Re: [PATCH 2/4] dt-bindings: introduce RPMH RSC bindings for Qualcomm SoCs
From: Rob Herring <robh@kernel.org>
Date: 2018-01-29 19:33:44
Also in:
linux-arm-msm, linux-pm
On Thu, Jan 18, 2018 at 05:01:55PM -0700, Lina Iyer wrote:
Add device binding documentation for Qualcomm Technology Inc's RPMH RSC driver. The hardware block is used for communicating resource state requests for shared resources. Cc: devicetree@vger.kernel.org Signed-off-by: Lina Iyer <redacted> --- .../devicetree/bindings/arm/msm/rpmh-rsc.txt | 134 +++++++++++++++++++++
bindings/mailbox instead?
quoted hunk ↗ jump to hunk
1 file changed, 134 insertions(+) create mode 100644 Documentation/devicetree/bindings/arm/msm/rpmh-rsc.txtdiff --git a/Documentation/devicetree/bindings/arm/msm/rpmh-rsc.txt b/Documentation/devicetree/bindings/arm/msm/rpmh-rsc.txt new file mode 100644 index 000000000000..b0cd55caf916 --- /dev/null +++ b/Documentation/devicetree/bindings/arm/msm/rpmh-rsc.txt@@ -0,0 +1,134 @@ +RPMH RSC: +------------ + +RPMH is the mechanism for communicating with the hardened resource +accelerators. Requests to the resources can be written to the TCS mailbox +registers and using a (addr, val) pair and triggered. Messages in the TCS are +then sent in sequence over an internal bus. + +The hardware block (Direct Resource Voter or DRV) is a part of the h/w entity +(Resource State Coordinator a.k.a RSC) that can handle a multiple sleep and +active/wake resource requests. Multiple such DRVs can exist in a SoC and can +be written to from Linux. The structure of each DRV follows the same template +with a few variations that are captured by the properties here. + +Each DRV could have 'm' TCS instances. Each TCS could have 'n' slots. Each +slot has a header (u32), address (u32), data (u32), status (u32) and a +read-response (u32). A TCS when triggered will send all the enabled commands +of the 'n' commands in that slot in sequence. + +A TCS may be triggered from Linux or triggered by the F/W after all the CPUs +have powered off to faciliate idle power saving. TCS could be classified as - + + SLEEP, /* Triggered by F/W */ + WAKE, /* Triggered by F/W */ + ACTIVE, /* Triggered by Linux */ + CONTROL /* Triggered by F/W */ + +The order in which they are described in the DT, should match the hardware +configuration. + +Requests can be made for the state of a resource, when the subsystem is active +or idle. When all subsystems like Modem, GPU, CPU are idle, the resource state +will be an aggregeate of the sleep votes from each of those subsystem. Drivers +may request a sleep value for their shared resources in addition to the active +mode requests. + +Control requests are instance specific requests that may or may not reach an +accelerator. Only one platform device in Linux can request a control channel +on a DRV. + +CONTROLLER: +---------- + +PROPERTIES: + +- compatible: + Usage: required + Value type: <string> + Definition: Should be "qcom,rpmh-rsc". + +- reg: + Usage: required + Value type: <prop-encoded-array> + Definition: the first element specifies the base address of the DRV, + the second element specifies the size of the region. + +- interrupts: + Usage: required + Value type: <prop-encoded-interrupt> + Definition: the interrupt that trips when a message complete/response + is received for this DRV from the accelertors. + +- qcom,drv-id: + Usage: required + Value type: <u32> + Definition: the id of the DRV in the RSC block. + +- qcom, tcs-config:
^ space
+ Usage: required + Value type: <prop-encoded-array> + Definition: the tuple definining the configuration of TCS. + Must have 2 cells which describe each TCS type. + <type number_of_tcs> + - Cell #1 (TCS Type): TCS types can be specified - + SLEEP_TCS + WAKE_TCS + ACTIVE_TCS + CONTROL_TCS
These defines belong in this patch.
+ - Cell #2 (Number of TCS): <u32>
Is there some sort of range of numbers?
+ +- label: + Usage: optional + Value type: <string> + Definition: Name for the RSC. The name would be used in trace logs. + +Clients the want to use the RSC to communicate with RPMH would specify their
Clients the want?
+bindings as child of the corresponding RSC controllers.
Need to be specific here about what the child nodes are.
+
+EXAMPLE 1:
+
+For a TCS whose RSC base address is is 0x179C0000 and is at a DRV of 2, the
+register offsets for DRV2 start at 0D00, the register calculations are like
+this -
+First tuple: 0x179C0000 + 0x10000 * 2 = 0x179E0000
+Second tuple: 0x179E0000 + 0xD00 = 0x179E0D00
+
+ apps_rsc: rsc@179e000 {
+ compatible = "qcom,rpmh-rsc";
+ label = "apps_rsc";
+ reg = <0x179e0000 0x10000>, <0x179e0d00 0x3000>;
+ interrupts = <0 5 0>;
+ qcom,drv-id = <2>;
+ qcom,tcs-config = <SLEEP_TCS 3>,
+ <WAKE_TCS 3>,
+ <ACTIVE_TCS 2>,
+ <CONTROL_TCS 1>;
+
+ foo-clk {
+ compatible = "foo-clk";
+ };
+ };
+
+EXAMPLE 2:
+
+For a TCS whose RSC base address is 0xAF20000 and is at DRV of 0, the register
+offsets for DRV0 start at 01C00, the register calculations are like this -
+First tuple: 0xAF20000
+Second tuple: 0xAF20000 + 0x1C00
+
+ disp_rsc: rsc@af20000 {
+ label = "disp_rsc";
+ compatible = "qcom,rpmh-rsc";
+ reg = <0xaf20000 0x10000>, <0xaf21c00 0x3000>;
+ interrupts = <0 129 0>;
+ qcom,drv-id = <0>;
+ qcom,tcs-config = <SLEEP_TCS 1>,
+ <WAKE_TCS 1>,
+ <ACTIVE_TCS 0>,
+ <CONTROL_TCS 1>;
+
+ foo-clk {
+ compatible = "foo-clk";
+ };
+ };
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html