[PATCH V3 1/5] dt-bindings: mailbox: allow mbox-cells to be equal to 0

[PATCH V3 1/5] dt-bindings: mailbox: allow mbox-cells to be equal to 0

[Dong Aisheng]

Mailbox devices may have only one channel which means the mbox-cells
at least 1 does not make sense for this type devices. Let's remove
that limitation to allow the mbox-cells to be equal to 0.

Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
---
ChangeLog:
 * New patch introduced in v3 series
 * Actually there're already users in kernel with mbox-cells set to 0.
   See:
   arch/arm/boot/dts/bcm283x.dtsi:145: #mbox-cells = <0>;
---
 Documentation/devicetree/bindings/mailbox/mailbox.txt | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/mailbox/mailbox.txt b/Documentation/devicetree/bindings/mailbox/mailbox.txt
index af8ecee..c2fcd05 100644
--- a/Documentation/devicetree/bindings/mailbox/mailbox.txt
+++ b/Documentation/devicetree/bindings/mailbox/mailbox.txt
@@ -6,8 +6,7 @@ assign appropriate mailbox channel to client drivers.
 * Mailbox Controller
 
 Required property:
-- #mbox-cells: Must be at least 1. Number of cells in a mailbox
-		specifier.
+- #mbox-cells: Number of cells in a mailbox specifier.
 
 Example:
 	mailbox: mailbox {
-- 
2.7.4

Re: [PATCH V3 1/5] dt-bindings: mailbox: allow mbox-cells to be equal to 0

[Rob Herring]

On Fri, Jun 22, 2018 at 10:11:56PM +0800, Dong Aisheng wrote:
> Mailbox devices may have only one channel which means the mbox-cells
> at least 1 does not make sense for this type devices. Let's remove
> that limitation to allow the mbox-cells to be equal to 0.
> 
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: Sudeep Holla <sudeep.holla@arm.com>
> Cc: devicetree@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
> ---
> ChangeLog:
>  * New patch introduced in v3 series
>  * Actually there're already users in kernel with mbox-cells set to 0.
>    See:
>    arch/arm/boot/dts/bcm283x.dtsi:145: #mbox-cells = <0>;
> ---
>  Documentation/devicetree/bindings/mailbox/mailbox.txt | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)

Reviewed-by: Rob Herring <robh@kernel.org>

[PATCH V3 3/5] dt-bindings: arm: fsl: add mu binding doc

[Dong Aisheng]

The Messaging Unit module enables two processors within
the SoC to communicate and coordinate by passing messages
(e.g. data, status and control) through the MU interface.

Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: devicetree@vger.kernel.org
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
---
v2->v3:
 * change to mailbox binding
   Currently mbox-cells has to be 0 for SCU MU.
   Generic MU Mailbox support binding could be extended later.
v1->v2:
 * typo fixes
 * remove status property
 * remove imx6&7 compatible string which may be added later for
   the generic mailbox binding
---
 .../devicetree/bindings/arm/freescale/fsl,mu.txt   | 34 ++++++++++++++++++++++
 1 file changed, 34 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/arm/freescale/fsl,mu.txt

diff --git a/Documentation/devicetree/bindings/arm/freescale/fsl,mu.txt b/Documentation/devicetree/bindings/arm/freescale/fsl,mu.txt
new file mode 100644
index 0000000..90e4905
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/freescale/fsl,mu.txt
@@ -0,0 +1,34 @@
+NXP i.MX Messaging Unit (MU)
+--------------------------------------------------------------------
+
+The Messaging Unit module enables two processors within the SoC to
+communicate and coordinate by passing messages (e.g. data, status
+and control) through the MU interface. The MU also provides the ability
+for one processor to signal the other processor using interrupts.
+
+Because the MU manages the messaging between processors, the MU uses
+different clocks (from each side of the different peripheral buses).
+Therefore, the MU must synchronize the accesses from one side to the
+other. The MU accomplishes synchronization using two sets of matching
+registers (Processor A-facing, Processor B-facing).
+
+Messaging Unit Device Node:
+=============================
+
+Required properties:
+-------------------
+- compatible :	should be "fsl,<chip>-mu", the supported chips include
+		imx8qxp, imx8qm.
+- reg :		Should contain the registers location and length
+- interrupts :	Interrupt number. The interrupt specifier format depends
+		on the interrupt controller parent.
+- #mbox-cells:  Must be 0. Number of cells in a mailbox
+
+Examples:
+--------
+lsio_mu0: mailbox@5d1b0000 {
+	compatible = "fsl,imx8qxp-mu";
+	reg = <0x0 0x5d1b0000 0x0 0x10000>;
+	interrupts = <GIC_SPI 176 IRQ_TYPE_LEVEL_HIGH>;
+	#mbox-cells = <0>;
+};
-- 
2.7.4

[PATCH V3 4/5] dt-bindings: arm: fsl: add scu binding doc

[Dong Aisheng]

The System Controller Firmware (SCFW) is a low-level system function
which runs on a dedicated Cortex-M core to provide power, clock, and
resource management. It exists on some i.MX8 processors. e.g. i.MX8QM
(QM, QP), and i.MX8QX (QXP, DX).

Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: devicetree@vger.kernel.org
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
---
v2->v3:
 * update a bit to mailbox binding
v1->v2:
 * remove status
 * changed to mu1
---
 .../devicetree/bindings/arm/freescale/fsl,scu.txt  | 39 ++++++++++++++++++++++
 1 file changed, 39 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/arm/freescale/fsl,scu.txt

diff --git a/Documentation/devicetree/bindings/arm/freescale/fsl,scu.txt b/Documentation/devicetree/bindings/arm/freescale/fsl,scu.txt
new file mode 100644
index 0000000..b51f9d1
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/freescale/fsl,scu.txt
@@ -0,0 +1,39 @@
+NXP i.MX System Controller Firmware (SCFW)
+--------------------------------------------------------------------
+
+The System Controller Firmware (SCFW) is a low-level system function
+which runs on a dedicated Cortex-M core to provide power, clock, and
+resource management. It exists on some i.MX8 processors. e.g. i.MX8QM
+(QM, QP), and i.MX8QX (QXP, DX).
+
+The AP communicates with the SC using a multi-ported MU module found
+in the LSIO subsystem. The current definition of this MU module provides
+5 remote AP connections to the SC to support up to 5 execution environments
+(TZ, HV, standard Linux, etc.). The SC side of this MU module interfaces
+with the LSIO DSC IP bus. The SC firmware will communicate with this MU
+using the MSI bus.
+
+System Controller Device Node:
+=============================
+
+Required properties:
+-------------------
+- compatible: should be "fsl,imx8qxp-scu" or "fsl,imx8qm-scu"
+- fsl,mu: a phandle to the Message Unit used by SCU. Should be
+	  one of LSIO MU0~M4 for imx8qxp and imx8qm. Users need
+	  to make sure not use the one which is conflict with
+	  other execution environments. e.g. ATF.
+
+Examples:
+--------
+lsio_mu1: mailbox@5d1c0000 {
+	compatible = "fsl,imx8qxp-mu";
+	reg = <0x0 0x5d1c0000 0x0 0x10000>;
+	interrupts = <GIC_SPI 176 IRQ_TYPE_LEVEL_HIGH>;
+	#mbox-cells = <0>;
+};
+
+scu {
+	compatible = "fsl,imx8qxp-scu";
+	fsl,mu = <&lsio_mu1>;
+};
-- 
2.7.4