Handling Signal1 in microchip-tcb-capture

[Kamel Bouhara]

On Sat, Oct 15, 2022 at 09:52:27AM -0400, William Breathitt Gray wrote:
> Hello Kamel,
>

Hello William,

> I was looking over the microchip-tcb-capture driver recently and noticed
> that the code doesn't seem to account for Signal1. In particular, it
> appears that mchp_tc_count_signal_read() and mchp_tc_count_action_read()
> don't check the Signal id at all and just assume they are handling
> Signal0. This creates a situation where the information returned for the
> Signal1 sysfs attributes are just duplicated reports of Signal0.
>
> What exactly is the relationship of Signal0 ("Channel A") and Signal1
> ("Channel B"); is SignalB only relevant when the counter device is
> configured for quadrature mode?

Indeed both signals are required when in quadrature mode, where the
signal0 is representing the speed and signal1 the revolution or number
of rotation.

We have described all availables modes in details in the following blog post: https://bootlin.com/blog/timer-counters-linux-microchip/

Regards,
Kamel

>
> Sincerely,
>
> William Breathitt Gray



--
Kamel Bouhara, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com