Re: [PATCH v7 3/6] dt-bindings: pinctrl: mt8183: add binding document

[Zhiyong Tao <zhiyong.tao@mediatek.com>]

On Fri, 2019-02-15 at 10:35 +0100, Matthias Brugger wrote:
> 
> On 15/02/2019 07:02, Erin Lo wrote:
> > From: Zhiyong Tao <zhiyong.tao@mediatek.com>
> > 
> > The commit adds mt8183 compatible node in binding document.
> > 
> > Signed-off-by: Zhiyong Tao <zhiyong.tao@mediatek.com>
> > Signed-off-by: Erin Lo <erin.lo@mediatek.com>
> > ---
> >  .../devicetree/bindings/pinctrl/pinctrl-mt8183.txt | 115 +++++++++++++++++++++
> >  1 file changed, 115 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/pinctrl/pinctrl-mt8183.txt
> > 
> > diff --git a/Documentation/devicetree/bindings/pinctrl/pinctrl-mt8183.txt b/Documentation/devicetree/bindings/pinctrl/pinctrl-mt8183.txt
> > new file mode 100644
> > index 0000000..364e673
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/pinctrl/pinctrl-mt8183.txt
> > @@ -0,0 +1,115 @@
> > +* Mediatek MT8183 Pin Controller
> > +
> > +The Mediatek's Pin controller is used to control SoC pins.
> > +
> > +Required properties:
> > +- compatible: value should be one of the following.
> > +	"mediatek,mt8183-pinctrl", compatible with mt8183 pinctrl.
> > +- gpio-controller : Marks the device node as a gpio controller.
> > +- #gpio-cells: number of cells in GPIO specifier. Since the generic GPIO
> > +  binding is used, the amount of cells must be specified as 2. See the below
> > +  mentioned gpio binding representation for description of particular cells.
> > +- gpio-ranges : gpio valid number range.
> > +- reg: physicall address base for gpio base registers. There are nine
> 
> s/physicall/physical

==>we will modify it.
> 
> > +  physicall address base in mt8183. They are 0x10005000, 0x11F20000,
> > +  0x11E80000, 0x11E70000, 0x11E90000, 0x11D30000, 0x11D20000, 0x11C50000,
> > +  0x11F30000.
> > +
> > +	Eg: <&pio 6 0>
> > +	<[phandle of the gpio controller node]
> > +	[line number within the gpio controller]
> > +	[flags]>
> > +
> > +	Values for gpio specifier:
> > +	- Line number: is a value between 0 to 202.
> > +	- Flags:  bit field of flags, as defined in <dt-bindings/gpio/gpio.h>.
> > +            Only the following flags are supported:
> > +            0 - GPIO_ACTIVE_HIGH
> > +            1 - GPIO_ACTIVE_LOW
> > +
> > +Optional properties:
> > +- reg-names: gpio base register names. There are nine gpio base register
> > +  names in mt8183. They are "iocfg0", "iocfg1", "iocfg2", "iocfg3", "iocfg4",
> > +  "iocfg5", "iocfg6", "iocfg7", "iocfg8".
> > +- interrupt-controller: Marks the device node as an interrupt controller
> > +- #interrupt-cells: Should be two.
> > +- interrupts : The interrupt outputs from the controller.
> 
> we are missing interrupt-parent here.

==> we will add it in next version. we will add like this:
- interrupts-parents : The interrupt connector. In mt8183, it is sysirq.

