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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /Documentation/devicetree/bindings/arm/msm
Initial import
Diffstat (limited to 'Documentation/devicetree/bindings/arm/msm')
-rw-r--r--Documentation/devicetree/bindings/arm/msm/qcom,idle-state.txt84
-rw-r--r--Documentation/devicetree/bindings/arm/msm/qcom,kpss-acc.txt30
-rw-r--r--Documentation/devicetree/bindings/arm/msm/qcom,saw2.txt57
-rw-r--r--Documentation/devicetree/bindings/arm/msm/ssbi.txt18
-rw-r--r--Documentation/devicetree/bindings/arm/msm/timer.txt47
5 files changed, 236 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/arm/msm/qcom,idle-state.txt b/Documentation/devicetree/bindings/arm/msm/qcom,idle-state.txt
new file mode 100644
index 000000000..06df04cc8
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/msm/qcom,idle-state.txt
@@ -0,0 +1,84 @@
+QCOM Idle States for cpuidle driver
+
+ARM provides idle-state node to define the cpuidle states, as defined in [1].
+cpuidle-qcom is the cpuidle driver for Qualcomm SoCs and uses these idle
+states. Idle states have different enter/exit latency and residency values.
+The idle states supported by the QCOM SoC are defined as -
+
+ * Standby
+ * Retention
+ * Standalone Power Collapse (Standalone PC or SPC)
+ * Power Collapse (PC)
+
+Standby: Standby does a little more in addition to architectural clock gating.
+When the WFI instruction is executed the ARM core would gate its internal
+clocks. In addition to gating the clocks, QCOM cpus use this instruction as a
+trigger to execute the SPM state machine. The SPM state machine waits for the
+interrupt to trigger the core back in to active. This triggers the cache
+hierarchy to enter standby states, when all cpus are idle. An interrupt brings
+the SPM state machine out of its wait, the next step is to ensure that the
+cache hierarchy is also out of standby, and then the cpu is allowed to resume
+execution. This state is defined as a generic ARM WFI state by the ARM cpuidle
+driver and is not defined in the DT. The SPM state machine should be
+configured to execute this state by default and after executing every other
+state below.
+
+Retention: Retention is a low power state where the core is clock gated and
+the memory and the registers associated with the core are retained. The
+voltage may be reduced to the minimum value needed to keep the processor
+registers active. The SPM should be configured to execute the retention
+sequence and would wait for interrupt, before restoring the cpu to execution
+state. Retention may have a slightly higher latency than Standby.
+
+Standalone PC: A cpu can power down and warmboot if there is a sufficient time
+between the time it enters idle and the next known wake up. SPC mode is used
+to indicate a core entering a power down state without consulting any other
+cpu or the system resources. This helps save power only on that core. The SPM
+sequence for this idle state is programmed to power down the supply to the
+core, wait for the interrupt, restore power to the core, and ensure the
+system state including cache hierarchy is ready before allowing core to
+resume. Applying power and resetting the core causes the core to warmboot
+back into Elevation Level (EL) which trampolines the control back to the
+kernel. Entering a power down state for the cpu, needs to be done by trapping
+into a EL. Failing to do so, would result in a crash enforced by the warm boot
+code in the EL for the SoC. On SoCs with write-back L1 cache, the cache has to
+be flushed in s/w, before powering down the core.
+
+Power Collapse: This state is similar to the SPC mode, but distinguishes
+itself in that the cpu acknowledges and permits the SoC to enter deeper sleep
+modes. In a hierarchical power domain SoC, this means L2 and other caches can
+be flushed, system bus, clocks - lowered, and SoC main XO clock gated and
+voltages reduced, provided all cpus enter this state. Since the span of low
+power modes possible at this state is vast, the exit latency and the residency
+of this low power mode would be considered high even though at a cpu level,
+this essentially is cpu power down. The SPM in this state also may handshake
+with the Resource power manager (RPM) processor in the SoC to indicate a
+complete application processor subsystem shut down.
+
+The idle-state for QCOM SoCs are distinguished by the compatible property of
+the idle-states device node.
+
+The devicetree representation of the idle state should be -
+
+Required properties:
+
+- compatible: Must be one of -
+ "qcom,idle-state-ret",
+ "qcom,idle-state-spc",
+ "qcom,idle-state-pc",
+ and "arm,idle-state".
+
+Other required and optional properties are specified in [1].
+
+Example:
+
+ idle-states {
+ CPU_SPC: spc {
+ compatible = "qcom,idle-state-spc", "arm,idle-state";
+ entry-latency-us = <150>;
+ exit-latency-us = <200>;
+ min-residency-us = <2000>;
+ };
+ };
+
+[1]. Documentation/devicetree/bindings/arm/idle-states.txt
diff --git a/Documentation/devicetree/bindings/arm/msm/qcom,kpss-acc.txt b/Documentation/devicetree/bindings/arm/msm/qcom,kpss-acc.txt
new file mode 100644
index 000000000..1333db9ac
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/msm/qcom,kpss-acc.txt
@@ -0,0 +1,30 @@
+Krait Processor Sub-system (KPSS) Application Clock Controller (ACC)
+
+The KPSS ACC provides clock, power domain, and reset control to a Krait CPU.
+There is one ACC register region per CPU within the KPSS remapped region as
+well as an alias register region that remaps accesses to the ACC associated
+with the CPU accessing the region.
+
+PROPERTIES
+
+- compatible:
+ Usage: required
+ Value type: <string>
+ Definition: should be one of:
+ "qcom,kpss-acc-v1"
+ "qcom,kpss-acc-v2"
+
+- reg:
+ Usage: required
+ Value type: <prop-encoded-array>
+ Definition: the first element specifies the base address and size of
+ the register region. An optional second element specifies
+ the base address and size of the alias register region.
