[PATCH v1 0/7] Add thermal cooling support to NVIDIA Tegra devfreq

[PATCH v1 0/7] Add thermal cooling support to NVIDIA Tegra devfreq

[Dmitry Osipenko]

Hi,

Some hardware versions of NVIDIA Tegra SoCs support higher freqs and they
are producing much more heat than the other versions. We found that CPU
throttling may be not enough on devices like Asus Transformer TF700T,
which is Tegra30 tablet device. This series adds thermal cooling support
to the NVIDIA Tegra30+ devfreq which cools down SoC by throttling memory
frequency on overheat.

Dmitry Osipenko (7):
  PM / devfreq: tegra30: Support thermal cooling
  ARM: tegra_defconfig: Enable CONFIG_DEVFREQ_THERMAL
  dt-bindings: devfreq: tegra30-actmon: Convert to schema
  dt-bindings: devfreq: tegra30-actmon: Add cooling-cells
  ARM: tegra: Add cooling cells to ACTMON device-tree node
  ARM: tegra: nexus7: Enable memory frequency thermal throttling using
    ACTMON
  ARM: tegra: ouya: Enable memory frequency thermal throttling using
    ACTMON

 .../arm/tegra/nvidia,tegra30-actmon.txt       |  57 --------
 .../devfreq/nvidia,tegra30-actmon.yaml        | 126 ++++++++++++++++++
 arch/arm/boot/dts/tegra124.dtsi               |   3 +-
 .../tegra30-asus-nexus7-grouper-common.dtsi   |   3 +-
 arch/arm/boot/dts/tegra30-ouya.dts            |   3 +-
 arch/arm/boot/dts/tegra30.dtsi                |   3 +-
 arch/arm/configs/tegra_defconfig              |   1 +
 drivers/devfreq/tegra30-devfreq.c             |   1 +
 8 files changed, 136 insertions(+), 61 deletions(-)
 delete mode 100644 Documentation/devicetree/bindings/arm/tegra/nvidia,tegra30-actmon.txt
 create mode 100644 Documentation/devicetree/bindings/devfreq/nvidia,tegra30-actmon.yaml

-- 
2.30.2

[PATCH v1 1/7] PM / devfreq: tegra30: Support thermal cooling

[Dmitry Osipenko]

Expose ACTMON devfreq device as a cooling device in order to throttle
memory freq on overheat. Throttling of memory freq has a significant
cooling effect on NVIDIA Tegra SoCs since higher memory freqs require
higher SoC core voltage which is one of the main causes of the heating.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/devfreq/tegra30-devfreq.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/devfreq/tegra30-devfreq.c b/drivers/devfreq/tegra30-devfreq.c
index ce83f883ca65..10661eb2aed8 100644
--- a/drivers/devfreq/tegra30-devfreq.c
+++ b/drivers/devfreq/tegra30-devfreq.c
@@ -688,6 +688,7 @@ static struct devfreq_dev_profile tegra_devfreq_profile = {
 	.polling_ms	= ACTMON_SAMPLING_PERIOD,
 	.target		= tegra_devfreq_target,
 	.get_dev_status	= tegra_devfreq_get_dev_status,
+	.is_cooling_device = true,
 };
 
 static int tegra_governor_get_target(struct devfreq *devfreq,
-- 
2.30.2

[PATCH v1 2/7] ARM: tegra_defconfig: Enable CONFIG_DEVFREQ_THERMAL

[Dmitry Osipenko]

Memory-related Tegra devfreq devices now could be used as a cooling
devices. Enable CONFIG_DEVFREQ_THERMAL by default since this option
enables cooling functionality of the devfreq drivers.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 arch/arm/configs/tegra_defconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/configs/tegra_defconfig b/arch/arm/configs/tegra_defconfig
index 13ef3e4dcbb7..3d8d8af9524d 100644
--- a/arch/arm/configs/tegra_defconfig
+++ b/arch/arm/configs/tegra_defconfig
@@ -167,6 +167,7 @@ CONFIG_SENSORS_LM95245=y
 CONFIG_THERMAL=y
 CONFIG_THERMAL_STATISTICS=y
 CONFIG_CPU_THERMAL=y
+CONFIG_DEVFREQ_THERMAL=y
 CONFIG_TEGRA_SOCTHERM=m
 CONFIG_WATCHDOG=y
 CONFIG_MAX77620_WATCHDOG=y
-- 
2.30.2

[PATCH v1 3/7] dt-bindings: devfreq: tegra30-actmon: Convert to schema

[Dmitry Osipenko]

Convert NVIDIA Tegra ACTMON binding to schema.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 .../arm/tegra/nvidia,tegra30-actmon.txt       |  57 ---------
 .../devfreq/nvidia,tegra30-actmon.yaml        | 121 ++++++++++++++++++
 2 files changed, 121 insertions(+), 57 deletions(-)
 delete mode 100644 Documentation/devicetree/bindings/arm/tegra/nvidia,tegra30-actmon.txt
 create mode 100644 Documentation/devicetree/bindings/devfreq/nvidia,tegra30-actmon.yaml

