誰在驅動程序代碼中調用「探測」功能？

Question

我想了解omap2熊貓板的mcspi的驅動代碼this。

我不明白是誰叫probe函數和this驅動代碼中的調用鏈是什麼？

設備連接時如何通知驅動程序？

Answer 1

spi-omap2-mcspi.c的探測功能保存在static struct platform_driver omap2_mcspi_driver中，該文件已在module_platform_driver(omap2_mcspi_driver);（在文件末尾）註冊。該module_platform_driver宏，在platform_device.h定義將結構傳遞到platform_driver_register宏觀和__platform_driver_register功能從drivers/base/platform.c

527 /** 
528 * __platform_driver_register - register a driver for platform-level devices 
529 * @drv: platform driver structure 
530 * @owner: owning module/driver 
531 */ 
532 int __platform_driver_register(struct platform_driver *drv, 
533         struct module *owner) 
534 { 
... 
536   drv->driver.bus = &platform_bus_type; 
537   if (drv->probe) 
538     drv->driver.probe = platform_drv_probe; 
... 
544   return driver_register(&drv->driver); 
545 } 
546 EXPORT_SYMBOL_GPL(__platform_driver_register); 

現在傳遞給driver_register功能的探頭從drivers/base/driver.c

139 /** 
140 * driver_register - register driver with bus 
141 * @drv: driver to register 
142 * 
143 * We pass off most of the work to the bus_add_driver() call, 
144 * since most of the things we have to do deal with the bus 
145 * structures. 
146 */ 
147 int driver_register(struct device_driver *drv) 
148 { 
... 
154   if ((drv->bus->probe && drv->probe) || 
... 
167   ret = bus_add_driver(drv); 
... 
178 } 

所以，現在的司機被註冊公共汽車（platform_bus_type）。

到探頭實際呼叫通過driver_probe_devicedrivers/base/dd.c做了，那麼really_probe（同一文件行265）：

265 static int really_probe(struct device *dev, struct device_driver *drv) 
266 { 
... 
270   pr_debug("bus: '%s': %s: probing driver %s with device %s\n", 
271     drv->bus->name, __func__, drv->name, dev_name(dev)); 
... 
287   if (dev->bus->probe) { 
288     ret = dev->bus->probe(dev);  /// <<<< HERE 
289     if (ret) 
290       goto probe_failed; 
291   } else if (drv->probe) { 
292     ret = drv->probe(dev);   /// <<<< OR HERE 
293     if (ret) 
294       goto probe_failed; 
295   } 
296 
297   driver_bound(dev); 
298   ret = 1; 
299   pr_debug("bus: '%s': %s: bound device %s to driver %s\n", 
300     drv->bus->name, __func__, dev_name(dev), drv->name); 
301   goto done;