On 08/22/2012 02:45 PM, Timur Tabi wrote:
An FPGA controls which sub-bus is connected to the master MDIO bus. The
FPGA must be memory-mapped and contain only 8-bit registers (which keeps
things simple).
Tested on a Freescale P5020DS board which uses the "PIXIS" FPGA attached
to the localbus.
Signed-off-by: Timur Tabi <[email protected]>
---
.../devicetree/bindings/net/mdio-mux-fpga.txt | 74 ++++++++
drivers/net/phy/Kconfig | 13 ++
drivers/net/phy/Makefile | 1 +
drivers/net/phy/mdio-mux-fpga.c | 186 ++++++++++++++++++++
I am fine with the general concept of the patch, so I am going to start
a Bike Shedding session with it over the names of some of the things here.
I wonder if *fpga is really a good name for this. It is a general
purpose multiplexer with a memory mapped control register. I would call
it something like mdio-mux-mmioreg.
4 files changed, 274 insertions(+), 0 deletions(-)
create mode 100644 Documentation/devicetree/bindings/net/mdio-mux-fpga.txt
create mode 100644 drivers/net/phy/mdio-mux-fpga.c
diff --git a/Documentation/devicetree/bindings/net/mdio-mux-fpga.txt
b/Documentation/devicetree/bindings/net/mdio-mux-fpga.txt
new file mode 100644
index 0000000..ef567c6
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/mdio-mux-fpga.txt
@@ -0,0 +1,74 @@
+Properties for an MDIO bus multiplexer/switch controlled by an FPGA register.
+
+This is a special case of a MDIO bus multiplexer. An FPGA register is used
+to control which child bus is connected.
+
+Required properties in addition to the generic multiplexer properties:
+
+- compatible : string, must contain "mdio-mux-fpga"
+
+- mdio-mux-device : phandle, points to the FPGA (or similar) node. This
+ must be a memory-mapped device with 8-bit registers.
You shouldn't need this. Just make the multiplexer a child of FPGA node
to indicate where it lives.
+
+- mdio-mux-register : integer, contains the offset of the register that
+ controls the bus multiplexer.
This should just be the normal "reg" properly
+
+- mdio-mux-mask : integer, contains an 8-bit mask that specifies which
+ bits in the register control the actual bus multiplexer. The
+ 'reg' property of each child mdio-mux node must be constrained by
+ this mask.
+
"reg-mask" ??
Do you need a shift too?
David Daney
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