tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Bus for UWB Multi-interface Controller capabilities.
4 *
5 * Copyright (C) 2007 Cambridge Silicon Radio Ltd.
6 */
7#include <linux/kernel.h>
8#include <linux/sysfs.h>
9#include <linux/workqueue.h>
10#include <linux/module.h>
11#include <linux/uwb/umc.h>
12#include <linux/pci.h>
13
14static int umc_bus_pre_reset_helper(struct device *dev, void *data)
15{
16 int ret = 0;
17
18 if (dev->driver) {
19 struct umc_dev *umc = to_umc_dev(dev);
20 struct umc_driver *umc_drv = to_umc_driver(dev->driver);
21
22 if (umc_drv->pre_reset)
23 ret = umc_drv->pre_reset(umc);
24 else
25 device_release_driver(dev);
26 }
27 return ret;
28}
29
30static int umc_bus_post_reset_helper(struct device *dev, void *data)
31{
32 int ret = 0;
33
34 if (dev->driver) {
35 struct umc_dev *umc = to_umc_dev(dev);
36 struct umc_driver *umc_drv = to_umc_driver(dev->driver);
37
38 if (umc_drv->post_reset)
39 ret = umc_drv->post_reset(umc);
40 } else
41 ret = device_attach(dev);
42
43 return ret;
44}
45
46/**
47 * umc_controller_reset - reset the whole UMC controller
48 * @umc: the UMC device for the radio controller.
49 *
50 * Drivers or all capabilities of the controller will have their
51 * pre_reset methods called or be unbound from their device. Then all
52 * post_reset methods will be called or the drivers will be rebound.
53 *
54 * Radio controllers must provide pre_reset and post_reset methods and
55 * reset the hardware in their start method.
56 *
57 * If this is called while a probe() or remove() is in progress it
58 * will return -EAGAIN and not perform the reset.
59 */
60int umc_controller_reset(struct umc_dev *umc)
61{
62 struct device *parent = umc->dev.parent;
63 int ret = 0;
64
65 if (!device_trylock(parent))
66 return -EAGAIN;
67 ret = device_for_each_child(parent, parent, umc_bus_pre_reset_helper);
68 if (ret >= 0)
69 ret = device_for_each_child(parent, parent, umc_bus_post_reset_helper);
70 device_unlock(parent);
71
72 return ret;
73}
74EXPORT_SYMBOL_GPL(umc_controller_reset);
75
76/**
77 * umc_match_pci_id - match a UMC driver to a UMC device's parent PCI device.
78 * @umc_drv: umc driver with match_data pointing to a zero-terminated
79 * table of pci_device_id's.
80 * @umc: umc device whose parent is to be matched.
81 */
82int umc_match_pci_id(struct umc_driver *umc_drv, struct umc_dev *umc)
83{
84 const struct pci_device_id *id_table = umc_drv->match_data;
85 struct pci_dev *pci;
86
87 if (!dev_is_pci(umc->dev.parent))
88 return 0;
89
90 pci = to_pci_dev(umc->dev.parent);
91 return pci_match_id(id_table, pci) != NULL;
92}
93EXPORT_SYMBOL_GPL(umc_match_pci_id);
94
95static int umc_bus_rescan_helper(struct device *dev, void *data)
96{
97 int ret = 0;
98
99 if (!dev->driver)
100 ret = device_attach(dev);
101
102 return ret;
103}
104
105static void umc_bus_rescan(struct device *parent)
106{
107 int err;
108
109 /*
110 * We can't use bus_rescan_devices() here as it deadlocks when
111 * it tries to retake the dev->parent semaphore.
112 */
113 err = device_for_each_child(parent, NULL, umc_bus_rescan_helper);
114 if (err < 0)
115 printk(KERN_WARNING "%s: rescan of bus failed: %d\n",
116 KBUILD_MODNAME, err);
117}
118
119static int umc_bus_match(struct device *dev, struct device_driver *drv)
120{
121 struct umc_dev *umc = to_umc_dev(dev);
122 struct umc_driver *umc_driver = to_umc_driver(drv);
123
124 if (umc->cap_id == umc_driver->cap_id) {
125 if (umc_driver->match)
126 return umc_driver->match(umc_driver, umc);
127 else
128 return 1;
129 }
130 return 0;
131}
132
133static int umc_device_probe(struct device *dev)
134{
135 struct umc_dev *umc;
136 struct umc_driver *umc_driver;
137 int err;
138
139 umc_driver = to_umc_driver(dev->driver);
140 umc = to_umc_dev(dev);
141
142 get_device(dev);
143 err = umc_driver->probe(umc);
144 if (err)
145 put_device(dev);
146 else
147 umc_bus_rescan(dev->parent);
148
149 return err;
150}
151
152static int umc_device_remove(struct device *dev)
153{
154 struct umc_dev *umc;
155 struct umc_driver *umc_driver;
156
157 umc_driver = to_umc_driver(dev->driver);
158 umc = to_umc_dev(dev);
159
160 umc_driver->remove(umc);
161 put_device(dev);
162 return 0;
163}
164
165static ssize_t capability_id_show(struct device *dev, struct device_attribute *attr, char *buf)
166{
167 struct umc_dev *umc = to_umc_dev(dev);
168
169 return sprintf(buf, "0x%02x\n", umc->cap_id);
170}
171static DEVICE_ATTR_RO(capability_id);
172
173static ssize_t version_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%04x\n", umc->version);
178}
179static DEVICE_ATTR_RO(version);
180
181static struct attribute *umc_dev_attrs[] = {
182 &dev_attr_capability_id.attr,
183 &dev_attr_version.attr,
184 NULL,
185};
186ATTRIBUTE_GROUPS(umc_dev);
187
188struct bus_type umc_bus_type = {
189 .name = "umc",
190 .match = umc_bus_match,
191 .probe = umc_device_probe,
192 .remove = umc_device_remove,
193 .dev_groups = umc_dev_groups,
194};
195EXPORT_SYMBOL_GPL(umc_bus_type);
196
197static int __init umc_bus_init(void)
198{
199 return bus_register(&umc_bus_type);
200}
201module_init(umc_bus_init);
202
203static void __exit umc_bus_exit(void)
204{
205 bus_unregister(&umc_bus_type);
206}
207module_exit(umc_bus_exit);
208
209MODULE_DESCRIPTION("UWB Multi-interface Controller capability bus");
210MODULE_AUTHOR("Cambridge Silicon Radio Ltd.");
211MODULE_LICENSE("GPL");