Re: [PATCH v5 01/10] pinctrl: generic: Add bi-directional and output-enable

[Andy Shevchenko]

On Thu, Apr 27, 2017 at 11:19 AM, Jacopo Mondi
<jacopo+renesas@xxxxxxxxxx> wrote:
> Add bi-directional and output-enable pin configuration properties.
>
> bi-directional allows to specify when a pin shall operate in input and
> output mode at the same time. This is particularly useful in platforms
> where input and output buffers have to be manually enabled.
>
> output-enable is just syntactic sugar to specify that a pin shall
> operate in output mode, ignoring the provided argument.
> This pairs with input-enable pin configuration option.

For me it looks like you are trying to alias open-drain + bias or
alike. Don't actually see the benefit of it.

> Signed-off-by: Jacopo Mondi <jacopo+renesas@xxxxxxxxxx>
> ---
>  Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt | 2 ++
>  drivers/pinctrl/pinconf-generic.c                              | 3 +++
>  include/linux/pinctrl/pinconf-generic.h                        | 3 +++
>  3 files changed, 8 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt b/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
> index bf3f7b0..f2ed458 100644
> --- a/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
> +++ b/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
> @@ -222,6 +222,7 @@ bias-bus-hold               - latch weakly
>  bias-pull-up           - pull up the pin
>  bias-pull-down         - pull down the pin
>  bias-pull-pin-default  - use pin-default pull state
> +bi-directional         - pin supports simultaneous input/output operations
>  drive-push-pull                - drive actively high and low
>  drive-open-drain       - drive with open drain
>  drive-open-source      - drive with open source
> @@ -234,6 +235,7 @@ input-debounce              - debounce mode with debound time X
>  power-source           - select between different power supplies
>  low-power-enable       - enable low power mode
>  low-power-disable      - disable low power mode
> +output-enable          - enable output on pin regardless of output value
>  output-low             - set the pin to output mode with low level
>  output-high            - set the pin to output mode with high level
>  slew-rate              - set the slew rate
> diff --git a/drivers/pinctrl/pinconf-generic.c b/drivers/pinctrl/pinconf-generic.c
> index ce3335a..03e6808 100644
> --- a/drivers/pinctrl/pinconf-generic.c
> +++ b/drivers/pinctrl/pinconf-generic.c
> @@ -35,6 +35,7 @@ static const struct pin_config_item conf_items[] = {
>         PCONFDUMP(PIN_CONFIG_BIAS_PULL_PIN_DEFAULT,
>                                 "input bias pull to pin specific state", NULL, false),
>         PCONFDUMP(PIN_CONFIG_BIAS_PULL_UP, "input bias pull up", NULL, false),
> +       PCONFDUMP(PIN_CONFIG_BIDIRECTIONAL, "bi-directional pin operations", NULL, false),
>         PCONFDUMP(PIN_CONFIG_DRIVE_OPEN_DRAIN, "output drive open drain", NULL, false),
>         PCONFDUMP(PIN_CONFIG_DRIVE_OPEN_SOURCE, "output drive open source", NULL, false),
>         PCONFDUMP(PIN_CONFIG_DRIVE_PUSH_PULL, "output drive push pull", NULL, false),
> @@ -160,6 +161,7 @@ static const struct pinconf_generic_params dt_params[] = {
>         { "bias-pull-up", PIN_CONFIG_BIAS_PULL_UP, 1 },
>         { "bias-pull-pin-default", PIN_CONFIG_BIAS_PULL_PIN_DEFAULT, 1 },
>         { "bias-pull-down", PIN_CONFIG_BIAS_PULL_DOWN, 1 },
> +       { "bi-directional", PIN_CONFIG_BIDIRECTIONAL, 1 },
>         { "drive-open-drain", PIN_CONFIG_DRIVE_OPEN_DRAIN, 0 },
>         { "drive-open-source", PIN_CONFIG_DRIVE_OPEN_SOURCE, 0 },
>         { "drive-push-pull", PIN_CONFIG_DRIVE_PUSH_PULL, 0 },
> @@ -172,6 +174,7 @@ static const struct pinconf_generic_params dt_params[] = {
>         { "input-schmitt-enable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 1 },
>         { "low-power-disable", PIN_CONFIG_LOW_POWER_MODE, 0 },
>         { "low-power-enable", PIN_CONFIG_LOW_POWER_MODE, 1 },
> +       { "output-enable", PIN_CONFIG_OUTPUT, 1, },
>         { "output-high", PIN_CONFIG_OUTPUT, 1, },
>         { "output-low", PIN_CONFIG_OUTPUT, 0, },
>         { "power-source", PIN_CONFIG_POWER_SOURCE, 0 },
> diff --git a/include/linux/pinctrl/pinconf-generic.h b/include/linux/pinctrl/pinconf-generic.h
> index 7620eb1..279e3c5 100644
> --- a/include/linux/pinctrl/pinconf-generic.h
> +++ b/include/linux/pinctrl/pinconf-generic.h
> @@ -42,6 +42,8 @@
>   * @PIN_CONFIG_BIAS_PULL_UP: the pin will be pulled up (usually with high
>   *     impedance to VDD). If the argument is != 0 pull-up is enabled,
>   *     if it is 0, pull-up is total, i.e. the pin is connected to VDD.
> + * @PIN_CONFIG_BIDIRECTIONAL: the pin will be configured to allow simultaneous
> + *     input and output operations.
>   * @PIN_CONFIG_DRIVE_OPEN_DRAIN: the pin will be driven with open drain (open
>   *     collector) which means it is usually wired with other output ports
>   *     which are then pulled up with an external resistor. Setting this
> @@ -96,6 +98,7 @@ enum pin_config_param {
>         PIN_CONFIG_BIAS_PULL_DOWN,
>         PIN_CONFIG_BIAS_PULL_PIN_DEFAULT,
>         PIN_CONFIG_BIAS_PULL_UP,
> +       PIN_CONFIG_BIDIRECTIONAL,
>         PIN_CONFIG_DRIVE_OPEN_DRAIN,
>         PIN_CONFIG_DRIVE_OPEN_SOURCE,
>         PIN_CONFIG_DRIVE_PUSH_PULL,
> --
> 2.7.4
>



-- 
With Best Regards,
Andy Shevchenko