Re: [PATCH 02/12] pinctrl: Add core pinctrl support for Aspeed SoCs

[Joel Stanley]

On Wed, Jul 20, 2016 at 3:28 PM, Andrew Jeffery <andrew@xxxxxxxx> wrote:
> The Aspeed SoCs provide typically more than 200 pins for GPIO and other
> functions. The signal enabled on a pin is determined on a priority
> basis, where a given pin can provide a number of different signal types.
>
> In addition to the priority levels, the Aspeed pin controllers describe
> the signal active on a pin by compound logical expressions involving
> multiple operators, registers and bits. Some difficulty arises as a
> pin's function bit masks for each priority level are frequently not the
> same (i.e. we cannot just flip a bit to change from a high to low
> priority signal), or even in the same register(s). Some configuration
> bits affect multiple pins, while in other cases the signals for a bus
> must each be enabled individually.
>
> Together, these features give rise to some complexity in the
> implementation. A more complete description of the complexities is
> provided in the associated header file in an attempt to justify the
> approach.
>
> Note that the patch doesn't implement pinctrl/pinmux/pinconf for any
> particular SoC, just adds the framework for defining mux configurations
> for any available functions.
>
> Signed-off-by: Andrew Jeffery <andrew@xxxxxxxx>

Reviewed-by: Joel Stanley <joel@xxxxxxxxx>

> ---
>  MAINTAINERS                             |   1 +
>  arch/arm/mach-aspeed/Kconfig            |   1 +
>  drivers/pinctrl/Kconfig                 |   1 +
>  drivers/pinctrl/Makefile                |   1 +
>  drivers/pinctrl/aspeed/Kconfig          |   8 +
>  drivers/pinctrl/aspeed/Makefile         |   3 +
>  drivers/pinctrl/aspeed/pinctrl-aspeed.c | 373 +++++++++++++++++++++
>  drivers/pinctrl/aspeed/pinctrl-aspeed.h | 562 ++++++++++++++++++++++++++++++++
>  8 files changed, 950 insertions(+)
>  create mode 100644 drivers/pinctrl/aspeed/Kconfig
>  create mode 100644 drivers/pinctrl/aspeed/Makefile
>  create mode 100644 drivers/pinctrl/aspeed/pinctrl-aspeed.c
>  create mode 100644 drivers/pinctrl/aspeed/pinctrl-aspeed.h