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Subject: Re: [PATCH v3] arm64: dts: meson-a1: add I2C nodes
To:     Jerome Brunet <jbrunet@baylibre.com>,
        Neil Armstrong <narmstrong@baylibre.com>
CC:     Kevin Hilman <khilman@baylibre.com>, Rob Herring <robh@kernel.org>,
        Martin Blumenstingl <martin.blumenstingl@googlemail.com>,
        Michael Turquette <mturquette@baylibre.com>,
        Wolfram Sang <wsa@the-dreams.de>,
        Mark Rutland <mark.rutland@arm.com>,
        Jianxin Pan <jianxin.pan@amlogic.com>,
        <linux-amlogic@lists.infradead.org>, <linux-i2c@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>, <devicetree@vger.kernel.org>
References: <20191220091611.36319-1-jian.hu@amlogic.com>
 <1ja76zsi4r.fsf@starbuckisacylon.baylibre.com>
From:   Jian Hu <jian.hu@amlogic.com>
Message-ID: <484f2273-80d2-87fe-2637-33f5313c580d@amlogic.com>
Date:   Thu, 9 Jan 2020 10:43:13 +0800
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Hi Jerome

Thanks for your review

On 2020/1/7 17:58, Jerome Brunet wrote:
> 
> On Fri 20 Dec 2019 at 10:16, Jian Hu <jian.hu@amlogic.com> 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@amlogic.com>
>>
>> ---
>> 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@amlogic.com
>> [1] https://lkml.kernel.org/r/20191202111253.94872-1-jian.hu@amlogic.com
>> [2] https://lkml.kernel.org/r/20191211032802.83309-1-jian.hu@amlogic.com
>> [3] https://lkml.kernel.org/r/20191206074052.15557-1-jian.hu@amlogic.com
>> ---
>> ---
>>   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 ?
> 
OK, I will put them under 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.
Yes, there is pull-up resistor on PCB, I will replace it as
'bias-disable'
> 
>> +			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>;
>> +		};
>> +	};
>> +};
> 
> .
>