other kernel subsystems. As a result, many driver authors can ignore the device model entirely, and trust it to take care of itself. There are times, however, when an understanding of the device model is a good
the basics of Linux operation even if they are not expecting to write a driverThe new edition of Linux Device Drivers is better than ever. The book covers all the significant changes to Version 2.6 of the Linux kernel, which simplifies many activities, and contains subtle new features that ca...
USB Device Basics | 331 USB_ENDPOINT_XFER_ISOC, USB_ENDPOINT_XFER_BULK, or of type USB_ENDPOINT_ XFER_INT. These macros define a isochronous, bulk, and interrupt endpoint, respectively. wMaxPacketSize This is the maximum size in bytes that this endpoint can handle at once. Note ...
Overall, Linux Device Drivers 4 is a must-have resource for anyone interested in Linux device driver development. Whether you are a beginner looking to learn the basics of device driver programming or an experienced developer seeking to enhance your skills, this book offers valuable insights and p...
Under “Device drivers.” Turns on debugging information in the driver core, which can be useful for tracking down problems in the low-level support code. We’ll look at the driver core inChapter 14. CONFIG_SCSI_CONSTANTS This option, found under “Device drivers/SCSI device support,” build...
调用bus_register可以把自己的bus注册给kernel,在bus_register完成以后,在/sys/bus/下就可以看到这个bus了,之后可以向bus添加device。如果要移除bus,调用bus_unregister。 14.4.1.2 Bus methods 在struct bus_type中有一些callback,这些callback就是bus methods。他们作为device core和device driver的中间层提供服务。
即便如此,了解了kernel的设备模型,对于driver developer来说有很大的好处,而且,在某些情况下,driver需要直接和某些设备模型交互,使用他们提供的部分功能。 14.1. Kobjects, Ksets, and Subsystems 在kernel中,kobj是一个非常基础的东西,它可以把很多的device module组合在一起。kobj最开始只是一个reference counter,后来...
start_kernel() -> rest_init() ->kernel_init() -> do_basic_setup() -> driver_init() -> platform_bus_init()。注:kernel_init()是在rest_init函数中创建内核线程来执行的。int __init platform_bus_init(void){ int error; early_platform_cleanup(); error = device_register(&platform_bus);...
bus_attach_device函数执行时,将设备添加到总线的设备链表中,同时也会尝试绑定驱动,不过会失败。 接着,由于dev->parent的存在,将SPI主控制器设备添加到父设备platform虚拟设备的儿子链表中。 7. driver举例 我们已经介绍过platform总线的注册,也讲述了SPI主控制器设备作为平台设备的注册过程,在本节,将描述SPI主控制器...
programmers learn: * how to support computer peripherals under the Linux operating system * how to develop and write software for new hardware under Linux * the basics of Linux operation even if they are not expecting to write a driver The new edition of Linux Device Drivers is better than ...