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在网上有很多介绍Linux驱动程序开发的文章，看下来，很多写的不尽完善，找了一下Linux的内核源码，将其贴出共享,也督促自己尽量的搞懂这些东西。
/*
* Copyright (c) 2001 Red Hat, Inc. All rights reserved.
*
* This software may be freely redistributed under the terms
* of the GNU public license.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* Author: Arjan van de Ven <arjanv@redhat.com>
*
*/
/*
* Generic PCI driver for PCI bridges for powermanagement purposes
*
*/
#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/init.h>
static struct pci_device_id bridge_pci_table[] __devinitdata = {
{/* handle all PCI bridges */
class: ((PCI_CLASS_BRIDGE_PCI << 8) | 0x00),
class_mask: ~0,
vendor: PCI_ANY_ID,
device: PCI_ANY_ID,
subvendor: PCI_ANY_ID,
subdevice: PCI_ANY_ID,
},
,
};
static int bridge_probe(struct pci_dev *pdev, const struct pci_device_id *id);
static int pci_bridge_save_state_bus(struct pci_bus *bus, int force);
int pci_generic_resume_compare(struct pci_dev *pdev);
int pci_bridge_force_restore = 0;
static int __init bridge_setup(char *str)
{
if (!strcmp(str,"force"))
pci_bridge_force_restore = 1;
else if (!strcmp(str,"noforce"))
pci_bridge_force_restore = 0;
return 0;
}
__setup("resume=",bridge_setup);
static int pci_bridge_save_state_bus(struct pci_bus *bus, int force)
{
struct list_head *list;
int error = 0;
list_for_each(list, &bus->children) {
error = pci_bridge_save_state_bus(pci_bus_b(list),force);
if (error) return error;
}
list_for_each(list, &bus->devices) {
pci_generic_suspend_save(pci_dev_b(list),0);
}
return 0;
}
static int pci_bridge_restore_state_bus(struct pci_bus *bus, int force)
{
struct list_head *list;
int error = 0;
static int printed_warning=0;
list_for_each(list, &bus->children) {
error = pci_bridge_restore_state_bus(pci_bus_b(list),force);
if (error) return error;
}
list_for_each(list, &bus->devices) {
if (force)
pci_generic_resume_restore(pci_dev_b(list));
else {
error = pci_generic_resume_compare(pci_dev_b(list));
if (error && !printed_warning++) {
printk(KERN_WARNING "resume warning: bios doesn't restore PCI state properlyn");
printk(KERN_WARNING "resume warning: if resume failed, try booting with resume=forcen");
}
if (error)
return error;
}
}
return 0;
}
static int bridge_suspend(struct pci_dev *dev, u32 force)
{
pci_generic_suspend_save(dev,force);
if (dev->subordinate)
pci_bridge_save_state_bus(dev->subordinate,force);
return 0;
}
static int bridge_resume(struct pci_dev *dev)
{
pci_generic_resume_restore(dev);
if (dev->subordinate)
pci_bridge_restore_state_bus(dev->subordinate,pci_bridge_force_restore);
return 0;
}
MODULE_DEVICE_TABLE(pci, bridge_pci_table);
static struct pci_driver bridge_ops = {
name: "PCI Bridge",
id_table: bridge_pci_table,
probe: bridge_probe,
suspend: bridge_suspend,
resume: bridge_resume
};
static int __devinit bridge_probe(struct pci_dev *pdev, const struct pci_device_id *id)
{
return 0;
}
static int __init bridge_init(void)
{
pci_register_driver(&bridge_ops);
return 0;
}
static void __exit bridge_exit(void)
{
pci_unregister_driver(&bridge_ops);
}
module_init(bridge_init)
module_exit(bridge_exit)
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