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From: Tushar Khandelwal <tushar.khandelwal@arm.com>
To: linux-kernel@vger.kernel.org
Cc: tushar.2nov@gmail.com, morten_bp@live.dk,
	jassisinghbrar@gmail.com, nd@arm.com,
	Morten Borup Petersen <morten.petersen@arm.com>,
	Tushar Khandelwal <tushar.khandelwal@arm.com>,
	robh+dt@kernel.org, mark.rutland@arm.com,
	devicetree@vger.kernel.org
Subject: [PATCH 1/4] mailbox: arm_mhuv2: add device tree binding documentation
Date: Wed, 17 Jul 2019 20:26:13 +0100	[thread overview]
Message-ID: <20190717192616.1731-2-tushar.khandelwal@arm.com> (raw)
In-Reply-To: <20190717192616.1731-1-tushar.khandelwal@arm.com>

From: Morten Borup Petersen <morten.petersen@arm.com>

This patch adds device tree binding for Message Handling Unit
controller version 2 from Arm.

Signed-off-by: Morten Borup Petersen <morten.petersen@arm.com>
Signed-off-by: Tushar Khandelwal <tushar.khandelwal@arm.com>
Cc: robh+dt@kernel.org
Cc: mark.rutland@arm.com
Cc: devicetree@vger.kernel.org
Cc: jassisinghbrar@gmail.com
---
 .../devicetree/bindings/mailbox/arm,mhuv2.txt | 108 ++++++++++++++++++
 1 file changed, 108 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mailbox/arm,mhuv2.txt

diff --git a/Documentation/devicetree/bindings/mailbox/arm,mhuv2.txt b/Documentation/devicetree/bindings/mailbox/arm,mhuv2.txt
new file mode 100644
index 000000000000..3a05593414bc
--- /dev/null
+++ b/Documentation/devicetree/bindings/mailbox/arm,mhuv2.txt
@@ -0,0 +1,108 @@
+Arm MHUv2 Mailbox Driver
+========================
+
+The Arm Message-Handling-Unit (MHU) Version 2 is a mailbox controller that has
+between 1 and 124 channel windows to provide unidirectional communication with
+remote processor(s).
+
+Given the unidirectional nature of the device, an MHUv2 mailbox may only be
+written to or read from. If a pair of MHU devices is implemented between two
+processing elements to provide bidirectional communication, these must be
+specified as two separate mailboxes.
+
+A device tree node for an Arm MHUv2 device must specify either a receiver frame
+or a sender frame, indicating which end of the unidirectional MHU device which
+the device node entry describes.
+
+An MHU device must be specified with a transport protocol. The transport
+protocol of an MHU device determines the method of data transmission as well as
+the number of provided mailboxes.
+Following are the possible transport protocol types:
+- Single-word:	An MHU device implements as many mailboxes as it
+		provides channel windows. Data is transmitted through
+		the MHU registers.
+- Multi-word:	An MHU device implements a single mailbox. All channel windows
+		will be used during transmission. Data is transmitted through
+		the MHU registers.
+- Doorbell:	An MHU device implements as many mailboxes as there are flag
+		bits available in its channel windows. Optionally, data may
+		be transmitted through a shared memory region, wherein the MHU
+		is used strictly as an interrupt generation mechanism.
+
+Mailbox Device Node:
+====================
+
+Required properties:
+--------------------
+- compatible:	Shall be "arm,mhuv2" & "arm,primecell"
+- reg:		Contains the mailbox register address range (base
+		address and length)
+- #mbox-cells	Shall be 1 - the index of the channel needed.
+- mhu-frame	Frame type of the device.
+		Shall be either "sender" or "receiver"
+- mhu-protocol	Transport protocol of the device. Shall be one of the
+		following: "single-word", "multi-word", "doorbell"
+
+Required properties (receiver frame):
+-------------------------------------
+- interrupts:	Contains the interrupt information corresponding to the
+		combined interrupt of the receiver frame
+
+Example:
+--------
+
+	mbox_mw_tx: mhu@10000000 {
+		compatible = "arm,mhuv2","arm,primecell";
+		reg = <0x10000000 0x1000>;
+		clocks = <&refclk100mhz>;
+		clock-names = "apb_pclk";
+		#mbox-cells = <1>;
+		mhu-protocol = "multi-word";
+		mhu-frame = "sender";
+	};
+
+	mbox_sw_tx: mhu@10000000 {
+		compatible = "arm,mhuv2","arm,primecell";
+		reg = <0x11000000 0x1000>;
+		clocks = <&refclk100mhz>;
+		clock-names = "apb_pclk";
+		#mbox-cells = <1>;
+		mhu-protocol = "single-word";
+		mhu-frame = "sender";
+	};
+
+	mbox_db_rx: mhu@10000000 {
+		compatible = "arm,mhuv2","arm,primecell";
+		reg = <0x12000000 0x1000>;
+		clocks = <&refclk100mhz>;
+		clock-names = "apb_pclk";
+		#mbox-cells = <1>;
+		interrupts = <0 45 4>;
+		interrupt-names = "mhu_rx";
+		mhu-protocol = "doorbell";
+		mhu-frame = "receiver";
+	};
+
+	mhu_client: scb@2e000000 {
+	compatible = "fujitsu,mb86s70-scb-1.0";
+	reg = <0 0x2e000000 0x4000>;
+	mboxes =
+		// For multi-word frames, client may only instantiate a single
+		// mailbox for a mailbox controller
+		<&mbox_mw_tx 0>,
+
+		// For single-word frames, client may instantiate as many
+		// mailboxes as there are channel windows in the MHU
+		 <&mbox_sw_tx 0>,
+		 <&mbox_sw_tx 1>,
+		 <&mbox_sw_tx 2>,
+		 <&mbox_sw_tx 3>,
+
+		// For doorbell frames, client may instantiate as many mailboxes
+		// as there are bits available in the combined number of channel
+		// windows ((channel windows * 32) mailboxes)
+		 <mbox_db_rx 0>,
+		 <mbox_db_rx 1>,
+		 ...
+		 <mbox_db_rx 17>;
+	};
\ No newline at end of file
-- 
2.17.1


