diff options
| author | Johan Hovold <johan+linaro@kernel.org> | 2025-04-23 09:51:41 +0200 |
|---|---|---|
| committer | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2025-05-24 23:39:41 +0200 |
| commit | ead4532832795f700fd8962cb1f2aad74f3dfca7 (patch) | |
| tree | e6a3389bc9e8decb1a0c47c2e244a7489427fcb5 | |
| parent | b23b91d56863d280af81c9ca11594484782ceea5 (diff) | |
rtc: pm8xxx: fix uefi offset lookup
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 a
driver can take into account.
On platforms where the offset is stored in a Qualcomm specific UEFI
variable the variables are also accessed in a non-standard way, which
means that the OS cannot assume that the variable service is available
by the time the driver probes.
Use the new 'qcom,uefi-rtc-info' property to determine whether to probe
defer until the UEFI offset becomes available so that the offset can be
used also when the RTC driver is built in or when a dependency of the
UEFI variable driver is built as a module (e.g. the driver for the SCM
interconnects).
Fixes: bba38b874886 ("rtc: pm8xxx: add support for uefi offset")
Reported-by: Rob Clark <robdclark@gmail.com>
Link: https://lore.kernel.org/lkml/CAF6AEGsfke=x0p1b2-uNX6DuQfRyEjVbJaxTbVLDT2YvSkGJbg@mail.gmail.com/
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20250423075143.11157-3-johan+linaro@kernel.org
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
| -rw-r--r-- | drivers/rtc/rtc-pm8xxx.c | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/drivers/rtc/rtc-pm8xxx.c b/drivers/rtc/rtc-pm8xxx.c index 3c1dddcc81df..5da237e7b9b2 100644 --- a/drivers/rtc/rtc-pm8xxx.c +++ b/drivers/rtc/rtc-pm8xxx.c @@ -576,13 +576,20 @@ static int pm8xxx_rtc_probe_offset(struct pm8xxx_rtc *rtc_dd) } /* Use UEFI storage as fallback if available */ - if (efivar_is_available()) { - rc = pm8xxx_rtc_read_uefi_offset(rtc_dd); - if (rc == 0) - rtc_dd->use_uefi = true; + rtc_dd->use_uefi = of_property_read_bool(rtc_dd->dev->of_node, + "qcom,uefi-rtc-info"); + if (!rtc_dd->use_uefi) + return 0; + + if (!efivar_is_available()) { + if (IS_ENABLED(CONFIG_EFI)) + return -EPROBE_DEFER; + + dev_warn(rtc_dd->dev, "efivars not available\n"); + rtc_dd->use_uefi = false; } - return 0; + return pm8xxx_rtc_read_uefi_offset(rtc_dd); } static int pm8xxx_rtc_probe(struct platform_device *pdev) |