From b0a5cde57cf14383205ed147bb51320372b8c113 Mon Sep 17 00:00:00 2001 From: Krzysztof Kozlowski Date: Sun, 23 Jun 2024 15:46:00 +0200 Subject: [PATCH] dt-bindings: mfd: Explain lack of child dependency in simple-mfd Common mistake of usage of 'simple-mfd' compatible is a dependency of children on resources acquired and managed by the parent, e.g. clocks. Extend the simple-mfd documentation to cover this case. Cc: Linus Walleij Cc: Arnd Bergmann Signed-off-by: Krzysztof Kozlowski Reviewed-by: Conor Dooley Reviewed-by: Rob Herring (Arm) Link: https://lore.kernel.org/r/20240623134600.115098-1-krzysztof.kozlowski@linaro.org Signed-off-by: Lee Jones --- Documentation/devicetree/bindings/mfd/mfd.txt | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/Documentation/devicetree/bindings/mfd/mfd.txt b/Documentation/devicetree/bindings/mfd/mfd.txt index 336c0495c8a3a..b938fa26d2ce3 100644 --- a/Documentation/devicetree/bindings/mfd/mfd.txt +++ b/Documentation/devicetree/bindings/mfd/mfd.txt @@ -17,13 +17,14 @@ A typical MFD can be: Optional properties: -- compatible : "simple-mfd" - this signifies that the operating system should - consider all subnodes of the MFD device as separate devices akin to how - "simple-bus" indicates when to see subnodes as children for a simple - memory-mapped bus. For more complex devices, when the nexus driver has to - probe registers to figure out what child devices exist etc, this should not - be used. In the latter case the child devices will be determined by the - operating system. +- compatible : "simple-mfd" - this signifies that the operating system + should consider all subnodes of the MFD device as separate and independent + devices, so not needing any resources to be provided by the parent device. + Similarly to how "simple-bus" indicates when to see subnodes as children for + a simple memory-mapped bus. + For more complex devices, when the nexus driver has to probe registers to + figure out what child devices exist etc, this should not be used. In the + latter case the child devices will be determined by the operating system. - ranges: Describes the address mapping relationship to the parent. Should set the child's base address to 0, the physical address within parent's address -- 2.47.2