Re: [PATCH 6/7] pinctrl: tegra: Add DT binding for io pads control

From	Laxman Dewangan <ldewangan@nvidia.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH 6/7] pinctrl: tegra: Add DT binding for io pads control
Date	2016-04-15 20:10 +0200
Message-ID	<roglQ-7dz-5@gated-at.bofh.it> (permalink)
References	(4 earlier) <rodHk-535-17@gated-at.bofh.it> <rodR0-57f-15@gated-at.bofh.it> <roeam-5jh-27@gated-at.bofh.it> <rofg7-67R-39@gated-at.bofh.it> <rog2u-6M8-17@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Friday 15 April 2016 11:14 PM, Jon Hunter wrote:
> On 15/04/16 17:41, Laxman Dewangan wrote:
>> On Friday 15 April 2016 09:15 PM, Jon Hunter wrote:
>>> On 15/04/16 16:14, Laxman Dewangan wrote:
>>>> I used pins as this is the property from pincon generic so that I can
>>>> use the generic implementation.
>>>>
>>>> Here, I will not go to the pin level control as HW does not support pin
>>>> level control.
>>>>
>>>> I will say the unit should be interface level. Should we say
>>>> IO_GROUP_CSIA, IO_GROUP_CSIB etc?
>>> So we need to reflect the hardware in device-tree and although yes the
>>> power-down for the CSI_x_xxx pads are all controlled together as a
>>> single group, it does not feel right that we add a pseudo pin called
>>> csix to represent these.
>>>
>>> The CSI_x_xxx pads are already in device-tree and so why not add a
>>> property to each of these pads which has the IO rail information for
>>> power-down and voltage-select?
>> Which dt binding docs have these?
>> I looked for nvidia,tegra210-pinmux.txt and not able to find csi_xxx.
> For CSI you are right they are not included by the current DT binding
> docs, however, the sdmmc1/3 pads are. So that makes things a bit more
> messy as some are and some are not.

Yaah and so lets have the names in new dt files. Names may be same but 
define all possible names f groups in dt binding and need not to refer 
from other file which does not have all.

>> Here I dont want to refer the individual pins as control should be as
>> group.
> I understand, however, at least for power-down control I don't see why
> we cannot refer to the individual pins and once all are inactive then
> the rail can be powered down.
>
> For switching the voltage it is a bit more complex, but may be we could
> still look-up the IO rail based upon the pads the device uses.
>

Yes, it can be done with ref count also for power down.
But interfaces are complex. As a client, it is easy to say power down 
SDMMC1 IO interface rather than saying power down 10 pins (names) of 
that group.
We need to provide all these from DT for dynamic and static 
configuration and listing all pins of groups are complicate then the pad 
names.

