diff options
| author | Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> | 2024-06-23 15:46:00 +0200 |
|---|---|---|
| committer | Lee Jones <lee@kernel.org> | 2024-07-04 17:38:41 +0100 |
| commit | b0a5cde57cf14383205ed147bb51320372b8c113 (patch) | |
| tree | b1b767545ac754760a2efbfa828e40ac2b9369f7 | |
| parent | 1d845319dc819c39e2ee568f1c6bd0cdb2fbc035 (diff) | |
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 <linus.walleij@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://lore.kernel.org/r/20240623134600.115098-1-krzysztof.kozlowski@linaro.org
Signed-off-by: Lee Jones <lee@kernel.org>
| -rw-r--r-- | Documentation/devicetree/bindings/mfd/mfd.txt | 15 |
1 files changed, 8 insertions, 7 deletions
diff --git a/Documentation/devicetree/bindings/mfd/mfd.txt b/Documentation/devicetree/bindings/mfd/mfd.txt index 336c0495c8a3..b938fa26d2ce 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 |