From 38d9268bb5f97387a7a1941fb9af0edc67aa47aa Mon Sep 17 00:00:00 2001
From: Maxwell Pray <synthead@gmail.com>
Date: Sun, 28 Nov 2021 01:37:51 -0800
Subject: [PATCH 1/2] Use externs in common.h.

---
 ext/rpi_gpio/common.h | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/ext/rpi_gpio/common.h b/ext/rpi_gpio/common.h
index 0680d7f..82fb7cf 100644
--- a/ext/rpi_gpio/common.h
+++ b/ext/rpi_gpio/common.h
@@ -34,14 +34,14 @@ SOFTWARE.
 #define I2C          42
 #define PWM          43
 
-int gpio_mode;
-const int pin_to_gpio_rev1[41];
-const int pin_to_gpio_rev2[41];
-const int pin_to_gpio_rev3[41];
-const int (*pin_to_gpio)[41];
-int gpio_direction[54];
-rpi_info rpiinfo;
-int setup_error;
-int module_setup;
+extern int gpio_mode;
+extern const int pin_to_gpio_rev1[41];
+extern const int pin_to_gpio_rev2[41];
+extern const int pin_to_gpio_rev3[41];
+extern const int (*pin_to_gpio)[41];
+extern int gpio_direction[54];
+extern rpi_info rpiinfo;
+extern int setup_error;
+extern int module_setup;
 int check_gpio_priv(void);
 int get_gpio_number(int channel, unsigned int *gpio);

From 5be5c6d6314a83feefcd3d2e989d17dbc4291c00 Mon Sep 17 00:00:00 2001
From: Maxwell Pray <synthead@gmail.com>
Date: Sun, 28 Nov 2021 02:29:17 -0800
Subject: [PATCH 2/2] Add some declarations to match externs in common.c.

---
 ext/rpi_gpio/common.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/ext/rpi_gpio/common.c b/ext/rpi_gpio/common.c
index 1a6f60f..fc64620 100644
--- a/ext/rpi_gpio/common.c
+++ b/ext/rpi_gpio/common.c
@@ -34,6 +34,9 @@ const int pin_to_gpio_rev2[41] = {-1, -1, -1, 2, -1, 3, -1, 4, 14, -1, 15, 17, 1
 const int pin_to_gpio_rev3[41] = {-1, -1, -1, 2, -1, 3, -1, 4, 14, -1, 15, 17, 18, 27, -1, 22, 23, -1, 24, 10, -1, 9, 25, 11, 8, -1, 7, -1, -1, 5, -1, 6, 12, 13, -1, 19, 16, 26, 20, -1, 21 };
 int setup_error = 0;
 int module_setup = 0;
+const int (*pin_to_gpio)[41];
+int gpio_direction[54];
+rpi_info rpiinfo;
 
 int check_gpio_priv(void)
 {