soc: apple: pmgr: Add externally-clocked property

MCA power states require an external clock to be provided. If they are
powered on while this clock is not active, the power state will only go
into the "clock gated" state.

This is effectively working as intended, so add a property that
instructs the pwrstate driver to consider the PS to be successfully
powered on when it reaches the clock gated state.

Signed-off-by: Hector Martin <marcan@marcan.st>

Author: marcan

drivers/pmdomain/apple/pmgr-pwrstate.c

@@ -47,6 +47,7 @@ struct apple_pmgr_ps {
 	u32 min_state;
 	bool force_disable;
 	bool force_reset;
+	bool externally_clocked;
 };
 
 #define genpd_to_apple_pmgr_ps(_genpd) container_of(_genpd, struct apple_pmgr_ps, genpd)
@@ -96,10 +97,21 @@ static int apple_pmgr_ps_set(struct generic_pm_domain *genpd, u32 pstate, bool a
 
 	regmap_write(ps->regmap, ps->offset, reg);
 
-	ret = regmap_read_poll_timeout_atomic(
-		ps->regmap, ps->offset, cur,
-		FIELD_GET(APPLE_PMGR_PS_ACTUAL, cur) == pstate, 1,
-		APPLE_PMGR_PS_SET_TIMEOUT);
+	if (ps->externally_clocked && pstate == APPLE_PMGR_PS_ACTIVE) {
+		/*
+		 * If this clock domain requires an external clock, then
+		 * consider the "clock gated" state to be good enough.
+		 */
+		ret = regmap_read_poll_timeout_atomic(
+			ps->regmap, ps->offset, cur,
+			FIELD_GET(APPLE_PMGR_PS_ACTUAL, cur) >= APPLE_PMGR_PS_CLKGATE, 1,
+			APPLE_PMGR_PS_SET_TIMEOUT);
+	} else {
+		ret = regmap_read_poll_timeout_atomic(
+			ps->regmap, ps->offset, cur,
+			FIELD_GET(APPLE_PMGR_PS_ACTUAL, cur) == pstate, 1,
+			APPLE_PMGR_PS_SET_TIMEOUT);
+	}
 
 	if (ret < 0)
 		dev_err(ps->dev, "PS %s: Failed to reach power state 0x%x (now: 0x%x)\n",
@@ -259,6 +271,15 @@ static int apple_pmgr_ps_probe(struct platform_device *pdev)
 		regmap_update_bits(regmap, ps->offset, APPLE_PMGR_FLAGS | APPLE_PMGR_PS_MIN,
 				   FIELD_PREP(APPLE_PMGR_PS_MIN, ps->min_state));
 
+	if (of_property_read_bool(node, "apple,force-disable"))
+		ps->force_disable = true;
+
+	if (of_property_read_bool(node, "apple,force-reset"))
+		ps->force_reset = true;
+
+	if (of_property_read_bool(node, "apple,externally-clocked"))
+		ps->externally_clocked = true;
+
 	active = apple_pmgr_ps_is_active(ps);
 	if (of_property_read_bool(node, "apple,always-on")) {
 		ps->genpd.flags |= GENPD_FLAG_ALWAYS_ON;
@@ -269,12 +290,6 @@ static int apple_pmgr_ps_probe(struct platform_device *pdev)
 		}
 	}
 
-	if (of_property_read_bool(node, "apple,force-disable"))
-		ps->force_disable = true;
-
-	if (of_property_read_bool(node, "apple,force-reset"))
-		ps->force_reset = true;
-
 	/* Turn on auto-PM if the domain is already on */
 	if (active)
 		regmap_update_bits(regmap, ps->offset, APPLE_PMGR_FLAGS | APPLE_PMGR_AUTO_ENABLE,