[SRU][jammy:linux][PATCH] platform/x86/intel/pmc: Alder Lake PCH slp_s0_residency fix

[Philip Cox]

From: Rajvi Jingar <rajvi.jingar at linux.intel.com>

BugLink: https://bugs.launchpad.net/bugs/2019250

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 at linux.intel.com>
Signed-off-by: David E. Box <david.e.box at linux.intel.com>
Reviewed-by: Rajneesh Bhardwaj <irenic.rajneesh at gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko at gmail.com>
Link: https://lore.kernel.org/r/20230320212029.3154407-1-david.e.box@linux.intel.com
Reviewed-by: Hans de Goede <hdegoede at redhat.com>
Signed-off-by: Hans de Goede <hdegoede at redhat.com>
(cherry picked from commit fb5755100a0a5aa5957bdb204fd1e249684557fc)
Signed-off-by: Philip Cox <philip.cox at canonical.com>
---
 drivers/platform/x86/intel/pmc/core.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/platform/x86/intel/pmc/core.c b/drivers/platform/x86/intel/pmc/core.c
index ac19fcc9abbf..b8d67bc4acb0 100644
--- a/drivers/platform/x86/intel/pmc/core.c
+++ b/drivers/platform/x86/intel/pmc/core.c
@@ -958,7 +958,18 @@ 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)
-- 
2.34.1