Thread

[PATCH 0/7] pinctrl: soc/tegra: Add support to configure IO rail voltage and pad power states Laxman Dewangan <ldewangan@nvidia.com> - 2016-04-12 17:20 +0200
  [PATCH 2/7] soc/tegra: pmc: Add new Tegra210 IO rails Laxman Dewangan <ldewangan@nvidia.com> - 2016-04-12 17:20 +0200
    Re: [PATCH 2/7] soc/tegra: pmc: Add new Tegra210 IO rails Thierry Reding <thierry.reding@gmail.com> - 2016-04-12 17:30 +0200
      Re: [PATCH 2/7] soc/tegra: pmc: Add new Tegra210 IO rails Laxman Dewangan <ldewangan@nvidia.com> - 2016-04-12 19:20 +0200
        Re: [PATCH 2/7] soc/tegra: pmc: Add new Tegra210 IO rails Laxman Dewangan <ldewangan@nvidia.com> - 2016-04-12 20:10 +0200
        Re: [PATCH 2/7] soc/tegra: pmc: Add new Tegra210 IO rails Jon Hunter <jonathanh@nvidia.com> - 2016-04-12 20:10 +0200
  [PATCH 6/7] pinctrl: tegra: Add DT binding for io pads control Laxman Dewangan <ldewangan@nvidia.com> - 2016-04-12 17:20 +0200
    Re: [PATCH 6/7] pinctrl: tegra: Add DT binding for io pads control Jon Hunter <jonathanh@nvidia.com> - 2016-04-13 11:10 +0200
      Re: [PATCH 6/7] pinctrl: tegra: Add DT binding for io pads control Laxman Dewangan <ldewangan@nvidia.com> - 2016-04-13 11:20 +0200
        Re: [PATCH 6/7] pinctrl: tegra: Add DT binding for io pads control Jon Hunter <jonathanh@nvidia.com> - 2016-04-13 11:40 +0200
    Re: [PATCH 6/7] pinctrl: tegra: Add DT binding for io pads control Jon Hunter <jonathanh@nvidia.com> - 2016-04-15 16:20 +0200
      Re: [PATCH 6/7] pinctrl: tegra: Add DT binding for io pads control Laxman Dewangan <ldewangan@nvidia.com> - 2016-04-15 16:30 +0200
        Re: [PATCH 6/7] pinctrl: tegra: Add DT binding for io pads control Jon Hunter <jonathanh@nvidia.com> - 2016-04-15 17:20 +0200
          Re: [PATCH 6/7] pinctrl: tegra: Add DT binding for io pads control Laxman Dewangan <ldewangan@nvidia.com> - 2016-04-15 17:30 +0200
            Re: [PATCH 6/7] pinctrl: tegra: Add DT binding for io pads control Jon Hunter <jonathanh@nvidia.com> - 2016-04-15 17:50 +0200
              Re: [PATCH 6/7] pinctrl: tegra: Add DT binding for io pads control Laxman Dewangan <ldewangan@nvidia.com> - 2016-04-15 19:00 +0200
                Re: [PATCH 6/7] pinctrl: tegra: Add DT binding for io pads control Jon Hunter <jonathanh@nvidia.com> - 2016-04-15 19:50 +0200
                Re: [PATCH 6/7] pinctrl: tegra: Add DT binding for io pads control Laxman Dewangan <ldewangan@nvidia.com> - 2016-04-15 20:10 +0200
                Re: [PATCH 6/7] pinctrl: tegra: Add DT binding for io pads control Jon Hunter <jonathanh@nvidia.com> - 2016-04-15 20:40 +0200
                Re: [PATCH 6/7] pinctrl: tegra: Add DT binding for io pads control Laxman Dewangan <ldewangan@nvidia.com> - 2016-04-15 21:00 +0200
    Re: [PATCH 6/7] pinctrl: tegra: Add DT binding for io pads control Stephen Warren <swarren@wwwdotorg.org> - 2016-04-15 18:40 +0200
      Re: [PATCH 6/7] pinctrl: tegra: Add DT binding for io pads control Laxman Dewangan <ldewangan@nvidia.com> - 2016-04-15 18:50 +0200
  [PATCH 7/7] pinctrl: tegra: Add driver to configure voltage and power state of io pads Laxman Dewangan <ldewangan@nvidia.com> - 2016-04-12 17:20 +0200
    Re: [PATCH 7/7] pinctrl: tegra: Add driver to configure voltage and  power state of io pads Linus Walleij <linus.walleij@linaro.org> - 2016-04-15 10:10 +0200
      Re: [PATCH 7/7] pinctrl: tegra: Add driver to configure voltage and  power state of io pads Laxman Dewangan <ldewangan@nvidia.com> - 2016-04-15 11:00 +0200
        Re: [PATCH 7/7] pinctrl: tegra: Add driver to configure voltage and  power state of io pads Linus Walleij <linus.walleij@linaro.org> - 2016-04-15 11:30 +0200
          Re: [PATCH 7/7] pinctrl: tegra: Add driver to configure voltage and  power state of io pads Laxman Dewangan <ldewangan@nvidia.com> - 2016-04-15 12:10 +0200
            Re: [PATCH 7/7] pinctrl: tegra: Add driver to configure voltage and  power state of io pads Linus Walleij <linus.walleij@linaro.org> - 2016-04-15 13:20 +0200
              Re: [PATCH 7/7] pinctrl: tegra: Add driver to configure voltage and  power state of io pads Laxman Dewangan <ldewangan@nvidia.com> - 2016-04-15 14:00 +0200
                Re: [PATCH 7/7] pinctrl: tegra: Add driver to configure voltage and  power state of io pads Linus Walleij <linus.walleij@linaro.org> - 2016-04-15 16:10 +0200
                Re: [PATCH 7/7] pinctrl: tegra: Add driver to configure voltage and  power state of io pads Laxman Dewangan <ldewangan@nvidia.com> - 2016-04-15 16:20 +0200
                Re: [PATCH 7/7] pinctrl: tegra: Add driver to configure voltage and  power state of io pads Laxman Dewangan <ldewangan@nvidia.com> - 2016-04-19 12:10 +0200
                Re: [PATCH 7/7] pinctrl: tegra: Add driver to configure voltage and  power state of io pads Laxman Dewangan <ldewangan@nvidia.com> - 2016-04-26 15:50 +0200
                Re: [PATCH 7/7] pinctrl: tegra: Add driver to configure voltage and  power state of io pads Stephen Warren <swarren@wwwdotorg.org> - 2016-04-26 17:40 +0200
        Re: [PATCH 7/7] pinctrl: tegra: Add driver to configure voltage and  power state of io pads Stephen Warren <swarren@wwwdotorg.org> - 2016-04-15 18:40 +0200
  [PATCH 1/7] soc/tegra: pmc: Use BIT macro for register field definition Laxman Dewangan <ldewangan@nvidia.com> - 2016-04-12 17:20 +0200
    Re: [PATCH 1/7] soc/tegra: pmc: Use BIT macro for register field  definition Thierry Reding <thierry.reding@gmail.com> - 2016-04-12 17:30 +0200
      Re: [PATCH 1/7] soc/tegra: pmc: Use BIT macro for register field  definition Laxman Dewangan <ldewangan@nvidia.com> - 2016-04-12 19:10 +0200
      Re: [PATCH 1/7] soc/tegra: pmc: Use BIT macro for register field definition Linus Walleij <linus.walleij@linaro.org> - 2016-04-15 09:50 +0200

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