Question

我正在尝试了解oc2 panda board的mcspi的this驱动程序代码。

我不明白谁调用probe函数以及this驱动程序代码中的调用链是什么？

连接设备时如何通知驱动程序？

Answer 1

来自spi-omap2-mcspi.c的探测功能保存在static struct platform_driver omap2_mcspi_driver中，该module_platform_driver(omap2_mcspi_driver);已在module_platform_driver注册（在文件末尾）。 platform_device.h中定义的platform_driver_register宏会将结构传递给__platform_driver_register宏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);函数driver_register

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 }

探针现在从drivers/base/platform.c

传递到platform_bus_type函数

driver_probe_device

所以，现在驱动程序已在总线（really_probe）中注册。

通过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; drivers/base/driver.c，然后{{1}}（同一文件行265）完成对探测的实际调用：

{{1}}

谁在驱动程序代码中调用“探测”功能？

1 个答案: