[RFC PATCH 2/2] dt-bindings: net: Add mctp-i2c bus-attach property
flat view
STALE1890d
SUPERSEDED
From: Matt Johnston <matt@codeconstruct.com.au>
Date: 2021-08-02 04:12:53
Subsystem:
networking drivers, open firmware and flattened device tree bindings, the rest · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Rob Herring, Krzysztof Kozlowski, Conor Dooley, Linus Torvalds
Revision rfc of 2 in this series.
Revisions (2)
- rfc current
- v2 [diff vs current]
Allows attaching multiple child busses in a mux topology to an mctp-i2c instance on the root bus. In general I2C slave mode does not make sense for mux busses, but the MCTP request/response protocol means the the root can switch between child muxes for incoming I2C messages. Signed-off-by: Matt Johnston <matt@codeconstruct.com.au> --- .../devicetree/bindings/net/mctp-i2c.yaml | 42 +++++++++++++++++-- 1 file changed, 38 insertions(+), 4 deletions(-)
diff --git a/Documentation/devicetree/bindings/net/mctp-i2c.yaml b/Documentation/devicetree/bindings/net/mctp-i2c.yaml
index f9378cd845d4..45429cbcc6a1 100644
--- a/Documentation/devicetree/bindings/net/mctp-i2c.yaml
+++ b/Documentation/devicetree/bindings/net/mctp-i2c.yaml@@ -12,11 +12,10 @@ maintainers: description: The MCTP I2C binding defines an MCTP endpoint on the I2C bus to communicate with I2C peripherals using MCTP (DMTF specification DSP0237). - - An mctp-i2c device must be attached to a hardware bus adapter which supports + A single binding node can attach to multiple child busses in a mux topology. + An mctp-i2c node's parent must be a hardware bus adapter which supports slave functionality. The reg address must include I2C_OWN_SLAVE_ADDRESS. - properties: compatible: const: mctp-i2c
@@ -24,6 +23,17 @@ properties: reg: maxItems: 1 + bus-attach: + $ref: "/schemas/types.yaml#/definitions/phandle-array" + description: | + List of phandles of I2C busses to attach to. I2C mux busses may only + be attached to an mctp-i2c binding on their parent root adapter in the + mux topology. + If no bus-attach property is specified then only the direct parent + I2C bus is attached. Otherwise to include a direct parent bus it + must be included in the bus-attach list if needed. + + additionalProperties: true required:
@@ -33,12 +43,36 @@ required: examples: - | #include <dt-bindings/i2c/i2c.h> - i2c { + + // simple attaching to a root adapter i2c0 + i2c0: i2cbus0 { + #address-cells = <1>; + #size-cells = <0>; + + mctp@50 { + compatible = "mctp-i2c"; + reg = <(0x50 | I2C_OWN_SLAVE_ADDRESS)>; + }; + }; + + // attaching to a root adapter i2c5 and a child mux bus i2c14 + i2c5: i2cbus5 { #address-cells = <1>; #size-cells = <0>; mctp@50 { compatible = "mctp-i2c"; reg = <(0x50 | I2C_OWN_SLAVE_ADDRESS)>; + attach-bus = <&i2c5 &i2c14>; }; }; + + i2cmux0 { + compatible = "i2c-mux-gpio"; + #address-cells = <1>; + #size-cells = <0>; + i2c-parent = <&i2c0>; + i2c14: i2c@5 { + reg = <0>; + }; + };
--
2.30.2