| Message ID | 20240506-rk-dts-additions-v4-6-271023ddfd40@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | RK3588 and Rock 5B dts additions: thermal, OPP and fan | expand |
Hi Alexey, On 5/6/24 11:36 AM, Alexey Charkov wrote: > By default the CPUs on RK3588 start up in a conservative performance > mode. Add frequency and voltage mappings to the device tree to enable > dynamic scaling via cpufreq. > > OPP values are adapted from Radxa's downstream kernel for Rock 5B [1], > stripping them down to the minimum frequency and voltage combinations > as expected by the generic upstream cpufreq-dt driver, and also dropping > those OPPs that don't differ in voltage but only in frequency (keeping > the top frequency OPP in each case). > > Note that this patch ignores voltage scaling for the CPU memory > interface which the downstream kernel does through a custom cpufreq > driver, and which is why the downstream version has two sets of voltage > values for each OPP (the second one being meant for the memory > interface supply regulator). This is done instead via regulator > coupling between CPU and memory interface supplies on affected boards. > I'm not sure this is everything we need though. For the LITTLE cores cluster, all OPPs up to 1.416GHz are using the same opp-supported-hw, however the ones above, aren't. 1.608GHz, 1.704GHz and 1.8GHz are all using different opp-supported-hw. Similarly, for the big cores clusters, all OPPs up to 1.608GHz are using the same opp-supported-hw, but not the ones above. 1.8GHz and 2.016GHz, 2.208GHz, 2.256GHz, 2.304GHz, 2.352GHz and 2.4GHz all have a different opp-supported-hw. The values in that array are coming from cpu leakage (different for LITTLE, big0 and big1 clusters) and "specification serial number" (whatever that means), those are coming from the SoC OTP. In the downstream kernel from Rockchip, the former value is called "SoC Version" and the latter "Speed Grade". I think this may have something to do with "binning" and I would see the ones above the "common" OPPs as "overclocking". Not all CPUs would support them and some may not run stable at some lower frequency than their stable max. Adding Kever from Rockchip in Cc to have some input on the need to support those. Cheers, Quentin
Hello Quentin, On 2024-05-08 11:12, Quentin Schulz wrote: > On 5/6/24 11:36 AM, Alexey Charkov wrote: >> By default the CPUs on RK3588 start up in a conservative performance >> mode. Add frequency and voltage mappings to the device tree to enable >> dynamic scaling via cpufreq. >> >> OPP values are adapted from Radxa's downstream kernel for Rock 5B [1], >> stripping them down to the minimum frequency and voltage combinations >> as expected by the generic upstream cpufreq-dt driver, and also >> dropping >> those OPPs that don't differ in voltage but only in frequency (keeping >> the top frequency OPP in each case). >> >> Note that this patch ignores voltage scaling for the CPU memory >> interface which the downstream kernel does through a custom cpufreq >> driver, and which is why the downstream version has two sets of >> voltage >> values for each OPP (the second one being meant for the memory >> interface supply regulator). This is done instead via regulator >> coupling between CPU and memory interface supplies on affected boards. > > I'm not sure this is everything we need though. > > For the LITTLE cores cluster, all OPPs up to 1.416GHz are using the > same opp-supported-hw, however the ones above, aren't. > > 1.608GHz, 1.704GHz and 1.8GHz are all using different opp-supported-hw. > > Similarly, for the big cores clusters, all OPPs up to 1.608GHz are > using the same opp-supported-hw, but not the ones above. > > 1.8GHz and 2.016GHz, 2.208GHz, 2.256GHz, 2.304GHz, 2.352GHz and 2.4GHz > all have a different opp-supported-hw. > > The values in that array are coming from cpu leakage (different for > LITTLE, big0 and big1 clusters) and "specification serial number" > (whatever that means), those are coming from the SoC OTP. In the > downstream kernel from Rockchip, the former value is called "SoC > Version" and the latter "Speed Grade". > > I think this may have something to do with "binning" and I would see > the ones above the "common" OPPs as "overclocking". Not all CPUs would > support them and some may not run stable at some lower frequency than > their stable max. Adding Kever from Rockchip in Cc to have some input > on the need to support those. Good point. We should remove the OPPs for both clusters that aren't supported by all RK3588(s) binnings, to be on the safe side. I'll hopefully dive into supporting different Rockchip binnings rather soon. There's even more about that, and not just with the RK3588(s), which I think I'll get all covered.
