[PATCH v2 05/12] dt-bindings: remoteproc: Add Qualcomm RPM processor/subsystem

From: Stephan Gerhold
Date: Thu Jun 08 2023 - 03:11:39 EST

On Qualcomm platforms, most subsystems (e.g. audio/modem DSP) are
described as remote processors in the device tree, with a dedicated
node where properties and services related to them can be described.

The Resource Power Manager (RPM) is also such a subsystem, with a
remote processor that is running a special firmware. Unfortunately,
the RPM never got a dedicated node representing it properly in the
device tree. Most of the RPM services are described below a top-level
/smd or /rpm-glink node.

However, SMD/GLINK is just one of the communication channels to the RPM
firmware. For example, the MPM interrupt functionality provided by the
RPM does not use SMD/GLINK but writes directly to a special memory
region allocated by the RPM firmware in combination with a mailbox.
Currently there is no good place in the device tree to describe this
functionality. It doesn't belong below SMD/GLINK but it's not an
independent top-level device either.

Introduce a new "qcom,rpm-proc" compatible that allows describing the
RPM as a remote processor/subsystem like all others. The SMD/GLINK node
is moved to a "smd-edge"/"glink-edge" subnode consistent with other
existing bindings. Additional subnodes (e.g. interrupt-controller for
MPM, rpm-master-stats) can be also added there.

Deprecate using the old top-level /smd node since all SMD edges
are now specified as subnodes of the remote processor.

Signed-off-by: Stephan Gerhold <stephan@xxxxxxxxxxx>
---
This patch is based on qcom/for-next, since it needs the new
qcom,rpm-master-stats.yaml schema that is only applied there.
---
.../bindings/remoteproc/qcom,rpm-proc.yaml | 171 +++++++++++++++++++++
.../devicetree/bindings/soc/qcom/qcom,smd-rpm.yaml | 6 +-
.../devicetree/bindings/soc/qcom/qcom,smd.yaml | 7 +
3 files changed, 181 insertions(+), 3 deletions(-)

