Update, encapsulate and expand the RK356x SoC dtsi files

This series tackles the Rockchip RK356x SoC dtsi files in a few different ways. First, it updates the lower and upper voltage limits and the exact voltages for the Rockchip RK356x CPU OPPs, using the most conservative per-OPP values for different SoC bins. This is rather similar to the already performed adjustment of the GPU OPP voltages. [1]

Next, this series prepares the RK356x SoC dtsi files for per-variant OPPs, with the RK3566T being the first new RK356x SoC variant to be introduced. This follows the approach used for the RK3588 SoC variants. [2]

Lastly, this series introduces new SoC dtsi for the RK3566T variant, which is capable of operating at the CPU and GPU OPPs/frequencies lower than the "full-fat" RK3566 variant's. The RK3566T is found on some of the already supported boards and rather importantly, this stops the CPU cores and the GPU from being overclocked on these boards.

Changes in v2:
- Improved the wording of the patch 3/3 description, to make it more clear which of the mentioned RK3566T-based SBCs are already supported
- Renumbered the references in patch 3/3, so their numbering follows the order in which the references appear in the patch description
- Adjusted the patch generation options passed to git-format-patch(1), to make the patch 2/3 a bit more readable, [3] and added a note about the git-log(1) options to the description of patch 2/3
- No changes to the actual patches are introduced

Link to v1: https://lore.kernel.org/linux-rockchip/[email protected]/T/#u

[1] https://lore.kernel.org/linux-rockchip/[email protected]/T/#m786f0e0a45377d29aea826f05c95b5052a8bb3d9
[2] https://lore.kernel.org/all/9ffedc0e2ca7f167d9d795b2a8f43cb9f56a653b.1717923308.git.dsimic@manjaro.org/T/#u
[3] https://lore.kernel.org/linux-rockchip/[email protected]/

Dragan Simic (3):
arm64: dts: rockchip: Update CPU OPP voltages in RK356x SoC dtsi
arm64: dts: rockchip: Prepare RK356x SoC dtsi files for per-variant
OPPs
arm64: dts: rockchip: Add new SoC dtsi for the RK3566T variant

 .../{rk3566.dtsi => rk3566-base.dtsi}         |   2 +-
 .../dts/rockchip/rk3566-radxa-zero-3.dtsi     |   2 +-
 .../boot/dts/rockchip/rk3566-rock-3c.dts      |   2 +-
 arch/arm64/boot/dts/rockchip/rk3566.dtsi      | 142 +++++++++++++-----
 arch/arm64/boot/dts/rockchip/rk3566t.dtsi     |  90 +++++++++++
 arch/arm64/boot/dts/rockchip/rk3568.dtsi      | 113 +++++++++++++-
 .../{rk356x.dtsi => rk356x-base.dtsi}         |  81 ----------
 7 files changed, 307 insertions(+), 125 deletions(-)
 copy arch/arm64/boot/dts/rockchip/{rk3566.dtsi => rk3566-base.dtsi} (95%)
 rewrite arch/arm64/boot/dts/rockchip/rk3566.dtsi (87%)
 create mode 100644 arch/arm64/boot/dts/rockchip/rk3566t.dtsi
 rename arch/arm64/boot/dts/rockchip/{rk356x.dtsi => rk356x-base.dtsi} (96%)

Update the lower/upper voltage limits and the exact voltages for the Rockchip RK356x CPU OPPs, using the most conservative values (i.e. the highest per-OPP voltages) found in the vendor kernel source. [1]

Using the most conservative per-OPP voltages ensures reliable CPU operation regardless of the actual CPU binning, with the downside of possibly using a bit more power for the CPU cores than absolutely needed.

Additionally, fill in the missing "clock-latency-ns" CPU OPP properties, using the values found in the vendor kernel source. [1]

[1] https://raw.githubusercontent.com/rockchip-linux/kernel/f8b9431ee38ed561650be7092ab93f564598daa9/arch/arm64/boot/dts/rockchip/rk3568.dtsi

Related-to: eb665b1c06bc ("arm64: dts: rockchip: Update GPU OPP voltages in RK356x SoC dtsi")

---
 arch/arm64/boot/dts/rockchip/rk3568.dtsi |  1 +
 arch/arm64/boot/dts/rockchip/rk356x.dtsi | 18 ++++++++++++------
 2 files changed, 13 insertions(+), 6 deletions(-)

index 0946310e8c12..5c54898f6ed1 100644
@@ -273,6 +273,7 @@ &cpu0_opp_table {
 	opp-1992000000 {
 		opp-hz = /bits/ 64 <1992000000>;
 		opp-microvolt = <1150000 1150000 1150000>;
+		clock-latency-ns = <40000>;
 	};
 };
 

index 0ee0ada6f0ab..534593f2ed0b 100644
@@ -134,39 +134,45 @@ cpu0_opp_table: opp-table-0 {
 
