Hi Jisheng,
On 2023-11-13 9:14 AM, Jisheng Zhang wrote:
> On Mon, Nov 13, 2023 at 02:32:24PM +0000, Yixun Lan wrote:
>> On 08:55 Mon 13 Nov , Jisheng Zhang wrote:
>>> Add the reset device tree node to cv1800b SoC.
>>>
>>> Signed-off-by: Jisheng Zhang <jszhang@xxxxxxxxxx>
>>> ---
>>> arch/riscv/boot/dts/sophgo/cv1800b.dtsi | 6 ++++++
>>> 1 file changed, 6 insertions(+)
>>>
>>> diff --git a/arch/riscv/boot/dts/sophgo/cv1800b.dtsi b/arch/riscv/boot/dts/sophgo/cv1800b.dtsi
>>> index df40e87ee063..4032419486be 100644
>>> --- a/arch/riscv/boot/dts/sophgo/cv1800b.dtsi
>>> +++ b/arch/riscv/boot/dts/sophgo/cv1800b.dtsi
>>> @@ -54,6 +54,12 @@ soc {
>>> dma-noncoherent;
>>> ranges;
>>>
>>> + rst: reset-controller@3003000 {
>>> + compatible = "sophgo,cv1800b-reset";
>>> + reg = <0x03003000 0x1000>;
>> ~~~~~~~
>> it should be 0x28
>
> The reg space is 4KB, but only 0x28 are used. I think 0x1000 or 0x28 are fine
> since the ioremap granule is 4kB.
>>
>> while please also note the 0x24 == SOFT_CPUAC_RSTN, does not compatible
>> with the reset-simple driver, but as it's not implemented nor used in this driver,
>
> But the functionality of this "autoclear" reg isn't used at all since we also
> have "sticky" reset to acchieve the same feature, I.E reset cpusys. And in the
> usage case of reseting cpusys, I believe "sticky" reset is preferred.
>
> And except the cpusys reset which has both autoclear and sticky, other
> resets are sticky only. I'm not sure whether it's worth to write a new
> driver for almost useless feature.
As long as the device has its own binding/compatible string, it is always
possible to replace RESET_SIMPLE with a custom driver later if needed. (Or use a
more complicated driver in some other context, e.g. firmware).
Regards,
Samuel
>> so we should be fine with this?
>>
>>> + #reset-cells = <1>;
>>> + };
>>> +
>>> uart0: serial@4140000 {
>>> compatible = "snps,dw-apb-uart";
>>> reg = <0x04140000 0x100>;
>>> --
>>> 2.42.0
>>>
>>
>> --
>> Yixun Lan (dlan)
>> Gentoo Linux Developer
>> GPG Key ID AABEFD55
>
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