1. 程式人生 > >學習《Linux裝置模型淺析之驅動篇》筆記(一)

學習《Linux裝置模型淺析之驅動篇》筆記(一)

原文中說了,核心版本為2.6.29;這裡都貼3.15的核心原始碼;

檔案/drivers/rtc/rtc-s3c.c

static struct platform_driver s3c_rtc_driver = {
        .probe= s3c_rtc_probe,
        .remove= s3c_rtc_remove,
        .id_table= s3c_rtc_driver_ids,
        .driver= {
                .name= "s3c-rtc",
                .owner= THIS_MODULE,
                .pm= &s3c_rtc_pm_ops,
                .of_match_table= of_match_ptr(s3c_rtc_dt_match),
        },
};

檔案/include/linux/platform_device.h

/*
 * use a macro to avoid include chaining to get THIS_MODULE
 */
#define platform_driver_register(drv) \
__platform_driver_register(drv, THIS_MODULE)

檔案/drivers/base/platforms.c

/**
 * __platform_driver_register - 為平臺級別設備註冊一個驅動
 * @drv: platform驅動結構
 * @owner: module/driver所有者
 */
int __platform_driver_register

(struct platform_driver *drv,
struct module *owner)
{
drv->driver.owner = owner;
drv->driver.bus = &platform_bus_type;
if (drv->probe)
drv->driver.probe = platform_drv_probe;
if (drv->remove)
drv->driver.remove = platform_drv_remove;
if (drv->shutdown)
drv->driver.shutdown = platform_drv_shutdown;


return driver_register
(&drv->driver);
}

/**
 * driver_register - 為bus註冊驅動
 * @drv: 要註冊的驅動
 *
 * 我們把大部分工作交給了bus_add_driver() 呼叫,因為我們
 * 要處理的大部分事情是bus結構.
 */
int driver_register(struct device_driver *drv)
{
int ret;
struct device_driver *other;


BUG_ON(!drv->bus->p);


if ((drv->bus->probe && drv->probe) ||
   (drv->bus->remove && drv->remove) ||
   (drv->bus->shutdown && drv->shutdown))
printk(KERN_WARNING "Driver '%s' needs updating - please use "
"bus_type methods\n", drv->name);


other = driver_find(drv->name, drv->bus);
if (other) {
printk(KERN_ERR "Error: Driver '%s' is already registered, "
"aborting...\n", drv->name);
return -EBUSY;
}


ret = bus_add_driver(drv);
if (ret)
return ret;
ret = driver_add_groups(drv, drv->groups);
if (ret) {
bus_remove_driver(drv);
return ret;
}
kobject_uevent(&drv->p->kobj, KOBJ_ADD);


return ret;
}

/**
 * driver_find - locate driver on a bus by its name.
 * @name: name of the driver.
 * @bus: bus to scan for the driver.
 *
 * Call kset_find_obj() to iterate over list of drivers on
 * a bus to find driver by name. Return driver if found.
 *
 * This routine provides no locking to prevent the driver it returns
 * from being unregistered or unloaded while the caller is using it.
 * The caller is responsible for preventing this.
 */
struct device_driver *driver_find(const char *name, struct bus_type *bus)
{
struct kobject *k = kset_find_obj(bus->p->drivers_kset, name);
struct driver_private *priv;


if (k) {
/* Drop reference added by kset_find_obj() */
kobject_put(k);
priv = to_driver(k);
return priv->driver;
}
return NULL;
}