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You're reading from  Mastering Linux Device Driver Development

Product typeBook
Published inJan 2021
PublisherPackt
ISBN-139781789342048
Edition1st Edition
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Author (1)
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.
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Writing a clock provider driver

While the purpose of a device tree is to describe the hardware at hand (the clock provider, in this case), it is worth noting that the code used to manage the underlying hardware needs to be written. This section deals with writing code for clock providers so that once their clock lines have been assigned to consumers, they behave the way they were designed to. When writing clock device drivers, it is a good practice to embed the full struct clk_hw (not a pointer) into your private and bigger data structure, since it is given as the first parameter to each callback in clk_ops. This lets you define a custom to_<my-data-structure> helper upon the container_of macro, which gives you back a pointer to your private data structure, as follows:

/* forward reference */
struct max9485_driver_data;
struct max9485_clk_hw {
    struct clk_hw hw;
    struct clk_init_data init;     u8 enable_bit...
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Mastering Linux Device Driver Development
Published in: Jan 2021Publisher: PacktISBN-13: 9781789342048

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