diff mbox series

[v2,2/4] arm64: dts: qcom: sm6350: Add camera clock controller

Message ID 20221213-sm6350-cci-v2-2-15c2c14c34bb@fairphone.com (mailing list archive)
State Accepted
Commit 4ab96c9c4012770f50f90bda2e61ef774bb63be5
Headers show
Series Add CCI bus support for SM6350 | expand

Commit Message

Luca Weiss Jan. 20, 2023, 1:13 p.m. UTC
Add a node for the camcc found on SM6350 SoC.

Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Luca Weiss <luca.weiss@fairphone.com>
---
 arch/arm64/boot/dts/qcom/sm6350.dtsi | 9 +++++++++
 1 file changed, 9 insertions(+)

Comments

Bryan O'Donoghue Jan. 20, 2023, 4:49 p.m. UTC | #1
On 20/01/2023 13:13, Luca Weiss wrote:
> +		camcc: clock-controller@ad00000 {
> +			compatible = "qcom,sm6350-camcc";
> +			reg = <0 0x0ad00000 0 0x16000>;
> +			clocks = <&rpmhcc RPMH_CXO_CLK>;
> +			#clock-cells = <1>;
> +			#reset-cells = <1>;
> +			#power-domain-cells = <1>;
> +		};

Should you include

required-opps = <&rpmhpd_opp_low_svs>;

?

---
bod
Luca Weiss Jan. 24, 2023, 2:48 p.m. UTC | #2
On Fri Jan 20, 2023 at 5:49 PM CET, Bryan O'Donoghue wrote:
> On 20/01/2023 13:13, Luca Weiss wrote:
> > +		camcc: clock-controller@ad00000 {
> > +			compatible = "qcom,sm6350-camcc";
> > +			reg = <0 0x0ad00000 0 0x16000>;
> > +			clocks = <&rpmhcc RPMH_CXO_CLK>;
> > +			#clock-cells = <1>;
> > +			#reset-cells = <1>;
> > +			#power-domain-cells = <1>;
> > +		};
>
> Should you include
>
> required-opps = <&rpmhpd_opp_low_svs>;
>
> ?

I don't know, it works without. But doesn't this property not just
affect power-domains? I haven't passed any here.

>
> ---
> bod
Bryan O'Donoghue Jan. 24, 2023, 3:25 p.m. UTC | #3
On 24/01/2023 14:48, Luca Weiss wrote:
> On Fri Jan 20, 2023 at 5:49 PM CET, Bryan O'Donoghue wrote:
>> On 20/01/2023 13:13, Luca Weiss wrote:
>>> +		camcc: clock-controller@ad00000 {
>>> +			compatible = "qcom,sm6350-camcc";
>>> +			reg = <0 0x0ad00000 0 0x16000>;
>>> +			clocks = <&rpmhcc RPMH_CXO_CLK>;
>>> +			#clock-cells = <1>;
>>> +			#reset-cells = <1>;
>>> +			#power-domain-cells = <1>;
>>> +		};
>>
>> Should you include
>>
>> required-opps = <&rpmhpd_opp_low_svs>;
>>
>> ?
> 
> I don't know, it works without. But doesn't this property not just
> affect power-domains? I haven't passed any here.
> 

Should you have a TITAN_TOP pd though ?

---
bod
Luca Weiss Jan. 27, 2023, 12:45 p.m. UTC | #4
On Tue Jan 24, 2023 at 4:25 PM CET, Bryan O'Donoghue wrote:
> On 24/01/2023 14:48, Luca Weiss wrote:
> > On Fri Jan 20, 2023 at 5:49 PM CET, Bryan O'Donoghue wrote:
> >> On 20/01/2023 13:13, Luca Weiss wrote:
> >>> +		camcc: clock-controller@ad00000 {
> >>> +			compatible = "qcom,sm6350-camcc";
> >>> +			reg = <0 0x0ad00000 0 0x16000>;
> >>> +			clocks = <&rpmhcc RPMH_CXO_CLK>;
> >>> +			#clock-cells = <1>;
> >>> +			#reset-cells = <1>;
> >>> +			#power-domain-cells = <1>;
> >>> +		};
> >>
> >> Should you include
> >>
> >> required-opps = <&rpmhpd_opp_low_svs>;
> >>
> >> ?
> > 
> > I don't know, it works without. But doesn't this property not just
> > affect power-domains? I haven't passed any here.
> > 
>
> Should you have a TITAN_TOP pd though ?

