[v2 2/2] ramips: pinctrl: support requesting different functions for same group

[Shiji Yang]

From: Shiji Yang <yangshiji66 at qq.com>

MT7620 wireless radio needs change the pin group function between
"gpio" and "pa" during the calibration process. However, ralink
pinctrl driver doesn't support requesting different functions for
the same group. This patch enables pinctrl consumers to perform
such operations.

Signed-off-by: Shiji Yang <yangshiji66 at qq.com>
---
 ...upport-requesting-different-function.patch | 45 +++++++++++++++++++
 1 file changed, 45 insertions(+)
 create mode 100644 target/linux/ramips/patches-5.15/808-pinctrl-mtmips-support-requesting-different-function.patch

diff --git a/target/linux/ramips/patches-5.15/808-pinctrl-mtmips-support-requesting-different-function.patch b/target/linux/ramips/patches-5.15/808-pinctrl-mtmips-support-requesting-different-function.patch
new file mode 100644
index 0000000000..047808f1e6
--- /dev/null
+++ b/target/linux/ramips/patches-5.15/808-pinctrl-mtmips-support-requesting-different-function.patch
@@ -0,0 +1,45 @@
+From: Shiji Yang <yangshiji66 at 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 at outlook.com>
+---
+ drivers/pinctrl/ralink/pinctrl-ralink.c | 21 +++++++++++++++++----
+ 1 file changed, 17 insertions(+), 4 deletions(-)
+
+--- a/drivers/pinctrl/ralink/pinctrl-ralink.c
++++ b/drivers/pinctrl/ralink/pinctrl-ralink.c
+@@ -123,11 +123,24 @@ static int ralink_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;
-- 
2.39.2