clk: qcom: apss-ipq6018: ipq5332: add safe source switch for a53pll

Stromer Plus PLL found on IPQ53xx doesn't support dynamic
frequency scaling. To achieve the same, we need to park the APPS
PLL source to GPLL0, re configure the PLL and then switch the
source to APSS_PLL_EARLY.

To support this, register a clock notifier to get the PRE_RATE
and POST_RATE notification. Change the APSS PLL source to GPLL0
when PRE_RATE notification is received, then configure the PLL
and then change back the source to APSS_PLL_EARLY.

Additionally, not all SKUs of IPQ53xx support scaling. Hence,
do the above to the SKUs that support scaling.

Reviewed-by: Dmitry Baryshkov <[email protected]>
Signed-off-by: Kathiravan T <[email protected]>
Signed-off-by: Varadarajan Narayanan <[email protected]>
Link: https://lore.kernel.org/r/49422d258d67d33a2547fbb7f4f6e72d489c2301.1697781921.git.quic_varada@quicinc.com
Signed-off-by: Bjorn Andersson <[email protected]>

0 files changed, 0 insertions, 0 deletions