diff --git a/Documentation/devicetree/bindings/remoteproc/qcom,rpm-proc.yaml b/Documentation/devicetree/bindings/remoteproc/qcom,rpm-proc.yaml
new file mode 100644
index 000000000000..9c016613463f
--- /dev/null
+++ b/Documentation/devicetree/bindings/remoteproc/qcom,rpm-proc.yaml
@@ -0,0 +1,171 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/remoteproc/qcom,rpm-proc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Qualcomm Resource Power Manager (RPM) Processor/Subsystem
+
+maintainers:
+ - Bjorn Andersson <andersson@xxxxxxxxxx>
+ - Konrad Dybcio <konrad.dybcio@xxxxxxxxxx>
+ - Stephan Gerhold <stephan@xxxxxxxxxxx>
+
+description: |
+ Resource Power Manager (RPM) subsystem found in various Qualcomm platforms:
+
+ +--------------------------------------------+
+ | RPM subsystem (qcom,rpm-proc) |
+ | |
+ reset | +---------------+ +-----+ +-----+ |
+ --------->| | | MPM | | CPR | ... |
+ IPC interrupts | | ARM Cortex-M3 |--- +-----+ +-----+ |
+ ----------------->| | | | | |
+ | +---------------+ |---------------------- |
+ | +---------------+ | |
+ | | Code RAM |--| +------------------+ |
+ | +---------------+ | | | |
+ | +---------------+ |--| Message RAM | |
+ | | Data RAM |--| | | |
+ | +---------------+ | +------------------+ |
+ +--------------------|-----------------------+
+ v
+ NoC
+
+ The firmware running on the processor inside the RPM subsystem allows each
+ component in the system to vote for state of the system resources, such as
+ clocks, regulators and bus frequencies. It implements multiple separate
+ communication interfaces that are described in subnodes, e.g. SMD and MPM:
+
+ +------------------------------+
+ | ARM Cortex-M3 |
+ | | +------------------------------+
+ | +--------------------------+ | | Message RAM |
+ | | RPM firmware | | | |
+ IPC IRQ 0 | | +----------------------+ | | | +--------------------------+ |
+ -------------->| SMD server |<------->| SMD data structures | |
+ | | | +--------------+ | | | | | +--------------+ | |
+ | | | | rpm_requests | ... | | | | | | rpm_requests | ... | |
+ | | | +--------------+ | | | | | +--------------+ | |
+ IPC IRQ 1 | | +----------------------+ | | | +--------------------------+ |
+ -------------->| MPM virtualization |<--------| MPM register copy (vMPM) | |
+ | | +----------------------+ | | | +--------------------------+ |
+ | | ... | | | | ... |
+ | +--------------------|-----+ | +------------------------------+
+ +----------------------|-------+
+ v
+ +--------------+
+ | MPM Hardware |
+ +--------------+
+
+ The services provided by the firmware are only available after the firmware
+ has been loaded and the processor has been released from reset. Usually this
+ happens early in the boot process before the operating system is started.
+
+properties:
+ compatible:
+ items:
+ - enum:
+ - qcom,apq8084-rpm-proc
+ - qcom,ipq6018-rpm-proc
+ - qcom,ipq9574-rpm-proc
+ - qcom,mdm9607-rpm-proc
+ - qcom,msm8226-rpm-proc
+ - qcom,msm8610-rpm-proc
+ - qcom,msm8909-rpm-proc
+ - qcom,msm8916-rpm-proc
+ - qcom,msm8917-rpm-proc
+ - qcom,msm8936-rpm-proc
+ - qcom,msm8937-rpm-proc
+ - qcom,msm8952-rpm-proc
+ - qcom,msm8953-rpm-proc
+ - qcom,msm8974-rpm-proc
+ - qcom,msm8976-rpm-proc
+ - qcom,msm8994-rpm-proc
+ - qcom,msm8996-rpm-proc
+ - qcom,msm8998-rpm-proc
+ - qcom,qcm2290-rpm-proc
+ - qcom,qcs404-rpm-proc
+ - qcom,sdm660-rpm-proc
+ - qcom,sm6115-rpm-proc
+ - qcom,sm6125-rpm-proc
+ - qcom,sm6375-rpm-proc
+ - const: qcom,rpm-proc
+
+ smd-edge:
+ $ref: /schemas/remoteproc/qcom,smd-edge.yaml#
+ description:
+ Qualcomm Shared Memory subnode which represents communication edge,
+ channels and devices related to the RPM subsystem.
+
+ glink-rpm:
+ $ref: /schemas/remoteproc/qcom,glink-rpm-edge.yaml#
+ description:
+ Qualcomm G-Link subnode which represents communication edge,
+ channels and devices related to the RPM subsystem.
+
+ interrupt-controller:
+ type: object
+ $ref: /schemas/interrupt-controller/qcom,mpm.yaml#
+ description:
+ MSM Power Manager (MPM) interrupt controller that monitors interrupts
+ when the system is asleep.
+
+ master-stats:
+ $ref: /schemas/soc/qcom/qcom,rpm-master-stats.yaml#
+ description:
+ Subsystem-level low-power mode statistics provided by RPM.
+
+required:
+ - compatible
+
+oneOf:
+ - required:
+ - smd-edge
+ - required:
+ - glink-rpm
+
+additionalProperties: false
+
+examples:
+ # SMD
+ - |
+ #include <dt-bindings/interrupt-controller/arm-gic.h>
+ #include <dt-bindings/interrupt-controller/irq.h>
+
+ remoteproc {
+ compatible = "qcom,msm8916-rpm-proc", "qcom,rpm-proc";
+
+ smd-edge {
+ interrupts = <GIC_SPI 168 IRQ_TYPE_EDGE_RISING>;
+ qcom,ipc = <&apcs 8 0>;
+ qcom,smd-edge = <15>;
+
+ rpm-requests {
+ compatible = "qcom,rpm-msm8916";
+ qcom,smd-channels = "rpm_requests";
+ /* ... */
+ };
+ };
+ };
+ # GLINK
+ - |
+ #include <dt-bindings/interrupt-controller/arm-gic.h>
+ #include <dt-bindings/interrupt-controller/irq.h>
+
+ remoteproc {
+ compatible = "qcom,qcm2290-rpm-proc", "qcom,rpm-proc";
+
+ glink-rpm {
+ compatible = "qcom,glink-rpm";
+ interrupts = <GIC_SPI 194 IRQ_TYPE_EDGE_RISING>;
+ qcom,rpm-msg-ram = <&rpm_msg_ram>;
+ mboxes = <&apcs_glb 0>;
+
+ rpm-requests {
+ compatible = "qcom,rpm-qcm2290";
+ qcom,glink-channels = "rpm_requests";
+ /* ... */
+ };
+ };
+ };
diff --git a/Documentation/devicetree/bindings/soc/qcom/qcom,smd-rpm.yaml b/Documentation/devicetree/bindings/soc/qcom/qcom,smd-rpm.yaml
index c6930706bfa9..2fa725b8af5d 100644
--- a/Documentation/devicetree/bindings/soc/qcom/qcom,smd-rpm.yaml
+++ b/Documentation/devicetree/bindings/soc/qcom/qcom,smd-rpm.yaml
@@ -120,10 +120,10 @@ examples:
#include <dt-bindings/interrupt-controller/arm-gic.h>
#include <dt-bindings/interrupt-controller/irq.h>

- smd {
- compatible = "qcom,smd";
+ remoteproc {
+ compatible = "qcom,msm8916-rpm-proc", "qcom,rpm-proc";

- rpm {
+ smd-edge {
interrupts = <GIC_SPI 168 IRQ_TYPE_EDGE_RISING>;
qcom,ipc = <&apcs 8 0>;
qcom,smd-edge = <15>;
diff --git a/Documentation/devicetree/bindings/soc/qcom/qcom,smd.yaml b/Documentation/devicetree/bindings/soc/qcom/qcom,smd.yaml
index 063e595c12f7..4819ce90d206 100644
--- a/Documentation/devicetree/bindings/soc/qcom/qcom,smd.yaml
+++ b/Documentation/devicetree/bindings/soc/qcom/qcom,smd.yaml
@@ -15,6 +15,12 @@ description:
The Qualcomm Shared Memory Driver is a FIFO based communication channel for
sending data between the various subsystems in Qualcomm platforms.

+ Using the top-level SMD node is deprecated. Instead, the SMD edges are defined
+ directly below the device node representing the respective remote subsystem
+ or remote processor.
+
+deprecated: true
+
properties:
compatible:
const: qcom,smd
@@ -37,6 +43,7 @@ examples:
# The following example represents a smd node, with one edge representing the
# "rpm" subsystem. For the "rpm" subsystem we have a device tied to the
# "rpm_request" channel.
+ # NOTE: This is deprecated, represent the RPM using "qcom,rpm-proc" instead.
- |
#include <dt-bindings/interrupt-controller/arm-gic.h>


--
2.40.1