Le 31/07/2025 à 01:56, Rob Herring a écrit :
On Wed, Jul 30, 2025 at 07:02:44PM +0200, Louis Chauvet wrote:
The dt-bindings for the display, specifically ti,am65x-dss, need to
include a clock property for data edge synchronization. The current
implementation does not correctly apply the data edge sampling property.
To address this, synchronization of writes to two different registers is
required: one in the TIDSS IP (which is already described in the tidss
node) and one is in the Memory Mapped Control Register Modules (added by
the previous commit).
As the Memory Mapped Control Register Modules is located in a different
IP, we need to use a phandle to write values in its registers.
You can always just lookup the target node by compatible. Then you don't
need a DT update to solve your problem.
I just followed what was already done for dss_oldi_io_ctrl/ti,oldi-io-ctrl.
I will use syscon_regmap_lookup_by_compatible for the v2.
Fixes: 32a1795f57ee ("drm/tidss: New driver for TI Keystone platform Display
SubSystem")
Signed-off-by: Louis Chauvet <louis.chau...@bootlin.com>
---
Cc: sta...@vger.kernel.org
---
Documentation/devicetree/bindings/display/ti/ti,am65x-dss.yaml | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/Documentation/devicetree/bindings/display/ti/ti,am65x-dss.yaml
b/Documentation/devicetree/bindings/display/ti/ti,am65x-dss.yaml
index
361e9cae6896c1f4d7fa1ec47a6e3a73bca2b102..b9a373b569170332f671416eb7bbc0c83f7b5ea6
100644
--- a/Documentation/devicetree/bindings/display/ti/ti,am65x-dss.yaml
+++ b/Documentation/devicetree/bindings/display/ti/ti,am65x-dss.yaml
@@ -133,6 +133,12 @@ properties:
and OLDI_CLK_IO_CTRL registers. This property is needed for OLDI
interface to work.
+ ti,clk-ctrl:
+ $ref: /schemas/types.yaml#/definitions/phandle
+ description:
+ phandle to syscon device node mapping CFG0_CLK_CTRL registers.
+ This property is needed for proper data sampling edge.
+
max-memory-bandwidth:
$ref: /schemas/types.yaml#/definitions/uint32
description:
--
2.50.1
--
Louis Chauvet, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
