Document the use of (msi|iommu)-map for PCI Endpoint (EP) controllers,
which can use MSI as a doorbell mechanism. Each EP controller can support
up to 8 physical functions and 65,536 virtual functions.
Define how to construct device IDs using function bits [2:0] and virtual
function index bits [31:3], enabling (msi|iommu)-map to associate each
child device with a specific (msi|iommu)-specifier.
The EP cannot rely on PCI Requester ID (RID) because the RID is determined
by the PCI topology of the host system. Since the EP may be connected to
different PCI hosts, the RID can vary between systems and is therefore not
a reliable identifier.
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://lore.kernel.org/all/20250414-ep-msi-v18-4-f69b49917464@nxp.com
json-schema versions draft7 and earlier have a weird behavior in that
any keywords combined with a '$ref' are ignored (silently). The correct
form was to put a '$ref' under an 'allOf'. This behavior is now changed
in the 2019-09 json-schema spec and '$ref' can be mixed with other
keywords. The json-schema library doesn't yet support this, but the
tooling now does a fixup for this and either way works.
This has been a constant source of review comments, so let's change this
treewide so everyone copies the simpler syntax.
Scripted with ruamel.yaml with some manual fixups. Some minor whitespace
changes from the script.
Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Maxime Ripard <mripard@kernel.org>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-By: Vinod Koul <vkoul@kernel.org>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Wolfram Sang <wsa@the-dreams.de> # for I2C
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> #for-iio
Reviewed-by: Stephen Boyd <sboyd@kernel.org> # clock
Signed-off-by: Rob Herring <robh@kernel.org>
