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You're reading from  Linux Device Drivers Development

Product typeBook
Published inOct 2017
Reading LevelIntermediate
PublisherPackt
ISBN-139781785280009
Edition1st Edition
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John Madieu
John Madieu
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John Madieu

John Madieu is an embedded Linux and kernel engineer living in Paris, France. His main activities consist of developing device drivers and Board Support Packages (BSPs) for companies in domains such as IoT, automation, transport, healthcare, energy, and the military. John is the founder and chief consultant at LABCSMART, a company that provides training and services for embedded Linux and Linux kernel engineering. He is an open source and embedded systems enthusiast, convinced that it is only by sharing knowledge that we can learn more. He is passionate about boxing, which he practiced for 6 years professionally, and continues to channel this passion through training sessions that he provides voluntarily.
Read more about John Madieu

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Advanced peripheral IRQs management

In Chapter 3, Kernel Facilities and Helper Functions, we introduced peripheral IRQs, using request_irq() and request_threaded_irq(). With request_irq(), one registers a handler (top half) that will be executed in atomic context, from which one can schedule a bottom half using one of a differing mechanism discussed in that same chapter. On the other hand, with request_thread_irq(), one can provide top and bottom halves to the function, so that the former will be run as a hardirq handler, which may decide to raise the second and threaded handler, which will be run in a kernel thread.

The problem with those approaches is that sometimes, drivers requesting an IRQ do not know about the nature of the interrupt that provides this IRQ line, especially when the interrupt controller is a discrete chip (typically a GPIO expander connected over SPI or I2C...

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Linux Device Drivers Development
Published in: Oct 2017Publisher: PacktISBN-13: 9781785280009

Author (1)

author image
John Madieu

John Madieu is an embedded Linux and kernel engineer living in Paris, France. His main activities consist of developing device drivers and Board Support Packages (BSPs) for companies in domains such as IoT, automation, transport, healthcare, energy, and the military. John is the founder and chief consultant at LABCSMART, a company that provides training and services for embedded Linux and Linux kernel engineering. He is an open source and embedded systems enthusiast, convinced that it is only by sharing knowledge that we can learn more. He is passionate about boxing, which he practiced for 6 years professionally, and continues to channel this passion through training sessions that he provides voluntarily.
Read more about John Madieu