Re: [PATCH 00/10] spi: Add driver to support AMD eSPI controller
From: Rangoju, Raju
Date: Wed Mar 26 2025 - 05:55:45 EST
On 3/17/2025 7:44 PM, Mark Brown wrote:
Hi Mark,
Thanks for reviewing the patch and apologies for delayed response.
On Fri, Mar 14, 2025 at 12:04:30AM +0530, Raju Rangoju wrote:
The eSPI protocol serves as a communication interface between the main
processor and peripheral devices in computer systems. It offers several
advantages over the traditional LPC bus, including higher data transfer
rates, increased scalability and improved system management capabilities.
The eSPI protocol supports multiple channels, each serving a specific
purpose in the communication process.
I see nothing in this series that registers a SPI controller with the
SPI core. You need to use the standard frameworks the kernel offers to
provide standard functionality.
The AMD SPI controller hardware has only the chip select line enabled,
which is connected to the EC slave in AMD EMB platforms. Currently,
there is no support from the slave device to register as an SPI slave
device with the SPI framework and provide SPI communication.
For this reason, the AMD eSPI driver is designed to handle device
initialization itself and provide a character device file as an
interface with user space for dynamic interaction and configurations.