diff --git a/Documentation/devicetree/bindings/arm/tegra/nvidia,tegra30-actmon.txt b/Documentation/devicetree/bindings/arm/tegra/nvidia,tegra30-actmon.txt
deleted file mode 100644
index 897eedfa2bc8..000000000000
--- a/Documentation/devicetree/bindings/arm/tegra/nvidia,tegra30-actmon.txt
+++ /dev/null
@@ -1,57 +0,0 @@
-NVIDIA Tegra Activity Monitor
-
-The activity monitor block collects statistics about the behaviour of other
-components in the system. This information can be used to derive the rate at
-which the external memory needs to be clocked in order to serve all requests
-from the monitored clients.
-
-Required properties:
-- compatible: should be "nvidia,tegra<chip>-actmon"
-- reg: offset and length of the register set for the device
-- interrupts: standard interrupt property
-- clocks: Must contain a phandle and clock specifier pair for each entry in
-clock-names. See ../../clock/clock-bindings.txt for details.
-- clock-names: Must include the following entries:
-  - actmon
-  - emc
-- resets: Must contain an entry for each entry in reset-names. See
-../../reset/reset.txt for details.
-- reset-names: Must include the following entries:
-  - actmon
-- operating-points-v2: See ../bindings/opp/opp.txt for details.
-- interconnects: Should contain entries for memory clients sitting on
-                 MC->EMC memory interconnect path.
-- interconnect-names: Should include name of the interconnect path for each
-                      interconnect entry. Consult TRM documentation for
-                      information about available memory clients, see MEMORY
-                      CONTROLLER section.
-
-For each opp entry in 'operating-points-v2' table:
-- opp-supported-hw: bitfield indicating SoC speedo ID mask
-- opp-peak-kBps: peak bandwidth of the memory channel
-
-Example:
-	dfs_opp_table: opp-table {
-		compatible = "operating-points-v2";
-
-		opp@12750000 {
-			opp-hz = /bits/ 64 <12750000>;
-			opp-supported-hw = <0x000F>;
-			opp-peak-kBps = <51000>;
-		};
-		...
-	};
-
-	actmon@6000c800 {
-		compatible = "nvidia,tegra124-actmon";
-		reg = <0x0 0x6000c800 0x0 0x400>;
-		interrupts = <GIC_SPI 45 IRQ_TYPE_LEVEL_HIGH>;
-		clocks = <&tegra_car TEGRA124_CLK_ACTMON>,
-			 <&tegra_car TEGRA124_CLK_EMC>;
-		clock-names = "actmon", "emc";
-		resets = <&tegra_car 119>;
-		reset-names = "actmon";
-		operating-points-v2 = <&dfs_opp_table>;
-		interconnects = <&mc TEGRA124_MC_MPCORER &emc>;
-		interconnect-names = "cpu";
-	};
diff --git a/Documentation/devicetree/bindings/devfreq/nvidia,tegra30-actmon.yaml b/Documentation/devicetree/bindings/devfreq/nvidia,tegra30-actmon.yaml
new file mode 100644
index 000000000000..2a940d5d7ab4
--- /dev/null
+++ b/Documentation/devicetree/bindings/devfreq/nvidia,tegra30-actmon.yaml
@@ -0,0 +1,121 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/devfreq/nvidia,tegra30-actmon.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: NVIDIA Tegra30 Activity Monitor
+
+maintainers:
+  - Dmitry Osipenko <digetx@gmail.com>
+  - Jon Hunter <jonathanh@nvidia.com>
+  - Thierry Reding <thierry.reding@gmail.com>
+
+description: |
+  The activity monitor block collects statistics about the behaviour of other
+  components in the system. This information can be used to derive the rate at
+  which the external memory needs to be clocked in order to serve all requests
+  from the monitored clients.
+
+properties:
+  compatible:
+    enum:
+      - nvidia,tegra30-actmon
+      - nvidia,tegra114-actmon
+      - nvidia,tegra124-actmon
+      - nvidia,tegra210-actmon
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 2
+
+  clock-names:
+    items:
+      - const: actmon
+      - const: emc
+
+  resets:
+    maxItems: 1
+
+  reset-names:
+    items:
+      - const: actmon
+
+  interrupts:
+    maxItems: 1
+
+  interconnects:
+    minItems: 1
+    maxItems: 12
+
+  interconnect-names:
+    minItems: 1
+    maxItems: 12
+    description:
+      Should include name of the interconnect path for each interconnect
+      entry. Consult TRM documentation for information about available
+      memory clients, see ACTIVITY MONITOR section.
+
+  operating-points-v2:
+    description:
+      Should contain freqs and voltages and opp-supported-hw property, which
+      is a bitfield indicating SoC speedo ID mask.
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - clock-names
+  - resets
+  - reset-names
+  - interrupts
+  - interconnects
+  - interconnect-names
+  - operating-points-v2
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/memory/tegra30-mc.h>
+
+    mc: memory-controller@7000f000 {
+        compatible = "nvidia,tegra30-mc";
+        reg = <0x7000f000 0x400>;
+        clocks = <&clk 32>;
+        clock-names = "mc";
+
+        interrupts = <0 77 4>;
+
+        #iommu-cells = <1>;
+        #reset-cells = <1>;
+        #interconnect-cells = <1>;
+    };
+
+    emc: external-memory-controller@7000f400 {
+        compatible = "nvidia,tegra30-emc";
+        reg = <0x7000f400 0x400>;
+        interrupts = <0 78 4>;
+        clocks = <&clk 57>;
+
+        nvidia,memory-controller = <&mc>;
+        operating-points-v2 = <&dvfs_opp_table>;
+        power-domains = <&domain>;
+
+        #interconnect-cells = <0>;
+    };
+
+    actmon@6000c800 {
+        compatible = "nvidia,tegra30-actmon";
+        reg = <0x6000c800 0x400>;
+        interrupts = <0 45 4>;
+        clocks = <&clk 119>, <&clk 57>;
+        clock-names = "actmon", "emc";
+        resets = <&rst 119>;
+        reset-names = "actmon";
+        operating-points-v2 = <&dvfs_opp_table>;
+        interconnects = <&mc TEGRA30_MC_MPCORER &emc>;
+        interconnect-names = "cpu-read";
+    };
-- 
2.30.2

[PATCH v1 4/7] dt-bindings: devfreq: tegra30-actmon: Add cooling-cells

[Dmitry Osipenko]

The ACTMON watches activity of memory clients. Decisions about a minimum
required frequency are made based on the info from ACTMON. We can use
ACTMON as a thermal cooling device by limiting the required frequency.
Document new cooling-cells property of NVIDIA Tegra ACTMON hardware unit.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 .../devicetree/bindings/devfreq/nvidia,tegra30-actmon.yaml   | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Documentation/devicetree/bindings/devfreq/nvidia,tegra30-actmon.yaml b/Documentation/devicetree/bindings/devfreq/nvidia,tegra30-actmon.yaml
index 2a940d5d7ab4..0aa9459b7751 100644
--- a/Documentation/devicetree/bindings/devfreq/nvidia,tegra30-actmon.yaml
+++ b/Documentation/devicetree/bindings/devfreq/nvidia,tegra30-actmon.yaml
@@ -63,6 +63,9 @@ properties:
       Should contain freqs and voltages and opp-supported-hw property, which
       is a bitfield indicating SoC speedo ID mask.
 
