arm64: dts: ti: k3-pinctrl: Enable Schmitt Trigger by default

commit 5b27212 upstream.

Switch Schmitt Trigger functions for PIN_INPUT* macros by default. This is
HW PoR configuration, the slew rate requirements without ST enabled are
pretty tough for these devices. We've noticed spurious GPIO interrupts even
with noise-free edges but not meeting slew rate requirements (3.3E+6 V/s
for 3.3v LVCMOS).

It's not obvious why one might want to disable the PoR-enabled ST on any
pin. Just enable it by default. As it's not possible to provide OR-able
macros to disable the ST, shall anyone require it, provide a set of
new macros with _NOST suffix.

Fixes: fe49f2d ("arm64: dts: ti: Use local header for pinctrl register values")
Cc: stable@vger.kernel.org
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@siemens.com>
Link: https://lore.kernel.org/r/20250701105437.3539924-1-alexander.sverdlin@siemens.com
[vigneshr@ti.com: Add Fixes tag]
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: ccpalex

arch/arm64/boot/dts/ti/k3-pinctrl.h

@@ -8,6 +8,7 @@
 #ifndef DTS_ARM64_TI_K3_PINCTRL_H
 #define DTS_ARM64_TI_K3_PINCTRL_H
 
+#define ST_EN_SHIFT		(14)
 #define PULLUDEN_SHIFT		(16)
 #define PULLTYPESEL_SHIFT	(17)
 #define RXACTIVE_SHIFT		(18)
@@ -19,6 +20,10 @@
 #define DS_PULLUD_EN_SHIFT	(27)
 #define DS_PULLTYPE_SEL_SHIFT	(28)
 
+/* Schmitt trigger configuration */
+#define ST_DISABLE		(0 << ST_EN_SHIFT)
+#define ST_ENABLE		(1 << ST_EN_SHIFT)
+
 #define PULL_DISABLE		(1 << PULLUDEN_SHIFT)
 #define PULL_ENABLE		(0 << PULLUDEN_SHIFT)
 
@@ -32,9 +37,13 @@
 #define PIN_OUTPUT		(INPUT_DISABLE | PULL_DISABLE)
 #define PIN_OUTPUT_PULLUP	(INPUT_DISABLE | PULL_UP)
 #define PIN_OUTPUT_PULLDOWN	(INPUT_DISABLE | PULL_DOWN)
-#define PIN_INPUT		(INPUT_EN | PULL_DISABLE)
-#define PIN_INPUT_PULLUP	(INPUT_EN | PULL_UP)
-#define PIN_INPUT_PULLDOWN	(INPUT_EN | PULL_DOWN)
+#define PIN_INPUT		(INPUT_EN | ST_ENABLE | PULL_DISABLE)
+#define PIN_INPUT_PULLUP	(INPUT_EN | ST_ENABLE | PULL_UP)
+#define PIN_INPUT_PULLDOWN	(INPUT_EN | ST_ENABLE | PULL_DOWN)
+/* Input configurations with Schmitt Trigger disabled */
+#define PIN_INPUT_NOST		(INPUT_EN | PULL_DISABLE)
+#define PIN_INPUT_PULLUP_NOST	(INPUT_EN | PULL_UP)
+#define PIN_INPUT_PULLDOWN_NOST	(INPUT_EN | PULL_DOWN)
 
 #define PIN_DEBOUNCE_DISABLE	(0 << DEBOUNCE_SHIFT)
 #define PIN_DEBOUNCE_CONF1	(1 << DEBOUNCE_SHIFT)