[PATCH v4 05/19] dt-bindings: display: imx: Add i.MX8qxp Display Controller AXI performance counter

Liu Ying victor.liu at nxp.com
Mon Nov 25 01:33:02 PST 2024


i.MX8qxp Display Controller contains a AXI performance counter which allows
measurement of average bandwidth and latency during operation.

Signed-off-by: Liu Ying <victor.liu at nxp.com>
Reviewed-by: Rob Herring (Arm) <robh at kernel.org>
---
v4:
* Collect Rob's R-b tag.

v3:
* New patch. (Rob)

 ...sl,imx8qxp-dc-axi-performance-counter.yaml | 57 +++++++++++++++++++
 1 file changed, 57 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/display/imx/fsl,imx8qxp-dc-axi-performance-counter.yaml

diff --git a/Documentation/devicetree/bindings/display/imx/fsl,imx8qxp-dc-axi-performance-counter.yaml b/Documentation/devicetree/bindings/display/imx/fsl,imx8qxp-dc-axi-performance-counter.yaml
new file mode 100644
index 000000000000..1d6501afc7f2
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/imx/fsl,imx8qxp-dc-axi-performance-counter.yaml
@@ -0,0 +1,57 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/display/imx/fsl,imx8qxp-dc-axi-performance-counter.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Freescale i.MX8qxp Display Controller AXI Performance Counter
+
+description: |
+  Performance counters are provided to allow measurement of average bandwidth
+  and latency during operation. The following features are supported:
+
+  * Manual and timer controlled measurement mode.
+
+  * Measurement counters:
+    - GLOBAL_COUNTER for overall measurement time
+    - BUSY_COUNTER for number of data bus busy cycles
+    - DATA_COUNTER for number of data transfer cycles
+    - TRANSFER_COUNTER for number of transfers
+    - ADDRBUSY_COUNTER for number of address bus busy cycles
+    - LATENCY_COUNTER for average latency
+
+  * Counter overflow detection.
+
+  * Outstanding Transfer Counters (OTC) which are used for latency measurement
+    have to run immediately after reset, but can be disabled by software when
+    there is no need for latency measurement.
+
+maintainers:
+  - Liu Ying <victor.liu at nxp.com>
+
+properties:
+  compatible:
+    const: fsl,imx8qxp-dc-axi-performance-counter
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - clocks
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/imx8-lpcg.h>
+
+    pmu at 5618f000 {
+        compatible = "fsl,imx8qxp-dc-axi-performance-counter";
+        reg = <0x5618f000 0x90>;
+        clocks = <&dc0_lpcg IMX_LPCG_CLK_5>;
+    };
-- 
2.34.1




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