+
+Example:
+
+ clock-controller@2088000 {
+ compatible = "qcom,kpss-acc-v2";
+ reg = <0x02088000 0x1000>,
+ <0x02008000 0x1000>;
+ };
diff --git a/Documentation/devicetree/bindings/arm/msm/qcom,saw2.txt b/Documentation/devicetree/bindings/arm/msm/qcom,saw2.txt
new file mode 100644
index 000000000..ae4afc6dc
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/msm/qcom,saw2.txt
@@ -0,0 +1,57 @@
+SPM AVS Wrapper 2 (SAW2)
+
+The SAW2 is a wrapper around the Subsystem Power Manager (SPM) and the
+Adaptive Voltage Scaling (AVS) hardware. The SPM is a programmable
+power-controller that transitions a piece of hardware (like a processor or
+subsystem) into and out of low power modes via a direct connection to
+the PMIC. It can also be wired up to interact with other processors in the
+system, notifying them when a low power state is entered or exited.
+
+Multiple revisions of the SAW hardware are supported using these Device Nodes.
+SAW2 revisions differ in the register offset and configuration data. Also, the
+same revision of the SAW in different SoCs may have different configuration
+data due the the differences in hardware capabilities. Hence the SoC name, the
+version of the SAW hardware in that SoC and the distinction between cpu (big
+or Little) or cache, may be needed to uniquely identify the SAW register
+configuration and initialization data. The compatible string is used to
+indicate this parameter.
+
+PROPERTIES
+
+- compatible:
+ Usage: required
+ Value type: <string>
+ Definition: Must have
+ "qcom,saw2"
+ A more specific value could be one of:
+ "qcom,apq8064-saw2-v1.1-cpu"
+ "qcom,msm8974-saw2-v2.1-cpu"
+ "qcom,apq8084-saw2-v2.1-cpu"
+
+- reg:
+ Usage: required
+ Value type: <prop-encoded-array>
+ Definition: the first element specifies the base address and size of
+ the register region. An optional second element specifies
+ the base address and size of the alias register region.
+
+- regulator:
+ Usage: optional
+ Value type: boolean
+ Definition: Indicates that this SPM device acts as a regulator device
+ device for the core (CPU or Cache) the SPM is attached
+ to.
+
+Example 1:
+
+ power-controller@2099000 {
+ compatible = "qcom,saw2";
+ reg = <0x02099000 0x1000>, <0x02009000 0x1000>;
+ regulator;
+ };
+
+Example 2:
+ saw0: power-controller@f9089000 {
+ compatible = "qcom,apq8084-saw2-v2.1-cpu", "qcom,saw2";
+ reg = <0xf9089000 0x1000>, <0xf9009000 0x1000>;
+ };
diff --git a/Documentation/devicetree/bindings/arm/msm/ssbi.txt b/Documentation/devicetree/bindings/arm/msm/ssbi.txt
new file mode 100644
index 000000000..54fd5ced3
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+++ b/Documentation/devicetree/bindings/arm/msm/ssbi.txt
@@ -0,0 +1,18 @@
+* Qualcomm SSBI
+
+Some Qualcomm MSM devices contain a point-to-point serial bus used to
+communicate with a limited range of devices (mostly power management
+chips).
+
+These require the following properties:
+
+- compatible: "qcom,ssbi"
+
+- qcom,controller-type
+ indicates the SSBI bus variant the controller should use to talk
+ with the slave device. This should be one of "ssbi", "ssbi2", or
+ "pmic-arbiter". The type chosen is determined by the attached
+ slave.
+
+The slave device should be the single child node of the ssbi device
+with a compatible field.
diff --git a/Documentation/devicetree/bindings/arm/msm/timer.txt b/Documentation/devicetree/bindings/arm/msm/timer.txt
new file mode 100644
index 000000000..5e10c3455
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+++ b/Documentation/devicetree/bindings/arm/msm/timer.txt
@@ -0,0 +1,47 @@
+* MSM Timer
+
+Properties:
+
+- compatible : Should at least contain "qcom,msm-timer". More specific
+ properties specify which subsystem the timers are paired with.
+
+ "qcom,kpss-timer" - krait subsystem
+ "qcom,scss-timer" - scorpion subsystem
+
+- interrupts : Interrupts for the debug timer, the first general purpose
+ timer, and optionally a second general purpose timer, and
+ optionally as well, 2 watchdog interrupts, in that order.
+
+- reg : Specifies the base address of the timer registers.
+
+- clocks: Reference to the parent clocks, one per output clock. The parents
+ must appear in the same order as the clock names.
+
+- clock-names: The name of the clocks as free-form strings. They should be in
+ the same order as the clocks.
+
+- clock-frequency : The frequency of the debug timer and the general purpose
+ timer(s) in Hz in that order.
+
+Optional:
+
+- cpu-offset : per-cpu offset used when the timer is accessed without the
+ CPU remapping facilities. The offset is
+ cpu-offset + (0x10000 * cpu-nr).
+
+Example:
+
+ timer@200a000 {
+ compatible = "qcom,scss-timer", "qcom,msm-timer";
+ interrupts = <1 1 0x301>,
+ <1 2 0x301>,
+ <1 3 0x301>,
+ <1 4 0x301>,
+ <1 5 0x301>;
+ reg = <0x0200a000 0x100>;
+ clock-frequency = <19200000>,
+ <32768>;
+ clocks = <&sleep_clk>;
+ clock-names = "sleep";
+ cpu-offset = <0x40000>;
+ };