Hi Chen-Yu,

On 21 March 2016 at 12:08, Chen-Yu Tsai [off-list ref] wrote:

On Mon, Mar 21, 2016 at 6:45 PM, Alexandre Torgue
[off-list ref] wrote:

quoted

Hi,

2016-03-18 17:00 GMT+01:00 Chen-Yu Tsai [off-list ref]:

quoted

Hi,

On Fri, Mar 18, 2016 at 11:37 PM, Alexandre TORGUE
[off-list ref] wrote:

quoted

Signed-off-by: Alexandre TORGUE <redacted>

diff --git a/Documentation/devicetree/bindings/net/stm32-dwmac.txt b/Documentation/devicetree/bindings/net/stm32-dwmac.txt
new file mode 100644
index 0000000..ada2aa4
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/stm32-dwmac.txt

@@ -0,0 +1,32 @@
+STMicroelectronics STM32 / MCU DWMAC glue layer controller
+
+This file documents platform glue layer for stmmac.
+Please see stmmac.txt for the other unchanged properties.
+
+The device node has following properties.
+
+Required properties:
+- compatible:  Should be "st,stm32-dwmac" to select glue, and
+              "snps,dwmac-3.50a" to select IP vesrion.

s/vesrion/version

quoted

quoted

If you need have sort of hardware glue, then it is not compatible.

We could have the case where the glue is set by a bootloader.
In this case, we will select IP version in compatible and we will use
generic dwmac glue to probe stmmac driver.

It seems most platforms using DWMAC follow this design set by
the original stmmac bindings. I'm arguing that the requirement
of setting up the glue makes them incompatible.

What happens when the bootloader didn't setup the glue? And one
forgets to build the STM32 driver, only the generic one? The
generic driver even matches to some, but not all, version
strings.

Maybe it would've been better if the versioned strings were
only used to indicate functionality, and not used to bind
the drivers. But the bindings were set some time ago.

Since Alexandre has not added "snps,dwmac-3.50a" to dwmac-generic
doesn't he use it as you suggest here?

Note that we can not remove all the generic compatible strings from
dwmac-generic because there is one platform that depend on one of
them.
(see arch/arm/boot/dts/exynos5440.dtsi:190)

So we can not remove "snps,dwmac-3.70a" from the dwmac-generic driver
if we want to keep backwards compatibility with exynos5440. But I
guess we could remove the others if we want to.


regards,
Joachim Eastwood