> 
> > +
> > +Please refer to pinctrl-bindings.txt in this directory for details of the
> > +common pinctrl bindings used by client devices.
> > +
> > +Subnode format
> > +A pinctrl node should contain at least one subnodes representing the
> > +pinctrl groups available on the machine. Each subnode will list the
> > +pins it needs, and how they should be configured, with regard to muxer
> > +configuration, pullups, drive strength, input enable/disable and input schmitt.
> > +
> > +    node {
> > +	pinmux = <PIN_NUMBER_PINMUX>;
> > +	GENERIC_PINCONFIG;
> > +    };
> > +
> > +Required properties:
> > +- pinmux: integer array, represents gpio pin number and mux setting.
> > +    Supported pin number and mux varies for different SoCs, and are defined
> > +    as macros in boot/dts/<soc>-pinfunc.h directly.
> > +
> > +Optional properties:
> > +- GENERIC_PINCONFIG: is the generic pinconfig options to use, bias-disable,
> > +    bias-pull-down, bias-pull-up, input-enable, input-disable, output-low, output-high,
> > +    input-schmitt-enable, input-schmitt-disable and drive-strength are valid.
> > +
> > +    Some special pins have extra pull up strength, there are R0 and R1 pull-up
> > +    resistors available, but for user, it's only need to set R1R0 as 00, 01, 10 or 11.
> > +    So when config mediatek,pull-up-adv or mediatek,pull-down-adv,
> > +    it support arguments for those special pins.
> 
> I wonder if we should mention which this special pins are. A look at the driver
> told me that it is not possible to know that by reading the source code neither.
> Linus, what do you think?
> 
> What about mediatek,tdsel and mediatek,rdsel? They are not supported?
> 
> Wouldn't it make sense to have one binding description for paris and then just
> create SoC specifics bindings?
==> It can support mediatek,tdsel and mediatek,rdsel in mt8183 design.
I will try to create one new binding description and separate it from
soc specifics bindings.

> 
> > +
> > +    When config drive-strength, it can support some arguments, such as
> > +    MTK_DRIVE_4mA, MTK_DRIVE_6mA, etc. See dt-bindings/pinctrl/mt65xx.h.
> 
> It can support all drive strength defined in that header file, 2, 4, 6, 8, 10,
> 12, 14, 16, 20, 24, 28 and 32 mA?

==>It can only support drive strength 2,4,6,8,10,12,14,16mA in mt8183. 

> 
> > +
> > +Examples:
> > +
> > +#include "mt8183-pinfunc.h"
> > +
> > +...
> > +{
> > +	pio: pinctrl@10005000 {
> > +		compatible = "mediatek,mt8183-pinctrl";
> > +		reg = <0 0x10005000 0 0x1000>,
> > +		      <0 0x11F20000 0 0x1000>,
> > +		      <0 0x11E80000 0 0x1000>,
> > +		      <0 0x11E70000 0 0x1000>,
> > +		      <0 0x11E90000 0 0x1000>,
> > +		      <0 0x11D30000 0 0x1000>,
> > +		      <0 0x11D20000 0 0x1000>,
> > +		      <0 0x11C50000 0 0x1000>,
> > +		      <0 0x11F30000 0 0x1000>;
> > +		reg-names = "iocfg0", "iocfg1", "iocfg2",
> > +			    "iocfg3", "iocfg4", "iocfg5",
> > +			    "iocfg6", "iocfg7", "iocfg8";
> > +		gpio-controller;
> > +		#gpio-cells = <2>;
> > +		gpio-ranges = <&pio 0 0 192>;
> > +		interrupt-controller;
> > +		interrupts = <GIC_SPI 153 IRQ_TYPE_LEVEL_HIGH>;
> > +		interrupt-parent = <&gic>;
> > +		#interrupt-cells = <2>;
> > +
> > +		i2c0_pins_a: i2c0 {
> > +			pins1 {
> > +				pinmux = <PINMUX_GPIO48__FUNC_SCL5>,
> > +					 <PINMUX_GPIO49__FUNC_SDA5>;
> > +				mediatek,pull-up-adv = <11>;
> > +			};
> > +		};
> > +
> > +		i2c1_pins_a: i2c1 {
> > +			pins {
> > +				pinmux = <PINMUX_GPIO50__FUNC_SCL3>,
> > +					 <PINMUX_GPIO51__FUNC_SDA3>;
> > +				mediatek,pull-down-adv = <10>;
> > +			};
> > +		};
> > +		...
> > +	};
> > +};
> >