+  "#cooling-cells":
+    const: 2
+
 required:
   - compatible
   - reg
@@ -74,6 +77,7 @@ required:
   - interconnects
   - interconnect-names
   - operating-points-v2
+  - "#cooling-cells"
 
 additionalProperties: false
 
@@ -118,4 +122,5 @@ examples:
         operating-points-v2 = <&dvfs_opp_table>;
         interconnects = <&mc TEGRA30_MC_MPCORER &emc>;
         interconnect-names = "cpu-read";
+        #cooling-cells = <2>;
     };
-- 
2.30.2

[PATCH v1 5/7] ARM: tegra: Add cooling cells to ACTMON device-tree node

[Dmitry Osipenko]

The ACTMON module monitors activity of memory clients and decisions
about a minimum required memory frequency are made based on info from
ACTMON. Add cooling cells to ACTMON device-tree node in order to turn
it into a cooling device that will throttle memory freq on overheat.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 arch/arm/boot/dts/tegra124.dtsi | 3 ++-
 arch/arm/boot/dts/tegra30.dtsi  | 3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/arm/boot/dts/tegra124.dtsi b/arch/arm/boot/dts/tegra124.dtsi
index 0b678afb2a5c..8b38f123f554 100644
--- a/arch/arm/boot/dts/tegra124.dtsi
+++ b/arch/arm/boot/dts/tegra124.dtsi
@@ -283,7 +283,7 @@ flow-controller@60007000 {
 		reg = <0x0 0x60007000 0x0 0x1000>;
 	};
 
-	actmon@6000c800 {
+	actmon: actmon@6000c800 {
 		compatible = "nvidia,tegra124-actmon";
 		reg = <0x0 0x6000c800 0x0 0x400>;
 		interrupts = <GIC_SPI 45 IRQ_TYPE_LEVEL_HIGH>;
@@ -295,6 +295,7 @@ actmon@6000c800 {
 		operating-points-v2 = <&emc_bw_dfs_opp_table>;
 		interconnects = <&mc TEGRA124_MC_MPCORER &emc>;
 		interconnect-names = "cpu-read";
+		#cooling-cells = <2>;
 	};
 
 	gpio: gpio@6000d000 {
diff --git a/arch/arm/boot/dts/tegra30.dtsi b/arch/arm/boot/dts/tegra30.dtsi
index 44a6dbba7081..c577c191be4b 100644
--- a/arch/arm/boot/dts/tegra30.dtsi
+++ b/arch/arm/boot/dts/tegra30.dtsi
@@ -410,7 +410,7 @@ ahb: ahb@6000c000 {
 		reg = <0x6000c000 0x150>; /* AHB Arbitration + Gizmo Controller */
 	};
 
-	actmon@6000c800 {
+	actmon: actmon@6000c800 {
 		compatible = "nvidia,tegra30-actmon";
 		reg = <0x6000c800 0x400>;
 		interrupts = <GIC_SPI 45 IRQ_TYPE_LEVEL_HIGH>;
@@ -422,6 +422,7 @@ actmon@6000c800 {
 		operating-points-v2 = <&emc_bw_dfs_opp_table>;
 		interconnects = <&mc TEGRA30_MC_MPCORER &emc>;
 		interconnect-names = "cpu-read";
+		#cooling-cells = <2>;
 	};
 
 	gpio: gpio@6000d000 {
-- 
2.30.2

[PATCH v1 6/7] ARM: tegra: nexus7: Enable memory frequency thermal throttling using ACTMON

[Dmitry Osipenko]

The ACTMON module monitors activity of memory clients and then devfreq
driver makes decisions about a required memory frequency based on info
from ACTMON. Add ACTMON device to the thermal zone of Nexus 7 in order
to use it as a cooling device which throttles memory freq on overheat.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 arch/arm/boot/dts/tegra30-asus-nexus7-grouper-common.dtsi | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/arm/boot/dts/tegra30-asus-nexus7-grouper-common.dtsi b/arch/arm/boot/dts/tegra30-asus-nexus7-grouper-common.dtsi
index c6264738f593..27adca7f4175 100644
--- a/arch/arm/boot/dts/tegra30-asus-nexus7-grouper-common.dtsi
+++ b/arch/arm/boot/dts/tegra30-asus-nexus7-grouper-common.dtsi
@@ -1279,7 +1279,8 @@ map0 {
 					cooling-device = <&cpu0 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
 							 <&cpu1 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
 							 <&cpu2 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
-							 <&cpu3 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
+							 <&cpu3 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
+							 <&actmon THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
 				};
 			};
 		};
-- 
2.30.2

[PATCH v1 7/7] ARM: tegra: ouya: Enable memory frequency thermal throttling using ACTMON

[Dmitry Osipenko]

The ACTMON module monitors activity of memory clients and then devfreq
driver makes decisions about a required memory frequency based on info
from ACTMON. Add ACTMON device to the thermal zone of Ouya in order to
use it as a cooling device which throttles memory freq on overheat.

