Summary

In this chapter, we tackled SPI drivers and can now take the advantage of this serial (and full duplex) bus, which is way faster than I2C. We walked through all the data structures in this framework and discussed transferring over SPI, which is the most important section we covered. That said, the memory we accessed over those buses was off-chip – we may need more abstraction in order to avoid the SPI and I2C APIs.

This is where the next chapter comes in, dealing with the regmap API, which offers a higher and more unified level of abstraction so that SPI (and I2C) commands will become transparent to you.