gcc 10 compatibility for Drop alt (#9485)

* Split dmac_desc declaration and definition

According to the official documentation[1] gcc 10 is more strict about
correct extern usage.

I've had to move the definition of dmac_desc and dmac_desc_wb from
i2c_master.h to the corresponding .c file. This could be an issue if
anyone includes the i2c_master.h file without liking with the object
file.

[1]: https://gcc.gnu.org/gcc-10/porting_to.html

* Remove the keymap_config definition from keymaps

The keymap_config def was conflicting with the one found in
tmk_core/common/magic.c. Declaring it extern in magic.c breaks a bunch
of keyboard that rely on that declaration (like the ergodox). Instead
I've removed the one found in the keymap.c of the massdrop alt.

The same change will have to be made to other keyboards.

6 files changed, 5 insertions, 10 deletions

diff --git a/keyboards/massdrop/alt/keymaps/abishalom/keymap.c b/keyboards/massdrop/alt/keymaps/abishalom/keymap.c
index f6f79ad91..a08123b0f 100644
--- a/keyboards/massdrop/alt/keymaps/abishalom/keymap.c
+++ b/keyboards/massdrop/alt/keymaps/abishalom/keymap.c
@@ -12,8 +12,6 @@ enum alt_keycodes {
 
 #define TG_NKRO MAGIC_TOGGLE_NKRO //Toggle 6KRO / NKRO mode
 
-keymap_config_t keymap_config;
-
 const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
     [0] = LAYOUT(
         KC_ESC,  KC_1,    KC_2,    KC_3,    KC_4,    KC_5,    KC_6,    KC_7,    KC_8,    KC_9,    KC_0,    KC_MINS, KC_EQL,  KC_BSPC, KC_DEL,  \
diff --git a/keyboards/massdrop/alt/keymaps/bonta/keymap.c b/keyboards/massdrop/alt/keymaps/bonta/keymap.c
index c1acf2c15..9ac27f57e 100644
--- a/keyboards/massdrop/alt/keymaps/bonta/keymap.c
+++ b/keyboards/massdrop/alt/keymaps/bonta/keymap.c
@@ -14,8 +14,6 @@ enum alt_keycodes {
 #define RGB_BRU RGB_VAI
 #define RGB_BRD RGB_VAD
 
-keymap_config_t keymap_config;
-
 const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
     [0] = LAYOUT(
         KC_ESC,  KC_1,    KC_2,    KC_3,    KC_4,    KC_5,    KC_6,    KC_7,    KC_8,    KC_9,    KC_0,    KC_MINS, KC_EQL,  KC_BSPC, KC_DEL,  \
diff --git a/keyboards/massdrop/alt/keymaps/favorable-mutation/keymap.c b/keyboards/massdrop/alt/keymaps/favorable-mutation/keymap.c
index 873d18449..4c079a6aa 100644
--- a/keyboards/massdrop/alt/keymaps/favorable-mutation/keymap.c
+++ b/keyboards/massdrop/alt/keymaps/favorable-mutation/keymap.c
@@ -28,8 +28,6 @@ enum alt_keycodes {
 //
 //TODO tap/toggle for layers
 
-keymap_config_t keymap_config;
-
 const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
     [0] = LAYOUT(
         KC_GRV,  KC_1,    KC_2,    KC_3,    KC_4,    KC_5,    KC_6,    KC_7,    KC_8,    KC_9,    KC_0,    KC_MINS, KC_EQL,  KC_BSPC, KC_SPOT,
diff --git a/keyboards/massdrop/alt/keymaps/reywood/keymap.c b/keyboards/massdrop/alt/keymaps/reywood/keymap.c
index cf60acfe6..6279b509b 100644
--- a/keyboards/massdrop/alt/keymaps/reywood/keymap.c
+++ b/keyboards/massdrop/alt/keymaps/reywood/keymap.c
@@ -26,8 +26,6 @@ enum alt_keycodes {
 #define TG_NKRO MAGIC_TOGGLE_NKRO //Toggle 6KRO / NKRO mode
 #define ______ KC_TRNS
 
-keymap_config_t keymap_config;
-
 const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
   [0] = LAYOUT(
     KC_ESC,  KC_1,    KC_2,    KC_3,    KC_4,    KC_5,    KC_6,    KC_7,    KC_8,    KC_9,    KC_0,    KC_MINS, KC_EQL,  KC_BSPC, KC_DEL,  \
diff --git a/tmk_core/protocol/arm_atsam/i2c_master.c b/tmk_core/protocol/arm_atsam/i2c_master.c
index d3319ab44..dda2f85b0 100644
--- a/tmk_core/protocol/arm_atsam/i2c_master.c
+++ b/tmk_core/protocol/arm_atsam/i2c_master.c
@@ -28,6 +28,9 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 #    define I2C_LED_USE_DMA 1  // Set 1 to use background DMA transfers for leds, Set 0 to use inline software transfers
 
+DmacDescriptor dmac_desc;
+DmacDescriptor dmac_desc_wb;
+
 static uint8_t i2c_led_q[I2C_Q_SIZE];  // I2C queue circular buffer
 static uint8_t i2c_led_q_s;            // Start of circular buffer
 static uint8_t i2c_led_q_e;            // End of circular buffer
diff --git a/tmk_core/protocol/arm_atsam/i2c_master.h b/tmk_core/protocol/arm_atsam/i2c_master.h
index 44dbdfbff..68773f213 100644
--- a/tmk_core/protocol/arm_atsam/i2c_master.h
+++ b/tmk_core/protocol/arm_atsam/i2c_master.h
@@ -24,8 +24,8 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #    include "issi3733_driver.h"
 #    include "config.h"
 
-__attribute__((__aligned__(16))) DmacDescriptor dmac_desc;
-__attribute__((__aligned__(16))) DmacDescriptor dmac_desc_wb;
+extern __attribute__((__aligned__(16))) DmacDescriptor dmac_desc;
+extern __attribute__((__aligned__(16))) DmacDescriptor dmac_desc_wb;
 
 uint8_t I2C3733_Init_Control(void);
 uint8_t I2C3733_Init_Drivers(void);