This documents a device tree binding for exposing the Qualcomm Shared
Memory State Machine as a set of gpio- and interrupt-controllers.
Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxxxxxx>
---
.../devicetree/bindings/gpio/qcom,smsm.txt | 114 +++++++++++++++++++++
drivers/gpio/Kconfig | 8 ++
drivers/gpio/Makefile | 1 +
3 files changed, 123 insertions(+)
create mode 100644 Documentation/devicetree/bindings/gpio/qcom,smsm.txt
diff --git a/Documentation/devicetree/bindings/gpio/qcom,smsm.txt b/Documentation/devicetree/bindings/gpio/qcom,smsm.txt
new file mode 100644
index 000000000000..06201ba76594
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/qcom,smsm.txt
@@ -0,0 +1,114 @@
+Qualcomm Shared Memory State Machine
+
+The Shared Memory State Machine facilitates broadcasting of single bit state
+information between the processors in a Qualcomm SoC. Each processor is
+assigned 32 bits of state that can be modified. A processor can through a
+matrix of bitmaps signal subscription of notifications upon changes to a
+certain bit owned by a certain remote processor.
+
+This document defines the binding for a driver that implements and exposes this
+a GPIO controller and a set of interrupt controllers.
+
+- compatible:
+ Usage: required
+ Value type: <string>
+ Definition: must be one of:
+ "qcom,smsm"
+
+- qcom,ipc-N:
+ Usage: required
+ Value type: <prop-encoded-array>
+ Definition: three entries specifying the outgoing ipc bit used for
+ signaling the N:th remote processor
+ - phandle to a syscon node representing the apcs registers
+ - u32 representing offset to the register within the syscon
+ - u32 representing the ipc bit within the register
+
+- qcom,local-host:
+ Usage: optional
+ Value type: <u32>
+ Definition: identifier of the local processor in the list of hosts, or
+ in other words specifier of the column in the subscription
+ matrix representing the local processor
+ defaults to host 0
+
+- #address-cells:
+ Usage: required
+ Value type: <u32>
+ Definition: must be 1
+
+- #size-cells:
+ Usage: required
+ Value type: <u32>
+ Definition: must be 0
+
+= SUBNODES
+Each processor's state bits are described by a subnode of the smsm device node.
+A node can either be a gpio-controller - denoting the local processors bits -
+or an interrupt-controller - denoting a remote processors state bits. The node
+names are not important.
+
+- reg:
+ Usage: required
+ Value type: <u32>
+ Definition: specifies the offset, in words, of the first bit for this
+ entry
+
+- gpio-controller:
+ Usage: required for local entry
+ Value type: <empty>
+ Definition: marks the entry as a gpio-controller and the state bits to
+ belong to the local processor
+
+- #gpio-cells:
+ Usage: required for local entry
+ Value type: <u32>
+ Definition: must be 2 - denotes bit number and GPIO flags
+
+- interrupt-controller:
+ Usage: required for remote entries
+ Value type: <empty>
+ Definition: marks the entry as a interrupt-controller and the state bits
+ to belong to a remote processor
+
+- #interrupt-cells:
+ Usage: required for remote entries
+ Value type: <u32>
+ Definition: must be 2 - denotes bit number and IRQ flags
+
+- interrupts:
+ Usage: required for remote entries
+ Value type: <prop-encoded-array>
+ Definition: one entry specifying remote IRQ used by the remote processor
+ to signal changes of its state bits
+
+
+= EXAMPLE
+The following example shows the SMEM setup for controlling properties of the
+wireless processor, defined from the 8974 apps processor's point-of-view. It
+encompasses one outbound entry and the outgoing interrupt for the wireless
+processor.
+
+smsm {
+ compatible = "qcom,smsm";
+
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ qcom,ipc-3 = <&apcs 8 19>;
+
+ apps_smsm: apps@0 {
+ reg = <0>;
+
+ gpio-controller;
+ #gpio-cells = <2>;
+ };
+
+ wcnss_smsm: wcnss@7 {
+ reg = <7>;
+ interrupts = <0 144 1>;
+
+ interrupt-controller;
+ #interrupt-cells = <2>;
+ };
+};
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index b4fc9e4d24c6..0e57b60faae8 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -354,6 +354,14 @@ config GPIO_PXA
help
Say yes here to support the PXA GPIO device
+config GPIO_QCOM_SMSM
+ bool "Qualcomm Shared Memory State Machine"
+ depends on QCOM_SMEM
+ help
+ Say yes here to support the Qualcomm Shared Memory State Machine.
+ The state machine is represented by bits in shared memory and is
+ exposed to the system as GPIOs.
+
config GPIO_RCAR
tristate "Renesas R-Car GPIO"
depends on ARM && (ARCH_SHMOBILE || COMPILE_TEST)
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index f79a7c482a99..0fd213892403 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -75,6 +75,7 @@ obj-$(CONFIG_GPIO_PCF857X) += gpio-pcf857x.o
obj-$(CONFIG_GPIO_PCH) += gpio-pch.o
obj-$(CONFIG_GPIO_PL061) += gpio-pl061.o
obj-$(CONFIG_GPIO_PXA) += gpio-pxa.o
+obj-$(CONFIG_GPIO_QCOM_SMSM) += gpio-qcom-smsm.o
obj-$(CONFIG_GPIO_RC5T583) += gpio-rc5t583.o
obj-$(CONFIG_GPIO_RDC321X) += gpio-rdc321x.o
obj-$(CONFIG_GPIO_RCAR) += gpio-rcar.o
--
1.8.2.2
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