On 31/07/15 17:00, Mark Rutland wrote:
Hi,

On Thu, Jul 23, 2015 at 12:10:21PM +0100, Sudeep Holla wrote:
This patch adds devicetree binding for System Control and Power
Interface (SCPI) Message Protocol used between the Application Cores(AP)
and the System Control Processor(SCP). The MHU peripheral provides a
mechanism for inter-processor communication between SCP's M3 processor
and AP.

SCP offers control and management of the core/cluster power states,
various power domain DVFS including the core/cluster, certain system
clocks configuration, thermal sensors and many others.

Signed-off-by: Sudeep Holla <sudeep.ho...@arm.com>
Cc: Rob Herring <robh...@kernel.org>
Cc: Mark Rutland <mark.rutl...@arm.com>
CC: Jassi Brar <jassisinghb...@gmail.com>
Cc: Liviu Dudau <liviu.du...@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieral...@arm.com>
Cc: Jon Medhurst (Tixy) <t...@linaro.org>
Cc: devicet...@vger.kernel.org
---
  Documentation/devicetree/bindings/arm/arm,scpi.txt | 151 +++++++++++++++++++++
  MAINTAINERS                                        |   6 +
  2 files changed, 157 insertions(+)
  create mode 100644 Documentation/devicetree/bindings/arm/arm,scpi.txt

diff --git a/Documentation/devicetree/bindings/arm/arm,scpi.txt 
b/Documentation/devicetree/bindings/arm/arm,scpi.txt
new file mode 100644
index 000000000000..e21cce646561
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/arm,scpi.txt
@@ -0,0 +1,151 @@
+System Control and Power Interface (SCPI) Message Protocol
+----------------------------------------------------------
+
+Firmware implementing the SCPI described in ARM document number ARM DUI 0922B
+("ARM Compute Subsystem SCP: Message Interface Protocols")[0] can be used
+by Linux to initiate various system control and power operations.
+
+Required properties:
+
+- compatible : should be "arm,scpi"
+- mboxes: List of phandle and mailbox channel specifiers
+         All the channels reserved by remote SCP firmware for use by
+         SCPI message protocol should be specified in any order
+- shmem : List of phandle pointing to the shared memory(SHM) area between the
+         processors using these mailboxes for IPC, one for each mailbox
+         SHM can be any memory reserved for the purpose of this communication
+         between the processors.
+
+See Documentation/devicetree/bindings/mailbox/mailbox.txt
+for more details about the generic mailbox controller and
+client driver bindings.
+
+Clock bindings for the clocks based on SCPI Message Protocol
+------------------------------------------------------------
+
+This binding uses the common clock binding[1].
+
+Container Node
+==============
+Required properties:
+- compatible : should be "arm,scpi-clocks"
+              All the clocks provided by SCP firmware via SCPI message
+              protocol much be listed as sub-nodes under this node.
+
+Sub-nodes
+=========
+Required properties:
+- compatible : shall include one of the following
+       "arm,scpi-dvfs-clocks" - all the clocks that are variable and index 
based.
+               These clocks don't provide an entire range of values between the
+               limits but only discrete points within the range. The firmware
+               provides the mapping for each such operating frequency and the
+               index associated with it. The firmware also manages the
+               voltage scaling appropriately with the clock scaling.
+       "arm,scpi-variable-clocks" - all the clocks that are variable and 
provide full
+               range within the specified range. The firmware provides the
+               range of values within a specified range.
+
+Other required properties for all clocks(all from common clock binding):
+- #clock-cells : should be set to 1 as each of the SCPI clocks have multiple
+       outputs.

Could you change this to:

#clock-cells: Should be 1. Contains the Clock ID value used by SCPI
               commands.


Changed now.

That will make it clear what value should be used when writing a dts
(the raw value commands use, as opposed to some logical abstraction
thereof).


Agreed.

With that:

Acked-by: Mark Rutland <mark.rutl...@arm.com>


Thanks.

Regards,
Sudeep
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to