Summary
DMA is a feature that is found in many modern CPUs. This chapter gives you the necessary steps to get the most out of this device, using the kernel DMA mapping and DMA engine APIs. After this chapter, I have no doubt you will be able to set up at least a memory-to-memory DMA transfer. Further information can be found at Documentation/dmaengine/, in the kernel source tree.
However, the next chapter deals with the regmap, which introduces memory-oriented abstractions, and which unify access to memory-oriented devices (I2C, SPI, or memory-mapped).