Hi Quentin, On Wed, May 8, 2024 at 1:12 PM Quentin Schulz <quentin.schulz@cherry.de> wrote: > > Hi Alexey, > > On 5/6/24 11:36 AM, Alexey Charkov wrote: > > By default the CPUs on RK3588 start up in a conservative performance > > mode. Add frequency and voltage mappings to the device tree to enable > > dynamic scaling via cpufreq. > > > > OPP values are adapted from Radxa's downstream kernel for Rock 5B [1], > > stripping them down to the minimum frequency and voltage combinations > > as expected by the generic upstream cpufreq-dt driver, and also dropping > > those OPPs that don't differ in voltage but only in frequency (keeping > > the top frequency OPP in each case). > > > > Note that this patch ignores voltage scaling for the CPU memory > > interface which the downstream kernel does through a custom cpufreq > > driver, and which is why the downstream version has two sets of voltage > > values for each OPP (the second one being meant for the memory > > interface supply regulator). This is done instead via regulator > > coupling between CPU and memory interface supplies on affected boards. > > > > I'm not sure this is everything we need though. > > For the LITTLE cores cluster, all OPPs up to 1.416GHz are using the same > opp-supported-hw, however the ones above, aren't. Thanks a lot for pointing this out - could you please elaborate which downstream kernel you referred to? > 1.608GHz, 1.704GHz and 1.8GHz are all using different opp-supported-hw. In Radxa's downstream kernel source that I looked at [1] the LITTLE core cluster has all OPPs listed with opp-supported-hw = <0xff 0xffff>; > Similarly, for the big cores clusters, all OPPs up to 1.608GHz are using > the same opp-supported-hw, but not the ones above. > > 1.8GHz and 2.016GHz, 2.208GHz, 2.256GHz, 2.304GHz, 2.352GHz and 2.4GHz > all have a different opp-supported-hw. Hmm, only 2.256GHz, 2.304GHz and 2.352GHz in the sources I'm looking at have a different opp-supported-hw = <0xff 0x0>; (but note that I dropped them all from my patch here) > The values in that array are coming from cpu leakage (different for > LITTLE, big0 and big1 clusters) and "specification serial number" > (whatever that means), those are coming from the SoC OTP. In the > downstream kernel from Rockchip, the former value is called "SoC > Version" and the latter "Speed Grade". From what I understood by studying Radxa's downstream kernel sources and TF-A sources [2], the "leakage" in NVMEM cells drives the selection of power-optimized voltage levels (opp-microvolt-L1 through opp-microvolt-L7) for each OPP depending on a OTP-programmed silicon quality metric, whereas in my patch I only kept the most conservative voltage values for each OPP (i.e. highest-voltage default ones) and not the power-optimized ones. So the proposed patch should (supposedly?) work on any silicon, only the heat death of the universe becomes marginally closer :) > I think this may have something to do with "binning" and I would see the > ones above the "common" OPPs as "overclocking". Not all CPUs would > support them and some may not run stable at some lower frequency than > their stable max. Adding Kever from Rockchip in Cc to have some input on > the need to support those. Would be great to understand those in more detail, indeed! Thanks a lot, Alexey [1] https://github.com/radxa/kernel/blob/c428536281d69aeb2b3480f65b2b227210b61535/arch/arm64/boot/dts/rockchip/rk3588s.dtsi#L588 [2] https://lore.kernel.org/linux-rockchip/CABjd4YzTL=5S7cS8ACNAYVa730WA3iGd5L_wP1Vn9=f83RCORA@mail.gmail.com/