Tested-by: Peter Geis <pgwipeout@gmail.com>
Tested-by: Matt Merhar <mattmerhar@protonmail.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 arch/arm/boot/dts/tegra30-ouya.dts | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/arm/boot/dts/tegra30-ouya.dts b/arch/arm/boot/dts/tegra30-ouya.dts
index 9a10e0d69762..e767ac227a81 100644
--- a/arch/arm/boot/dts/tegra30-ouya.dts
+++ b/arch/arm/boot/dts/tegra30-ouya.dts
@@ -463,7 +463,8 @@ map1 {
 					cooling-device = <&cpu0 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
 							 <&cpu1 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
 							 <&cpu2 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
-							 <&cpu3 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
+							 <&cpu3 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
+							 <&actmon THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
 				};
 			};
 		};
-- 
2.30.2

Re: [PATCH v1 3/7] dt-bindings: devfreq: tegra30-actmon: Convert to schema

[Rob Herring]

On Tue, 11 May 2021 00:10:04 +0300, Dmitry Osipenko wrote:
> Convert NVIDIA Tegra ACTMON binding to schema.
> 
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
>  .../arm/tegra/nvidia,tegra30-actmon.txt       |  57 ---------
>  .../devfreq/nvidia,tegra30-actmon.yaml        | 121 ++++++++++++++++++
>  2 files changed, 121 insertions(+), 57 deletions(-)
>  delete mode 100644 Documentation/devicetree/bindings/arm/tegra/nvidia,tegra30-actmon.txt
>  create mode 100644 Documentation/devicetree/bindings/devfreq/nvidia,tegra30-actmon.yaml
> 

Reviewed-by: Rob Herring <robh@kernel.org>

Re: [PATCH v1 4/7] dt-bindings: devfreq: tegra30-actmon: Add cooling-cells

[Rob Herring]

On Tue, 11 May 2021 00:10:05 +0300, Dmitry Osipenko wrote:
> The ACTMON watches activity of memory clients. Decisions about a minimum
> required frequency are made based on the info from ACTMON. We can use
> ACTMON as a thermal cooling device by limiting the required frequency.
> Document new cooling-cells property of NVIDIA Tegra ACTMON hardware unit.
> 
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
>  .../devicetree/bindings/devfreq/nvidia,tegra30-actmon.yaml   | 5 +++++
>  1 file changed, 5 insertions(+)
> 

Reviewed-by: Rob Herring <robh@kernel.org>

Re: [PATCH v1 4/7] dt-bindings: devfreq: tegra30-actmon: Add cooling-cells

[Chanwoo Choi]

On 5/11/21 6:10 AM, Dmitry Osipenko wrote:
> The ACTMON watches activity of memory clients. Decisions about a minimum
> required frequency are made based on the info from ACTMON. We can use
> ACTMON as a thermal cooling device by limiting the required frequency.
> Document new cooling-cells property of NVIDIA Tegra ACTMON hardware unit.
> 
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
>  .../devicetree/bindings/devfreq/nvidia,tegra30-actmon.yaml   | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/devfreq/nvidia,tegra30-actmon.yaml b/Documentation/devicetree/bindings/devfreq/nvidia,tegra30-actmon.yaml
> index 2a940d5d7ab4..0aa9459b7751 100644
> --- a/Documentation/devicetree/bindings/devfreq/nvidia,tegra30-actmon.yaml
> +++ b/Documentation/devicetree/bindings/devfreq/nvidia,tegra30-actmon.yaml
> @@ -63,6 +63,9 @@ properties:
>        Should contain freqs and voltages and opp-supported-hw property, which
>        is a bitfield indicating SoC speedo ID mask.
>  
> +  "#cooling-cells":
> +    const: 2
> +
>  required:
>    - compatible
>    - reg
> @@ -74,6 +77,7 @@ required:
>    - interconnects
>    - interconnect-names
>    - operating-points-v2
> +  - "#cooling-cells"
>  
>  additionalProperties: false
>  
> @@ -118,4 +122,5 @@ examples:
>          operating-points-v2 = <&dvfs_opp_table>;
>          interconnects = <&mc TEGRA30_MC_MPCORER &emc>;
>          interconnect-names = "cpu-read";
> +        #cooling-cells = <2>;
>      };
> 

Acked-by: Chanwoo Choi <cw00.choi@samsung.com>

-- 
Best Regards,
Chanwoo Choi
Samsung Electronics

Re: [PATCH v1 3/7] dt-bindings: devfreq: tegra30-actmon: Convert to schema

[Chanwoo Choi]

