openwrt/target/linux/bcm27xx/patches-6.6/950-0828-pinctrl-bcm2712-Fix-for-the-first-valid-GPIO.patch

From 61e034cd7f7a66c61a791d86bb866c56067b599a Mon Sep 17 00:00:00 2001
From: Phil Elwell <phil@raspberrypi.com>
Date: Thu, 30 Nov 2023 12:57:03 +0000
Subject: [PATCH 0828/1085] pinctrl: bcm2712: Fix for the first valid GPIO

A non-zero mux bit number is used to detect a valid entry in the
pin_regs tables, but GPIO 0 (GPIO 1 on D0) is a valid GPIO with a mux
bit number of zero, so add a high-bit on all valid entries to
distinguish this from an uninitialised row in the table.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>
---
 drivers/pinctrl/bcm/pinctrl-bcm2712.c | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

--- a/drivers/pinctrl/bcm/pinctrl-bcm2712.c
+++ b/drivers/pinctrl/bcm/pinctrl-bcm2712.c
@@ -60,22 +60,24 @@
 		}, \
 	}
 
-#define REG_BIT_INVALID 0xffff
+#define MUX_BIT_VALID	0x8000
+#define REG_BIT_INVALID	0xffff
 
 #define BIT_TO_REG(b) (((b) >> 5) << 2)
 #define BIT_TO_SHIFT(b) ((b) & 0x1f)
 
+#define MUX_BIT(mr, mb) (MUX_BIT_VALID + ((mr)*4)*8 + (mb)*4)
 #define GPIO_REGS(n, mr, mb, pr, pb) \
-	[n] = { ((mr)*4)*8 + (mb)*4, ((pr)*4)*8 + (pb)*2 }
+	[n] = { MUX_BIT(mr, mb), ((pr)*4)*8 + (pb)*2 }
 
-#define EMMC_REGS(n, r, b) \
-	[n] = { 0, ((r)*4)*8 + (b)*2 }
+#define EMMC_REGS(n, pr, pb) \
+	[n] = { 0, ((pr)*4)*8 + (pb)*2 }
 
 #define AGPIO_REGS(n, mr, mb, pr, pb) \
-	[n] = { ((mr)*4)*8 + (mb)*4, ((pr)*4)*8 + (pb)*2 }
+	[n] = { MUX_BIT(mr, mb), ((pr)*4)*8 + (pb)*2 }
 
 #define SGPIO_REGS(n, mr, mb) \
-	[n+32] = { ((mr)*4)*8 + (mb)*4, REG_BIT_INVALID }
+	[n+32] = { MUX_BIT(mr, mb), REG_BIT_INVALID }
 
 #define GPIO_PIN(a) PINCTRL_PIN(a, "gpio" #a)
 #define AGPIO_PIN(a) PINCTRL_PIN(a, "aon_gpio" #a)
@@ -740,6 +742,7 @@ static enum bcm2712_funcs bcm2712_pinctr
 
 	if (!bit)
 		return func_gpio;
+	bit &= ~MUX_BIT_VALID;
 
 	val = bcm2712_reg_rd(pc, BIT_TO_REG(bit));
 	fsel = (val >> BIT_TO_SHIFT(bit)) & BCM2712_FSEL_MASK;
@@ -767,6 +770,7 @@ static void bcm2712_pinctrl_fsel_set(
 
 	if (!bit || func >= func_count)
 		return;
+	bit &= ~MUX_BIT_VALID;
 
 	fsel = BCM2712_FSEL_COUNT;