From: Sudeep Holla <sudeep.holla@arm.com>
To: linux-kernel@vger.kernel.org, Jassi Brar <jassisinghbrar@gmail.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>,
devicetree@vger.kernel.org, Alexey Klimov <alexey.klimov@arm.com>,
Jassi Brar <jaswinder.singh@linaro.org>,
Rob Herring <robh+dt@kernel.org>
Subject: [PATCH v2 2/6] Documentation: devicetree: add bindings to support ARM MHU doorbells
Date: Wed, 24 May 2017 11:16:39 +0100 [thread overview]
Message-ID: <1495621003-4291-3-git-send-email-sudeep.holla@arm.com> (raw)
In-Reply-To: <1495621003-4291-1-git-send-email-sudeep.holla@arm.com>
The ARM MHU has mechanism to assert interrupt signals to facilitate
inter-processor message based communication. It drives the signal using
a 32-bit register, with all 32-bits logically ORed together. It also
enables software to set, clear and check the status of each of the bits
of this register independently. Each bit of the register can be
associated with a type of event that can contribute to raising the
interrupt thereby allowing it to be used as independent doorbells.
Since the first version of this binding can't support doorbells,
this patch extends the existing binding to support them.
Cc: Alexey Klimov <alexey.klimov@arm.com>
Cc: Jassi Brar <jaswinder.singh@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
---
.../devicetree/bindings/mailbox/arm-mhu.txt | 46 ++++++++++++++++++++--
1 file changed, 43 insertions(+), 3 deletions(-)
diff --git a/Documentation/devicetree/bindings/mailbox/arm-mhu.txt b/Documentation/devicetree/bindings/mailbox/arm-mhu.txt
index 4971f03f0b33..bd9a3a267caf 100644
--- a/Documentation/devicetree/bindings/mailbox/arm-mhu.txt
+++ b/Documentation/devicetree/bindings/mailbox/arm-mhu.txt
@@ -10,21 +10,42 @@ STAT register and the remote clears it after having read the data.
The last channel is specified to be a 'Secure' resource, hence can't be
used by Linux running NS.
+The MHU drives the interrupt signal using a 32-bit register, with all
+32-bits logically ORed together. It provides a set of registers to
+enable software to set, clear and check the status of each of the bits
+of this register independently. The use of 32 bits per interrupt line
+enables software to provide more information about the source of the
+interrupt. For example, each bit of the register can be associated with
+a type of event that can contribute to raising the interrupt. Each of
+the 32-bits can be used as "doorbell" to alert the remote processor.
+
Mailbox Device Node:
====================
Required properties:
--------------------
-- compatible: Shall be "arm,mhu" & "arm,primecell"
+- compatible: Shall be "arm,primecell" and one of the below:
+ "arm,mhu" - if the controller doesn't support
+ doorbell model
+ "arm,mhu-doorbell" - if the controller supports
+ doorbell model
- reg: Contains the mailbox register address range (base
address and length)
-- #mbox-cells Shall be 1 - the index of the channel needed.
+- #mbox-cells Shall be 1 - the index of the channel needed when
+ compatible is "arm,mhu"
+ Shall be 2 - the index of the channel needed, and
+ the index of the doorbell bit with the channel when
+ compatible is "arm,mhu-doorbell"
- interrupts: Contains the interrupt information corresponding to
- each of the 3 links of MHU.
+ each of the 3 physical channels of MHU namely low
+ priority non-secure, high priority non-secure and
+ secure channels.
Example:
--------
+1. Controller which doesn't support doorbells
+
mhu: mailbox@2b1f0000 {
#mbox-cells = <1>;
compatible = "arm,mhu", "arm,primecell";
@@ -41,3 +62,22 @@ used by Linux running NS.
