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Subject[PATCH RFC 4/9] dt-bindings: devfreq: Add bindings for devfreq dev-icbw driver
Date
Add dt-bindings support for a generic interconnect bandwidth voting
devfreq driver.

Signed-off-by: Sibi Sankar <sibis@codeaurora.org>
---
.../devicetree/bindings/devfreq/icbw.txt | 146 ++++++++++++++++++
1 file changed, 146 insertions(+)
create mode 100644 Documentation/devicetree/bindings/devfreq/icbw.txt

diff --git a/Documentation/devicetree/bindings/devfreq/icbw.txt b/Documentation/devicetree/bindings/devfreq/icbw.txt
new file mode 100644
index 000000000000..389aa77a2363
--- /dev/null
+++ b/Documentation/devicetree/bindings/devfreq/icbw.txt
@@ -0,0 +1,146 @@
+Interconnect bandwidth device
+
+icbw is a device that represents an interconnect path that connects two
+devices. This device is typically used to vote for BW requirements between
+two devices. Eg: CPU to DDR, GPU to DDR, etc. This device is expected to
+use passive govenor by default.
+
+Required properties:
+- compatible: Must be "devfreq-icbw"
+- interconnects: Pairs of phandles and interconnect provider specifier
+ to denote the edge source and destination ports of
+ the interconnect path. See also:
+ Documentation/devicetree/bindings/interconnect/interconnect.txt
+- operating-points-v2: A phandle to an OPP v2 table that holds frequency,
+ bandwidth values (in MB/s) and required-opp's populated
+ with phandles pointing to the required per cpu opp. The
+ bandwidth (in MB/s) values depend on multiple properties
+ of the interconnect path like frequency, interconnect
+ width, etc.
+
+Example:
+
+cpus {
+ ...
+
+ CPU0: cpu@0 {
+ ...
+ operating-points-v2 = <&cpu0_opp_table>;
+ ...
+ };
+
+ CPU1: cpu@100 {
+ ...
+ operating-points-v2 = <&cpu0_opp_table>;
+ ...
+ };
+
+ CPU2: cpu@200 {
+ ...
+ operating-points-v2 = <&cpu0_opp_table>;
+ ...
+ };
+
+ CPU3: cpu@300 {
+ ...
+ operating-points-v2 = <&cpu0_opp_table>;
+ ...
+ };
+
+ CPU4: cpu@400 {
+ ...
+ operating-points-v2 = <&cpu4_opp_table>;
+ ...
+ };
+
+ CPU5: cpu@500 {
+ ...
+ operating-points-v2 = <&cpu4_opp_table>;
+ ...
+ };
+
+ CPU6: cpu@600 {
+ ...
+ operating-points-v2 = <&cpu4_opp_table>;
+ ...
+ };
+
+ CPU7: cpu@700 {
+ ...
+ operating-points-v2 = <&cpu4_opp_table>;
+ ...
+ };
+};
+
+cpu0_opp_table: cpu0_opp_table {
+ compatible = "operating-points-v2";
+ opp-shared;
+
+ cpu0_opp1: opp-300000000 {
+ opp-hz = /bits/ 64 <300000000>;
+ };
+
+ ...
+
+ cpu0_opp16: opp-1612800000 {
+ opp-hz = /bits/ 64 <1612800000>;
+ };
+
+ ...
+};
+
+cpu4_opp_table: cpu4_opp_table {
+ compatible = "operating-points-v2";
+ opp-shared;
+
+ ...
+
+ cpu4_opp4: opp-1056000000 {
+ opp-hz = /bits/ 64 <1056000000>;
+ };
+
+ cpu4_opp5: opp-1209600000 {
+ opp-hz = /bits/ 64 <1209600000>;
+ };
+
+ ...
+};
+
+bw_opp_table: bw-opp-table {
+ compatible = "operating-points-v2";
+
+ opp-200 {
+ opp-hz = /bits/ 64 < 200000000 >; /* 200 MHz */
+ required-opps = <&cpu0_opp1>;
+ /* 0 MB/s average and 762 MB/s peak bandwidth */
+ opp-bw-MBs = <0 762>;
+ };
+
+ opp-300 {
+ opp-hz = /bits/ 64 < 300000000 >; /* 300 MHz */
+ /* 0 MB/s average and 1144 MB/s peak bandwidth */
+ opp-bw-MBs = <0 1144>;
+ };
+
+ ...
+
+ opp-768 {
+ opp-hz = /bits/ 64 < 768000000 >; /* 768 MHz */
+ /* 0 MB/s average and 2929 MB/s peak bandwidth */
+ opp-bw-MBs = <0 2929>;
+ required-opps = <&cpu4_opp4>;
+ };
+
+ opp-1017 {
+ opp-hz = /bits/ 64 < 1017000000 >; /* 1017 MHz */
+ /* 0 MB/s average and 3879 MB/s peak bandwidth */
+ opp-bw-MBs = <0 3879>;
+ required-opps = <&cpu0_opp16>, <&cpu4_opp5>;
+ };
+};
+
+cpubw {
+ compatible = "devfreq-icbw";
+ interconnects = <&snoc MASTER_APSS_1 &bimc SLAVE_EBI_CH0>;
+ operating-points-v2 = <&bw_opp_table>;
+};
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
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