 		opp-408000000 {
 			opp-hz = /bits/ 64 <408000000>;
-			opp-microvolt = <900000 900000 1150000>;
+			opp-microvolt = <850000 850000 1150000>;
 			clock-latency-ns = <40000>;
 		};
 
 		opp-600000000 {
 			opp-hz = /bits/ 64 <600000000>;
-			opp-microvolt = <900000 900000 1150000>;
+			opp-microvolt = <850000 850000 1150000>;
+			clock-latency-ns = <40000>;
 		};
 
 		opp-816000000 {
 			opp-hz = /bits/ 64 <816000000>;
-			opp-microvolt = <900000 900000 1150000>;
+			opp-microvolt = <850000 850000 1150000>;
+			clock-latency-ns = <40000>;
 			opp-suspend;
 		};
 
 		opp-1104000000 {
 			opp-hz = /bits/ 64 <1104000000>;
 			opp-microvolt = <900000 900000 1150000>;
+			clock-latency-ns = <40000>;
 		};
 
 		opp-1416000000 {
 			opp-hz = /bits/ 64 <1416000000>;
-			opp-microvolt = <900000 900000 1150000>;
+			opp-microvolt = <1025000 1025000 1150000>;
+			clock-latency-ns = <40000>;
 		};
 
 		opp-1608000000 {
 			opp-hz = /bits/ 64 <1608000000>;
-			opp-microvolt = <975000 975000 1150000>;
+			opp-microvolt = <1100000 1100000 1150000>;
+			clock-latency-ns = <40000>;
 		};
 
 		opp-1800000000 {
 			opp-hz = /bits/ 64 <1800000000>;
-			opp-microvolt = <1050000 1050000 1150000>;
+			opp-microvolt = <1150000 1150000 1150000>;
+			clock-latency-ns = <40000>;
 		};
 	};
 

Rename the Rockchip RK356x SoC dtsi files and, consequently, adjust their contents appropriately, to prepare them for the ability to specify different CPU and GPU OPPs for each of the supported RK356x SoC variants.

The first new RK356x SoC variant to be introduced is the RK3566T, which the Pine64 Quartz64 Zero SBC is officially based on. [1] Some other SBCs are also based on the RK3566T variant, including Radxa ROCK 3C and ZERO 3E/3W, but the slight trouble is that Radxa doesn't state that officially. Though, it's rather easy to spot the RK3566T on such boards, because their official specifications state that the maximum frequency for the Cortex-A55 cores is lower than the "full-fat" RK3566's 1.8 GHz. [2][3][4]

These changes follow the approach used for the Rockchip RK3588 SoC variants, which was introduced and described further in commit def88eb4d836 ("arm64:
dts: rockchip: Prepare RK3588 SoC dtsi files for per-variant OPPs"). Please see that commit for a more detailed explanation.

No functional changes are introduced, which was validated by decompiling and comparing all affected board dtb files before and after these changes. In more detail, the affected dtb files have some of their blocks shuffled around a bit and some of their phandles have different values, as a result of the changes to the order in which the building blocks from the parent dtsi files are included, but they effectively remain the same as the originals.

As a side note, due to the nature of introduced changes, this commit is a bit more readable when viewed using the --break-rewrites option for git-log(1).

[1] https://wiki.pine64.org/wiki/Quartz64
[2] https://dl.radxa.com/rock3/docs/hw/3c/radxa_rock3c_product_brief.pdf
[3] https://dl.radxa.com/zero3/docs/hw/3e/radxa_zero_3e_product_brief.pdf
[4] https://dl.radxa.com/zero3/docs/hw/3w/radxa_zero_3w_product_brief.pdf

Related-to: def88eb4d836 ("arm64: dts: rockchip: Prepare RK3588 SoC dtsi files for per-variant OPPs")

---
 .../{rk3566.dtsi => rk3566-base.dtsi}         |   2 +-
 arch/arm64/boot/dts/rockchip/rk3566.dtsi      | 142 +++++++++++++-----
 arch/arm64/boot/dts/rockchip/rk3568.dtsi      | 114 +++++++++++++-
 .../{rk356x.dtsi => rk356x-base.dtsi}         |  87 -----------
 4 files changed, 215 insertions(+), 130 deletions(-)
 copy arch/arm64/boot/dts/rockchip/{rk3566.dtsi => rk3566-base.dtsi} (95%)
 rewrite arch/arm64/boot/dts/rockchip/rk3566.dtsi (87%)
 rename arch/arm64/boot/dts/rockchip/{rk356x.dtsi => rk356x-base.dtsi} (96%)

similarity index 95%
copy from arch/arm64/boot/dts/rockchip/rk3566.dtsi
copy to arch/arm64/boot/dts/rockchip/rk3566-base.dtsi
index 6c4b17d27bdc..e56e0b6ba941 100644
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: (GPL-2.0+ OR MIT)
 
-#include "rk356x.dtsi"
+#include "rk356x-base.dtsi"
 
 / {
 	compatible = "rockchip,rk3566";

Add new SoC dtsi file for the RK3566T variant of the Rockchip RK3566 SoC. The difference between the RK3566T variant and the "full-fat" RK3566 variant is in fewer supported CPU and GPU OPPs on the RK3566T, and in the absence of a functional NPU, which we currently don't have to worry about.

