Re: [PATCH v3 11/11] serial: sc16is7xx: add dump registers function

[Hugo Villeneuve]

On Thu, 25 May 2023 14:26:43 +0300
andy.shevchenko@xxxxxxxxx wrote:

> Thu, May 25, 2023 at 12:03:25AM -0400, Hugo Villeneuve kirjoitti:
> > From: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx>
> > 
> > With this driver, it is very hard to debug the registers using
> > the /sys/kernel/debug/regmap interface.
> > 
> > The main reason is that bits 0 and 1 of the register address
> > correspond to the channels bits, so the register address itself starts
> > at bit 2, so we must 'mentally' shift each register address by 2 bits
> > to get its offset.
> > 
> > Also, only channels 0 and 1 are supported, so combinations of bits
> > 0 and 1 being 10b and 11b are invalid, and the display of these
> > registers is useless.
> > 
> > For example:
> > 
> > cat /sys/kernel/debug/regmap/spi0.0/registers
> > 04: 10 -> Port 0, register offset 1
> > 05: 10 -> Port 1, register offset 1
> > 06: 00 -> Port 2, register offset 1 -> invalid
> > 07: 00 -> port 3, register offset 1 -> invalid
> > ...
> > 
> > Add a debug module parameter to call a custom dump function for each
> > port registers after the probe phase to help debug.
> 
> Not sure about this. Can we rather create an abstract mapping on regmap?
> (Something like gpio-pca953x.c has)

Hi,
maybe we can, but more like they do in the driver max310x.c (single, dual and quad UART versions).

I will look into it, but it will probably be a patch that affects a lot of the code, and that I would like to submit separately after this serie, and so I will probably simply drop this current patch (11/11) since it will not be needed anymore.

Hugo.