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From:   Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Date:   Sat, 16 Mar 2019 23:14:51 +0100
Message-ID: <CAFBinCBHiLjrwXA4jXSg3qnGa925r--Nj_RH7xUFqyTkYzhKGA@mail.gmail.com>
Subject: Re: [PATCH 6/9] arm64: dts: meson: g12a: Add UART A, B & C nodes and pins
To:     Neil Armstrong <narmstrong@baylibre.com>,
        Jianxin Pan <jianxin.pan@amlogic.com>
Cc:     khilman@baylibre.com, linux-amlogic@lists.infradead.org,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org
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Hi Neil,

On Sat, Mar 16, 2019 at 3:35 PM Neil Armstrong <narmstrong@baylibre.com> wrote:
[...]
> >> +                                       uart_ao_a_c_pins: uart_ao_a_c {
> >> +                                               mux {
> >> +                                                       groups = "uart_ao_a_rx_c",
> >> +                                                                "uart_ao_a_tx_c";
> >> +                                                       function = "uart_ao_a_c";
> >> +                                                       bias-disable;
> >> +                                               };
> >> +                                       };
> > I'm fine with this part if you mention it in the subject and/or the description
> > uart_ao_a_c routes two pins from bank C (from the EE domain) to the
> > uart_AO controller (from the AO domain)
>
> Not sure DT is the right place for that, I think I'll remove this until
> we have it actually used somewhere.
I'm fine with that as well

[...]
> >> +
> >> +                       uart_C: serial@22000 {
> >> +                               compatible = "amlogic,meson-gx-uart";
> >> +                               reg = <0x0 0x22000 0x0 0x18>;
> >> +                               interrupts = <GIC_SPI 93 IRQ_TYPE_EDGE_RISING>;
> >> +                               clocks = <&xtal>, <&clkc CLKID_UART1>, <&xtal>;
> > does uart_C really use CLKID_UART1? on GX uart_C uses CLKID_UART2
>
> It seems so :
> https://github.com/hardkernel/linux/blob/odroidn2-4.9.y/arch/arm64/boot/dts/amlogic/mesong12a.dtsi#L1020
it's weird but we can always fix it up later if needed. so let's keep
it for now to stay consistent with the vendor kernel until we know
better

Jianxin, can you please check with the hardware team whether the
uart_C gate clock (pclk) is CLKID_UART1 or CLKID_UART2 on G12A?


Regards
Martin