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