> From: Bean Huo <beanhuo@xxxxxxxxxx> > > Add Real Time Clock (RTC) support for UFS device. This enhancement is > crucial for the internal maintenance operations of the UFS device. The patch > enables the device to handle both absolute and relative time information. > Furthermore, it includes periodic task to update the RTC in accordance with > the UFS Spec, ensuring the accuracy of RTC information for the device's > internal processes. > > RTC and qTimestamp serve distinct purposes. The RTC provides a coarse > level of granularity with, at best, approximate single-second resolution. This > makes the RTC well-suited for the device to determine the approximate age > of programmed blocks after being updated by the host. On the other hand, > qTimestamp offers nanosecond granularity and is specifically designed for > synchronizing Device Error Log entries with corresponding host-side logs. > > Given that the RTC has been a standard feature since UFS Spec 2.0, and > qTimestamp was introduced in UFS Spec 4.0, the majority of UFS devices > currently on the market rely on RTC. Therefore, it is advisable to continue > supporting RTC in the Linux kernel. This ensures compatibility with the > prevailing UFS device implementations and facilitates seamless integration > with existing hardware. > By maintaining support for RTC, we ensure broad compatibility and avoid > potential issues arising from deviations in device specifications across > different UFS versions. > > Signed-off-by: Bean Huo <beanhuo@xxxxxxxxxx> > Signed-off-by: Mike Bi <mikebi@xxxxxxxxxx> > Signed-off-by: Luca Porzio <lporzio@xxxxxxxxxx> Acked-by: Avri Altman <avri.altman@xxxxxxx>