Examples of the boards based on the RK3566T include the Pine64 Quartz64 Zero SBC, [1] which is yet to be supported, the Radxa ROCK 3C, and the Radxa ZERO 3E/3W SBCs, which are both already supported. Though, Radxa doesn't mention the use of RK3566T officially, but its official SBC specifications do state that the maximum frequency for the Cortex-A55 cores on those SBCs is lower than the "full-fat" RK3566's 1.8 GHz, which makes spotting the presence of the RK3566T SoC variant rather easy. [2][3][4] An additional, helpful cue is that Radxa handles the CPU and GPU OPPs for the RK3566T variant separately in its downstream kernel source. [5]

The CPU and GPU OPPs supported on the RK3566T SoC variant are taken from the vendor kernel source, [6] which uses the values of the "opp-supported-hw" OPP properties to determine which ones are supported on a particular SoC variant. The actual values of the "opp-supported-hw" properties make it rather easy to see what OPPs are supported on the RK3566T SoC variant, but that, rather unfortunately, clashes with the maximum frequencies advertised officially for the Cortex-A55 CPU cores on the above-mentioned SBCs. [1][2][3][4] The vendor kernel source indicates that the maximum frequency for the CPU cores is 1.4 GHz, while the SBC specifications state that to be 1.6 GHz. Until that discrepancy is resolved somehow, let's take the safe approach and use the lower maximum frequency for the CPU cores.

Update the dts files of the currently supported RK3566T-based boards to use the new SoC dtsi for the RK3566T variant. This actually takes the CPU cores and the GPUs found on these boards out of their earlier overclocks, but it also means that the officially advertised specifications [1][2][3][4] of the highest supported frequencies for the Cortex-A55 CPU cores on these boards may actually be wrong, as already explained above.

The correctness of the introduced changes was validated by decompiling and comparing all affected board dtb files before and after these changes.

[1] https://wiki.pine64.org/wiki/Quartz64
[2] https://dl.radxa.com/rock3/docs/hw/3c/radxa_rock3c_product_brief.pdf
[3] https://dl.radxa.com/zero3/docs/hw/3e/radxa_zero_3e_product_brief.pdf
[4] https://dl.radxa.com/zero3/docs/hw/3w/radxa_zero_3w_product_brief.pdf
[5] https://github.com/radxa/kernel/commit/2dfd51da472e7ebb5ef0d3db78f902454af826b8
[6] https://raw.githubusercontent.com/rockchip-linux/kernel/f8b9431ee38ed561650be7092ab93f564598daa9/arch/arm64/boot/dts/rockchip/rk3568.dtsi

---
 .../dts/rockchip/rk3566-radxa-zero-3.dtsi     |  2 +-
 .../boot/dts/rockchip/rk3566-rock-3c.dts      |  2 +-
 arch/arm64/boot/dts/rockchip/rk3566t.dtsi     | 90 +++++++++++++++++++
 3 files changed, 92 insertions(+), 2 deletions(-)
 create mode 100644 arch/arm64/boot/dts/rockchip/rk3566t.dtsi

index de390d92c35e..1ee5d96a46a1 100644
@@ -3,7 +3,7 @@
 #include <dt-bindings/gpio/gpio.h>
 #include <dt-bindings/leds/common.h>
 #include <dt-bindings/soc/rockchip,vop2.h>
-#include "rk3566.dtsi"
+#include "rk3566t.dtsi"
 
 / {
 	chosen {

index f2cc086e5001..9a8f4f774dbc 100644
@@ -5,7 +5,7 @@
 #include <dt-bindings/leds/common.h>
 #include <dt-bindings/pinctrl/rockchip.h>
 #include <dt-bindings/soc/rockchip,vop2.h>
-#include "rk3566.dtsi"
+#include "rk3566t.dtsi"
 
 / {
 	model = "Radxa ROCK 3C";

Applied, thanks!

[1/3] arm64: dts: rockchip: Update CPU OPP voltages in RK356x SoC dtsi

      commit: 0e183fcc92b0eaa13b33b39846d86c3d65b8330a
[2/3] arm64: dts: rockchip: Prepare RK356x SoC dtsi files for per-variant OPPs
      commit: 853f9632a17624e9264c68be5c9587f13d04be54
[3/3] arm64: dts: rockchip: Add new SoC dtsi for the RK3566T variant
      commit: e4832d190b4fb69cf28630543804825bf1636ff1

Best regards,

Heiko Stuebner <[email protected]>