Re: [PATCH v2 16/35] brcmfmac: acpi: Add support for fetching Apple ACPI properties

[Hector Martin]

On 2022/01/10 18:11, Arend van Spriel wrote:
> On 1/4/2022 8:26 AM, Hector Martin wrote:
>> On DT platforms, the module-instance and antenna-sku-info properties
>> are passed in the DT. On ACPI platforms, module-instance is passed via
>> the analogous Apple device property mechanism, while the antenna SKU
>> info is instead obtained via an ACPI method that grabs it from
>> non-volatile storage.
>>
>> Add support for this, to allow proper firmware selection on Apple
>> platforms.
>>
>> Signed-off-by: Hector Martin <marcan@xxxxxxxxx>
>> ---
>>   .../broadcom/brcm80211/brcmfmac/Makefile      |  2 +
>>   .../broadcom/brcm80211/brcmfmac/acpi.c        | 47 +++++++++++++++++++
>>   .../broadcom/brcm80211/brcmfmac/common.c      |  1 +
>>   .../broadcom/brcm80211/brcmfmac/common.h      |  9 ++++
>>   4 files changed, 59 insertions(+)
>>   create mode 100644 drivers/net/wireless/broadcom/brcm80211/brcmfmac/acpi.c
> 
> [...]
> 
>> diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/acpi.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/acpi.c
>> new file mode 100644
>> index 000000000000..2b1a4448b291
>> --- /dev/null
>> +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/acpi.c
>> @@ -0,0 +1,47 @@
>> +// SPDX-License-Identifier: ISC
>> +/*
>> + * Copyright The Asahi Linux Contributors
>> + */
>> +
>> +#include <linux/acpi.h>
>> +#include "debug.h"
>> +#include "core.h"
>> +#include "common.h"
>> +
>> +void brcmf_acpi_probe(struct device *dev, enum brcmf_bus_type bus_type,
>> +		      struct brcmf_mp_device *settings)
>> +{
>> +	acpi_status status;
>> +	const union acpi_object *o;
>> +	struct acpi_buffer buf = {ACPI_ALLOCATE_BUFFER, NULL};
>> +	struct acpi_device *adev = ACPI_COMPANION(dev);
>> +
>> +	if (!adev)
>> +		return;
>> +
>> +	if (!ACPI_FAILURE(acpi_dev_get_property(adev, "module-instance",
>> +						ACPI_TYPE_STRING, &o))) {
>> +		brcmf_dbg(INFO, "ACPI module-instance=%s\n", o->string.pointer);
>> +		settings->board_type = devm_kasprintf(dev, GFP_KERNEL,
>> +						      "apple,%s",
>> +						      o->string.pointer);
>> +	} else {
>> +		brcmf_dbg(INFO, "No ACPI module-instance\n");
> 
> Do you need to obtain the antenna-sku when there is no module-instance?

In principle I don't think any machines would have antenna-sku and no
module-instance, though the firmware selection will still work without
it (it'll just end up using the DMI machine name instead).

> 
>> +	}
>> +
>> +	status = acpi_evaluate_object(adev->handle, "RWCV", NULL, &buf);
> 
> Can you clarify what the above does? What does the "RWCV" mean?

No idea what it *means* :-)

What it is, though, is the ACPI method name to get the antenna-sku.

-- 
Hector Martin (marcan@xxxxxxxxx)
Public Key: https://mrcn.st/pub