pinctrl: rockchip: rv1126: Fix support for IOMUX_L_SOURCE_PMU flag

GPIO0_C0-C4 iomux is set using PMUGRF_GPIO0C_IOMUX_L reg on RV1126. This
is indicated using the IOMUX_L_SOURCE_PMU flag. Fix reading current mux
by fully adopting the IOMUX_L_SOURCE_PMU related code in Linux kernel.

Based on Linux commit fd4ea48688c6 ("pinctrl: rockchip: Add RV1126
pinctrl support").

Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/drivers/pinctrl/rockchip/pinctrl-rockchip-core.c b/drivers/pinctrl/rockchip/pinctrl-rockchip-core.c
index a3cdadb..ca93b52 100644
--- a/drivers/pinctrl/rockchip/pinctrl-rockchip-core.c
+++ b/drivers/pinctrl/rockchip/pinctrl-rockchip-core.c
@@ -132,8 +132,12 @@
 	if (bank->iomux[iomux_num].type & IOMUX_GPIO_ONLY)
 		return RK_FUNC_GPIO;
 
-	regmap = (bank->iomux[iomux_num].type & IOMUX_SOURCE_PMU)
-				? priv->regmap_pmu : priv->regmap_base;
+	if (bank->iomux[iomux_num].type & IOMUX_SOURCE_PMU)
+		regmap = priv->regmap_pmu;
+	else if (bank->iomux[iomux_num].type & IOMUX_L_SOURCE_PMU)
+		regmap = (pin % 8 < 4) ? priv->regmap_pmu : priv->regmap_base;
+	else
+		regmap = priv->regmap_base;
 
 	/* get basic quadrupel of mux registers and the correct reg inside */
 	mux_type = bank->iomux[iomux_num].type;
@@ -532,12 +536,14 @@
 
 			/* preset iomux offset value, set new start value */
 			if (iom->offset >= 0) {
-				if (iom->type & IOMUX_SOURCE_PMU)
+				if ((iom->type & IOMUX_SOURCE_PMU) ||
+				    (iom->type & IOMUX_L_SOURCE_PMU))
 					pmu_offs = iom->offset;
 				else
 					grf_offs = iom->offset;
 			} else { /* set current iomux offset */
-				iom->offset = (iom->type & IOMUX_SOURCE_PMU) ?
+				iom->offset = ((iom->type & IOMUX_SOURCE_PMU) ||
+					       (iom->type & IOMUX_L_SOURCE_PMU)) ?
 							pmu_offs : grf_offs;
 			}