openwrt/target/linux/bcm27xx/patches-6.6/950-1043-pinctrl-rp1-Add-strict_gpiod-module-parameter.patch

From ddceddec2cedffd4af0e54dec3ab54843b1d5894 Mon Sep 17 00:00:00 2001
From: Phil Elwell <phil@raspberrypi.com>
Date: Fri, 19 Apr 2024 15:00:52 +0100
Subject: [PATCH 1043/1085] pinctrl: rp1: Add strict_gpiod module parameter

Setting strict_gpiod to Y makes libgpiod and the gpiod utilities behave
as documented, i.e. pins are returned to being GPIO inputs when they are
released.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>
---
 drivers/pinctrl/pinctrl-rp1.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

--- a/drivers/pinctrl/pinctrl-rp1.c
+++ b/drivers/pinctrl/pinctrl-rp1.c
@@ -573,6 +573,10 @@ static const char * const irq_type_names
 	[IRQ_TYPE_LEVEL_LOW] = "level-low",
 };
 
+static bool strict_gpiod;
+module_param(strict_gpiod, bool, 0644);
+MODULE_PARM_DESC(strict_gpiod, "unless true, outputs remain outputs when freed");
+
 static int rp1_pinconf_set(struct pinctrl_dev *pctldev,
 			   unsigned int offset, unsigned long *configs,
 			   unsigned int num_configs);
@@ -1201,8 +1205,8 @@ static int rp1_pmx_free(struct pinctrl_d
 	struct rp1_pin_info *pin = rp1_get_pin_pctl(pctldev, offset);
 	u32 fsel = rp1_get_fsel(pin);
 
-	/* Return non-GPIOs to GPIO_IN */
-	if (fsel != RP1_FSEL_GPIO) {
+	/* Return non-GPIOs to GPIO_IN, unless strict_gpiod is set */
+	if (strict_gpiod || fsel != RP1_FSEL_GPIO) {
 		rp1_set_dir(pin, RP1_DIR_INPUT);
 		rp1_set_fsel(pin, RP1_FSEL_GPIO);
 	}