linux-kernel - Re: [PATCH] regulator: bd718x7, bd71828, Fix dvs voltage levels

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Date:   Fri, 15 Jan 2021 14:41:32 +0000
From:   Lee Jones <lee.jones@...aro.org>
To:     Matti Vaittinen <matti.vaittinen@...rohmeurope.com>
Cc:     mazziesaccount@...il.com, Liam Girdwood <lgirdwood@...il.com>,
        Mark Brown <broonie@...nel.org>, linux-power@...rohmeurope.com,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] regulator: bd718x7, bd71828, Fix dvs voltage levels

On Fri, 15 Jan 2021, Matti Vaittinen wrote:

> The ROHM BD718x7 and BD71828 drivers support setting HW state
> specific voltages from device-tree. This is used also by various
> in-tree DTS files.
> 
> These drivers do incorrectly try to compose bit-map using enum
> values. By a chance this works for first two valid levels having
> values 1 and 2 - but setting values for the rest of the levels
> do indicate capbility of setting values for first levels as
> well. Luckily the regulators which support settin values for
> SUSPEND/LPSR do usually also support setting values for RUN
> and IDLE too - thus this has not been such a fatal issue.
> 
> Fix this by defining the old enum values as bits and using
> new enum in parsing code. This allows keeping existing IC
> specific drivers intact and only adding the defines and
> slightly changing the rohm-regulator.c
> 
> Fixes: 21b72156ede8b ("regulator: bd718x7: Split driver to common and bd718x7 specific parts")
> Signed-off-by: Matti Vaittinen <matti.vaittinen@...rohmeurope.com>
> ---
> 
> One more attempt today. I did test the driver is not causing a crash
> when load but no further tests concluded as I don't have BD71837/47/50
> at home. This looks now trivial though so I decided to give it a go.
> Sorry for all the trouble this far - and also for the mistakes to come.

Why don't you wait until next week when you can run this on real h/w
with some pretty debug to ensure it does the right thing?

>  drivers/regulator/rohm-regulator.c |  9 ++++++---
>  include/linux/mfd/rohm-generic.h   | 14 ++++++--------
>  2 files changed, 12 insertions(+), 11 deletions(-)

-- 
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
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