On 11/06/13 23:03, Laurent Pinchart wrote:
> Document DT properties for the generic pinctrl parameters and add a
> parser function.
>
> Signed-off-by: Laurent Pinchart <laurent.pinchart+rene...@ideasonboard.com>
> ---
> .../bindings/pinctrl/pinctrl-bindings.txt | 29 +++++++
> drivers/pinctrl/pinconf-generic.c | 94
> ++++++++++++++++++++++
> drivers/pinctrl/pinconf.h | 17 ++++
> 3 files changed, 140 insertions(+)
>
> I've successfully tested this patch (or more accurately only the pull-up and
> pull-down properties) with the Renesas sh-pfc pinctrl device driver. I will
> resent the sh-pfc DT bindings patch series rebased on the generic pinconf
> bindings.
>
> Not all generic pinconf properties are currently implemented, but I don't
> think that should be a showstopper. We can add them later as needed.
>
> The code is based on both the sh-pfc pinconf DT parser and James Hogan's
> tz1090 DT parser ("[PATCH v2 6/9] pinctrl-tz1090: add TZ1090 pinctrl driver").
Thanks for this patch. I haven't tested it (yet), but have a few
comments below.
>
> diff --git a/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
> b/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
> index c95ea82..e499ff0 100644
> --- a/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
> +++ b/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
> @@ -126,3 +126,32 @@ device; they may be grandchildren, for example. Whether
> this is legal, and
> whether there is any interaction between the child and intermediate parent
> nodes, is again defined entirely by the binding for the individual pin
> controller device.
> +
> +== Generic pinconf parameters ==
> +
> +Pin configuration parameters are expressed by DT properties in the pin
> +controller device state nodes and child nodes. For devices that use the
> generic
> +pinconf parameters the following properties are defined.
> +
> +- tristate: A boolean, put the pin into high impedance state when set.
> +
> +- pull-up: An integer representing the pull-up strength. 0 disables the
> pull-up,
> + non-zero values enable it.
> +
> +- pull-down: An integer representing the pull-down strength. 0 disables the
> + pull-down, non-zero values enables it.
> +
> +- schmitt: An integer, enable or disable Schmitt trigger mode for the pins.
> + Valid values are
> + 0: Schmitt trigger disabled (no hysteresis)
> + 1: Schmitt trigger enabled
this is set as a flag, so I think it should be described like tristate,
"A boolean, ... when set."? Same for pull-up and pull-down (see comment
below).
<snip>
> + { "pull-up", PIN_CONFIG_BIAS_PULL_UP, false },
> + { "pull-down", PIN_CONFIG_BIAS_PULL_DOWN, false },
pinconf-generic.h says "If the argument is != 0 pull-up is enabled, if
it is 0, pull-up is disabled", so I think these should be flags unless
it's changed there first.
Any chance of adding the new "bus-hold" entry too
(PIN_CONFIG_BIAS_BUS_HOLD, and flag=true I suppose)? see
aa69352252a7a952e6e77734cb87135143a377d2 in LinuxW's pinctrl for-next
branch.
<snip>
> +EXPORT_SYMBOL_GPL(pinconf_generic_parse_params);
> diff --git a/drivers/pinctrl/pinconf.h b/drivers/pinctrl/pinconf.h
> index 92c7267..eb8550b 100644
> --- a/drivers/pinctrl/pinconf.h
> +++ b/drivers/pinctrl/pinconf.h
> @@ -90,6 +90,23 @@ static inline void pinconf_init_device_debugfs(struct
> dentry *devroot,
> * pin config.
> */
>
> +#if defined(CONFIG_GENERIC_PINCONF)
> +
> +int pinconf_generic_parse_params(struct device *dev, struct device_node *np,
> + unsigned long **cfgs);
> +
> +#else
> +
> +static inline int pinconf_generic_parse_params(struct device *dev,
> + struct device_node *np,
> + unsigned long **cfgs)
> +{
> + *cfgs = NULL;
> + return 0;
> +}
Should this ever be necessary? Sounds like if the driver wanted to use
this it should already have selected GENERIC_PINCONF anyway.
Cheers
James
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