  reply	other threads:[~2019-07-17 19:26 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-17 19:26 [PATCH 0/4] Arm MHUv2 Mailbox Controller Driver Tushar Khandelwal
2019-07-17 19:26 ` Tushar Khandelwal [this message]
2019-07-21 21:58   ` [PATCH 1/4] mailbox: arm_mhuv2: add device tree binding documentation Jassi Brar
2019-07-25  5:49     ` Jassi Brar
2019-07-28 21:28       ` Morten Borup Petersen
2019-07-31  7:31         ` Jassi Brar
2019-08-02 10:41           ` Morten Borup Petersen
2019-08-13 16:36             ` Jassi Brar
2019-08-14 10:05               ` Sudeep Holla
2019-08-14 14:52                 ` Jassi Brar
2019-08-14 16:51                   ` Sudeep Holla
2019-08-14 22:22                     ` tushar.khandelwal
2019-08-14 22:20               ` tushar.khandelwal
2019-08-02 10:53       ` Sudeep Holla
2019-08-07 11:11         ` Tushar Khandelwal
2019-07-28 21:27     ` Morten Borup Petersen
2019-08-02 10:59     ` Sudeep Holla
2019-08-07 11:17       ` Tushar Khandelwal
2019-08-08 10:31         ` Morten Borup Petersen
2019-07-17 19:26 ` [PATCH 2/4] mailbox: arm_mhuv2: add arm mhuv2 driver Tushar Khandelwal
2019-07-17 19:26 ` [PATCH 3/4] mailbox: arm_mhuv2: add doorbell transport protocol operations Tushar Khandelwal
2019-07-17 19:26 ` [PATCH 4/4] mailbox: arm_mhuv2: add multi word " Tushar Khandelwal

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