Hands-On Embedded Programming with C++17

Custom drivers

The exact format and integration of drivers (kernel modules) with the OS kernel differs for each OS and thus would be impossible to fully cover here. We will, however, look at how the driver for the RTC module we used earlier is implemented for Linux.

In addition, we will look at how to use an I2C peripheral from user space later in this chapter, in the club room monitoring example. Using a user space-based driver (library) is often a good alternative to implementing it as a kernel module.

The RTC functionality is integrated into the Linux kernel, with the code for it found in the /drivers/rtc folder (on GitHub, at https://github.com/torvalds/linux/tree/master/drivers/rtc).

The rtc-ds1307.c file contains two functions we need ...