Thread (36 messages) 36 messages, 6 authors, 2019-11-17

Re: [PATCH V4 01/11] dt-bindings: firmware: imx-scu: new binding to parse clocks from device tree

From: Rob Herring <robh@kernel.org>
Date: 2019-08-27 17:04:48
Also in: linux-clk, linux-devicetree

On Tue, 20 Aug 2019 07:13:15 -0400, Dong Aisheng wrote:
There's a few limitations on the original one cell clock binding
(#clock-cells = <1>) that we have to define some SW clock IDs for device
tree to reference. This may cause troubles if we want to use common
clock IDs for multi platforms support when the clock of those platforms
are mostly the same.
e.g. Current clock IDs name are defined with SS prefix.

However the device may reside in different SS across CPUs, that means the
SS prefix may not valid anymore for a new SoC. Furthermore, the device
availability of those clocks may also vary a bit.

For such situation, we want to eliminate the using of SW Clock IDs and
change to use a more close to HW one instead.
For SCU clocks usage, only two params required: Resource id + Clock Type.
Both parameters are platform independent. So we could use two cells binding
to pass those parameters,

Cc: Rob Herring <robh+dt@kernel.org>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: devicetree@vger.kernel.org
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
---
ChangeLog:
v3->v4:
 * add some comments for various clock types
v2->v3:
 * Changed to two cells binding and register all clocks in driver
   instead of parse from device tree.
v1->v2:
 * changed to one cell binding inspired by arm,scpi.txt
   Documentation/devicetree/bindings/arm/arm,scpi.txt
   Resource ID is encoded in 'reg' property.
   Clock type is encoded in generic clock-indices property.
   Then we don't have to search all the DT nodes to fetch
   those two value to construct clocks which is relatively
   low efficiency.
 * Add required power-domain property as well.
---
 .../devicetree/bindings/arm/freescale/fsl,scu.txt  | 12 ++++++-----
 include/dt-bindings/firmware/imx/rsrc.h            | 23 ++++++++++++++++++++++
 2 files changed, 30 insertions(+), 5 deletions(-)
Reviewed-by: Rob Herring <robh@kernel.org>

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