From: Linus Walleij <linus.walleij@linaro.org>
To: Shobhit Kumar <shobhit.kumar@intel.com>,
"Zhu, Lejun" <lejun.zhu@linux.intel.com>,
Aaron Lu <aaron.lu@intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>,
Daniel Vetter <daniel.vetter@intel.com>,
intel-gfx <intel-gfx@lists.freedesktop.org>,
Thierry Reding <thierry.reding@gmail.com>,
Alexandre Courbot <gnurou@gmail.com>
Subject: Re: [PATCH 1/2] gpio/crystalcove: Export Panel and backlight en/disable signals as GPIO
Date: Fri, 6 Mar 2015 12:04:04 +0100 [thread overview]
Message-ID: <CACRpkdZcpftmzpmthwrOC2LK-4ck2PfT3tDP0Yc+eV9Qy4ovqQ@mail.gmail.com> (raw)
In-Reply-To: <1424261894-24983-2-git-send-email-shobhit.kumar@intel.com>
On Wed, Feb 18, 2015 at 1:18 PM, Shobhit Kumar <shobhit.kumar@intel.com> wrote:
> Export Panel BACKLIGHT_EN(offset 0x51) and PANEL_EN(offset 0x52) as two
> additional GPIOs. Needed by display driver to enable the DSI panel on
> BYT platform where the Panel EN/Disable and Backlight control are
> routed thorugh CRC PMIC
>
> Cc: Linus Walleij <linus.walleij@linaro.org>
> Cc: Alexandre Courbot <gnurou@gmail.com>
> Cc: Thierry Reding <thierry.reding@gmail.com>
> Signed-off-by: Shobhit Kumar <shobhit.kumar@intel.com>
This seems very unintuitive. I have a hard time believeing this:
> +#define GPIOPANELCTL 0x51
A special GPIO only designated to panel control? That is totally
counter to the *meaning* of "general purpose input/output".
It is not general purpose at all, it is special-purpose.
If the data sheet says a special-purpose pin is a "GPIO" when
it isn't the map of the world (the datasheet terminology) is wrong,
not the world, the usage is dedicated for the panel. Look
at the usecase, not the name.
Obviously that line is only for controlling the backlight, and you
should spin a new child device from the Inte SoC PMIC MFD hub
and put a driver for it in drivers/video/backlight or wherever this
goes.
Lee: do you agree?
Yours,
Linus Walleij
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next prev parent reply other threads:[~2015-03-06 11:04 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-02-18 12:18 [PATCH 0/2] Crystal Cove PMIC based Panel Control Shobhit Kumar
2015-02-18 12:18 ` [PATCH 1/2] gpio/crystalcove: Export Panel and backlight en/disable signals as GPIO Shobhit Kumar
2015-03-06 11:04 ` Linus Walleij [this message]
2015-03-06 16:23 ` Kumar, Shobhit
2015-03-09 17:15 ` Linus Walleij
2015-03-12 15:06 ` Kumar, Shobhit
2015-03-18 11:50 ` Linus Walleij
2015-03-18 13:27 ` Daniel Vetter
2015-03-24 9:50 ` Linus Walleij
2015-03-25 12:27 ` Linus Walleij
2015-03-25 14:15 ` Kumar, Shobhit
2015-03-25 14:39 ` Linus Walleij
2015-02-18 12:18 ` [PATCH 2/2] drm/i915: Use the CRC gpio_chip for panel enable/disable Shobhit Kumar
2015-02-26 10:13 ` Alexandre Courbot
2015-03-01 13:24 ` Kumar, Shobhit
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