On 5/11/21 6:10 AM, Dmitry Osipenko wrote:
> Convert NVIDIA Tegra ACTMON binding to schema.
> 
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
>  .../arm/tegra/nvidia,tegra30-actmon.txt       |  57 ---------
>  .../devfreq/nvidia,tegra30-actmon.yaml        | 121 ++++++++++++++++++
>  2 files changed, 121 insertions(+), 57 deletions(-)
>  delete mode 100644 Documentation/devicetree/bindings/arm/tegra/nvidia,tegra30-actmon.txt
>  create mode 100644 Documentation/devicetree/bindings/devfreq/nvidia,tegra30-actmon.yaml
> 
> diff --git a/Documentation/devicetree/bindings/arm/tegra/nvidia,tegra30-actmon.txt b/Documentation/devicetree/bindings/arm/tegra/nvidia,tegra30-actmon.txt
> deleted file mode 100644
> index 897eedfa2bc8..000000000000
> --- a/Documentation/devicetree/bindings/arm/tegra/nvidia,tegra30-actmon.txt
> +++ /dev/null
> @@ -1,57 +0,0 @@
> -NVIDIA Tegra Activity Monitor
> -
> -The activity monitor block collects statistics about the behaviour of other
> -components in the system. This information can be used to derive the rate at
> -which the external memory needs to be clocked in order to serve all requests
> -from the monitored clients.
> -
> -Required properties:
> -- compatible: should be "nvidia,tegra<chip>-actmon"
> -- reg: offset and length of the register set for the device
> -- interrupts: standard interrupt property
> -- clocks: Must contain a phandle and clock specifier pair for each entry in
> -clock-names. See ../../clock/clock-bindings.txt for details.
> -- clock-names: Must include the following entries:
> -  - actmon
> -  - emc
> -- resets: Must contain an entry for each entry in reset-names. See
> -../../reset/reset.txt for details.
> -- reset-names: Must include the following entries:
> -  - actmon
> -- operating-points-v2: See ../bindings/opp/opp.txt for details.
> -- interconnects: Should contain entries for memory clients sitting on
> -                 MC->EMC memory interconnect path.
> -- interconnect-names: Should include name of the interconnect path for each
> -                      interconnect entry. Consult TRM documentation for
> -                      information about available memory clients, see MEMORY
> -                      CONTROLLER section.
> -
> -For each opp entry in 'operating-points-v2' table:
> -- opp-supported-hw: bitfield indicating SoC speedo ID mask
> -- opp-peak-kBps: peak bandwidth of the memory channel
> -
> -Example:
> -	dfs_opp_table: opp-table {
> -		compatible = "operating-points-v2";
> -
> -		opp@12750000 {
> -			opp-hz = /bits/ 64 <12750000>;
> -			opp-supported-hw = <0x000F>;
> -			opp-peak-kBps = <51000>;
> -		};
> -		...
> -	};
> -
> -	actmon@6000c800 {
> -		compatible = "nvidia,tegra124-actmon";
> -		reg = <0x0 0x6000c800 0x0 0x400>;
> -		interrupts = <GIC_SPI 45 IRQ_TYPE_LEVEL_HIGH>;
> -		clocks = <&tegra_car TEGRA124_CLK_ACTMON>,
> -			 <&tegra_car TEGRA124_CLK_EMC>;
> -		clock-names = "actmon", "emc";
> -		resets = <&tegra_car 119>;
> -		reset-names = "actmon";
> -		operating-points-v2 = <&dfs_opp_table>;
> -		interconnects = <&mc TEGRA124_MC_MPCORER &emc>;
> -		interconnect-names = "cpu";
> -	};
> diff --git a/Documentation/devicetree/bindings/devfreq/nvidia,tegra30-actmon.yaml b/Documentation/devicetree/bindings/devfreq/nvidia,tegra30-actmon.yaml
> new file mode 100644
> index 000000000000..2a940d5d7ab4
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/devfreq/nvidia,tegra30-actmon.yaml
> @@ -0,0 +1,121 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: https://protect2.fireeye.com/v1/url?k=45c89d0a-1a53a410-45c91645-000babff24ad-23dabc3fb0c14687&q=1&e=3278a7b6-8f85-494f-a1fa-d926c45f4529&u=http%3A%2F%2Fdevicetree.org%2Fschemas%2Fdevfreq%2Fnvidia%2Ctegra30-actmon.yaml%23
> +$schema: https://protect2.fireeye.com/v1/url?k=f9f2037e-a6693a64-f9f38831-000babff24ad-e0e7e870e2aea6e2&q=1&e=3278a7b6-8f85-494f-a1fa-d926c45f4529&u=http%3A%2F%2Fdevicetree.org%2Fmeta-schemas%2Fcore.yaml%23
> +
> +title: NVIDIA Tegra30 Activity Monitor
> +
> +maintainers:
> +  - Dmitry Osipenko <digetx@gmail.com>
> +  - Jon Hunter <jonathanh@nvidia.com>
> +  - Thierry Reding <thierry.reding@gmail.com>
> +
> +description: |
> +  The activity monitor block collects statistics about the behaviour of other
> +  components in the system. This information can be used to derive the rate at
> +  which the external memory needs to be clocked in order to serve all requests
> +  from the monitored clients.
> +
> +properties:
> +  compatible:
> +    enum:
> +      - nvidia,tegra30-actmon
> +      - nvidia,tegra114-actmon
> +      - nvidia,tegra124-actmon
> +      - nvidia,tegra210-actmon
> +
> +  reg:
> +    maxItems: 1
> +
> +  clocks:
> +    maxItems: 2
> +
> +  clock-names:
> +    items:
> +      - const: actmon
> +      - const: emc
> +
> +  resets:
> +    maxItems: 1
> +
> +  reset-names:
> +    items:
> +      - const: actmon
> +
> +  interrupts:
> +    maxItems: 1
> +
> +  interconnects:
> +    minItems: 1
> +    maxItems: 12
> +
> +  interconnect-names:
> +    minItems: 1
> +    maxItems: 12
> +    description:
> +      Should include name of the interconnect path for each interconnect
> +      entry. Consult TRM documentation for information about available
> +      memory clients, see ACTIVITY MONITOR section.
> +
> +  operating-points-v2:
> +    description:
> +      Should contain freqs and voltages and opp-supported-hw property, which
> +      is a bitfield indicating SoC speedo ID mask.
> +
> +required:
> +  - compatible
> +  - reg
> +  - clocks
> +  - clock-names
> +  - resets
> +  - reset-names
> +  - interrupts
> +  - interconnects
> +  - interconnect-names
> +  - operating-points-v2
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/memory/tegra30-mc.h>
> +
> +    mc: memory-controller@7000f000 {
> +        compatible = "nvidia,tegra30-mc";
> +        reg = <0x7000f000 0x400>;
> +        clocks = <&clk 32>;
> +        clock-names = "mc";
> +
> +        interrupts = <0 77 4>;
> +
> +        #iommu-cells = <1>;
> +        #reset-cells = <1>;
> +        #interconnect-cells = <1>;
> +    };
> +
> +    emc: external-memory-controller@7000f400 {
> +        compatible = "nvidia,tegra30-emc";
> +        reg = <0x7000f400 0x400>;
> +        interrupts = <0 78 4>;
> +        clocks = <&clk 57>;
> +
> +        nvidia,memory-controller = <&mc>;
> +        operating-points-v2 = <&dvfs_opp_table>;
> +        power-domains = <&domain>;
> +
> +        #interconnect-cells = <0>;
> +    };
> +
> +    actmon@6000c800 {
> +        compatible = "nvidia,tegra30-actmon";
> +        reg = <0x6000c800 0x400>;
> +        interrupts = <0 45 4>;
> +        clocks = <&clk 119>, <&clk 57>;
> +        clock-names = "actmon", "emc";
> +        resets = <&rst 119>;
> +        reset-names = "actmon";
> +        operating-points-v2 = <&dvfs_opp_table>;
> +        interconnects = <&mc TEGRA30_MC_MPCORER &emc>;
> +        interconnect-names = "cpu-read";
> +    };
> 

Acked-by: Chanwoo Choi <cw00.choi@samsung.com>

After tegra SoC maintainer review this patch, I'll take it.