Can I reference <&camcc TITAN_TOP_GDSC> from itself? I know that having
it on is required to turn on at least some clocks (maybe all clocks).
But from what I understand how power domains are normally handled, the
driver core enables them before the driver is probed, so self
referencing wouldn't work.

And at least no other SoC upstream references TITAN_TOP_GDSC in camcc.

Regards
Luca

>
> ---
> bod
Bryan O'Donoghue Jan. 27, 2023, 12:49 p.m. UTC | #5
On 27/01/2023 12:45, Luca Weiss wrote:
> Can I reference <&camcc TITAN_TOP_GDSC> from itself? I know that having
> it on is required to turn on at least some clocks (maybe all clocks).
> But from what I understand how power domains are normally handled, the
> driver core enables them before the driver is probed, so self
> referencing wouldn't work.
> 
> And at least no other SoC upstream references TITAN_TOP_GDSC in camcc.
> 
> Regards
> Luca

Doh I meant to say a power-domain to an mmcx a la

power-domains = <&rpmhpd SM8250_MMCX>;
required-opps = <&rpmhpd_opp_low_svs>;

TITAN_TOP should be in your cci and camss dt nodes.

---
bod
Luca Weiss Jan. 27, 2023, 1:11 p.m. UTC | #6
On Fri Jan 27, 2023 at 1:49 PM CET, Bryan O'Donoghue wrote:
> On 27/01/2023 12:45, Luca Weiss wrote:
> > Can I reference <&camcc TITAN_TOP_GDSC> from itself? I know that having
> > it on is required to turn on at least some clocks (maybe all clocks).
> > But from what I understand how power domains are normally handled, the
> > driver core enables them before the driver is probed, so self
> > referencing wouldn't work.
> > 
> > And at least no other SoC upstream references TITAN_TOP_GDSC in camcc.
> > 
> > Regards
> > Luca
>
> Doh I meant to say a power-domain to an mmcx a la
>
> power-domains = <&rpmhpd SM8250_MMCX>;
> required-opps = <&rpmhpd_opp_low_svs>;
>
> TITAN_TOP should be in your cci and camss dt nodes.

Okay, that makes more sense.

What I don't quite understand is why sm8250 only has MMCX listed there
since downstream has both vdd_mx-supply = <&VDD_MX_LEVEL> and
vdd_mm-supply = <&VDD_MMCX_LEVEL> and both "supplies" are used for
different clocks using .vdd_class

But back to sm6350, downstream has vdd_mx-supply = <&VDD_MX_LEVEL> and
vdd_cx-supply = <&VDD_CX_LEVEL> and like sm8250 uses cx and mx for
different clocks.
Not sure if I should add both, and I guess mainline also currently
doesn't use higher ops for the power domain when higher clock rate is
needed, from what I understand?

>
> ---
> bod
Konrad Dybcio Jan. 27, 2023, 1:14 p.m. UTC | #7
On 27.01.2023 14:11, Luca Weiss wrote:
> On Fri Jan 27, 2023 at 1:49 PM CET, Bryan O'Donoghue wrote:
>> On 27/01/2023 12:45, Luca Weiss wrote:
>>> Can I reference <&camcc TITAN_TOP_GDSC> from itself? I know that having
>>> it on is required to turn on at least some clocks (maybe all clocks).
>>> But from what I understand how power domains are normally handled, the
>>> driver core enables them before the driver is probed, so self
>>> referencing wouldn't work.
>>>
>>> And at least no other SoC upstream references TITAN_TOP_GDSC in camcc.
>>>
>>> Regards
>>> Luca
>>
>> Doh I meant to say a power-domain to an mmcx a la
>>
>> power-domains = <&rpmhpd SM8250_MMCX>;
>> required-opps = <&rpmhpd_opp_low_svs>;
>>
>> TITAN_TOP should be in your cci and camss dt nodes.
> 
> Okay, that makes more sense.
> 
> What I don't quite understand is why sm8250 only has MMCX listed there
> since downstream has both vdd_mx-supply = <&VDD_MX_LEVEL> and
> vdd_mm-supply = <&VDD_MMCX_LEVEL> and both "supplies" are used for
> different clocks using .vdd_class
> 
> But back to sm6350, downstream has vdd_mx-supply = <&VDD_MX_LEVEL> and
> vdd_cx-supply = <&VDD_CX_LEVEL> and like sm8250 uses cx and mx for
> different clocks.
> Not sure if I should add both, and I guess mainline also currently
> doesn't use higher ops for the power domain when higher clock rate is
> needed, from what I understand?
Basically if you don't need to power any of these power rails to
have access to the clock controller, you don't need any of them.

