[v1,21/50] ARM: dts: exynos: add OPP into FSYS APB bus in Exynos5420

Commit Message

Lukasz Luba July 15, 2019, 12:43 p.m. UTC

Add an OPP for FSYS APB which reflects the real possible frequency.
The bus will have a new parent clock which speed has 600MHz, thus
a new possible frequency provided by the clock divider is 150MHz.
According to the documentation max possible frequency for this bus is
200MHz.

Signed-off-by: Lukasz Luba <[e-mail]>
---
 arch/arm/boot/dts/exynos5420.dtsi | 3 +++
 1 file changed, 3 insertions(+)

Comments

Krzysztof Kozlowski July 17, 2019, 8:48 a.m. UTC | #1

On Mon, 15 Jul 2019 at 14:44, Lukasz Luba <[e-mail]> wrote:
>
> Add an OPP for FSYS APB which reflects the real possible frequency.
> The bus will have a new parent clock which speed has 600MHz, thus
> a new possible frequency provided by the clock divider is 150MHz.
> According to the documentation max possible frequency for this bus is
> 200MHz.

Commit msg is good but title could be improved. Focus in the title
what problem/issue you are solving - add intermediate step in scaling
of FSYS APB?

Best regards,
Krzysztof

Lukasz Luba July 22, 2019, 10:47 a.m. UTC | #2

Hi Krzysztof,

On 7/17/19 10:48 AM, Krzysztof Kozlowski wrote:
> On Mon, 15 Jul 2019 at 14:44, Lukasz Luba <[e-mail]> wrote:
>>
>> Add an OPP for FSYS APB which reflects the real possible frequency.
>> The bus will have a new parent clock which speed has 600MHz, thus
>> a new possible frequency provided by the clock divider is 150MHz.
>> According to the documentation max possible frequency for this bus is
>> 200MHz.
> 
> Commit msg is good but title could be improved. Focus in the title
> what problem/issue you are solving - add intermediate step in scaling
> of FSYS APB?
The devfreq governor for this bus device follows the set OPP of the
master device - WCORE bus and sets the OPP with corresponding ID.
Thus, jumping to max frequency 200MHz when the WCORE bus and other
devices are operating in the middle of their min-max speed is not
needed for FSYS APB and this patch adds the intermediate speed step.

Regards,
Lukasz

> 
> Best regards,
> Krzysztof
> 
>

Patch

diff --git a/arch/arm/boot/dts/exynos5420.dtsi b/arch/arm/boot/dts/exynos5420.dtsi
index c7fc4b829b2a..2b36c2f77a10 100644
--- a/arch/arm/boot/dts/exynos5420.dtsi
+++ b/arch/arm/boot/dts/exynos5420.dtsi
@@ -1153,6 +1153,9 @@ 
 				opp-hz = /bits/ 64 <100000000>;
 			};
 			opp01 {
+				opp-hz = /bits/ 64 <150000000>;
+			};
+			opp02 {
 				opp-hz = /bits/ 64 <200000000>;
 			};
 		};