[PATCH] mailbox: arm-mhu: update the binding document
From: Sudeep Holla
Date: Mon Apr 27 2015 - 06:52:45 EST
The initial version of the binding document pushed along with the driver
is not clear/explicit about couple of the required properties namely:
clocks and clock-names, though the AMBA primecell binding used by the
arm-mhu specifies them clearly. Without these property the driver will
not even get probed, so it is mandatory to have them in DT.
This patch adds the above mentioned required properties to the binding.
It also adds the optional interrupt-names property which is good to have
along with some minor updates to replace references to the driver with
the hardware IP.
Cc: Rob Herring <robh+dt@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Jassi Brar <jaswinder.singh@xxxxxxxxxx>
Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx>
.../devicetree/bindings/mailbox/arm-mhu.txt | 29 ++++++++++++++--------
1 file changed, 19 insertions(+), 10 deletions(-)
diff --git a/Documentation/devicetree/bindings/mailbox/arm-mhu.txt b/Documentation/devicetree/bindings/mailbox/arm-mhu.txt
index 4971f03f0b33..68146c9a0332 100644
@@ -1,14 +1,15 @@
-ARM MHU Mailbox Driver
+ARM Message Handling Unit(MHU)
-The ARM's Message-Handling-Unit (MHU) is a mailbox controller that has
+The ARM's Message Handling Unit (MHU) is a mailbox controller that has
3 independent channels/links to communicate with remote processor(s).
- MHU links are hardwired on a platform. A link raises interrupt for any
-received data. However, there is no specified way of knowing if the sent
-data has been read by the remote. This driver assumes the sender polls
-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.
+MHU links are hardwired on a platform. A link raises interrupt for any
+received data. The platform/firmware must clear the STAT register after
+having receiving the data and sender can poll on the same if the platform
+lacks interrupt mechanism for sending data to remote processor.
+Out of 3 channels, the last channel is 'Secure', hence must not be used
+by OS or any software running in non-secure state.
Mailbox Device Node:
@@ -20,7 +21,15 @@ used by Linux running NS.
address and length)
- #mbox-cells Shall be 1 - the index of the channel needed.
- interrupts: Contains the interrupt information corresponding to
- each of the 3 links of MHU.
+ each of the MHU links.
+- clocks phandle to clock for apb pclk as specified in the
+ primecell binding
+- clock-names Shall be "apb_pclk"
+- interrupt-names contains names of the interrupt in the order in which
+ they were specified in the interrupts property
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