Messages in this thread | | | Date | Tue, 8 Nov 2016 21:18:54 +0530 | From | Laxman Dewangan <> | Subject | Re: [PATCH 2/2] pinctrl: tegra: Add driver to configure voltage and power of io pads |
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On Tuesday 08 November 2016 09:16 PM, Linus Walleij wrote: > On Tue, Nov 8, 2016 at 2:35 PM, Laxman Dewangan <ldewangan@nvidia.com> wrote: > >> There is two types of configuration in given platform, the IO voltage does >> not get change (fixed in given platform) and in some of cases, get change >> dynamically like SDIO3.0 where the voltage switches to 3.3V and 1.8V. >> >> Yes, it can be integrated with the regulator handle and then it can call the >> required configurations through notifier and regulator_get_voltage(). >> But I think it is too much complex for the static configurations. This >> mandate also to populate the regulator handle and all power tree. >> >> The simple way for static configuration (case where voltage does not get >> change), just take the power tree IO voltage from DT and configure the IO >> pad control register. >> >> For dynamic case, there is some sequence need to be followed based on >> voltage direction change (towards lower or towards higher) for the voltage >> change and the IO pad voltage configuration and it is simple to do it from >> client driver. > The devicetree should describe the platform. > > Adding this custom attribute does not describe the platform very > well since the dependency to the corresponding regulator is hidden. > > The point of device tree is not as much to make things simple as > to describe the world properly. > > So to me it is simple: use regulators and phandles. > > It might require a bit of upfront coding but the result will look > much nicer.
Oops, I asked same clarification when replying the Thierry's comment.
Got answer now.. only via regulator support.
I am going to support the IO pad voltage control with regulator only. No custom attribute for this. However, for support for low-power will be same as this patch.
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