linux-kernel - Re: [PATCH 5/6] pwm: sun4i: Add support to output source clock directly

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Date:   Sat, 27 Jul 2019 16:28:38 +0200
From:   Jernej Škrabec <jernej.skrabec@...l.net>
To:     Maxime Ripard <mripard@...nel.org>
Cc:     thierry.reding@...il.com, wens@...e.org, robh+dt@...nel.org,
        mark.rutland@....com, linux-pwm@...r.kernel.org,
        devicetree@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-kernel@...r.kernel.org, linux-sunxi@...glegroups.com
Subject: Re: [PATCH 5/6] pwm: sun4i: Add support to output source clock directly

Dne sobota, 27. julij 2019 ob 12:50:08 CEST je Maxime Ripard napisal(a):
> On Fri, Jul 26, 2019 at 08:40:44PM +0200, Jernej Skrabec wrote:
> > PWM core has an option to bypass whole logic and output unchanged source
> > clock as PWM output. This is achieved by enabling bypass bit.
> > 
> > Note that when bypass is enabled, no other setting has any meaning, not
> > even enable bit.
> > 
> > This mode of operation is needed to achieve high enough frequency to
> > serve as clock source for AC200 chip, which is integrated into same
> > package as H6 SoC.
> > 
> > Signed-off-by: Jernej Skrabec <jernej.skrabec@...l.net>
> 
> It doesn't seem to be available on the A10 (at least) though. The A13
> seem to have it, so you should probably check that, and make that
> conditional to the compatible if not available on all of them.

Ok, can you suggest the name for the quirk? "has_bypass" is suspiciously 
similar to "has_prescaler_bypass".

Also, how to name these sun4i_pwm_data structures? Now that there are (will 
be) three new quirks, name of the structure would be just too long, like 
"sun50i_pwm_dual_prescaler_bypass_clk_rst_bypass". 

Best regards,
Jernej

> 
> Maxime
> 
> --
> Maxime Ripard, Bootlin
> Embedded Linux and Kernel engineering
> https://bootlin.com