From: khilman@kernel•org (Kevin Hilman)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v3] PM / AVS: rockchip-io: add driver handling Rockchip io domains
Date: Fri, 12 Sep 2014 09:25:04 -0700 [thread overview]
Message-ID: <7hy4tog61r.fsf@deeprootsystems.com> (raw)
In-Reply-To: <1410475735-10278-1-git-send-email-dianders@chromium.org> (Doug Anderson's message of "Thu, 11 Sep 2014 15:48:55 -0700")
Rafael,
Doug Anderson <dianders@chromium•org> writes:
> From: Heiko St?bner <heiko@sntech•de>
>
> IO domain voltages on some Rockchip SoCs are variable but need to be
> kept in sync between the regulators and the SoC using a special
> register.
>
> A specific example using rk3288:
> - If the regulator hooked up to a pin like SDMMC0_VDD is 3.3V then
> bit 7 of GRF_IO_VSEL needs to be 0. If the regulator hooked up to
> that same pin is 1.8V then bit 7 of GRF_IO_VSEL needs to be 1.
>
> Said another way, this driver simply handles keeping bits in the SoC's
> general register file (GRF) in sync with the actual value of a voltage
> hooked up to the pins.
>
> Note that this driver specifically doesn't include:
> - any logic for deciding what voltage we should set regulators to
> - any logic for deciding whether regulators (or internal SoC blocks)
> should have power or not have power
>
> If there were some other software that had the smarts of making
> decisions about regulators, it would work in conjunction with this
> driver. When that other software adjusted a regulator's voltage then
> this driver would handle telling the SoC about it. A good example is
> vqmmc for SD. In that case the dw_mmc driver simply is told about a
> regulator. It changes the regulator between 3.3V and 1.8V at the
> right time. This driver notices the change and makes sure that the
> SoC is on the same page.
>
> Signed-off-by: Heiko St?bner <heiko@sntech•de>
> Signed-off-by: Doug Anderson <dianders@chromium•org>
> Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti•com>
> ---
> Changes in v3:
> - Changed compatible string as per Santosh.
Thanks, I like the new string better.
> - Added code docs about the slop in 1.8V and 3.3V as per Santosh.
> - Moved some #defines to the top as per Santosh.
All nice changes, thanks Santosh!
Reviewed-by: Kevin Hilman <khilman@linaro•org>
Rafael, how do you want to handle drivers/avs/* ? Along with Nishanth,
I'm maintaining everything there currently (only one driver :)), and
since I recommended $SUBJECT driver go into drivers/avs[1], I'm happy to
queue it for you and update MAINTAINERS to cover drivers/avs/* instead
of just smartreflex.c.
Let me know how you'd like to proceed.
Kevin
[1] http://lists.infradead.org/pipermail/linux-arm-kernel/2014-September/286276.html
next prev parent reply other threads:[~2014-09-12 16:25 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-11 22:48 [PATCH v3] PM / AVS: rockchip-io: add driver handling Rockchip io domains Doug Anderson
2014-09-12 16:25 ` Kevin Hilman [this message]
2014-09-24 23:27 ` Kevin Hilman
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