-- 
Best Regards,
Chanwoo Choi
Samsung Electronics

Re: [PATCH v1 1/7] PM / devfreq: tegra30: Support thermal cooling

[Chanwoo Choi]

On 5/11/21 6:10 AM, Dmitry Osipenko wrote:
> Expose ACTMON devfreq device as a cooling device in order to throttle
> memory freq on overheat. Throttling of memory freq has a significant
> cooling effect on NVIDIA Tegra SoCs since higher memory freqs require
> higher SoC core voltage which is one of the main causes of the heating.
> 
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
>  drivers/devfreq/tegra30-devfreq.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/devfreq/tegra30-devfreq.c b/drivers/devfreq/tegra30-devfreq.c
> index ce83f883ca65..10661eb2aed8 100644
> --- a/drivers/devfreq/tegra30-devfreq.c
> +++ b/drivers/devfreq/tegra30-devfreq.c
> @@ -688,6 +688,7 @@ static struct devfreq_dev_profile tegra_devfreq_profile = {
>  	.polling_ms	= ACTMON_SAMPLING_PERIOD,
>  	.target		= tegra_devfreq_target,
>  	.get_dev_status	= tegra_devfreq_get_dev_status,
> +	.is_cooling_device = true,
>  };
>  
>  static int tegra_governor_get_target(struct devfreq *devfreq,
> 

Applied it. Thanks.

-- 
Best Regards,
Chanwoo Choi
Samsung Electronics

Re: [PATCH v1 3/7] dt-bindings: devfreq: tegra30-actmon: Convert to schema

[Thierry Reding]

[-- Attachment #1: Type: text/plain, Size: 5433 bytes --]

On Tue, May 11, 2021 at 12:10:04AM +0300, Dmitry Osipenko wrote:
> Convert NVIDIA Tegra ACTMON binding to schema.
> 
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
>  .../arm/tegra/nvidia,tegra30-actmon.txt       |  57 ---------
>  .../devfreq/nvidia,tegra30-actmon.yaml        | 121 ++++++++++++++++++
>  2 files changed, 121 insertions(+), 57 deletions(-)
>  delete mode 100644 Documentation/devicetree/bindings/arm/tegra/nvidia,tegra30-actmon.txt
>  create mode 100644 Documentation/devicetree/bindings/devfreq/nvidia,tegra30-actmon.yaml
> 
> diff --git a/Documentation/devicetree/bindings/arm/tegra/nvidia,tegra30-actmon.txt b/Documentation/devicetree/bindings/arm/tegra/nvidia,tegra30-actmon.txt
> deleted file mode 100644
> index 897eedfa2bc8..000000000000
> --- a/Documentation/devicetree/bindings/arm/tegra/nvidia,tegra30-actmon.txt
> +++ /dev/null
> @@ -1,57 +0,0 @@
> -NVIDIA Tegra Activity Monitor
> -
> -The activity monitor block collects statistics about the behaviour of other
> -components in the system. This information can be used to derive the rate at
> -which the external memory needs to be clocked in order to serve all requests
> -from the monitored clients.
> -
> -Required properties:
> -- compatible: should be "nvidia,tegra<chip>-actmon"
> -- reg: offset and length of the register set for the device
> -- interrupts: standard interrupt property
> -- clocks: Must contain a phandle and clock specifier pair for each entry in
> -clock-names. See ../../clock/clock-bindings.txt for details.
> -- clock-names: Must include the following entries:
> -  - actmon
> -  - emc
> -- resets: Must contain an entry for each entry in reset-names. See
> -../../reset/reset.txt for details.
> -- reset-names: Must include the following entries:
> -  - actmon
> -- operating-points-v2: See ../bindings/opp/opp.txt for details.
> -- interconnects: Should contain entries for memory clients sitting on
> -                 MC->EMC memory interconnect path.
> -- interconnect-names: Should include name of the interconnect path for each
> -                      interconnect entry. Consult TRM documentation for
> -                      information about available memory clients, see MEMORY
> -                      CONTROLLER section.
> -
> -For each opp entry in 'operating-points-v2' table:
> -- opp-supported-hw: bitfield indicating SoC speedo ID mask
> -- opp-peak-kBps: peak bandwidth of the memory channel
> -
> -Example:
> -	dfs_opp_table: opp-table {
> -		compatible = "operating-points-v2";
> -
> -		opp@12750000 {
> -			opp-hz = /bits/ 64 <12750000>;
> -			opp-supported-hw = <0x000F>;
> -			opp-peak-kBps = <51000>;
> -		};
> -		...
> -	};
> -
> -	actmon@6000c800 {
> -		compatible = "nvidia,tegra124-actmon";
> -		reg = <0x0 0x6000c800 0x0 0x400>;
> -		interrupts = <GIC_SPI 45 IRQ_TYPE_LEVEL_HIGH>;
> -		clocks = <&tegra_car TEGRA124_CLK_ACTMON>,
> -			 <&tegra_car TEGRA124_CLK_EMC>;
> -		clock-names = "actmon", "emc";
> -		resets = <&tegra_car 119>;
> -		reset-names = "actmon";
> -		operating-points-v2 = <&dfs_opp_table>;
> -		interconnects = <&mc TEGRA124_MC_MPCORER &emc>;
> -		interconnect-names = "cpu";
> -	};
> diff --git a/Documentation/devicetree/bindings/devfreq/nvidia,tegra30-actmon.yaml b/Documentation/devicetree/bindings/devfreq/nvidia,tegra30-actmon.yaml
> new file mode 100644
> index 000000000000..2a940d5d7ab4
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/devfreq/nvidia,tegra30-actmon.yaml
> @@ -0,0 +1,121 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/devfreq/nvidia,tegra30-actmon.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: NVIDIA Tegra30 Activity Monitor
> +
> +maintainers:
> +  - Dmitry Osipenko <digetx@gmail.com>
> +  - Jon Hunter <jonathanh@nvidia.com>
> +  - Thierry Reding <thierry.reding@gmail.com>
> +
> +description: |
> +  The activity monitor block collects statistics about the behaviour of other
> +  components in the system. This information can be used to derive the rate at
> +  which the external memory needs to be clocked in order to serve all requests
> +  from the monitored clients.
> +
> +properties:
> +  compatible:
> +    enum:
> +      - nvidia,tegra30-actmon
> +      - nvidia,tegra114-actmon
> +      - nvidia,tegra124-actmon
> +      - nvidia,tegra210-actmon
> +
> +  reg:
> +    maxItems: 1
> +
> +  clocks:
> +    maxItems: 2
> +
> +  clock-names:
> +    items:
> +      - const: actmon
> +      - const: emc
> +
> +  resets:
> +    maxItems: 1
> +
> +  reset-names:
> +    items:
> +      - const: actmon
> +
> +  interrupts:
> +    maxItems: 1
> +
> +  interconnects:
> +    minItems: 1
> +    maxItems: 12
> +
> +  interconnect-names:
> +    minItems: 1
> +    maxItems: 12
> +    description:
> +      Should include name of the interconnect path for each interconnect
> +      entry. Consult TRM documentation for information about available
> +      memory clients, see ACTIVITY MONITOR section.

