Using gpio-generic and irq_chip_generic subsystems for gpio driver

Intoduction This article is a logical continuation of the previous one and it is recommended to stady after reading the previous material. The current note is necessary for understanding the subsequent material, a further understanding gpio subsystem as a whole and helps with the development of own gpio drivers. The provisions of this article have not only apply to our virtual driver gpio, but also to any mmio gpio driver in general. It will focus on “optimizing” referred to in the preceding article. ...

September 10, 2016 · 7 min · maquefel

QEMU ivshmem Introducing interrupt capable virtual gpio concept

Introduction It’s hard to underestimate the role of GPIO’s, especially in ARM embedded systems. Apart of being a very popular material for starters, GPIO’s provide a way for controlling the many peripheral devices, act as source of valuable interrupts, or even can be the only way to communicate the world for a SOC. ...

July 14, 2016 · 21 min · maquefel