[OE] Mix/Max SPI clock ranges?


#1

What are the supported Min/Max SPI clock ranges?

I’m figuring this range is independent of a given CPU governor.


SPI Minimum Speed
#2

Hi @Joel:

I did play with the SPI Speed a while ago. At the time the SPI speed seemed to be somewhat broken. Here are my results, note that this is an older kernel, Debian, not Yocto, and the bug (feature?) may have been fixed, I haven’t retried it lately.

Requested Speed            measured           frequency
10,000                     1us                1MHz
100,000                    1us                1MHz
1,000,000                  200ns              5MHz
2,000,000                  200ns              5MHz
10,000,000                 62.5ns             16MHz
50,000,000                 20ns               50MHz

Full Disclosure: I am an employee of Qualcomm Canada, any opinions expressed in this or any other post may not reflect the opinions of my employer.


#3

Thanks Lawrence!

@jwinarske