Date:   Thu, 14 Jun 2018 12:10:28 +0000
From:   Michel Pollet <michel.pollet@...renesas.com>
To:     jacopo mondi <jacopo@...ndi.org>
CC:     "linux-renesas-soc@...r.kernel.org" 
        <linux-renesas-soc@...r.kernel.org>,
        Simon Horman <horms@...ge.net.au>,
        Phil Edworthy <phil.edworthy@...esas.com>,
        Michel Pollet <buserror+upstream@...il.com>,
        Linus Walleij <linus.walleij@...aro.org>,
        Rob Herring <robh+dt@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        "linux-gpio@...r.kernel.org" <linux-gpio@...r.kernel.org>,
        "devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: RE: [PATCH v1 2/5] dt-bindings: clock: renesas,r9a06g032-pinctrl:
 documentation

Hi Jacopo,

On 14 June 2018 13:05, Jacopo wrote:
> Hi Michel,
>
> On Thu, Jun 14, 2018 at 12:00:18PM +0100, Michel Pollet wrote:
> > The Renesas R9A06G032 PINCTRL node description.
> >
> > Signed-off-by: Michel Pollet <michel.pollet@...renesas.com>
> > ---
> >  .../bindings/pinctrl/renesas,r9a06g032-pinctrl.txt | 124
> > +++++++++++++++++++++
> >  1 file changed, 124 insertions(+)
> >  create mode 100644
> > Documentation/devicetree/bindings/pinctrl/renesas,r9a06g032-pinctrl.tx
> > t
> >
> > diff --git
> > a/Documentation/devicetree/bindings/pinctrl/renesas,r9a06g032-pinctrl.
> > txt
> > b/Documentation/devicetree/bindings/pinctrl/renesas,r9a06g032-pinctrl.
> > txt
> > new file mode 100644
> > index 0000000..f63696f
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/pinctrl/renesas,r9a06g032-pinc
> > +++ trl.txt
> > @@ -0,0 +1,124 @@
> > +Renesas RZ/A1 combined Pin and GPIO controller
> > +
> > +The Renesas SoCs of the RZ/A1 family feature a combined Pin and GPIO
> > +controller, named "Ports" in the hardware reference manual.
> > +Pin multiplexing and GPIO configuration is performed on a per-pin
> > +basis writing configuration values to per-port register sets.
> > +Each "port" features up to 16 pins, each of them configurable for
> > +GPIO function (port mode) or in alternate function mode.
> > +Up to 8 different alternate function modes exist for each single pin.
>
> This is a plain copy of the RZ/A1 pin controller documentation.
> I don't know RZ/N devices and cannot tell if it applies here too, but this needs
> an s/A1/N at the least.
>
> From a very superficial look at the proposed bindings and pinctrl driver, I
> wonder if the rza1 pinctrl driver could be expanded and re-used.
> Have you considered that before starting one from scratch?

Sorry it's just the start of the documentation which I wrongly cut/pasted -- the
rest is completely different; the only reason A1 is mentioned here is that I used
that file as a template for the header/sections etc... Somehow the title+blurb
went unedited!

And no, in terms of functionalities, they are completely different IPs.