reg = <0 0x2e000000 0x4000>;
mboxes = <&mhu 1>; /* HP-NonSecure */
};
+
+2. Controller which supports doorbells
+
+ mhu: mailbox@2b1f0000 {
+ #mbox-cells = <2>;
+ compatible = "arm,mhu-doorbell", "arm,primecell";
+ reg = <0 0x2b1f0000 0x1000>;
+ interrupts = <0 36 4>, /* LP-NonSecure */
+ <0 35 4>, /* HP-NonSecure */
+ <0 37 4>; /* Secure */
+ clocks = <&clock 0 2 1>;
+ clock-names = "apb_pclk";
+ };
+
+ mhu_client: scb@2e000000 {
+ compatible = "arm,scpi";
+ reg = <0 0x2e000000 0x200>;
+ mboxes = <&mhu 1 4>; /* HP-NonSecure 5th doorbell bit */
+ };
--
2.7.4
next prev parent reply other threads:[~2017-05-24 10:16 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-24 10:16 [PATCH v2 0/6] mailbox: arm_mhu: add support for doorbell mode Sudeep Holla
2017-05-24 10:16 ` [PATCH v2 1/6] mailbox: arm_mhu: reorder header inclusion and drop unneeded ones Sudeep Holla
2017-05-24 10:16 ` Sudeep Holla [this message]
[not found] ` <1495621003-4291-3-git-send-email-sudeep.holla-5wv7dgnIgG8@public.gmane.org>
2017-05-25 13:22 ` [PATCH v2 2/6] Documentation: devicetree: add bindings to support ARM MHU doorbells Jassi Brar
[not found] ` <CABb+yY0gXDEfoRmfHPOoEKgGjp_e5B5orYZ2qjcypL7ven50hw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2017-05-25 13:23 ` Sudeep Holla
2017-05-31 17:08 ` Rob Herring
2017-05-31 17:12 ` Sudeep Holla
2017-06-02 5:45 ` Jassi Brar
[not found] ` <CABb+yY1mA5Hzce5c5JGVtqmRjoTBj=YTZcajVpANq1oQP0Gc0A-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2017-06-02 9:32 ` Sudeep Holla
[not found] ` <9a38040c-8062-870e-ab2a-beb4934428b3-5wv7dgnIgG8@public.gmane.org>
2017-07-05 18:02 ` Sudeep Holla
[not found] ` <73cf3d55-f2ec-eb15-746a-0db5e7e28dad-5wv7dgnIgG8@public.gmane.org>
2017-07-06 6:28 ` Jassi Brar
[not found] ` <CABb+yY04F0zuiD8iW=m2wPCqftoe+VmcGzzRCXp184JKr25KPw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2017-07-06 9:18 ` Sudeep Holla
2017-07-06 9:27 ` Jassi Brar
[not found] ` <CABb+yY3QRz9pcSTMsgNUnBkzQAedFFbbwu0fXY-2oJCFARz60g-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2017-07-06 9:33 ` Sudeep Holla
2017-07-06 14:37 ` Jassi Brar
[not found] ` <CABb+yY3GdAGeWUUyFfofff7Y9=j5DK-QcLXua1o-a6Hb_+nNcQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2017-07-06 16:44 ` Sudeep Holla
[not found] ` <36ea8010-f22a-e0d9-b9a9-bb6be19db45d-5wv7dgnIgG8@public.gmane.org>
2017-07-06 18:37 ` Jassi Brar
[not found] ` <CABb+yY0j--t-VcOJnMxq25gnsb+QGi5ifw_K4qu1vgTJjKXBxg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2017-07-07 11:32 ` Sudeep Holla
[not found] ` <aef7fc89-5e4d-95c6-cee3-444c4c89a113-5wv7dgnIgG8@public.gmane.org>
2017-07-07 13:12 ` Jassi Brar
2017-07-07 13:32 ` Sudeep Holla
2017-05-25 16:04 ` Sudeep Holla
2017-05-24 10:16 ` [PATCH v2 4/6] mailbox: arm_mhu: re-factor data structure to add doorbell support Sudeep Holla
[not found] ` <1495621003-4291-1-git-send-email-sudeep.holla-5wv7dgnIgG8@public.gmane.org>
2017-05-24 10:16 ` [PATCH v2 3/6] mailbox: arm_mhu: migrate to threaded irq handler Sudeep Holla
2017-05-24 10:16 ` [PATCH v2 5/6] mailbox: arm_mhu: add full support for the doorbells Sudeep Holla
2017-05-24 10:56 ` [PATCH v2 0/6] mailbox: arm_mhu: add support for doorbell mode Jassi Brar
[not found] ` <CABb+yY1eS_cXjCCpgQs18-W3KXPy-K7mPJSkWNb6wFe-is5fDw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2017-05-25 11:30 ` Sudeep Holla
[not found] ` <cd57b90c-4250-64df-9142-d12ac7ed7ad3-5wv7dgnIgG8@public.gmane.org>
2017-05-25 13:20 ` Jassi Brar
[not found] ` <CABb+yY0jKPUW3i69jO+ZhmNum7-MS8xabns+R7hmjCOz+imgJA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2017-05-25 13:35 ` Sudeep Holla
2017-05-25 13:44 ` Jassi Brar
[not found] ` <CABb+yY1r+bQCHUxzsH3DLx1kTkz8g=jOT1_S9PnqjfBrLhe9TA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2017-05-25 13:53 ` Sudeep Holla
[not found] ` <7291e5d7-fb63-57cf-c029-7a9f3b757c35-5wv7dgnIgG8@public.gmane.org>
2017-05-25 14:07 ` Jassi Brar
[not found] ` <CABb+yY1feEpKTWA7hNzx+PjhVmX78zx8OM-uo_Z7r2TzFBSW4A-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2017-05-25 14:15 ` Sudeep Holla
2017-05-24 10:16 ` [PATCH v2 6/6] mailbox: arm_mhu: add support to read and record mbox-name Sudeep Holla
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