linux-kernel - Re: [PATCH] pinctrl: cy8c95x0: Cache muxed registers

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Date: Tue, 14 May 2024 08:27:37 +0300
From: Andy Shevchenko <andy.shevchenko@...il.com>
To: Patrick Rudolph <patrick.rudolph@...ements.com>
Cc: Linus Walleij <linus.walleij@...aro.org>, naresh.solanki@...ements.com,
	linux-gpio@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] pinctrl: cy8c95x0: Cache muxed registers

Tue, Dec 19, 2023 at 01:53:49PM +0100, Patrick Rudolph kirjoitti:
> Currently the port specific registers behind the PORTSEL mux aren't
> cached in the regmap and thus the typical setup time for a single pin
> on cy8c9560 is about 200msec on our system. The hotspot is the IRQ
> (un)masking, which causes lots of R/W operations.
> 
> Introduce a separate regmap for muxed registers and helper functions
> to use the newly introduced regmap for muxed register access under
> the i2c lock.
> 
> With the new cache in place the typical pin setup time is reduced to
> 20msec, making it about 10 times faster. As a side effect the system
> boot time is also reduced by 50%.

Interestingly that you have not Cc'ed me on your patches.
This, btw, a good reinvetion of a wheel which regmap supports already.

-- 
With Best Regards,
Andy Shevchenko