Hi Alexey, On 5/8/24 11:43 AM, Alexey Charkov wrote: > Hi Quentin, > > On Wed, May 8, 2024 at 1:12 PM Quentin Schulz <quentin.schulz@cherry.de> wrote: >> >> Hi Alexey, >> >> On 5/6/24 11:36 AM, Alexey Charkov wrote: >>> By default the CPUs on RK3588 start up in a conservative performance >>> mode. Add frequency and voltage mappings to the device tree to enable >>> dynamic scaling via cpufreq. >>> >>> OPP values are adapted from Radxa's downstream kernel for Rock 5B [1], >>> stripping them down to the minimum frequency and voltage combinations >>> as expected by the generic upstream cpufreq-dt driver, and also dropping >>> those OPPs that don't differ in voltage but only in frequency (keeping >>> the top frequency OPP in each case). >>> >>> Note that this patch ignores voltage scaling for the CPU memory >>> interface which the downstream kernel does through a custom cpufreq >>> driver, and which is why the downstream version has two sets of voltage >>> values for each OPP (the second one being meant for the memory >>> interface supply regulator). This is done instead via regulator >>> coupling between CPU and memory interface supplies on affected boards. >>> >> >> I'm not sure this is everything we need though. >> >> For the LITTLE cores cluster, all OPPs up to 1.416GHz are using the same >> opp-supported-hw, however the ones above, aren't. > > Thanks a lot for pointing this out - could you please elaborate which > downstream kernel you referred to? > The one provided by Rockchip directly :) No intermediates. I can give you the one we use on our products at the moment: https://git.embedded.cherry.de/tiger-linux.git/ (or jaguar-linux, doesn't matter). The one that is (publicly) "maintained" by Rockchip is: https://github.com/rockchip-linux/kernel/tree/develop-5.10 From Cherry's git repo: """ $ rg -B1 --color never -N opp-supported-hw arch/arm64/boot/dts/rockchip/rk3588s.dtsi opp-408000000 { opp-supported-hw = <0xff 0xffff>; -- opp-600000000 { opp-supported-hw = <0xff 0xffff>; -- opp-816000000 { opp-supported-hw = <0xff 0xffff>; -- opp-1008000000 { opp-supported-hw = <0xff 0xffff>; -- opp-1200000000 { opp-supported-hw = <0xff 0xffff>; -- opp-1416000000 { opp-supported-hw = <0xff 0xffff>; -- opp-1608000000 { opp-supported-hw = <0xfb 0xffff>; -- opp-1704000000 { opp-supported-hw = <0x02 0xffff>; -- opp-1800000000 { opp-supported-hw = <0xf9 0xffff>; -- opp-408000000 { opp-supported-hw = <0xff 0xffff>; -- opp-600000000 { opp-supported-hw = <0xff 0xffff>; -- opp-816000000 { opp-supported-hw = <0xff 0xffff>; -- opp-1008000000 { opp-supported-hw = <0xff 0xffff>; -- opp-1200000000 { opp-supported-hw = <0xff 0xffff>; -- opp-1416000000 { opp-supported-hw = <0xff 0xffff>; -- opp-1608000000 { opp-supported-hw = <0xff 0xffff>; -- opp-1800000000 { opp-supported-hw = <0xfb 0xffff>; -- opp-2016000000 { opp-supported-hw = <0xfb 0xffff>; -- opp-2208000000 { opp-supported-hw = <0xf9 0xffff>; -- opp-2256000000 { opp-supported-hw = <0xf9 0x13>; -- opp-2304000000 { opp-supported-hw = <0xf9 0x24>; -- opp-2352000000 { opp-supported-hw = <0xf9 0x48>; -- opp-2400000000 { opp-supported-hw = <0xf9 0x80>; -- opp-408000000 { opp-supported-hw = <0xff 0x0ffff>; -- opp-600000000 { opp-supported-hw = <0xff 0xffff>; -- opp-816000000 { opp-supported-hw = <0xff 0xffff>; -- opp-1008000000 { opp-supported-hw = <0xff 0xffff>; -- opp-1200000000 { opp-supported-hw = <0xff 0xffff>; -- opp-1416000000 { opp-supported-hw = <0xff 0xffff>; -- opp-1608000000 { opp-supported-hw = <0xff 0xffff>; -- opp-1800000000 { opp-supported-hw = <0xfb 0xffff>; -- opp-2016000000 { opp-supported-hw = <0xfb 0xffff>; -- opp-2208000000 { opp-supported-hw = <0xf9 0xffff>; -- opp-2256000000 { opp-supported-hw = <0xf9 0x13>; -- opp-2304000000 { opp-supported-hw = <0xf9 0x24>; -- opp-2352000000 { opp-supported-hw = <0xf9 0x48>; -- opp-2400000000 { opp-supported-hw = <0xf9 0x80>; -- opp-300000000 { opp-supported-hw = <0xff 0xffff>; -- opp-400000000 { opp-supported-hw = <0xff 0xffff>; -- opp-500000000 { opp-supported-hw = <0xff 0xffff>; -- opp-600000000 { opp-supported-hw = <0xff 0xffff>; -- opp-700000000 { opp-supported-hw = <0xff 0xffff>; -- opp-800000000 { opp-supported-hw = <0xff 0xffff>; -- opp-900000000 { opp-supported-hw = <0xfb 0xffff>; -- opp-1000000000 { opp-supported-hw = <0xfb 0xffff>; -- opp-300000000 { opp-supported-hw = <0xff 0xffff>; -- opp-400000000 { opp-supported-hw = <0xff 0xffff>; -- opp-500000000 { opp-supported-hw = <0xff 0xffff>; -- opp-600000000 { opp-supported-hw = <0xff 0xffff>; -- opp-700000000 { opp-supported-hw = <0xff 0xffff>; -- opp-800000000 { opp-supported-hw = <0xff 0xffff>; -- opp-900000000 { opp-supported-hw = <0xfb 0xffff>; -- opp-1000000000 { opp-supported-hw = <0xfb 0xffff>; """ In order: LITTLE, big0, big1, DMC (memory), GPU and then NPU OPP table. Looking at the 6.1 development branch from Rockchip (https://github.com/JeffyCN/mirrors/blob/kernel-6.1). The LITTLE cluster OPPs seem to all be using the same opp-supported-hw entry now (but different from the one in 5.10). But, the big cluster OPPs in 6.1 are matching the one in 5.10 (that is, not the ones from Radxa). >> 1.608GHz, 1.704GHz and 1.8GHz are all using different opp-supported-hw. > > In Radxa's downstream kernel source that I looked at [1] the LITTLE > core cluster has all OPPs listed with opp-supported-hw = <0xff > 0xffff>; > >> Similarly, for the big cores clusters, all OPPs up to 1.608GHz are using >> the same opp-supported-hw, but not the ones above. >> >> 1.8GHz and 2.016GHz, 2.208GHz, 2.256GHz, 2.304GHz, 2.352GHz and 2.4GHz >> all have a different opp-supported-hw. > > Hmm, only 2.256GHz, 2.304GHz and 2.352GHz in the sources I'm looking > at have a different opp-supported-hw = <0xff 0x0>; (but note that I > dropped them all from my patch here) > Seems to be a change made by Radxa folks: https://github.com/radxa/kernel/commit/cf277d5eb46ef55517afffa10d48dd71bdd00c61 (yay to no commit log \o/) >> The values in that array are coming from cpu leakage (different for >> LITTLE, big0 and big1 clusters) and "specification serial number" >> (whatever that means), those are coming from the SoC OTP. In