From: Chris Ball <chris@printf.net>
To: Stephen Warren <swarren@wwwdotorg.org>
Cc: Andrew Bresticker <abrestic@chromium.org>,
Thierry Reding <thierry.reding@gmail.com>,
Ulf Hansson <ulf.hansson@linaro.org>,
linux-mmc@vger.kernel.org, linux-tegra@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 4/4] ARM: tegra: fix Venice2 VQMMC regulators
Date: Tue, 15 Apr 2014 20:12:48 +0100 [thread overview]
Message-ID: <864n1uv233.fsf@void.printf.net> (raw)
In-Reply-To: <534D7AFD.7080807@wwwdotorg.org> (Stephen Warren's message of "Tue, 15 Apr 2014 12:31:25 -0600")
Hi Stephen,
On Tue, Apr 15 2014, Stephen Warren wrote:
> Is there documentation re: what vmmc-supply and vqmmc-supply actually
> refer to? I looked a long while ago and couldn't find any, and didn't
> get an answer when I asked.
>
> Neither
> Documentation/devicetree/bindings/mmc/{mmc.txt,nvidia,tegra20-sdhci.txt}
> seem to say:-(
MMC cards use the same voltage for the VDD pin on the card and to pull
up the signal lines. UHS SDHCI switches to using 1.8V vqmmc (signaling
voltage) and 3.3V vmmc (card supply voltage).
So the idea is to supply a vqmmc-supply if your board supports
ultra-high-speed modes on an SD 3.0 host, and a vmmc-supply if your
card power is controlled by a regulator. I agree that this ought to
be in the bindings somewhere.
Thanks,
- Chris.
--
Chris Ball <http://printf.net/>
next prev parent reply other threads:[~2014-04-15 19:12 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-15 1:42 [PATCH 0/4] Tegra SD/MMC fixes Andrew Bresticker
2014-04-15 1:42 ` [PATCH 1/4] mmc: tegra: disable UHS modes Andrew Bresticker
2014-04-15 1:42 ` [PATCH 2/4] mmc: tegra: fix reporting of base clock frequency Andrew Bresticker
2014-04-15 18:25 ` Stephen Warren
[not found] ` <534D797D.7030201-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org>
2014-04-15 19:36 ` Andrew Bresticker
[not found] ` <1397526163-20126-1-git-send-email-abrestic-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
2014-04-15 1:42 ` [PATCH 3/4] mmc: sdhci: defer probing on regulator_get_optional() failures Andrew Bresticker
2014-04-15 6:06 ` Alexandre Courbot
2014-04-15 22:56 ` Andrew Bresticker
[not found] ` <1397526163-20126-4-git-send-email-abrestic-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
2014-04-15 18:28 ` Stephen Warren
[not found] ` <534D7A5D.9090707-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org>
2014-04-15 19:59 ` Andrew Bresticker
2014-04-15 20:42 ` Russell King - ARM Linux
2014-04-15 19:03 ` Tim Kryger
[not found] ` <CAAYSxhrmCbGLsu43mK15ParXHa_FJ9OVQiCPUdqyWEpTE=r1uw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2014-04-15 19:44 ` Andrew Bresticker
2014-04-15 1:42 ` [PATCH 4/4] ARM: tegra: fix Venice2 VQMMC regulators Andrew Bresticker
2014-04-15 18:31 ` Stephen Warren
2014-04-15 19:12 ` Chris Ball [this message]
[not found] ` <1397526163-20126-5-git-send-email-abrestic-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
2014-04-16 0:29 ` Andrew Bresticker
2014-04-16 16:19 ` Stephen Warren
[not found] ` <534EAD91.90704-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org>
2014-04-16 20:24 ` Andrew Bresticker
2014-04-16 23:08 ` [PATCH v2 0/3] Tegra SD/MMC fixes Andrew Bresticker
2014-04-16 23:08 ` [PATCH v2 1/3] mmc: tegra: disable UHS modes Andrew Bresticker
2014-05-20 17:25 ` Stephen Warren
2014-05-21 0:43 ` Chris Ball
2014-05-22 11:00 ` Ulf Hansson
2014-05-22 15:25 ` Andrew Bresticker
[not found] ` <1397689719-28882-1-git-send-email-abrestic-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
2014-04-16 23:08 ` [PATCH v2 2/3] mmc: tegra: fix reporting of base clock frequency Andrew Bresticker
2014-04-16 23:08 ` [PATCH v2 3/3] ARM: tegra: fix Venice2 SD card VQMMC supply Andrew Bresticker
2014-04-16 23:16 ` Stephen Warren
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