Re: [PATCH] dt-bindings: display: bridge: ldb: Require reg property only for i.MX6SX/8MP LDBs
From: Marek Vasut
Date: Mon Mar 30 2026 - 23:06:54 EST
On 3/30/26 8:29 AM, Marco Felsch wrote:
Hello Marco,
On 26-03-29, Liu Ying wrote:Last time, I pointed out the hardware is part of syscon, but as a subnode
LDB's parent device could be a syscon which doesn't allow a reg property
to be present in it's child devices, e.g., NXP i.MX93 Media blk-ctrl
has a child device NXP i.MX93 Parallel Display Format Configuration(PDFC)
without a reg property(LDB is also a child device of the Media blk-ctrl).
To make the LDB schema be able to describe LDBs without the reg property
like i.MX93 LDB, require the reg property only for i.MX6SX/8MP LDBs.
NACK, we want to describe the HW and from HW PoV the LDB is and was
always part of a syscon. This is the case for all SoCs i.MX6SX/8MP/93.
Fixes: 8aa2f0ac08d3 ("dt-bindings: display: bridge: ldb: Add check for reg and reg-names")
Therefore I would just revert this patch completely.
and therefore with reg properties. What is the problem there ?
To quote the DT spec here:
"""
The reg property describes the address of the device’s resources within
the address space defined by its parent bus.
"""
That parent bus would be the syscon, wouldn't it.
The parent bus is not the parent iomuxc (i.MX6X) nor the blk-ctrl
(i.MX8MP/93) device. Therefore this is wrong IMHO and should be dropped.
How so ? What is the parent bus ?