brcmfmac support for BCM4359 sdio on arm64

[Christian Hewitt <christianshewitt@gmail.com>]

Hello Arend,

Last October Christoph Müllner reported BCM4359 SDIO issues here: https://www.spinics.net/lists/linux-wireless/msg178783.html but the investigation stalled after the needs/timescale of his project forced a change to an alternate (working) module.

BCM4359 is also being used in an increasing number of Amlogic devices the Kodi focussed distro LibreELEC supports. I’m one of the maintainers for the distro and I’d like to assist/resume the investigation.

To recap: using changes from Wright Feng that can be found here https://github.com/RobertCNelson/ti-linux-kernel-dev/blob/65f17112e1c883d3c9f3fa68837e5f9b5eb7cfad/patches/cypress/v4.14.52-2018_0928/cypress-patch/0050-brcmfmac-Add-support-for-BCM4359-SDIO-chipset.patch results in the BCM4359 device being identified but firmware loading fails:

[    8.557929] brcmfmac: F1 signature read @0x18000000=0x17294359
[    8.562087] brcmfmac: brcmf_fw_alloc_request: using brcm/brcmfmac4359-sdio for chip BCM4359/9
[    8.775655] brcmfmac: brcmf_sdiod_ramrw: membytes transfer failed
[    8.775667] brcmfmac: brcmf_sdio_verifymemory: error -84 on reading 2048 membytes at 0x0025f0c0
[    8.775670] brcmfmac: brcmf_sdio_download_firmware: dongle nvram file download failed

See: http://ix.io/1KfY for the full dmesg output on 5.1-rc1 kernel including a splat that may or may not be related/relevant. I am using the firmware and nvram files from https://github.com/LibreELEC/brcmfmac_sdio-firmware which match files found in several other github and public repo locations. The firmware/nvram are reported working in Android. 

BCMDHD is also reported working with the last few commits here: https://gitlab.com/baylibre/amlogic/atv/linux/commits/narmstrong/v5.1/aml/integ-5.1-bcmdhd but LibreELEC needs to support many different boards (with many different SDIO modules) from a single OS image, so BCMDHD is not the solution we need.

One additional patch I spotted mentioning BCM4359 (also from Wright Feng) was https://github.com/RobertCNelson/ti-linux-kernel-dev/blob/65f17112e1c883d3c9f3fa68837e5f9b5eb7cfad/patches/cypress/v4.14.52-2018_0928/cypress-patch/0073-non-upstream-reset-two-D11-cores-if-chip-has-two-D11.patch but it makes no difference (the dmesg log above is with this patch applied).

I’m happy building test kernels but I don’t write code so I can be fed patches and can provide logs/output as long as the instructions are fairly explicit. I’ve also CC’d LibreELEC colleague and linux-amlogic maintainer Neil Armstrong who has vastly superior skills to myself and can assist. NB: If direct access to hardware would help progress things I can easily organise remote access or get board samples shipped.

How to resume things again?

Christian