This used to be "see MEMORY CONTROLLER section", so I looked at the TRM
to see if this was perhaps a fix for an earlier typo, but looking at the
TRM (v3) I can't find a section named "ACTIVITY MONITOR".

Should this be changed back to "MEMORY CONTROLLER"?

Thierry

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]

Re: [PATCH v1 4/7] dt-bindings: devfreq: tegra30-actmon: Add cooling-cells

[Thierry Reding]

[-- Attachment #1: Type: text/plain, Size: 590 bytes --]

On Tue, May 11, 2021 at 12:10:05AM +0300, Dmitry Osipenko wrote:
> The ACTMON watches activity of memory clients. Decisions about a minimum
> required frequency are made based on the info from ACTMON. We can use
> ACTMON as a thermal cooling device by limiting the required frequency.
> Document new cooling-cells property of NVIDIA Tegra ACTMON hardware unit.
> 
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
>  .../devicetree/bindings/devfreq/nvidia,tegra30-actmon.yaml   | 5 +++++
>  1 file changed, 5 insertions(+)

Acked-by: Thierry Reding <treding@nvidia.com>

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]

Re: (subset) [PATCH v1 0/7] Add thermal cooling support to NVIDIA Tegra devfreq

[Thierry Reding]

From: Thierry Reding <treding@nvidia.com>

On Tue, 11 May 2021 00:10:01 +0300, Dmitry Osipenko wrote:
> Some hardware versions of NVIDIA Tegra SoCs support higher freqs and they
> are producing much more heat than the other versions. We found that CPU
> throttling may be not enough on devices like Asus Transformer TF700T,
> which is Tegra30 tablet device. This series adds thermal cooling support
> to the NVIDIA Tegra30+ devfreq which cools down SoC by throttling memory
> frequency on overheat.
> 
> [...]

Applied, thanks!

[5/7] ARM: tegra: Add cooling cells to ACTMON device-tree node
      commit: 592b74b1f0ebfe49d2e66b2b4bd95ff3678c5696
[6/7] ARM: tegra: nexus7: Enable memory frequency thermal throttling using ACTMON
      commit: fe7482b88590635939c4bb786e1cd3bbd9ea1682
[7/7] ARM: tegra: ouya: Enable memory frequency thermal throttling using ACTMON
      commit: 4c101a4466983abe7798493ef17279cc3f8eb028

Best regards,
-- 
Thierry Reding <treding@nvidia.com>

Re: (subset) [PATCH v1 0/7] Add thermal cooling support to NVIDIA Tegra devfreq

[Thierry Reding]

From: Thierry Reding <treding@nvidia.com>

On Tue, 11 May 2021 00:10:01 +0300, Dmitry Osipenko wrote:
> Some hardware versions of NVIDIA Tegra SoCs support higher freqs and they
> are producing much more heat than the other versions. We found that CPU
> throttling may be not enough on devices like Asus Transformer TF700T,
> which is Tegra30 tablet device. This series adds thermal cooling support
> to the NVIDIA Tegra30+ devfreq which cools down SoC by throttling memory
> frequency on overheat.
> 
> [...]

Applied, thanks!

[2/7] ARM: tegra_defconfig: Enable CONFIG_DEVFREQ_THERMAL
      commit: 4302331fdf4440b96dba583384a0e2b759cb13bd

Best regards,
-- 
Thierry Reding <treding@nvidia.com>

Re: [PATCH v1 3/7] dt-bindings: devfreq: tegra30-actmon: Convert to schema

[Dmitry Osipenko]

