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Re: [PATCH 7/7] pinctrl: tegra: Add driver to configure voltage and power state of io pads

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On Fri, Apr 15, 2016 at 1:47 PM, Laxman Dewangan <ldewangan@nvidia.com> wrote:
> On Friday 15 April 2016 04:45 PM, Linus Walleij wrote:
>> On Fri, Apr 15, 2016 at 11:55 AM, Laxman Dewangan <ldewangan@nvidia.com>
>> wrote:

>> But to be sure we would like to know what is actually happening,
>> electronically speaking, when you set this up. Do you have any
>> idea?
>
> From electronic point of view, the value of VIL, VIH, VOL, VOH (Input/output
> voltage level for low and high state) are different when talking for 0 t
> 1.8V and 0 to 3.3V.

Yeah that I get. But since it is switched on a per-pin basis, and
this is not about what voltage is actually supplied to the I/O cell,
because that comes from the outside, it is a mystery why it is
even needed.

I understand that there is a bit selecting driving voltage level in
the register range, what I don't understand is what that is
doing in the I/O cell.

The bit in the register must be routed to somehing in the I/O cell
and I would like to know what. I take it that an ordinary CMOS
totem-pole push-pull output is going to work the same with 1.8
and 3.3V alike so it's obviously not enabling any extra transistors
or anything.

Yours,
Linus Walleij

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[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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