linux-gpio.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Bjorn Andersson <bjorn.andersson@linaro.org>
To: Fenglin Wu <fenglinw@codeaurora.org>
Cc: linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org,
	Linus Walleij <linus.walleij@linaro.org>,
	linux-gpio@vger.kernel.org, collinsd@codeaurora.org,
	aghayal@codeaurora.org, wruan@codeaurora.org,
	subbaram@codeaurora.org, kgunda@codeaurora.org
Subject: Re: [PATCH V1] pinctrl: qcom: spmi-gpio: Update GPIO EN_CTL when setting pin config
Date: Tue, 10 Oct 2017 22:48:52 -0700	[thread overview]
Message-ID: <20171011054852.GH1165@minitux> (raw)
In-Reply-To: <35aec5d7-8808-9930-8d6d-e0399df12a9e@codeaurora.org>

On Mon 09 Oct 17:17 PDT 2017, Fenglin Wu wrote:

> On 10/9/2017 1:56 PM, Bjorn Andersson wrote:
> > On Sun 08 Oct 22:34 PDT 2017, Fenglin Wu wrote:
> > 
> > > On 10/6/2017 12:27 AM, Bjorn Andersson wrote:
[..]
> > > > But I spotted another issue while reviewing this; currently the initial
> > > > state of is_enabled is unconditionally set to enabled in
> > > > pmic_gpio_populate(), so reading the initial pinconf or configuring a
> > > > pinmux before setting a pinconf will operate on the potentially wrong
> > > > information.
> > > > 
> > > > So I think the initial value should be read out from REG_EN_CTL rather
> > > > than being just "true".
> > > > 
> > > > Can you please either submit another patch for this?
> > > 
> > > Hmm, considering a GPIO which is disabled by default in hardware
> > > setting, what's its expected state if we only define "function" for it?
> > > I was thinking we need to enable it once it has any setting in pinmux or
> > > pinconf. If you think that we need to keep its original state until we
> > > set pinconf for it, yes, I can submit a change to address this.
> > > 
> > 
> > Are there valid cases where only function should be selected and no
> > other configuration is used? If so it makes sense to make
> > pmic_gpio_set_mux() enable the block.
> > 
> > 
> > Regardless of this, if there are disabled pins that are not mentioned in
> > DT they will still appear as enabled in the debugfs interface; and this
> > I consider an error worth fixing.
> How about we do both: read the HW initial state in pmic_gpio_populate(),
> and also enable the GPIO block in pmic_gpio_set_mux()?
> 

That sounds good.

Please do this as two separate patches, with the commit message clearly
describing a case where the pinconf does not affect the function of the
pin, so a pinmux is the only thing needed.

Regards,
Bjorn

  reply	other threads:[~2017-10-11  5:48 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-09-12  0:32 [PATCH V1] pinctrl: qcom: spmi-gpio: Update GPIO EN_CTL when setting pin config fenglinw
2017-09-19  8:20 ` Linus Walleij
2017-10-05 16:27 ` Bjorn Andersson
2017-10-09  5:34   ` Fenglin Wu
2017-10-09  5:56     ` Bjorn Andersson
2017-10-10  0:17       ` Fenglin Wu
2017-10-11  5:48         ` Bjorn Andersson [this message]
2017-10-11  8:24 ` Linus Walleij

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=20171011054852.GH1165@minitux \
    --to=bjorn.andersson@linaro.org \
    --cc=aghayal@codeaurora.org \
    --cc=collinsd@codeaurora.org \
    --cc=fenglinw@codeaurora.org \
    --cc=kgunda@codeaurora.org \
    --cc=linus.walleij@linaro.org \
    --cc=linux-arm-msm@vger.kernel.org \
    --cc=linux-gpio@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=subbaram@codeaurora.org \
    --cc=wruan@codeaurora.org \
    /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
Be sure your reply has a Subject: header at the top and a blank line before the message body.
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).