[v4,5/5] arm64: dts: Add dts files for Hisilicon Hi6220 SoC

Commit Message

Brent Wang May 6, 2015, 4:03 p.m. UTC

Hi Mark,

2015-05-06 23:44 GMT+08:00, Mark Rutland <[e-mail]>:
> Hi,
>
>> How about add the following binding rule to my 2/5 patch:
>> ---------------------------
>> *Hisilicon Enhanced ARM AMBA Primecell PL011 serial UART
>>
>> Required properties:
>> - compatible: must be "hisilicon,hi6220-uart", "arm,primecell",
>> "arm,pl011"
>
> "arm,primecell" should come last.
>
>> - reg: exactly one register range with length 0x1000
>> - interrupts: exactly one interrupt specifier
>>
>> See also bindings/serial/pl011.txt
>>
>> Example:
>>
>> uart0: uart@f8015000 {
>>         compatible = "hisilicon,hi6220-uart", "arm,pl011",
>> "arm,primecell";
>>         reg = <0x0 0xf8015000 0x0 0x1000>;
>>         interrupts = <GIC_SPI 36 IRQ_TYPE_LEVEL_HIGH>;
>>         clocks = <&ao_ctrl HI6220_UART0_PCLK>, <&ao_ctrl
>> HI6220_UART0_PCLK>;
>>         clock-names = "uartclk", "apb_pclk";
>> };
>
> How about for the moment we just modify the existing pl011 binding
> document to allow for the hi6220-specific string in addition to its
> existing strings? We can always split it out later if the hi6220 UART
> binding needs to be significantly divergent.
How about adding the following rule to pl011.txt?
----------
>> > Is UART 0 different from UART1 and UART2?
>> Yes,  but my patch just includes UART0, we do some changements for
>> UART1/2
>> to improve performance.
>
> Sure, but we need to make sure we can choose a sane compatible string
> for them, that won't clash with whatever we choose for UART0.
OK, do I also need to add compatible ""hisilicon,hi6220-uart"," to UART0 node?

>
> Are they the same IP as UART0, or fundamentally different?
The same IP.
>
> Are they also PL011 derived?
Yes, just do some enhancements to improve performance.

Thanks,

Bintian

>
> Thanks,
> Mark.
>

Patch

diff --git a/Documentation/devicetree/bindings/serial/pl011.txt
b/Documentation/devicetree/bindings/serial/pl011.txt
index ba3ecb8..1221ccb 100644
--- a/Documentation/devicetree/bindings/serial/pl011.txt
+++ b/Documentation/devicetree/bindings/serial/pl011.txt
@@ -35,6 +35,10 @@  Optional properties:
 - poll-timeout-ms:
           Poll timeout when auto-poll is set, default
           3000ms.
+- compatible: "hisilicon,hi6220-uart":
+          Hisilicon does some enhancements (e.g. larger FIFO length)
+           based on PL011, so when using these UART hosts, this compatible
+           string should be added.

 See also bindings/arm/primecell.txt
------------
>