Re: [PATCH 0/2] rtc: Add Qualcomm PMIC RTC-GLINK support for Glymur

[Kamal Wadhwa]

On Tue, Aug 11, 2026 at 02:10:12PM +0200, Troels Vognbjerg wrote:
> Kamal Wadhwa <kamal.wadhwa@xxxxxxxxxxxxxxxx> wrote on Fri, 07 Aug 2026 02:26:29 +0530:
> > On some targets like Glymur, the permission for receving the RTC
> > alarms is routed to charger firmware running on remote subsystem.
> > 
> > This is because Glymur boards have to  support MSFT's `TAD feature`
> > on the windows OS devices.
> > 
> > So rtc-pm8xxx.c driver cannot recieve RTC alarm IRQs via SPMI on
> > Glymur. So in order to make the IRQ available on the Linux kernel,
> > the PMIC RTC Alarm IRQ must be routed to APPS via remote subsystem.
> > 
> > To implement this, add support for a New Qualcomm PMIC GLINK RTC
> > client, which will request for RTC set/get calls for time/alarm IRQ
> >  via the existing pmic_glink interface to the charger firmware.
> > 
> > Also, add a DT property to explicily support enabling the RTC
> > writes, keep RTC writes disabled by default to align behaviour
> > with the existing rtc-pm8xxx.c driver.
> 
> You mentioned this patch series applies to targets like Glymur. Does that include
> the ASUS Zenbook A16 UX3607OA, or did ASUS do something different on this
> laptop?
> 
> The reason I am asking is because when I build this as a kernel module,
> I get the following error message:
> [    2.241461] rtc-pm8xxx c426000.spmi:pmic@0:rtc@6100: probe with driver rtc-pm8xxx failed with error -2

This is a different driver error, this is for the one which works on the SPMI bus.
While the driver that i have posted in the current series is based on pmic_glink interface, which relays the
RTC alarm requests to charger firmware running in remote processor (which implements the Windows TAD feature)

do you have this `qcom,no-alarm` prop defined?
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm64/boot/dts/qcom/glymur-crd.dtsi?h=v7.2#n565


> [    2.499556] Modules linked in: rtc_pm8xxx aes_ce_blk ghash_ce gf128mul sm4_ce_gcm sm4_ce_ccm sm4_ce sm4_ce_cipher sm4 qcom_battmgr rtc_qcom_glink(+) simple_bridge display_connector
> [    3.277788] rtc_qcom_glink.qcom_pmic_rtc_glink pmic_glink.rtc-glink.0: 0x68 failed (-110), falling back
> [    4.318666] rtc_qcom_glink.qcom_pmic_rtc_glink pmic_glink.rtc-glink.0: all time sources failed
> [    4.319085] rtc_qcom_glink.qcom_pmic_rtc_glink pmic_glink.rtc-glink.0: registered as rtc0
> [    5.359404] rtc_qcom_glink.qcom_pmic_rtc_glink pmic_glink.rtc-glink.0: 0x68 failed (-110), falling back
> [    6.400331] rtc_qcom_glink.qcom_pmic_rtc_glink pmic_glink.rtc-glink.0: all time sources failed
> [    6.400496] rtc_qcom_glink.qcom_pmic_rtc_glink pmic_glink.rtc-glink.0: hctosys: unable to read the hardware clock
> [   25.447761] rtc_qcom_glink.qcom_pmic_rtc_glink pmic_glink.rtc-glink.0: 0x68 failed (-110), falling back
> [   26.488271] rtc_qcom_glink.qcom_pmic_rtc_glink pmic_glink.rtc-glink.0: all time sources failed
> [   27.517573] rtc_qcom_glink.qcom_pmic_rtc_glink pmic_glink.rtc-glink.0: 0x68 failed (-110), falling back
> [   28.560114] rtc_qcom_glink.qcom_pmic_rtc_glink pmic_glink.rtc-glink.0: all time sources failed
> [   29.609224] rtc_qcom_glink.qcom_pmic_rtc_glink pmic_glink.rtc-glink.0: 0x68 failed (-110), falling back
> [   30.638629] rtc_qcom_glink.qcom_pmic_rtc_glink pmic_glink.rtc-glink.0: all time sources failed
> [   31.677524] rtc_qcom_glink.qcom_pmic_rtc_glink pmic_glink.rtc-glink.0: 0x68 failed (-110), falling back
> [   32.720749] rtc_qcom_glink.qcom_pmic_rtc_glink pmic_glink.rtc-glink.0: all time sources failed
> [   33.757662] rtc_qcom_glink.qcom_pmic_rtc_glink pmic_glink.rtc-glink.0: 0x68 failed (-110), falling back
> [   34.808360] rtc_qcom_glink.qcom_pmic_rtc_glink pmic_glink.rtc-glink.0: all time sources failed
> [   35.837651] rtc_qcom_glink.qcom_pmic_rtc_glink pmic_glink.rtc-glink.0: 0x68 failed (-110), falling back
> 
> And the error message keeps repeating every second or so.

Sorry for this, i think the firmware needs to be updated for this feature, I will fix this by existing cleanly
if the firmware doesnt support it. To avoid repeated messages.

Also will check internally how you can get new firmware (if you want to use it?)

Again sorry for the trouble.

> 
> --
> Troels Vognbjerg

Regards,
Kamal