the >> downstream kernel from Rockchip, the former value is called "SoC >> Version" and the latter "Speed Grade". > > From what I understood by studying Radxa's downstream kernel sources > and TF-A sources [2], the "leakage" in NVMEM cells drives the > selection of power-optimized voltage levels (opp-microvolt-L1 through > opp-microvolt-L7) for each OPP depending on a OTP-programmed silicon > quality metric, whereas in my patch I only kept the most conservative > voltage values for each OPP (i.e. highest-voltage default ones) and > not the power-optimized ones. > > So the proposed patch should (supposedly?) work on any silicon, only > the heat death of the universe becomes marginally closer :) > An OPP from the DT is selected if _opp_is_supported returns true. This is based on supported_hw member of the opp_table, which we set through dev_pm_opp_set_supported_hw. This is called by drivers/cpufreq/rockchip-cpufreq.c with two values: SoC Version and Speed Grade. The SoC version is a bitmap set by rk3588_get_soc_info by reading specification_serial_number region in the OTP and reading the first byte. If it is anything but 0xd (RK3588M) or 0xa (RK3588J), it is BIT(0). To know if the opp is supported, you extract the first value of the array and mask it with the value gotten from rk3588_get_soc_info (the bitfield). This means that for RK3588 (and not the M or J variant), the first value of the OPP opp-supported-hw is a match if it is an odd number, so only opp-1704000000 in LITTLE cluster is excluded (on that sole match). The second value in opp-supported-hw seems to be derived somehow from the cpu_leakage OTP. This is likely the same rabbit hole you dug two months ago, so I'll trust your findings there to avoid getting my hands dirty :) In summary, false alarm (but still surprising changes made by Radxa here, not that they matter if they only run their kernel on "pure" RK3588). Sorry for the noise, and thanks for the explanations :) I'm surprised that we removed the lowest frequencies at the same voltage, are they not even allowing us to save a teeny tiny bit of power consumption? (I'm asking because I'm pretty sure we'll eventually get customers complaining the CPU freq doesn't go in super low frequency "so this must be a way to consume less power in idle!"). Cheers, Quentin
On 2024-05-08 12:50, Quentin Schulz wrote: > I'm surprised that we removed the lowest frequencies at the same > voltage, are they not even allowing us to save a teeny tiny bit of > power consumption? (I'm asking because I'm pretty sure we'll > eventually get customers complaining the CPU freq doesn't go in super > low frequency "so this must be a way to consume less power in idle!"). Same-voltage, different-frequency OPPs are seen as inefficient, although I don't share the same opinion. While the jury is still out, perhaps we can omit them, and possibly add them later.