31.05.2021 12:36, Thierry Reding пишет:
> On Tue, May 11, 2021 at 12:10:04AM +0300, Dmitry Osipenko wrote:
>> Convert NVIDIA Tegra ACTMON binding to schema.
>>
>> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
>> ---
>>  .../arm/tegra/nvidia,tegra30-actmon.txt       |  57 ---------
>>  .../devfreq/nvidia,tegra30-actmon.yaml        | 121 ++++++++++++++++++
>>  2 files changed, 121 insertions(+), 57 deletions(-)
>>  delete mode 100644 Documentation/devicetree/bindings/arm/tegra/nvidia,tegra30-actmon.txt
>>  create mode 100644 Documentation/devicetree/bindings/devfreq/nvidia,tegra30-actmon.yaml
>>
>> diff --git a/Documentation/devicetree/bindings/arm/tegra/nvidia,tegra30-actmon.txt b/Documentation/devicetree/bindings/arm/tegra/nvidia,tegra30-actmon.txt
>> deleted file mode 100644
>> index 897eedfa2bc8..000000000000
>> --- a/Documentation/devicetree/bindings/arm/tegra/nvidia,tegra30-actmon.txt
>> +++ /dev/null
>> @@ -1,57 +0,0 @@
>> -NVIDIA Tegra Activity Monitor
>> -
>> -The activity monitor block collects statistics about the behaviour of other
>> -components in the system. This information can be used to derive the rate at
>> -which the external memory needs to be clocked in order to serve all requests
>> -from the monitored clients.
>> -
>> -Required properties:
>> -- compatible: should be "nvidia,tegra<chip>-actmon"
>> -- reg: offset and length of the register set for the device
>> -- interrupts: standard interrupt property
>> -- clocks: Must contain a phandle and clock specifier pair for each entry in
>> -clock-names. See ../../clock/clock-bindings.txt for details.
>> -- clock-names: Must include the following entries:
>> -  - actmon
>> -  - emc
>> -- resets: Must contain an entry for each entry in reset-names. See
>> -../../reset/reset.txt for details.
>> -- reset-names: Must include the following entries:
>> -  - actmon
>> -- operating-points-v2: See ../bindings/opp/opp.txt for details.
>> -- interconnects: Should contain entries for memory clients sitting on
>> -                 MC->EMC memory interconnect path.
>> -- interconnect-names: Should include name of the interconnect path for each
>> -                      interconnect entry. Consult TRM documentation for
>> -                      information about available memory clients, see MEMORY
>> -                      CONTROLLER section.
>> -
>> -For each opp entry in 'operating-points-v2' table:
>> -- opp-supported-hw: bitfield indicating SoC speedo ID mask
>> -- opp-peak-kBps: peak bandwidth of the memory channel
>> -
>> -Example:
>> -	dfs_opp_table: opp-table {
>> -		compatible = "operating-points-v2";
>> -
>> -		opp@12750000 {
>> -			opp-hz = /bits/ 64 <12750000>;
>> -			opp-supported-hw = <0x000F>;
>> -			opp-peak-kBps = <51000>;
>> -		};
>> -		...
>> -	};
>> -
>> -	actmon@6000c800 {
>> -		compatible = "nvidia,tegra124-actmon";
>> -		reg = <0x0 0x6000c800 0x0 0x400>;
>> -		interrupts = <GIC_SPI 45 IRQ_TYPE_LEVEL_HIGH>;
>> -		clocks = <&tegra_car TEGRA124_CLK_ACTMON>,
>> -			 <&tegra_car TEGRA124_CLK_EMC>;
>> -		clock-names = "actmon", "emc";
>> -		resets = <&tegra_car 119>;
>> -		reset-names = "actmon";
>> -		operating-points-v2 = <&dfs_opp_table>;
>> -		interconnects = <&mc TEGRA124_MC_MPCORER &emc>;
>> -		interconnect-names = "cpu";
>> -	};
>> diff --git a/Documentation/devicetree/bindings/devfreq/nvidia,tegra30-actmon.yaml b/Documentation/devicetree/bindings/devfreq/nvidia,tegra30-actmon.yaml
>> new file mode 100644
>> index 000000000000..2a940d5d7ab4
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/devfreq/nvidia,tegra30-actmon.yaml
>> @@ -0,0 +1,121 @@
>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/devfreq/nvidia,tegra30-actmon.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: NVIDIA Tegra30 Activity Monitor
>> +
>> +maintainers:
>> +  - Dmitry Osipenko <digetx@gmail.com>
>> +  - Jon Hunter <jonathanh@nvidia.com>
>> +  - Thierry Reding <thierry.reding@gmail.com>
>> +
>> +description: |
>> +  The activity monitor block collects statistics about the behaviour of other
>> +  components in the system. This information can be used to derive the rate at
>> +  which the external memory needs to be clocked in order to serve all requests
>> +  from the monitored clients.
>> +
>> +properties:
>> +  compatible:
>> +    enum:
>> +      - nvidia,tegra30-actmon
>> +      - nvidia,tegra114-actmon
>> +      - nvidia,tegra124-actmon
>> +      - nvidia,tegra210-actmon
>> +
>> +  reg:
>> +    maxItems: 1
>> +
>> +  clocks:
>> +    maxItems: 2
>> +
>> +  clock-names:
>> +    items:
>> +      - const: actmon
>> +      - const: emc
>> +
>> +  resets:
>> +    maxItems: 1
>> +
>> +  reset-names:
>> +    items:
>> +      - const: actmon
>> +
>> +  interrupts:
>> +    maxItems: 1
>> +
>> +  interconnects:
>> +    minItems: 1
>> +    maxItems: 12
>> +
>> +  interconnect-names:
>> +    minItems: 1
>> +    maxItems: 12
>> +    description:
>> +      Should include name of the interconnect path for each interconnect
>> +      entry. Consult TRM documentation for information about available
>> +      memory clients, see ACTIVITY MONITOR section.
> 
> This used to be "see MEMORY CONTROLLER section", so I looked at the TRM
> to see if this was perhaps a fix for an earlier typo, but looking at the
> TRM (v3) I can't find a section named "ACTIVITY MONITOR".
> 
> Should this be changed back to "MEMORY CONTROLLER"?

The "ACTIVITY MONITOR" is documented only in the T124/210 TRMs, the h/w
modules supported by ACTMON are enumerated there. Both "ACTIVITY
MONITOR" and "MEMORY CONTROLLER" could be mentioned for completeness.