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Message-ID: <2b221339-3933-2a25-ab60-d4d772d2873a@gmail.com>
Date: Fri, 15 Feb 2019 10:35:39 +0100
From: Matthias Brugger <matthias.bgg@...il.com>
To: Erin Lo <erin.lo@...iatek.com>,
Linus Walleij <linus.walleij@...aro.org>,
Rob Herring <robh+dt@...nel.org>,
Mark Rutland <mark.rutland@....com>,
Thomas Gleixner <tglx@...utronix.de>,
Jason Cooper <jason@...edaemon.net>,
Marc Zyngier <marc.zyngier@....com>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
Stephen Boyd <sboyd@...eaurora.org>
Cc: devicetree@...r.kernel.org,
srv_heupstream <srv_heupstream@...iatek.com>,
linux-kernel@...r.kernel.org, linux-serial@...r.kernel.org,
linux-mediatek@...ts.infradead.org,
linux-arm-kernel@...ts.infradead.org, yingjoe.chen@...iatek.com,
mars.cheng@...iatek.com, eddie.huang@...iatek.com,
linux-clk@...r.kernel.org, Zhiyong Tao <zhiyong.tao@...iatek.com>
Subject: Re: [PATCH v7 3/6] dt-bindings: pinctrl: mt8183: add binding document
On 15/02/2019 07:02, Erin Lo wrote:
> From: Zhiyong Tao <zhiyong.tao@...iatek.com>
>
> The commit adds mt8183 compatible node in binding document.
>
> Signed-off-by: Zhiyong Tao <zhiyong.tao@...iatek.com>
> Signed-off-by: Erin Lo <erin.lo@...iatek.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
> + 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.
> +
> +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?
> +
> + 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?
> +
> +Examples:
> +
> +#include "mt8183-pinfunc.h"
> +
> +...
> +{
> + pio: pinctrl@...05000 {
> + 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>;
> + };
> + };
> + ...
> + };
> +};
>
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