On many Qualcomm platforms the PMIC RTC control and time registers are
read-only so that the RTC time can not be updated. Instead an offset
needs be stored in some machine-specific non-volatile memory, which the
driver can take into account.
Add support for storing a 32-bit offset from the GPS time epoch in a
UEFI variable so that the RTC time can be set on such platforms.
The UEFI variable is
882f8c2b-9646-435f-8de5-f208ff80c1bd-RTCInfo
and holds a 12-byte structure where the first four bytes is a GPS time
offset in little-endian byte order.
Note that this format is not arbitrary as the variable is shared with
the UEFI firmware (and Windows).
Tested-by: Jens Glathe <jens.glathe@oldschoolsolutions.biz>
Tested-by: Steev Klimaszewski <steev@kali.org>
Tested-by: Joel Stanley <joel@jms.id.au>
Tested-by: Sebastian Reichel <sre@kernel.org> # Lenovo T14s Gen6
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20250219134118.31017-3-johan+linaro@kernel.org
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
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| .. | ||
| acpi | ||
| asm-generic | ||
| clocksource | ||
| crypto | ||
| cxl | ||
| drm | ||
| dt-bindings | ||
| hyperv | ||
| keys | ||
| kunit | ||
| kvm | ||
| linux | ||
| math-emu | ||
| media | ||
| memory | ||
| misc | ||
| net | ||
| pcmcia | ||
| ras | ||
| rdma | ||
| rv | ||
| scsi | ||
| soc | ||
| sound | ||
| target | ||
| trace | ||
| uapi | ||
| ufs | ||
| vdso | ||
| video | ||
| xen | ||