From: Shiji Yang <yangshiji66@outlook.com>
Date: Wed, 26 Jul 2023 01:32:55 +0800
Subject: [PATCH] pinctrl: mtmips: support requesting different functions for
 same group

Sometimes pinctrl consumers may request different functions for the
same pin group in different situations. This patch can help to reset
the group function flag when requesting a different function.

Signed-off-by: Shiji Yang <yangshiji66@outlook.com>
---
 drivers/pinctrl/mediatek/pinctrl-mtmips.c | 21 +++++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

--- a/drivers/pinctrl/mediatek/pinctrl-mtmips.c
+++ b/drivers/pinctrl/mediatek/pinctrl-mtmips.c
@@ -123,11 +123,24 @@ static int mtmips_pmx_group_enable(struc
 	int i;
 	int shift;
 
-	/* dont allow double use */
+	/*
+	 * for the same pin group, if request a different function,
+	 * then clear the group function flag and continue, else exit.
+	 */
 	if (p->groups[group].enabled) {
-		dev_err(p->dev, "%s is already enabled\n",
-			p->groups[group].name);
-		return 0;
+		for (i = 0; i < p->groups[group].func_count; i++) {
+			if (p->groups[group].func[i].enabled == 1) {
+				if (!strcmp(p->func[func]->name,
+					p->groups[group].func[i].name))
+					return 0;
+				p->groups[group].func[i].enabled = 0;
+				break;
+			}
+		}
+
+		/* exit if request the "gpio" function again */
+		if (i == p->groups[group].func_count && func == 0)
+			return 0;
 	}
 
 	p->groups[group].enabled = 1;
