devicetree.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Stephen Boyd <sboyd@codeaurora.org>
To: Linus Walleij <linus.walleij@linaro.org>
Cc: linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	Timur Tabi <timur@codeaurora.org>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Bjorn Andersson <bjorn.andersson@linaro.org>,
	linux-gpio@vger.kernel.org, devicetree@vger.kernel.org
Subject: [PATCH 0/3] Support qcom pinctrl protected pins
Date: Tue,  9 Jan 2018 17:58:45 -0800	[thread overview]
Message-ID: <20180110015848.11480-1-sboyd@codeaurora.org> (raw)

This patchset proposes a solution to describing the valid
pins for a pin controller in a semi-generic way so that qcom
platforms can expose the pins that are really available.

Typically, this has been done by having drivers and firmware 
descriptions only use pins they know they have access to, and that
still works now because we no longer read the pin direction at
boot. But there are still some userspace drivers and debugfs facilities
that don't know what pins are available and attempt to read everything
they can. On qcom platforms, this may lead to a system hang, which isn't 
very nice behavior, even if root is the only user that can trigger it.

The proposal is to describe the valid pins and then not allow things to
cause problems by using the invalid pins. Obviously, the firmware may
mess this up, so this is mostly a nice to have feature or a safety net
so that things don't blow up easily.

Stephen Boyd (3):
  gpiolib: Export gpiochip_irqchip_irq_valid() to drivers
  dt-bindings: pinctrl: Add a ngpios-ranges property
  pinctrl: qcom: Don't allow protected pins to be requested

 .../bindings/pinctrl/qcom,msm8996-pinctrl.txt      |  6 ++
 drivers/gpio/gpiolib.c                             |  5 +-
 drivers/pinctrl/qcom/pinctrl-msm.c                 | 98 +++++++++++++++++++++-
 include/linux/gpio/driver.h                        |  3 +
 4 files changed, 106 insertions(+), 6 deletions(-)

-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

             reply	other threads:[~2018-01-10  1:58 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-01-10  1:58 Stephen Boyd [this message]
     [not found] ` <20180110015848.11480-1-sboyd-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
2018-01-10  1:58   ` [PATCH 1/3] gpiolib: Export gpiochip_irqchip_irq_valid() to drivers Stephen Boyd
2018-01-10  6:16     ` Bjorn Andersson
2018-01-10 13:22     ` Linus Walleij
2018-01-10  1:58 ` [PATCH 2/3] dt-bindings: pinctrl: Add a ngpios-ranges property Stephen Boyd
2018-01-10 12:54   ` Andy Shevchenko
     [not found]   ` <20180110015848.11480-3-sboyd-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
2018-01-10 13:37     ` Linus Walleij
2018-01-10 16:37       ` Stephen Boyd
2018-01-10 17:59         ` Andy Shevchenko
2018-01-11 16:33       ` Grant Likely
2018-01-11 16:36         ` Timur Tabi
2018-01-11 19:56           ` Grant Likely
2018-01-10  1:58 ` [PATCH 3/3] pinctrl: qcom: Don't allow protected pins to be requested Stephen Boyd
2018-01-10  6:11   ` Bjorn Andersson
2018-01-22 13:55   ` Timur Tabi
2018-01-22 20:03     ` Timur Tabi
2018-01-25 21:51     ` Stephen Boyd
2018-01-25 21:53       ` Timur Tabi
2018-01-25 20:48   ` Timur Tabi

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20180110015848.11480-1-sboyd@codeaurora.org \
    --to=sboyd@codeaurora.org \
    --cc=andriy.shevchenko@linux.intel.com \
    --cc=bjorn.andersson@linaro.org \
    --cc=devicetree@vger.kernel.org \
    --cc=linus.walleij@linaro.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-arm-msm@vger.kernel.org \
    --cc=linux-gpio@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=timur@codeaurora.org \
    --subject='Re: [PATCH 0/3] Support qcom pinctrl protected pins' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).