ipq40xx: add gpio pin function patch

Add a qcom pinctrl fix for ipq4019 that marks the gpio
function as a GPIO pin function.

With Linux 6.18 strict pinmuxing, ipq40xx can otherwise
hit conflicts when pins muxed to "gpio" are later
requested by GPIO consumers. [1]

This patch fixes that at the driver level and avoids DTS-side
workarounds, same as it is done for other Qualcomm boards. [2]

[1] https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=cc85cb96e2e4
[2] https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=480dc1952404

Signed-off-by: Til Kaiser <mail@tk154.de>
Link: https://github.com/openwrt/openwrt/pull/22930
Signed-off-by: Nick Hainke <vincent@systemli.org>

diff --git a/target/linux/ipq40xx/patches-6.18/708-pinctrl-qcom-ipq4019-mark-gpio-as-a-GPIO-pin-function.patch b/target/linux/ipq40xx/patches-6.18/708-pinctrl-qcom-ipq4019-mark-gpio-as-a-GPIO-pin-function.patch
new file mode 100644 (file)
index 0000000..762aa46
--- /dev/null
+++ b/target/linux/ipq40xx/patches-6.18/708-pinctrl-qcom-ipq4019-mark-gpio-as-a-GPIO-pin-function.patch
@@ -0,0 +1,51 @@
+From 437579ad9804055132ad40ccc1ba0cc64dbd828b Mon Sep 17 00:00:00 2001
+From: Til Kaiser <mail@tk154.de>
+Date: Mon, 13 Apr 2026 10:29:20 +0200
+Subject: [PATCH] pinctrl: qcom: ipq4019: mark gpio as a GPIO pin function
+
+The qcom pinctrl core supports marking functions that represent GPIO mode
+via PINCTRL_GPIO_PINFUNCTION(), so that strict pinmuxing does not reject
+GPIO requests for pins that are muxed to the GPIO function.
+
+ipq4019 still describes its gpio function with QCA_PIN_FUNCTION(gpio),
+so it is not treated as a GPIO pin function. As a result, GPIO consumers
+can still conflict with pinctrl states that select the "gpio" function.
+
+Add a QCA_GPIO_PIN_FUNCTION() helper and use it for the ipq4019 gpio
+function, matching how the msm-based qcom drivers handle this.
+
+This allows ipq4019 to keep the GPIO-related pin configuration in DTS
+without tripping over strict pinmux ownership checks.
+
+Fixes: cc85cb96e2e4 ("pinctrl: qcom: make the pinmuxing strict")
+Signed-off-by: Til Kaiser <mail@tk154.de>
+---
+ drivers/pinctrl/qcom/pinctrl-ipq4019.c | 2 +-
+ drivers/pinctrl/qcom/pinctrl-msm.h     | 5 +++++
+ 2 files changed, 6 insertions(+), 1 deletion(-)
+
+--- a/drivers/pinctrl/qcom/pinctrl-ipq4019.c
++++ b/drivers/pinctrl/qcom/pinctrl-ipq4019.c
+@@ -480,7 +480,7 @@ static const struct pinfunction ipq4019_
+       QCA_PIN_FUNCTION(blsp_uart0),
+       QCA_PIN_FUNCTION(blsp_uart1),
+       QCA_PIN_FUNCTION(chip_rst),
+-      QCA_PIN_FUNCTION(gpio),
++      QCA_GPIO_PIN_FUNCTION(gpio),
+       QCA_PIN_FUNCTION(i2s_rx),
+       QCA_PIN_FUNCTION(i2s_spdif_in),
+       QCA_PIN_FUNCTION(i2s_spdif_out),
+--- a/drivers/pinctrl/qcom/pinctrl-msm.h
++++ b/drivers/pinctrl/qcom/pinctrl-msm.h
+@@ -39,6 +39,11 @@ struct pinctrl_pin_desc;
+                                       fname##_groups,         \
+                                       ARRAY_SIZE(fname##_groups))
+ 
++#define QCA_GPIO_PIN_FUNCTION(fname)                          \
++      [qca_mux_##fname] = PINCTRL_GPIO_PINFUNCTION(#fname,    \
++                                      fname##_groups,         \
++                                      ARRAY_SIZE(fname##_groups))
++
+ /**
+  * struct msm_pingroup - Qualcomm pingroup definition
+  * @grp:                  Generic data of the pin group (name and pins)