What you will need to do however, is make sure that they are scaled with
child devices then.. but that's no bueno since they all need TITAN_GDSC.
That's why Bryan suggests leaving a vote on a power rail in the clock
controller, so that if no other votes are present (as improbable as
that may be), you will still be able to get the clocks going.

That OTOH will require you to add power management support (PM ops)
to the clock controller, as otherwise you can say goodbye to battery
life..

Konrad
> 
>>
>> ---
>> bod
>
Bryan O'Donoghue Jan. 27, 2023, 1:54 p.m. UTC | #8
On 27/01/2023 13:11, Luca Weiss wrote:
>> Doh I meant to say a power-domain to an mmcx a la
>>
>> power-domains = <&rpmhpd SM8250_MMCX>;
>> required-opps = <&rpmhpd_opp_low_svs>;
>>
>> TITAN_TOP should be in your cci and camss dt nodes.
> Okay, that makes more sense.
> 
> What I don't quite understand is why sm8250 only has MMCX listed there
> since downstream has both vdd_mx-supply = <&VDD_MX_LEVEL> and
> vdd_mm-supply = <&VDD_MMCX_LEVEL> and both "supplies" are used for
> different clocks using .vdd_class

power-domains = <&rpmhpd SM8250_MMCX>; == MMCX_LEVEL required for camcc
power-domains = <&camcc TITAN_TOP_GDSC>; required for cci/camss

now that you ask the question about MX_LEVEL you're making me doubt we 
have a 100% complete representation upstream TB perfectly honest, 
warrants a deep dive..

I just remember that on 8250 we tripped over MMCX not being switched on 
when - display I think was switched off.

---
bod
Konrad Dybcio Jan. 27, 2023, 1:56 p.m. UTC | #9
On 27.01.2023 14:54, Bryan O'Donoghue wrote:
> On 27/01/2023 13:11, Luca Weiss wrote:
>>> Doh I meant to say a power-domain to an mmcx a la
>>>
>>> power-domains = <&rpmhpd SM8250_MMCX>;
>>> required-opps = <&rpmhpd_opp_low_svs>;
>>>
>>> TITAN_TOP should be in your cci and camss dt nodes.
>> Okay, that makes more sense.
>>
>> What I don't quite understand is why sm8250 only has MMCX listed there
>> since downstream has both vdd_mx-supply = <&VDD_MX_LEVEL> and
>> vdd_mm-supply = <&VDD_MMCX_LEVEL> and both "supplies" are used for
>> different clocks using .vdd_class
> 
> power-domains = <&rpmhpd SM8250_MMCX>; == MMCX_LEVEL required for camcc
> power-domains = <&camcc TITAN_TOP_GDSC>; required for cci/camss
> 
> now that you ask the question about MX_LEVEL you're making me doubt we have a 100% complete representation upstream TB perfectly honest, warrants a deep dive..
> 
> I just remember that on 8250 we tripped over MMCX not being switched on when - display I think was switched off.
There's no MMCX on 6350 and MX is a parent of CX, so if we just stick
CX here and add the lowest level to required-opps and add corresponding
PM ops to the clk driver, it'll all be taken care of!

Konrad

> 
> ---
> bod
>
diff mbox series

Patch

diff --git a/arch/arm64/boot/dts/qcom/sm6350.dtsi b/arch/arm64/boot/dts/qcom/sm6350.dtsi
index 8224adb99948..300ced5cda57 100644
--- a/arch/arm64/boot/dts/qcom/sm6350.dtsi
+++ b/arch/arm64/boot/dts/qcom/sm6350.dtsi
@@ -1435,6 +1435,15 @@  usb_1_dwc3: usb@a600000 {
 			};
 		};
 
+		camcc: clock-controller@ad00000 {
+			compatible = "qcom,sm6350-camcc";
+			reg = <0 0x0ad00000 0 0x16000>;
+			clocks = <&rpmhcc RPMH_CXO_CLK>;
+			#clock-cells = <1>;
+			#reset-cells = <1>;
+			#power-domain-cells = <1>;
+		};
+
 		pdc: interrupt-controller@b220000 {
 			compatible = "qcom,sm6350-pdc", "qcom,pdc";
 			reg = <0 0x0b220000 0 0x30000>, <0 0x17c000f0 0 0x64>;