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

From: Kevin Hilman
Date: Tue Dec 10 2019 - 13:15:49 EST


Jian Hu <jian.hu@xxxxxxxxxxx> writes:

> Hi Kevin
>
> Thanks for your review
>
> On 2019/12/10 6:54, Kevin Hilman wrote:
>> Hi Jian,
>>
>> Jian Hu <jian.hu@xxxxxxxxxxx> writes:
>>
>>> There are four I2C controllers in A1 series,
>>> Share the same comptible with AXG.The I2C nodes
>>> depend on pinmux and clock controller.
>>>
>>> Signed-off-by: Jian Hu <jian.hu@xxxxxxxxxxx>
>>> ---
>>> arch/arm64/boot/dts/amlogic/meson-a1.dtsi | 149 ++++++++++++++++++++++
>>> 1 file changed, 149 insertions(+)
>>>
>>> diff --git a/arch/arm64/boot/dts/amlogic/meson-a1.dtsi b/arch/arm64/boot/dts/amlogic/meson-a1.dtsi
>>> index eab2ecd36aa8..d0a73d953f5e 100644
>>> --- a/arch/arm64/boot/dts/amlogic/meson-a1.dtsi
>>> +++ b/arch/arm64/boot/dts/amlogic/meson-a1.dtsi
>>> @@ -16,6 +16,13 @@
>>> #address-cells = <2>;
>>> #size-cells = <2>;
>>>
>>> + aliases {
>>> + i2c0 = &i2c0;
>>> + i2c1 = &i2c1;
>>> + i2c2 = &i2c2;
>>> + i2c3 = &i2c3;
>>> + };
>>> +
>>> cpus {
>>> #address-cells = <2>;
>>> #size-cells = <0>;
>>> @@ -117,6 +124,46 @@
>>> };
>>> };
>>>
>>> + i2c0: i2c@1400 {
>>> + compatible = "amlogic,meson-axg-i2c";
>>> + reg = <0x0 0x1400 0x0 0x24>;
>>
>> The AXG DT files use 0x20 for the length. You are using 0x24. I don't
>> see any additional registers added to the driver, so this doesn't look right.
> In fact, For G12 series and A1, the length should be 0x24. A new
> register is added, And it is for IRQ handler timeout. If the
> transmission is exceeding a limited time, it will abort the
> transmission.Now the function is not used, There is completion to deal
> the timeout in the driver. I will set the length 0x20 becouse of the new
> register is not used.

Yes, we can extend it to 0x24 when support for the new register is
added, because that will mean adding a new compatible string also.

>>
>>> + interrupts = <GIC_SPI 32 IRQ_TYPE_EDGE_RISING>;
>>> + #address-cells = <1>;
>>> + #size-cells = <0>;
>>> + clocks = <&clkc_periphs CLKID_I2C_M_A>;
>>> + status = "disabled";
>>> + };
>>> +
>>> + i2c1: i2c@5c00 {
>>> + compatible = "amlogic,meson-axg-i2c";
>>> + reg = <0x0 0x5c00 0x0 0x24>;
>>> + 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 0x24>;
>>> + 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 0x24>;
>>> + interrupts = <GIC_SPI 78 IRQ_TYPE_EDGE_RISING>;
>>> + #address-cells = <1>;
>>> + #size-cells = <0>;
>>> + clocks = <&clkc_periphs CLKID_I2C_M_D>;
>>> + status = "disabled";
>>> + };
>>> +
>>> uart_AO: serial@1c00 {
>>> compatible = "amlogic,meson-gx-uart",
>>> "amlogic,meson-ao-uart";
>>> @@ -171,3 +218,105 @@
>>> #clock-cells = <0>;
>>> };
>>> };
>>> +
>>> +&periphs_pinctrl {
>>> + i2c0_f11_pins:i2c0-f11 {
>>> + mux {
>>> + groups = "i2c0_sck_f11",
>>> + "i2c0_sda_f12";
>>> + function = "i2c0";
>>> + bias-pull-up;
>>> + drive-strength-microamp = <3000>;
>>
>> Can you also add some comment to the changelog about the need for
>> drive-strength compared to AXG.
>
> OK, Drive strength function is added for GPIO pins from G12 series.
> So does A1 series.

Yes, that's what I assumed. Please add that to the changelog as one of
the new features in A1 compared to AXG.

Thanks,

Kevin