platform/x86: pmc_atom: Check state of PMC clocks on s2idle

Extend the s2idle check with checking that none of the PMC clocks
is in the forced-on state. If one of the clocks is in forced on
state then S0i3 cannot be reached.

Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20240305105915.76242-5-hdegoede@redhat.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

Author: jwrdegoede

drivers/platform/x86/pmc_atom.c

@@ -477,6 +477,7 @@ static void pmc_s2idle_check(void)
 	u32 func_dis, func_dis_2;
 	u32 d3_sts_0, d3_sts_1;
 	u32 false_pos_sts_0, false_pos_sts_1;
+	int i;
 
 	func_dis = pmc_reg_read(pmc, PMC_FUNC_DIS);
 	func_dis_2 = pmc_reg_read(pmc, PMC_FUNC_DIS_2);
@@ -501,6 +502,16 @@ static void pmc_s2idle_check(void)
 
 	pmc_dev_state_check(d3_sts_0, m->d3_sts_0, func_dis, m->func_dis, false_pos_sts_0);
 	pmc_dev_state_check(d3_sts_1, m->d3_sts_1, func_dis_2, m->func_dis_2, false_pos_sts_1);
+
+	/* Forced-on PMC clocks prevent S0i3 */
+	for (i = 0; i < PMC_CLK_NUM; i++) {
+		u32 ctl = pmc_reg_read(pmc, PMC_CLK_CTL_OFFSET + 4 * i);
+
+		if ((ctl & PMC_MASK_CLK_CTL) != PMC_CLK_CTL_FORCE_ON)
+			continue;
+
+		pr_err("clock %d is ON prior to freeze (ctl 0x%08x)\n", i, ctl);
+	}
 }
 
 static struct acpi_s2idle_dev_ops pmc_s2idle_ops = {