Add thermal cooling support to NVIDIA Tegra devfreq

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 <[email protected]>

---
 drivers/devfreq/tegra30-devfreq.c | 1 +
 1 file changed, 1 insertion(+)

drivers/devfreq/tegra30-devfreq.c +0 -0

index ce83f883ca65..10661eb2aed8 100644

Convert NVIDIA Tegra ACTMON binding to schema.

Signed-off-by Dmitry Osipenko <[email protected]>

---
 .../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

Convert NVIDIA Tegra ACTMON binding to schema.

Signed-off-by Dmitry Osipenko <[email protected]>

---
 .../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

Documentation/devicetree/bindings/arm/tegra/nvidia,tegra30-actmon.txt deleted +0 -57

deleted file mode 100644
index 897eedfa2bc8..000000000000
@@ -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";
-	};

Documentation/devicetree/bindings/devfreq/nvidia,tegra30-actmon.yaml new file +111 -0

new file mode 100644
index 000000000000..2a940d5d7ab4
@@ -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 <[email protected]>
+  - Jon Hunter <[email protected]>
+  - Thierry Reding <[email protected]>
+
+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";

Convert NVIDIA Tegra ACTMON binding to schema.

Signed-off-by Dmitry Osipenko <[email protected]>

---
 .../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

Documentation/devicetree/bindings/arm/tegra/nvidia,tegra30-actmon.txt deleted +0 -57

deleted file mode 100644
index 897eedfa2bc8..000000000000
@@ -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";
-	};

Documentation/devicetree/bindings/devfreq/nvidia,tegra30-actmon.yaml new file +49 -0

new file mode 100644
index 000000000000..2a940d5d7ab4
@@ -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 <[email protected]>
+  - Jon Hunter <[email protected]>
+  - Thierry Reding <[email protected]>
+
+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:

Quoted 128 lines

Convert NVIDIA Tegra ACTMON binding to schema.

Signed-off-by Dmitry Osipenko <[email protected]>

---
 .../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

Documentation/devicetree/bindings/arm/tegra/nvidia,tegra30-actmon.txt deleted +0 -57

deleted file mode 100644
index 897eedfa2bc8..000000000000
@@ -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";
-	};

Documentation/devicetree/bindings/devfreq/nvidia,tegra30-actmon.yaml new file +49 -0

new file mode 100644
index 000000000000..2a940d5d7ab4
@@ -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 <[email protected]>
+  - Jon Hunter <[email protected]>
+  - Thierry Reding <[email protected]>
+
+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:

Documentation/devicetree/bindings/devfreq/nvidia,tegra30-actmon.yaml line 59

Quoted 10 lines

Documentation/devicetree/bindings/devfreq/nvidia,tegra30-actmon.yaml new file +10 -0

+    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 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 <[email protected]>

---
 .../devicetree/bindings/devfreq/nvidia,tegra30-actmon.yaml   | 5 +++++
 1 file changed, 5 insertions(+)

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 <[email protected]>

---
 .../devicetree/bindings/devfreq/nvidia,tegra30-actmon.yaml   | 5 +++++
 1 file changed, 5 insertions(+)

Documentation/devicetree/bindings/devfreq/nvidia,tegra30-actmon.yaml +4 -0

index 2a940d5d7ab4..0aa9459b7751 100644
@@ -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
 

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 <[email protected]>

---
 .../devicetree/bindings/devfreq/nvidia,tegra30-actmon.yaml   | 5 +++++
 1 file changed, 5 insertions(+)

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.

[...]

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.

[...]