clk: qcom: gdsc: add collapse-bit helper

Add a helper for updating the SW_COLLAPSE bit during initialisation and
state updates.

Note that the update during initialisation was relying on the
SW_COLLAPSE bit not having been set earlier rather than passing in zero
explicitly to clear the collapse vote.
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220520100948.19622-2-johan+linaro@kernel.org

drivers/clk/qcom/gdsc.c

@@ -132,10 +132,24 @@ static int gdsc_poll_status(struct gdsc *sc, enum gdsc_status status)
 	return -ETIMEDOUT;
 }
 
+static int gdsc_update_collapse_bit(struct gdsc *sc, bool val)
+{
+	u32 reg, mask;
+	int ret;
+
+	reg = sc->gdscr;
+	mask = SW_COLLAPSE_MASK;
+
+	ret = regmap_update_bits(sc->regmap, reg, mask, val ? mask : 0);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
 static int gdsc_toggle_logic(struct gdsc *sc, enum gdsc_status status)
 {
 	int ret;
-	u32 val = (status == GDSC_ON) ? 0 : SW_COLLAPSE_MASK;
 
 	if (status == GDSC_ON && sc->rsupply) {
 		ret = regulator_enable(sc->rsupply);
@@ -143,9 +157,7 @@ static int gdsc_toggle_logic(struct gdsc *sc, enum gdsc_status status)
 			return ret;
 	}
 
-	ret = regmap_update_bits(sc->regmap, sc->gdscr, SW_COLLAPSE_MASK, val);
-	if (ret)
-		return ret;
+	ret = gdsc_update_collapse_bit(sc, status == GDSC_OFF);
 
 	/* If disabling votable gdscs, don't poll on status */
 	if ((sc->flags & VOTABLE) && status == GDSC_OFF) {
@@ -425,8 +437,7 @@ static int gdsc_init(struct gdsc *sc)
 		 * If a Votable GDSC is ON, make sure we have a Vote.
 		 */
 		if (sc->flags & VOTABLE) {
-			ret = regmap_update_bits(sc->regmap, sc->gdscr,
-						 SW_COLLAPSE_MASK, val);
+			ret = gdsc_update_collapse_bit(sc, false);
 			if (ret)
 				return ret;
 		}