diff --git a/arch/arm64/boot/dts/rockchip/rk3588s.dtsi b/arch/arm64/boot/dts/rockchip/rk3588s.dtsi index 57c2d998ae75..85c25d5efdad 100644 --- a/arch/arm64/boot/dts/rockchip/rk3588s.dtsi +++ b/arch/arm64/boot/dts/rockchip/rk3588s.dtsi @@ -97,6 +97,7 @@ cpu_l0: cpu@0 { clocks = <&scmi_clk SCMI_CLK_CPUL>; assigned-clocks = <&scmi_clk SCMI_CLK_CPUL>; assigned-clock-rates = <816000000>; + operating-points-v2 = <&cluster0_opp_table>; cpu-idle-states = <&CPU_SLEEP>; i-cache-size = <32768>; i-cache-line-size = <64>; @@ -116,6 +117,7 @@ cpu_l1: cpu@100 { enable-method = "psci"; capacity-dmips-mhz = <530>; clocks = <&scmi_clk SCMI_CLK_CPUL>; + operating-points-v2 = <&cluster0_opp_table>; cpu-idle-states = <&CPU_SLEEP>; i-cache-size = <32768>; i-cache-line-size = <64>; @@ -135,6 +137,7 @@ cpu_l2: cpu@200 { enable-method = "psci"; capacity-dmips-mhz = <530>; clocks = <&scmi_clk SCMI_CLK_CPUL>; + operating-points-v2 = <&cluster0_opp_table>; cpu-idle-states = <&CPU_SLEEP>; i-cache-size = <32768>; i-cache-line-size = <64>; @@ -154,6 +157,7 @@ cpu_l3: cpu@300 { enable-method = "psci"; capacity-dmips-mhz = <530>; clocks = <&scmi_clk SCMI_CLK_CPUL>; + operating-points-v2 = <&cluster0_opp_table>; cpu-idle-states = <&CPU_SLEEP>; i-cache-size = <32768>; i-cache-line-size = <64>; @@ -175,6 +179,7 @@ cpu_b0: cpu@400 { clocks = <&scmi_clk SCMI_CLK_CPUB01>; assigned-clocks = <&scmi_clk SCMI_CLK_CPUB01>; assigned-clock-rates = <816000000>; + operating-points-v2 = <&cluster1_opp_table>; cpu-idle-states = <&CPU_SLEEP>; i-cache-size = <65536>; i-cache-line-size = <64>; @@ -194,6 +199,7 @@ cpu_b1: cpu@500 { enable-method = "psci"; capacity-dmips-mhz = <1024>; clocks = <&scmi_clk SCMI_CLK_CPUB01>; + operating-points-v2 = <&cluster1_opp_table>; cpu-idle-states = <&CPU_SLEEP>; i-cache-size = <65536>; i-cache-line-size = <64>; @@ -215,6 +221,7 @@ cpu_b2: cpu@600 { clocks = <&scmi_clk SCMI_CLK_CPUB23>; assigned-clocks = <&scmi_clk SCMI_CLK_CPUB23>; assigned-clock-rates = <816000000>; + operating-points-v2 = <&cluster2_opp_table>; cpu-idle-states = <&CPU_SLEEP>; i-cache-size = <65536>; i-cache-line-size = <64>; @@ -234,6 +241,7 @@ cpu_b3: cpu@700 { enable-method = "psci"; capacity-dmips-mhz = <1024>; clocks = <&scmi_clk SCMI_CLK_CPUB23>; + operating-points-v2 = <&cluster2_opp_table>; cpu-idle-states = <&CPU_SLEEP>; i-cache-size = <65536>; i-cache-line-size = <64>; @@ -348,6 +356,120 @@ l3_cache: l3-cache { }; }; + cluster0_opp_table: opp-table-cluster0 { + compatible = "operating-points-v2"; + opp-shared; + + opp-1008000000 { + opp-hz = /bits/ 64 <1008000000>; + opp-microvolt = <675000 675000 950000>; + clock-latency-ns = <40000>; + }; + opp-1200000000 { + opp-hz = /bits/ 64 <1200000000>; + opp-microvolt = <712500 712500 950000>; + clock-latency-ns = <40000>; + }; + opp-1416000000 { + opp-hz = /bits/ 64 <1416000000>; + opp-microvolt = <762500 762500 950000>; + clock-latency-ns = <40000>; + opp-suspend; + }; + opp-1608000000 { + opp-hz = /bits/ 64 <1608000000>; + opp-microvolt = <850000 850000 950000>; + clock-latency-ns = <40000>; + }; + opp-1800000000 { + opp-hz = /bits/ 64 <1800000000>; + opp-microvolt = <950000 950000 950000>; + clock-latency-ns = <40000>; + }; + }; + + cluster1_opp_table: opp-table-cluster1 { + compatible = "operating-points-v2"; + opp-shared; + + opp-1200000000 { + opp-hz = /bits/ 64 <1200000000>; + opp-microvolt = <675000 675000 1000000>; + clock-latency-ns = <40000>; + }; + opp-1416000000 { + opp-hz = /bits/ 64 <1416000000>; + opp-microvolt = <725000 725000 1000000>; + clock-latency-ns = <40000>; + }; + opp-1608000000 { + opp-hz = /bits/ 64 <1608000000>; + opp-microvolt = <762500 762500 1000000>; + clock-latency-ns = <40000>; + }; + opp-1800000000 { + opp-hz = /bits/ 64 <1800000000>; + opp-microvolt = <850000 850000 1000000>; + clock-latency-ns = <40000>; + }; + opp-2016000000 { + opp-hz = /bits/ 64 <2016000000>; + opp-microvolt = <925000 925000 1000000>; + clock-latency-ns = <40000>; + }; + opp-2208000000 { + opp-hz = /bits/ 64 <2208000000>; + opp-microvolt = <987500 987500 1000000>; + clock-latency-ns = <40000>; + }; + opp-2400000000 { + opp-hz = /bits/ 64 <2400000000>; + opp-microvolt = <1000000 1000000 1000000>; + clock-latency-ns = <40000>; + }; + }; + + cluster2_opp_table: opp-table-cluster2 { + compatible = "operating-points-v2"; + opp-shared; + + opp-1200000000 { + opp-hz = /bits/ 64 <1200000000>; + opp-microvolt = <675000 675000 1000000>; + clock-latency-ns = <40000>; + }; + opp-1416000000 { + opp-hz = /bits/ 64 <1416000000>; + opp-microvolt = <725000 725000 1000000>; + clock-latency-ns = <40000>; + }; + opp-1608000000 { + opp-hz = /bits/ 64 <1608000000>; + opp-microvolt = <762500 762500 1000000>; + clock-latency-ns = <40000>; + }; + opp-1800000000 { + opp-hz = /bits/ 64 <1800000000>; + opp-microvolt = <850000 850000 1000000>; + clock-latency-ns = <40000>; + }; + opp-2016000000 { + opp-hz = /bits/ 64 <2016000000>; + opp-microvolt = <925000 925000 1000000>; + clock-latency-ns = <40000>; + }; + opp-2208000000 { + opp-hz = /bits/ 64 <2208000000>; + opp-microvolt = <987500 987500 1000000>; + clock-latency-ns = <40000>; + }; + opp-2400000000 { + opp-hz = /bits/ 64 <2400000000>; + opp-microvolt = <1000000 1000000 1000000>; + clock-latency-ns = <40000>; + }; + }; + display_subsystem: display-subsystem { compatible = "rockchip,display-subsystem"; ports = <&vop_out>;
By default the CPUs on RK3588 start up in a conservative performance mode. Add frequency and voltage mappings to the device tree to enable dynamic scaling via cpufreq. OPP values are adapted from Radxa's downstream kernel for Rock 5B [1], stripping them down to the minimum frequency and voltage combinations as expected by the generic upstream cpufreq-dt driver, and also dropping those OPPs that don't differ in voltage but only in frequency (keeping the top frequency OPP in each case). Note that this patch ignores voltage scaling for the CPU memory interface which the downstream kernel does through a custom cpufreq driver, and which is why the downstream version has two sets of voltage values for each OPP (the second one being meant for the memory interface supply regulator). This is done instead via regulator coupling between CPU and memory interface supplies on affected boards. This has been tested on Rock 5B with u-boot 2023.11 compiled from Collabora's integration tree [2] with binary bl31 and appears to be stable both under active cooling and passive cooling (with throttling) [1] https://github.com/radxa/kernel/blob/stable-5.10-rock5/arch/arm64/boot/dts/rockchip/rk3588s.dtsi [2] https://gitlab.collabora.com/hardware-enablement/rockchip-3588/u-boot Signed-off-by: Alexey Charkov <alchark@gmail.com> --- arch/arm64/boot/dts/rockchip/rk3588s.dtsi | 122 ++++++++++++++++++++++++++++++ 1 file changed, 122 insertions(+)