AM623: AM623的Main_SPI0作为主机，FPGA作为从机，能否达到20ms 128*32 byte

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https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1317716/am623-main_spi0-performance

嗯嗯，谢谢，需求是FPGA做ADC采样，速度是20ms 128*32 byte，然后给个中断给到CPU，CPU在中断读取FPGA的数据

不客气~

已把您的项目需求更新到帖子里了。

工程师想了解您是否想知道怎么去用GPIO中断启动SPI传输？

下面是工程师的回复。

I understand that the customer is using FPGA(Field Programmable Gate Array) as peripheral and AM62x's MAIN_SPI0 as the master.

So currently I can interpret from your question that you want to know how to initiate SPI transfer using GPIO Interrupts. Is my understanding correct ?

对的，想在GPIO中断了去使用SPI读取，原本的方案是FPGA作为主机，A核作为从机，然后FPGA给数据A核接收，但是现在驱动没有从机，所以才使用A核作为主机，FPGA作为从机的方式，FPGA通过ADC采集到数据后触发GPIO中断，然后A核收到中断后在中断里直接去操控SPI读取数据

已跟进，请关注帖子的回复。

工程师还有一个问题。

您是使用linux还是使用MCU PLUS SDK?

如果使用的是MCU PLUS SDK，他想知道您是怎么初始化SoC的？因为有许多方式可以用来初始化SoC。

One more follow up question. 

So is this Linux centric approach customer is applying or are they using MCU PLUS SDK ?

If its MCU PLUS SDK, I want to know what has the customer used for SoC Initialization as they are many ways to initialize the SoC.

A核使用的是Linux

已跟进，请关注帖子的回复。

请看下面e2e工程师的回复。

Reading something from SPI every 20ms in an interrupt-driven way should not be an issue; interrupt response time and context switch times should be in the range of 10s of us (depending on system as well as kernel configuration), leaving plenty of time for processing.

On a high-level here's one way get the data moving from the FPGA to the AM62:

• Implement a custom Kernel driver leveraging the Linux IIO framework (https://www.kernel.org/doc/html/latest/driver-api/iio/index.html). It's almost perfectly tailored for this use case, and allows for easy access of the data though a sysfs interface
• In the custom driver, use/configure the SPI interface, and use a GPIO-based interrupt scheme. The reading/writing of data from the FPGA over SPI can either be done through SPI framework commands, or the 'regmap' abstraction layer, like many of the existing IIO drivers do.
• You can look for and clone an existing SPI-based IIO driver that uses interrupts as a template for a custom driver, such as this one here:
  https://git.ti.com/gitweb?p=ti-linux-kernel/ti-linux-kernel.git;a=blob;f=drivers/iio/temperature/ltc2983.c;hb=refs/heads/ti-linux-6.1.y
• Then you can also see at the associated device tree bindings to see how the device is configured, and how interrupts are connected, as an example to model after:
  https://git.ti.com/gitweb?p=ti-linux-kernel/ti-linux-kernel.git;a=blob;f=Documentation/devicetree/bindings/iio/temperature/adi%2Cltc2983.yaml;h=722781aa4697e46d5f4fa1ca03e48ddf7639ce39;hb=refs/heads/ti-linux-6.1.y#l401