Re: [PATCH wireless-next v2 07/12] brcmfmac: pcie: Perform firmware selection for Apple platforms

["Alvin Šipraga" <ALSI@bang-olufsen.dk>]

On Mon, Sep 12, 2022 at 10:53:12AM +0100, Russell King wrote:
> From: Hector Martin <marcan@marcan.st>
> 
> On Apple platforms, firmware selection uses the following elements:
> 
>   Property         Example   Source
>   ==============   =======   ========================
> * Chip name        4378      Device ID
> * Chip revision    B1        OTP
> * Platform         shikoku   DT (ARM64) or ACPI (x86)
> * Module type      RASP      OTP
> * Module vendor    m         OTP
> * Module version   6.11      OTP
> * Antenna SKU      X3        DT (ARM64) or ACPI (x86)
> 
> In macOS, these firmwares are stored using filenames in this format
> under /usr/share/firmware/wifi:
> 
>     C-4378__s-B1/P-shikoku-X3_M-RASP_V-m__m-6.11.txt
> 
> To prepare firmwares for Linux, we rename these to a scheme following
> the existing brcmfmac convention:
> 
>     brcmfmac<chip><lower(rev)>-pcie.apple,<platform>-<mod_type>-\
> 	<mod_vendor>-<mod_version>-<antenna_sku>.txt
> 
> The NVRAM uses all the components, while the firmware and CLM blob only
> use the chip/revision/platform/antenna_sku:
> 
>     brcmfmac<chip><lower(rev)>-pcie.apple,<platform>-<antenna_sku>.bin
> 
> e.g.
> 
>     brcm/brcmfmac4378b1-pcie.apple,shikoku-RASP-m-6.11-X3.txt
>     brcm/brcmfmac4378b1-pcie.apple,shikoku-X3.bin
> 
> In addition, since there are over 1000 files in total, many of which are
> symlinks or outright duplicates, we deduplicate and prune the firmware
> tree to reduce firmware filenames to fewer dimensions. For example, the
> shikoku platform (MacBook Air M1 2020) simplifies to just 4 files:
> 
>     brcm/brcmfmac4378b1-pcie.apple,shikoku.clm_blob
>     brcm/brcmfmac4378b1-pcie.apple,shikoku.bin
>     brcm/brcmfmac4378b1-pcie.apple,shikoku-RASP-m.txt
>     brcm/brcmfmac4378b1-pcie.apple,shikoku-RASP-u.txt
> 
> This reduces the total file count to around 170, of which 75 are
> symlinks and 95 are regular files: 7 firmware blobs, 27 CLM blobs, and
> 61 NVRAM config files. We also slightly process NVRAM files to correct
> some formatting issues.
> 
> To handle this, the driver must try the following path formats when
> looking for firmware files:
> 
>     brcm/brcmfmac4378b1-pcie.apple,shikoku-RASP-m-6.11-X3.txt
>     brcm/brcmfmac4378b1-pcie.apple,shikoku-RASP-m-6.11.txt
>     brcm/brcmfmac4378b1-pcie.apple,shikoku-RASP-m.txt
>     brcm/brcmfmac4378b1-pcie.apple,shikoku-RASP.txt
>     brcm/brcmfmac4378b1-pcie.apple,shikoku-X3.txt *
>     brcm/brcmfmac4378b1-pcie.apple,shikoku.txt
> 
> * Not relevant for NVRAM, only for firmware/CLM.
> 
> The chip revision nominally comes from OTP on Apple platforms, but it
> can be mapped to the PCI revision number, so we ignore the OTP revision
> and continue to use the existing PCI revision mechanism to identify chip
> revisions, as the driver already does for other chips. Unfortunately,
> the mapping is not consistent between different chip types, so this has
> to be determined experimentally.
> 
> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
> Signed-off-by: Hector Martin <marcan@marcan.st>
> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
> ---

Reviewed-by: Alvin Šipraga <alsi@bang-olufsen.dk>

>  .../broadcom/brcm80211/brcmfmac/pcie.c        | 41 ++++++++++++++++++-
>  1 file changed, 39 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c
> index 76ca835378bb..3fb590a6e03b 100644
> --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c
> +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c
> @@ -2068,8 +2068,45 @@ brcmf_pcie_prepare_fw_request(struct brcmf_pciedev_info *devinfo)
>  	fwreq->domain_nr = pci_domain_nr(devinfo->pdev->bus) + 1;
>  	fwreq->bus_nr = devinfo->pdev->bus->number;
>  
> -	brcmf_dbg(PCIE, "Board: %s\n", devinfo->settings->board_type);
> -	fwreq->board_types[0] = devinfo->settings->board_type;
> +	/* Apple platforms with fancy firmware/NVRAM selection */
> +	if (devinfo->settings->board_type &&
> +	    devinfo->settings->antenna_sku &&
> +	    devinfo->otp.valid) {
> +		const struct brcmf_otp_params *otp = &devinfo->otp;
> +		struct device *dev = &devinfo->pdev->dev;
> +		const char **bt = fwreq->board_types;
> +
> +		brcmf_dbg(PCIE, "Apple board: %s\n",
> +			  devinfo->settings->board_type);
> +
> +		/* Example: apple,shikoku-RASP-m-6.11-X3 */
> +		bt[0] = devm_kasprintf(dev, GFP_KERNEL, "%s-%s-%s-%s-%s",
> +				       devinfo->settings->board_type,
> +				       otp->module, otp->vendor, otp->version,
> +				       devinfo->settings->antenna_sku);
> +		bt[1] = devm_kasprintf(dev, GFP_KERNEL, "%s-%s-%s-%s",
> +				       devinfo->settings->board_type,
> +				       otp->module, otp->vendor, otp->version);
> +		bt[2] = devm_kasprintf(dev, GFP_KERNEL, "%s-%s-%s",
> +				       devinfo->settings->board_type,
> +				       otp->module, otp->vendor);
> +		bt[3] = devm_kasprintf(dev, GFP_KERNEL, "%s-%s",
> +				       devinfo->settings->board_type,
> +				       otp->module);
> +		bt[4] = devm_kasprintf(dev, GFP_KERNEL, "%s-%s",
> +				       devinfo->settings->board_type,
> +				       devinfo->settings->antenna_sku);
> +		bt[5] = devinfo->settings->board_type;
> +
> +		if (!bt[0] || !bt[1] || !bt[2] || !bt[3] || !bt[4]) {
> +			kfree(fwreq);
> +			return NULL;
> +		}
> +

Spurious newline?

> +	} else {
> +		brcmf_dbg(PCIE, "Board: %s\n", devinfo->settings->board_type);
> +		fwreq->board_types[0] = devinfo->settings->board_type;
> +	}
>  
>  	return fwreq;
>  }
> -- 
> 2.30.2
>