[PATCH 13/15] ARM: dts: sun8i: Add dt node for rtl8703as wifi chip on ga10h

[Hans de Goede]

Hi,

On 11-07-16 08:39, Maxime Ripard wrote:
> Hi,
>
> On Fri, Jul 08, 2016 at 06:05:54PM +0200, Hans de Goede wrote:
>> The ga10h tablet has a rtl8703as wifi chip, add a dt node describing it.
>>
>> This enables usage of wifi on this tablet (together with the out of
>> tree rtl8732bs driver).
>>
>> Signed-off-by: Hans de Goede <hdegoede at redhat.com>
>> ---
>>  arch/arm/boot/dts/sun8i-a33-ga10h-v1.1.dts | 18 ++++++++++++++++++
>>  1 file changed, 18 insertions(+)
>>
>> diff --git a/arch/arm/boot/dts/sun8i-a33-ga10h-v1.1.dts b/arch/arm/boot/dts/sun8i-a33-ga10h-v1.1.dts
>> index 6566032..de6269d 100644
>> --- a/arch/arm/boot/dts/sun8i-a33-ga10h-v1.1.dts
>> +++ b/arch/arm/boot/dts/sun8i-a33-ga10h-v1.1.dts
>> @@ -47,6 +47,11 @@
>>  / {
>>  	model = "Allwinner GA10H Quad Core Tablet (v1.1)";
>>  	compatible = "allwinner,ga10h-v1.1", "allwinner,sun8i-a33";
>> +
>> +	aliases {
>> +		/* Make u-boot set mac-address for rtl8703as (no eeprom) */
>> +		ethernet0 = &rtl8703as;
>> +	};
>>  };
>>
>>  &ehci0 {
>> @@ -62,6 +67,19 @@
>>  	};
>>  };
>>
>> +&mmc1 {
>> +	pinctrl-names = "default";
>> +	pinctrl-0 = <&mmc1_pins_a>;
>> +	vmmc-supply = <&reg_dldo1>;
>> +	bus-width = <4>;
>> +	non-removable;
>> +	status = "okay";
>> +
>> +	rtl8703as: sdio_wifi at 1 {
>
> Shouldn't that need a compatible ?

There is no upstream driver yet, so no devicetree binding for the specific
wifi chip used. But all we really need is to follow generic sdio / network
bindings:

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/mmc/mmc-card.txt

Describes how to create a mmc-host child-node describing an (e)mmc-card or
sdio-function, in this case we are adding a node for sdio-function 1,
hence the reg = <1>; in the child-node.

Linux implementation wise, this will make the mmc core set the dev->of_node
ptr to this node for the struct device it passes into the sdio-drivers
probe function.

And u-boot will add a local-mac-address property as documented here:
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/net/ethernet.txt

to the node pointed to by ethernet%d aliases.

To actually make use of this I've modified the out of tree driver to check
for the "local-mac-address" property:

https://github.com/jwrdegoede/rtl8723bs/commit/be5e87ea71677120ede457213208902ed9942653

So that each device actually gets a unique address rather then the
(stupid) behavior of the out of tree driver to set the same fixes
mac address on every device which does not have a mac address in
eeprom / nvram.

Since this follows the existing ethernet bindings standard I
believe the dts bits can go upstream as is, but since there
is no upstream-able driver yet, I do not believe that making up
a compatible string to add to the child-node is a good idea.

More-over on q8 tablets we will want to do the same (again for
eeprom / nvram less boards) but without pinning ourselves to
a specific sdio-wifi module / compatible, instead relying on
sdio enumeration to figure out which sdio-wifi module is present.

Regards,

Hans