On Tue, Jan 4, 2022 at 9:28 AM Hector Martin <marcan@xxxxxxxxx> wrote:
>
> 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.
...
> + /* Apple platforms with fancy firmware/NVRAM selection */
> + if (devinfo->settings->board_type &&
> + devinfo->settings->antenna_sku &&
> + devinfo->otp.valid) {
> + char *buf;
> + int len;
> +
> + brcmf_dbg(PCIE, "Apple board: %s\n",
> + devinfo->settings->board_type);
> +
> + /* Example: apple,shikoku-RASP-m-6.11-X3 */
> + len = (strlen(devinfo->settings->board_type) + 1 +
> + strlen(devinfo->otp.module) + 1 +
> + strlen(devinfo->otp.vendor) + 1 +
> + strlen(devinfo->otp.version) + 1 +
> + strlen(devinfo->settings->antenna_sku) + 1);
NIH devm_kasprrintf() ?
> + /* apple,shikoku */
> + fwreq->board_types[5] = devinfo->settings->board_type;
> +
> + buf = devm_kzalloc(&devinfo->pdev->dev, len, GFP_KERNEL);
> +
> + strscpy(buf, devinfo->settings->board_type, len);
> + strlcat(buf, "-", len);
> + strlcat(buf, devinfo->settings->antenna_sku, len);
> + /* apple,shikoku-X3 */
> + fwreq->board_types[4] = devm_kstrdup(&devinfo->pdev->dev, buf,
> + GFP_KERNEL);
> +
> + strscpy(buf, devinfo->settings->board_type, len);
> + strlcat(buf, "-", len);
> + strlcat(buf, devinfo->otp.module, len);
> + /* apple,shikoku-RASP */
> + fwreq->board_types[3] = devm_kstrdup(&devinfo->pdev->dev, buf,
> + GFP_KERNEL);
> +
> + strlcat(buf, "-", len);
> + strlcat(buf, devinfo->otp.vendor, len);
> + /* apple,shikoku-RASP-m */
> + fwreq->board_types[2] = devm_kstrdup(&devinfo->pdev->dev, buf,
> + GFP_KERNEL);
> +
> + strlcat(buf, "-", len);
> + strlcat(buf, devinfo->otp.version, len);
> + /* apple,shikoku-RASP-m-6.11 */
> + fwreq->board_types[1] = devm_kstrdup(&devinfo->pdev->dev, buf,
> + GFP_KERNEL);
> +
> + strlcat(buf, "-", len);
> + strlcat(buf, devinfo->settings->antenna_sku, len);
> + /* apple,shikoku-RASP-m-6.11-X3 */
> + fwreq->board_types[0] = buf;
--
With Best Regards,
Andy Shevchenko
