Re: [PATCH v3] arm64: dts: meson-a1: add I2C nodes

[Jerome Brunet]

On Fri 20 Dec 2019 at 10:16, Jian Hu <jian.hu@xxxxxxxxxxx> wrote:

> There are four I2C controllers in A1 series,
> Share the same comptible with AXG. Compared to AXG,
> Drive strength feature is newly added in A1.
>
> Signed-off-by: Jian Hu <jian.hu@xxxxxxxxxxx>
>
> ---
> This patch depends on A1 clock patchset at [0][3]
>
> Changes since v1 at [1]:
> -change reg length to 0x20
> -assign i2c bus alias in dts file
> -add new feature note compared to AXG in changelog
>
> Changes since v2 at [2]:
> -remove the dependence the commit description
> -remove i2c alias in dtsi
> -reorder the i2c nodes
> -reorder the i2c pins
>
> [0] https://lkml.kernel.org/r/20191206074052.15557-1-jian.hu@xxxxxxxxxxx
> [1] https://lkml.kernel.org/r/20191202111253.94872-1-jian.hu@xxxxxxxxxxx
> [2] https://lkml.kernel.org/r/20191211032802.83309-1-jian.hu@xxxxxxxxxxx
> [3] https://lkml.kernel.org/r/20191206074052.15557-1-jian.hu@xxxxxxxxxxx
> ---
> ---
>  arch/arm64/boot/dts/amlogic/meson-a1.dtsi | 142 ++++++++++++++++++++++
>  1 file changed, 142 insertions(+)
>
> diff --git a/arch/arm64/boot/dts/amlogic/meson-a1.dtsi b/arch/arm64/boot/dts/amlogic/meson-a1.dtsi
> index eab2ecd36aa8..1542eeee699d 100644
> --- a/arch/arm64/boot/dts/amlogic/meson-a1.dtsi
> +++ b/arch/arm64/boot/dts/amlogic/meson-a1.dtsi
> @@ -117,6 +117,16 @@
>  				};
>  			};
>  
> +			i2c0: i2c@1400 {
> +				compatible = "amlogic,meson-axg-i2c";
> +				reg = <0x0 0x1400 0x0 0x20>;
> +				interrupts = <GIC_SPI 32 IRQ_TYPE_EDGE_RISING>;
> +				#address-cells = <1>;
> +				#size-cells = <0>;
> +				clocks = <&clkc_periphs CLKID_I2C_M_A>;
> +				status = "disabled";
> +			};
> +
>  			uart_AO: serial@1c00 {
>  				compatible = "amlogic,meson-gx-uart",
>  					     "amlogic,meson-ao-uart";
> @@ -136,6 +146,36 @@
>  				clock-names = "xtal", "pclk", "baud";
>  				status = "disabled";
>  			};
> +
> +			i2c1: i2c@5c00 {
> +				compatible = "amlogic,meson-axg-i2c";
> +				reg = <0x0 0x5c00 0x0 0x20>;
> +				interrupts = <GIC_SPI 68 IRQ_TYPE_EDGE_RISING>;
> +				#address-cells = <1>;
> +				#size-cells = <0>;
> +				clocks = <&clkc_periphs CLKID_I2C_M_B>;
> +				status = "disabled";
> +			};
> +
> +			i2c2: i2c@6800 {
> +				compatible = "amlogic,meson-axg-i2c";
> +				reg = <0x0 0x6800 0x0 0x20>;
> +				interrupts = <GIC_SPI 76 IRQ_TYPE_EDGE_RISING>;
> +				#address-cells = <1>;
> +				#size-cells = <0>;
> +				clocks = <&clkc_periphs CLKID_I2C_M_C>;
> +				status = "disabled";
> +			};
> +
> +			i2c3: i2c@6c00 {
> +				compatible = "amlogic,meson-axg-i2c";
> +				reg = <0x0 0x6c00 0x0 0x20>;
> +				interrupts = <GIC_SPI 78 IRQ_TYPE_EDGE_RISING>;
> +				#address-cells = <1>;
> +				#size-cells = <0>;
> +				clocks = <&clkc_periphs CLKID_I2C_M_D>;
> +				status = "disabled";
> +			};
>  		};
>  
>  		gic: interrupt-controller@ff901000 {
> @@ -171,3 +211,105 @@
>  		#clock-cells = <0>;
>  	};
>  };
> +
> +&periphs_pinctrl {

Why is this not directly under the periphs_pinctrl node ?

> +	i2c0_f9_pins:i2c0-f9 {
                     ^
                     Missing space here. Same for the other nodes

> +		mux {
> +			groups = "i2c0_sck_f9",
> +				"i2c0_sda_f10";
> +			function = "i2c0";
> +			bias-pull-up;

Most device we have seen so far have the pull-up on the PCB.

If you look at the other dts file, the i2c pad bias is disabled. If the
pull-up resistor is missing on the PCB, this setting can overloaded in
the board dt.

Bottom line please put "bias-disable" or justify why a1 is different
from the SoC.

> +			drive-strength-microamp = <3000>;
> +		};
> +	};
> +
> +	i2c0_f11_pins:i2c0-f11 {
> +		mux {
> +			groups = "i2c0_sck_f11",
> +				"i2c0_sda_f12";
> +			function = "i2c0";
> +			bias-pull-up;
> +			drive-strength-microamp = <3000>;
> +		};
> +	};
> +
> +	i2c1_a_pins:i2c1-a {
> +		mux {
> +			groups = "i2c1_sck_a",
> +				"i2c1_sda_a";
> +			function = "i2c1";
> +			bias-pull-up;
> +			drive-strength-microamp = <3000>;
> +		};
> +	};
> +
> +	i2c1_x_pins:i2c1-x {
> +		mux {
> +			groups = "i2c1_sck_x",
> +				"i2c1_sda_x";
> +			function = "i2c1";
> +			bias-pull-up;
> +			drive-strength-microamp = <3000>;
> +		};
> +	};
> +
> +	i2c2_a4_pins:i2c2-a4 {
> +		mux {
> +			groups = "i2c2_sck_a4",
> +				"i2c2_sda_a5";
> +			function = "i2c2";
> +			bias-pull-up;
> +			drive-strength-microamp = <3000>;
> +		};
> +	};
> +
> +	i2c2_a8_pins:i2c2-a8 {
> +		mux {
> +			groups = "i2c2_sck_a8",
> +				"i2c2_sda_a9";
> +			function = "i2c2";
> +			bias-pull-up;
> +			drive-strength-microamp = <3000>;
> +		};
> +	};
> +
> +	i2c2_x0_pins:i2c2-x0 {
> +		mux {
> +			groups = "i2c2_sck_x0",
> +				"i2c2_sda_x1";
> +			function = "i2c2";
> +			bias-pull-up;
> +			drive-strength-microamp = <3000>;
> +		};
> +	};
> +
> +	i2c2_x15_pins:i2c2-x15 {
> +		mux {
> +			groups = "i2c2_sck_x15",
> +				"i2c2_sda_x16";
> +			function = "i2c2";
> +			bias-pull-up;
> +			drive-strength-microamp = <3000>;
> +		};
> +	};
> +
> +	i2c3_f_pins:i2c3-f {
> +		mux {
> +			groups = "i2c3_sck_f",
> +				"i2c3_sda_f";
> +			function = "i2c3";
> +			bias-pull-up;
> +			drive-strength-microamp = <3000>;
> +		};
> +	};
> +
> +	i2c3_x_pins:i2c3-x {
> +		mux {
> +			groups = "i2c3_sck_x",
> +				"i2c3_sda_x";
> +			function = "i2c3";
> +			bias-pull-up;
> +			drive-strength-microamp = <3000>;
> +		};
> +	};
> +};