An Introduction to SPI-NOR Subsystem

Explore the SPI-NOR subsystem in this 46-minute Linux Foundation conference talk by Vignesh Raghavendra from Texas Instruments India. Gain insights into modern embedded systems with dedicated SPI controllers supporting NOR flashes, their hardware features, and efficiency in accessing SPI NOR flashes. Discover the SPI-NOR framework introduced under Memory Technology Devices (MTD), learn about different types of NOR flashes supported (SPI/QSPI/OSPI), and understand their interaction with the SPI framework. Learn how to write a new controller driver or add support for a new flash device. Explore generic improvements and proposed enhancements for QSPI performance on TI SoCs, challenges associated with DMA usage, and framework limitations. Delve into topics such as SPI-NOR flash basics, communication protocols, controller types, accessing flash via SPI and SPI-NOR frameworks, specialized SPI controllers with MMIO interfaces, driver placement, performance comparisons, and DMA support implementation.

Intro
What's in the presentation?
What is a SPI-NOR Flash?
Why SPI-NOR flash?
Typical SPI-NOR flash
SPI-NOR Flash Hardware
Communication Protocol
Types of Controllers
Traditional SPI Controller
Accessing flash via SPI framework
Accessing flash via SPI-NOR framework
Specialized SPI controller-MMIO Interface
Where to put your driver?
Writing a SPI-NOR controller driver
Performance Comparison
Adding DMA support
References