Michel

>
> Thanks
>    j
>
> > +
> > +Pin controller node
> > +-------------------
> > +
> > +Required properties:
> > +  - compatible: should be:
> > +    - "renesas,r9a05g032-pinctrl"
> > +  - reg
> > +    address base and length of the memory area where the pin controller
> > +    hardware is mapped to.
> > +
> > +Example:
> > +pinctrl: pinctrl@...67000 {
> > +compatible = "renesas,r9a06g032-pinctrl";
> > +reg = <0x40067000 0x1000>, <0x51000000 0x800>;
> > +clocks = <&sysctrl R9A06G032_HCLK_PINCONFIG>;
> > +clock-names = "bus";
> > +status = "okay";
> > +};
> > +
> > +
> > +Sub-nodes
> > +---------
> > +  The child nodes of the pin controller node describe a pin
> > +multiplexing
> > +  group that can be used by driver nodes.
> > +
> > +  A pin multiplexing sub-node describes how to configure a set of
> > + (or a single) pin in some desired alternate function mode.
> > +  A single sub-node may define several pin configurations.
> > +
> > +  The allowed generic formats for a pin multiplexing sub-node are the
> > + following ones:
> > +
> > +  Client sub-nodes shall refer to pin multiplexing sub-nodes using
> > + the phandle  of the most external one.
> > +
> > +  Eg.
> > +
> > +  client-1 {
> > +      ...
> > +      pinctrl-0 = <&node-1>;
> > +      ...
> > +  };
> > +
> > +  client-2 {
> > +      ...
> > +      pinctrl-0 = <&node-2>;
> > +      ...
> > +  };
> > +
> > +  Required properties:
> > +    - renesas,rzn1-pinctrl:
> > +      Array of integers representing each 'pin' and it's configuration.
> > +
> > +      A 'pin number' does not correspond 1:1 to the hardware manual notion
> of
> > +      PL_GPIO directly. Numbers 0...169 are PL_GPIOs, however there is also
> two
> > +      extra 170 and 171 that corresponds to the MDIO0 and MDIO1 bus
> config.
> > +
> > +      A 'function' also does not correspond 1:1 to the hardware manual.
> There
> > +      are 2 levels of pin muxing, Level 1, level 2 -- to this are added the
> > +      MDIO configurations.
> > +
> > +      Helper macros to ease assembling the pin index and function identifier
> > +      are provided by the pin controller header file at:
> > +      <include/dt-bindings/pinctrl/r9a06g032-pinctrl.h>
> > +
> > +Example #1:
> > +  A simple case configuring only the function for a given 'pin' works as
> follow:
> > +#include <include/dt-bindings/pinctrl/r9a06g032-pinctrl.h>
> > +&pinctrl {
> > +pinsuart0: pinsuart0 {
> > +renesas,rzn1-pinmux-ids = <
> > +RZN1_MUX(103, UART0_I)/*
> UART0_TXD */
> > +RZN1_MUX(104, UART0_I)/*
> UART0_RXD */
> > +>;
> > +};
> > +};
> > +
> > +&uart0 {
> > +status = "okay";
> > +pinctrl-names = "default";
> > +pinctrl-0 = <&pinsuart0>;
> > +};
> > +  Note that in this case the other functions of the pins are not changed.
> > +
> > +Example #2:
> > +  Here we also set the pullups on the RXD pin:
> > +&pinctrl {
> > +pinsuart0: pinsuart0 {
> > +renesas,rzn1-pinmux-ids = <
> > +RZN1_MUX(103, UART0_I)/*
> UART0_TXD */
> > +RZN1_MUX_PUP(104, UART0_I)/*
> UART0_RXD */
> > +>;
> > +};
> > +};
> > +  There are many alternative macros to set the pullup/down/none and
> > +the drive
> > +  strenght in the r9a06g032-pinctrl.h header file.
> > +
> > +Example #3:
> > +  The Soc has two configurable MDIO muxes, these can also be
> > +configured
> > +  with this interface using the 'special' MDIO constants:
> > +
> > +&pinctrl {
> > +mdio_mux: mdiomux {
> > +renesas,rzn1-pinmux-ids = <
> > +RZN1_MUX(RZN1_MDIO_BUS0,
> RZN1_FUNC_MDIO_MUX_MAC0)
> > +RZN1_MUX(RZN1_MDIO_BUS1,
> RZN1_FUNC_MDIO_MUX_SWITCH)
> > +>;
> > +};
> > +};
> > +  Clearly the pull/up/none and drive constants will be ignored, even
> > +if
> > +  specified.
> > +
> > +Note that Renesas provides an extensive webapp that can generates a
> > +device tree file for your board. See their website for this part number for
> details.
> > --
> > 2.7.4
> >



Renesas Electronics Europe Ltd, Dukes Meadow, Millboard Road, Bourne End, Buckinghamshire, SL8 5FH, UK. Registered in England & Wales under Registered No. 04586709.

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