platform/x86/intel/pmc: Alder Lake PCH slp_s0_residency fix

For platforms with Alder Lake PCH (Alder Lake S and Raptor Lake S) the
slp_s0_residency attribute has been reporting the wrong value. Unlike other
platforms, ADL PCH does not have a counter for the time that the SLP_S0
signal was asserted. Instead, firmware uses the aggregate of the Low Power
Mode (LPM) substate counters as the S0ix value.  Since the LPM counters run
at a different frequency, this lead to misreporting of the S0ix time.

Add a check for Alder Lake PCH and adjust the frequency accordingly when
display slp_s0_residency.

Fixes: bbab31101f44 ("platform/x86/intel: pmc/core: Add Alderlake support to pmc core driver")
Signed-off-by: Rajvi Jingar <rajvi.jingar@linux.intel.com>
Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Reviewed-by: Rajneesh Bhardwaj <irenic.rajneesh@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20230320212029.3154407-1-david.e.box@linux.intel.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

diff --git a/drivers/platform/x86/intel/pmc/core.c b/drivers/platform/x86/intel/pmc/core.c
index 3a15d32..b959196 100644 (file)
--- a/drivers/platform/x86/intel/pmc/core.c
+++ b/drivers/platform/x86/intel/pmc/core.c
@@ -66,7 +66,18 @@ static inline void pmc_core_reg_write(struct pmc_dev *pmcdev, int reg_offset,
 
 static inline u64 pmc_core_adjust_slp_s0_step(struct pmc_dev *pmcdev, u32 value)
 {
-       return (u64)value * pmcdev->map->slp_s0_res_counter_step;
+       /*
+        * ADL PCH does not have the SLP_S0 counter and LPM Residency counters are
+        * used as a workaround which uses 30.5 usec tick. All other client
+        * programs have the legacy SLP_S0 residency counter that is using the 122
+        * usec tick.
+        */
+       const int lpm_adj_x2 = pmcdev->map->lpm_res_counter_step_x2;
+
+       if (pmcdev->map == &adl_reg_map)
+               return (u64)value * GET_X2_COUNTER((u64)lpm_adj_x2);
+       else
+               return (u64)value * pmcdev->map->slp_s0_res_counter_step;
 }
 
 static int set_etr3(struct pmc_dev *pmcdev)