[PATCH 00/15] ARM: sunxi: add A31 PL pins support

Wed Apr 9 10:14:26 PDT 2014

On Thu, Apr 10, 2014 at 12:14 AM, Boris BREZILLON
<boris.brezillon at free-electrons.com> wrote:
>
> On 09/04/2014 16:53, Chen-Yu Tsai wrote:
>> Hi Boris,
>>
>> On Wed, Apr 9, 2014 at 9:51 PM, Boris BREZILLON
>> <boris.brezillon at free-electrons.com> wrote:
>>> Hello,
>>>
>>> This series rework the sunxi pinctrl driver to support the PLx pins
>>> available on the A31 SoC.
>> Thanks for working on this. I mentioned to Maxime on IRC yesterday that
>> we have complete pinctrl drivers for both A31 and A23, based on our current
>> pinctrl-sunxi driver, in the A23 SDK. These have the complete pin mapping.
>
> Thanks for pointing this out, I'll take a look.
>
>>
>>> It also add missing A31 reset controller DT bindings documentation.
>>>
>>> I need those PL pins (actually I only need PL0 and PL1) to support
>>> the P2WI bus, which in turn is used to communicate with the AXP221
>>> PMIC.
>> If you could, please add all the PL and PM pins.
>
> Sure, I'll add pin macros for L and M ports.
>
>> As I said, you can find complete definitions in the A23 SDK.
>>
>>> Let me know if these changes are too intrusive.
>> I wonder if we should do a separate driver for the new PIO controller.
>> Clearly it's a separate IP block, with it's own clock and reset controls.
>
> This is what I had in mind in the first place, but then I encountered
> several issues when doing so:
>
>  1) the gpio chip is not dynamically allocated but is declared as a
> static variable instead

Hmm. Not sure if this is worth the change.

>  2) we have to tweak the pinctrl base field, otherwise the pin numbers
> overlap

Documentation says pin numbers are global, however the pinctrl core code
only looks up a pin by number in a pinctrl device only.

Also I see mfd pinctrl drivers (ab8500, as3722) have pin numbers starting
from 0. So definitely some confusion there.

>  3) other things I haven't noticed yet :-)

Reworking EINT to use one interrupt per bank will yield some more surprises.

There's also new gpiolib irqchip helpers, but that will require reworking
each pin bank into separate gpio chips. May be more work than just adding
different irq domains for different banks.

See: https://lkml.org/lkml/2014/3/25/175

> I'll try to rework the driver to be able to declare 2 separated pin
> controllers.

Thanks again.

ChenYu

>> Allwinner sources list this block as "R_PIO". I suggest using this name.
>> Clearly "pioL" does not cover all the functionality.
>
> Fair enough. I'll modify it.
>
>>
>> I have started to document the PRCM block: http://linux-sunxi.org/PRCM
>>
>> Last, please send the patches to the linux-sunxi mailing list as well.
>> At the very least, Hans will see them and add them to sunxi-devel branch.
>
> Sure, this is an oversight, I'm using get_maintainer and just forgot to
> add Hans and the linux-sunxi ML. But I'll take care to add you, hans and
> the sunxi ML in Cc next time.
>
> Thanks for your review.
>
> Best Regards,
>
> Boris
>
>>
>>
>> Cheers,
>> ChenYu
>>
>>> Best Regards,
>>>
>>> Boris
>>>
>>> Boris BREZILLON (15):
>>>   ARM: sunxi: dt: list all pinctrl compatible strings
>>>   ARM: sunxi: dt: document pinctrl clock related properties
>>>   ARM: sunxi: dt: add pinctrl clock-names properties
>>>   pinctrl: sunxi: specify clk name when retrieving pinctrl pio clk
>>>   clk: sunxi: add A31 APB0 clk gate defintions
>>>   clk: sunxi: add A31 APB0 gates compatible string to the documentation
>>>   ARM: sunxi: dt: define A31's APB0 clk gates node
>>>   reset: sunxi: document sunxi's reset controllers bindings
>>>   clk: sunxi: add A31 APB0 reset line defintions
>>>   pinctrl: sunxi: add PL pin definitions
>>>   pinctrl: sunxi: add support for A31 PL pins
>>>   pinctrl: sunxi: retrieve and enable PL clk gate for A31 SoC
>>>   pinctrl: sunxi: retrieve and enable PL reset line for A31 SoC
>>>   pinctrl: sunxi: define A31 PL0/PL1 pins
>>>   ARM: sunxi: dt: add support for A31's PL pins
>>>
>>>  Documentation/devicetree/bindings/clock/sunxi.txt  |   1 +
>>>  .../bindings/pinctrl/allwinner,sunxi-pinctrl.txt   |  13 +-
>>>  .../bindings/reset/allwinner,sunxi-clock-reset.txt |  21 +++
>>>  arch/arm/boot/dts/sun4i-a10.dtsi                   |   1 +
>>>  arch/arm/boot/dts/sun5i-a10s.dtsi                  |   1 +
>>>  arch/arm/boot/dts/sun5i-a13.dtsi                   |   1 +
>>>  arch/arm/boot/dts/sun6i-a31.dtsi                   |  25 ++-
>>>  arch/arm/boot/dts/sun7i-a20.dtsi                   |   1 +
>>>  drivers/clk/sunxi/clk-sunxi.c                      |   5 +
>>>  drivers/pinctrl/pinctrl-sunxi-pins.h               |   8 +
>>>  drivers/pinctrl/pinctrl-sunxi.c                    | 205 +++++++++++++++------
>>>  drivers/pinctrl/pinctrl-sunxi.h                    |  39 +++-
>>>  12 files changed, 264 insertions(+), 57 deletions(-)
>>>  create mode 100644 Documentation/devicetree/bindings/reset/allwinner,sunxi-clock-reset.txt
>>>
>>> --
>>> 1.8.3.2
>>>
>>>
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>>> linux-arm-kernel at lists.infradead.org
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>
> --
> Boris Brezillon, Free Electrons
> Embedded Linux and Kernel engineering
> http://free-electrons.com
>