Re: [PATCH] ARM: dts: BCM5301X: Add DT for Asus RT-AC88U
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From: Arınç ÜNAL <hidden>
Date: 2021-09-22 22:26:46
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linux-devicetree
On 22/09/2021 21:15, Florian Fainelli wrote:
On 9/21/21 5:19 AM, Arınç ÜNAL wrote:quoted
Hardware Info ------------- Processor - Broadcom BCM4709C0KFEBG dual-core @ 1.4 GHz Switch - BCM53012 in BCM4709C0KFEBG & external RTL8365MBThere is no Device Tree description of the RTL8365MB switch, can it be driven/controlled via MDIO, SPI or GPIOs by any chance? This is not a show stopper for accepting the patch, just wondering if you are somehow trying to get that switch controlled by the rtl8366 DSA driver as well?
There's a v1 patch on net-next adding DSA support for RTL8365MB by Alvin Šipraga, CC'ing them. There's also a v2 patch coming. https://lore.kernel.org/netdev/20210822193145.1312668-1-alvin@pqrs.dk/ (local) I've been mailing Alvin to figure out how to define it on the device tree. They have provided very useful information. Quoting a few:
quoted
I'm trying to write the device tree to support this switch. I'm not sure whether the default GPIO IDs of mdc-gpios, mdio-gpios, reset-gpios & interrupts on realtek-smi.txt kernel documentation are correct.
https://elixir.bootlin.com/linux/latest/source/Documentation/devicetree/bindings/net/dsa/realtek-smi.txt
These gpios are just an example. It really depends how your board is wired up. You have to figure out which SoC pad is wired to the MDC, MDIO, and RESET pins on the RTL8365MB. Then you have to make sure the pinmux is set up correctly so that these pads correspond to some GPIO with a given ID, and then pick the right GPIO controller (&chipcommon?) and put the ID after that. It will not necessarily be 21, 22, 14.
In summary: - figure out which pads are wired to MDC, MDIO, RESET - figure out pinmux to make them into gpios - figure out gpio ID and describe that in the device tree
I have backported the v1 patch to kernel 5.10 and tried an example definition on the device tree to test it out on RT-AC88U. It's on this branch: https://github.com/arinc9/openwrt/commits/realtek-work-asus_rt-ac88u It doesn't work as is, likely missing further configuration, which I'm clueless to figure out myself. I'd very appreciate it if you could weigh in. [ 1.598858] realtek-smi switch@1: failed to get RESET GPIO --- [ 3.015528] realtek-smi switch@1: deasserted RESET [ 3.021171] realtek-smi switch@1: found an RTL8365MB-VC switch (ver=0x0040) [ 3.028193] realtek-smi switch@1: unable to register switch ret = -517 --- [ 3.405527] realtek-smi switch@1: deasserted RESET [ 3.411165] realtek-smi switch@1: found an RTL8365MB-VC switch (ver=0x0040) [ 3.418449] DSA: tree 0 already setup! Disjoint trees? [ 3.423607] realtek-smi switch@1: unable to register switch ret = -17 [ 3.430137] realtek-smi: probe of switch@1 failed with error -17 --- I was thinking, we figure out how to define it properly on the device tree and make the driver work whilst the v2 patch is applied to net-next. Then we could send another patch defining the switch on the device tree. There's the "compatible = "realtek,rtl8365mb";" property, which would be undefined until the driver is added. Cheers. Arınç _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel