)
19 device_release_driver(dev);
20 return 0;
21}
22
23/**
24 * umc_controller_reset - reset the whole UMC controller
25 * @umc: the UMC device for the radio controller.
26 *
27 * Drivers will be unbound from all UMC devices belonging to the
28 * controller and then the radio controller will be rebound. The
29 * radio controller is expected to do a full hardware reset when it is
30 * probed.
31 *
32 * If this is called while a probe() or remove() is in progress it
33 * will return -EAGAIN and not perform the reset.
34 */
35int umc_controller_reset(struct umc_dev *umc)
36{
37 struct device *parent = umc->dev.parent;
38 int ret;
39
40 if (down_trylock(&parent->sem))
41 return -EAGAIN;
42 bus_for_each_dev(&umc_bus_type, NULL, parent, umc_bus_unbind_helper);
43 ret = device_attach(&umc->dev);
44 if (ret == 1)
45 ret = 0;
46 up(&parent->sem);
47
48 return ret;
49}
50EXPORT_SYMBOL_GPL(umc_controller_reset);
51
52/**
53 * umc_match_pci_id - match a UMC driver to a UMC device's parent PCI device.
54 * @umc_drv: umc driver with match_data pointing to a zero-terminated
55 * table of pci_device_id's.
56 * @umc: umc device whose parent is to be matched.
57 */
58int umc_match_pci_id(struct umc_driver *umc_drv, struct umc_dev *umc)
59{
60 const struct pci_device_id *id_table = umc_drv->match_data;
61 struct pci_dev *pci;
62
63 if (umc->dev.parent->bus != &pci_bus_type)
64 return 0;
65
66 pci = to_pci_dev(umc->dev.parent);
67 return pci_match_id(id_table, pci) != NULL;
68}
69EXPORT_SYMBOL_GPL(umc_match_pci_id);
70
71static int umc_bus_rescan_helper(struct device *dev, void *data)
72{
73 int ret = 0;
74
75 if (!dev->driver)
76 ret = device_attach(dev);
77
78 return ret < 0 ? ret : 0;
79}
80
81static void umc_bus_rescan(void)
82{
83 int err;
84
85 /*
86 * We can't use bus_rescan_devices() here as it deadlocks when
87 * it tries to retake the dev->parent semaphore.
88 */
89 err = bus_for_each_dev(&umc_bus_type, NULL, NULL, umc_bus_rescan_helper);
90 if (err < 0)
91 printk(KERN_WARNING "%s: rescan of bus failed: %d\n",
92 KBUILD_MODNAME, err);
93}
94
95static int umc_bus_match(struct device *dev, struct device_driver *drv)
96{
97 struct umc_dev *umc = to_umc_dev(dev);
98 struct umc_driver *umc_driver = to_umc_driver(drv);
99
100 if (umc->cap_id == umc_driver->cap_id) {
101 if (umc_driver->match)
102 return umc_driver->match(umc_driver, umc);
103 else
104 return 1;
105 }
106 return 0;
107}
108
109static int umc_device_probe(struct device *dev)
110{
111 struct umc_dev *umc;
112 struct umc_driver *umc_driver;
113 int err;
114
115 umc_driver = to_umc_driver(dev->driver);
116 umc = to_umc_dev(dev);
117
118 get_device(dev);
119 err = umc_driver->probe(umc);
120 if (err)
121 put_device(dev);
122 else
123 umc_bus_rescan();
124
125 return err;
126}
127
128static int umc_device_remove(struct device *dev)
129{
130 struct umc_dev *umc;
131 struct umc_driver *umc_driver;
132
133 umc_driver = to_umc_driver(dev->driver);
134 umc = to_umc_dev(dev);
135
136 umc_driver->remove(umc);
137 put_device(dev);
138 return 0;
139}
140
141static int umc_device_suspend(struct device *dev, pm_message_t state)
142{
143 struct umc_dev *umc;
144 struct umc_driver *umc_driver;
145 int err = 0;
146
147 umc = to_umc_dev(dev);
148
149 if (dev->driver) {
150 umc_driver = to_umc_driver(dev->driver);
151 if (umc_driver->suspend)
152 err = umc_driver->suspend(umc, state);
153 }
154 return err;
155}
156
157static int umc_device_resume(struct device *dev)
158{
159 struct umc_dev *umc;
160 struct umc_driver *umc_driver;
161 int err = 0;
162
163 umc = to_umc_dev(dev);
164
165 if (dev->driver) {
166 umc_driver = to_umc_driver(dev->driver);
167 if (umc_driver->resume)
168 err = umc_driver->resume(umc);
169 }
170 return err;
171}
172
173static ssize_t capability_id_show(struct device *dev, struct device_attribute *attr, char *buf)
174{
175 struct umc_dev *umc = to_umc_dev(dev);
176
177 return sprintf(buf, "0x%02x\n", umc->cap_id);
178}
179
180static ssize_t version_show(struct device *dev, struct device_attribute *attr, char *buf)
181{
182 struct umc_dev *umc = to_umc_dev(dev);
183
184 return sprintf(buf, "0x%04x\n", umc->version);
185}
186
187static struct device_attribute umc_dev_attrs[] = {
188 __ATTR_RO(capability_id),
189 __ATTR_RO(version),
190 __ATTR_NULL,
191};
192
193struct bus_type umc_bus_type = {
194 .name = "umc",
195 .match = umc_bus_match,
196 .probe = umc_device_probe,
197 .remove = umc_device_remove,
198 .suspend = umc_device_suspend,
199 .resume = umc_device_resume,
200 .dev_attrs = umc_dev_attrs,
201};
202EXPORT_SYMBOL_GPL(umc_bus_type);
203
204static int __init umc_bus_init(void)
205{
206 return bus_register(&umc_bus_type);
207}
208module_init(umc_bus_init);
209
210static void __exit umc_bus_exit(void)
211{
212 bus_unregister(&umc_bus_type);
213}
214module_exit(umc_bus_exit);
215
216MODULE_DESCRIPTION("UWB Multi-interface Controller capability bus");
217MODULE_AUTHOR("Cambridge Silicon Radio Ltd.");
218MODULE_LICENSE("GPL");