samd: Remove the existing provisional support for REPL on UART.

It was only partially working and will be rpelaced later by a full
machine.UART class implementation.

18 files changed, 7 insertions, 193 deletions

diff --git a/ports/samd/boards/ADAFRUIT_FEATHER_M0_EXPRESS/mpconfigboard.h b/ports/samd/boards/ADAFRUIT_FEATHER_M0_EXPRESS/mpconfigboard.h
index 6d3b7987e..bdb22d2e0 100644
--- a/ports/samd/boards/ADAFRUIT_FEATHER_M0_EXPRESS/mpconfigboard.h
+++ b/ports/samd/boards/ADAFRUIT_FEATHER_M0_EXPRESS/mpconfigboard.h
@@ -9,20 +9,4 @@
 #define MICROPY_HW_FLASH_STORAGE_BYTES      (0xFFFF)
 #define VFS_BLOCK_SIZE_BYTES                (1536) // 24x 64B flash pages;
 
-// ASF4 MCU package specific Pin definitions
-#include "samd21g18a.h"
-
-// Please consult the SAM_D21 Datasheet, I/O Multiplexing and Considerations.
-// On this board (see https://learn.adafruit.com/assets/40553) TX is D1 (PA10) and RX is D0 (PA11)
-// USART pin assignments: Tx=PA10=SERCOM0/PAD[2], Rx=PA11==SERCOM0/PAD[3]
 #define CPU_FREQ (48000000) // For selecting Baud from clock.
-#define MP_PIN_GRP 0 // A=0, B=1
-#define MP_TX_PIN 10 // 'n'
-#define MP_RX_PIN 11
-#define MP_PERIPHERAL_MUX 5 // 'n'th group of 2 pins
-#define USARTx SERCOM0 // SERCOM0: tx/rx
-#define MP_PORT_FUNC 0x22 // Sets PMUXE & PMUXO to the Alternative Function.(A-H=0-7)
-#define MP_RXPO_PAD 3 // RXPO- Receive Data Pinout
-#define MP_TXPO_PAD 1 // TXPO- Transmit Data Pinout
-#define MP_SERCOMx SERCOM0_ // APBCMASK
-#define MP_SERCOM_GCLK_ID_x_CORE GCLK_CLKCTRL_ID_SERCOM0_CORE // Generic Clock Control
diff --git a/ports/samd/boards/ADAFRUIT_FEATHER_M0_EXPRESS/pins.c b/ports/samd/boards/ADAFRUIT_FEATHER_M0_EXPRESS/pins.c
index e0dd752ec..fbb5032a4 100644
--- a/ports/samd/boards/ADAFRUIT_FEATHER_M0_EXPRESS/pins.c
+++ b/ports/samd/boards/ADAFRUIT_FEATHER_M0_EXPRESS/pins.c
@@ -27,6 +27,7 @@
  */
 
 #include "modmachine.h"
+#include "sam.h"
 #include "pins.h"
 
 // Ensure Declaration in 'pins.h' reflects # of Pins defined here.
diff --git a/ports/samd/boards/ADAFRUIT_ITSYBITSY_M4_EXPRESS/mpconfigboard.h b/ports/samd/boards/ADAFRUIT_ITSYBITSY_M4_EXPRESS/mpconfigboard.h
index c1c4fd8ca..80baf39e5 100644
--- a/ports/samd/boards/ADAFRUIT_ITSYBITSY_M4_EXPRESS/mpconfigboard.h
+++ b/ports/samd/boards/ADAFRUIT_ITSYBITSY_M4_EXPRESS/mpconfigboard.h
@@ -14,19 +14,4 @@
 #define MICROPY_HW_FLASH_STORAGE_BYTES      (0x1FFFF)
 #define VFS_BLOCK_SIZE_BYTES                (1536) //
 
-// ASF4 MCU package specific Pin definitions
-#include "samd51g19a.h"
-
-// Please consult the SAM_D51 Datasheet, I/O Multiplexing and Considerations.
-// USART pin assignments: Tx=TX_D1=PA17=SERCOM3/PAD[0], Rx=RX_D0=PA16=SERCOM3/PAD[1]
 #define CPU_FREQ (48000000) // For selecting Baud from clock.
-#define MP_PIN_GRP 1 // A-D=0-3
-#define MP_TX_PIN 17
-#define MP_RX_PIN 16 // 'n'
-#define MP_PERIPHERAL_MUX 8 // 'n'th group of 2 pins
-#define USARTx SERCOM3 //
-#define MP_PORT_FUNC 0x33 // Sets PMUXE & PMUXO to the Alternative Function.A-N=0-13
-#define MP_RXPO_PAD 1 // RXPO- Receive Data Pinout
-#define MP_TXPO_PAD 0 // TXPO- Tranmit Data Pinout
-#define MP_SERCOMx SERCOM3_ // APBCMASK
-#define MP_SERCOM_GCLK_ID_x_CORE SERCOM3_GCLK_ID_CORE
diff --git a/ports/samd/boards/ADAFRUIT_ITSYBITSY_M4_EXPRESS/pins.c b/ports/samd/boards/ADAFRUIT_ITSYBITSY_M4_EXPRESS/pins.c
index 82948ccbc..0342b0d00 100644
--- a/ports/samd/boards/ADAFRUIT_ITSYBITSY_M4_EXPRESS/pins.c
+++ b/ports/samd/boards/ADAFRUIT_ITSYBITSY_M4_EXPRESS/pins.c
@@ -27,6 +27,7 @@
  */
 
 #include "modmachine.h"
+#include "sam.h"
 #include "pins.h"
 
 // Ensure Declaration in 'pins.h' reflects # of Pins defined here.
diff --git a/ports/samd/boards/ADAFRUIT_TRINKET_M0/mpconfigboard.h b/ports/samd/boards/ADAFRUIT_TRINKET_M0/mpconfigboard.h
index 128689f4f..066c7ee14 100644
--- a/ports/samd/boards/ADAFRUIT_TRINKET_M0/mpconfigboard.h
+++ b/ports/samd/boards/ADAFRUIT_TRINKET_M0/mpconfigboard.h
@@ -9,19 +9,4 @@
 #define MICROPY_HW_FLASH_STORAGE_BYTES      (0xFFFF)
 #define VFS_BLOCK_SIZE_BYTES                (1536) // 24x 64B flash pages;
 
-// ASF4 MCU package specific Pin definitions
-#include "samd21e18a.h"
-
-// Please consult the SAM_D21 Datasheet, I/O Multiplexing and Considerations.
-// USART pin assignments: Tx=D4=PA06=SERCOM0/PAD[2], Rx=D3=PA07=SERCOM0/PAD[3]
 #define CPU_FREQ (48000000) // For selecting Baud from clock.
-#define MP_PIN_GRP 1 // A=0, B=1
-#define MP_TX_PIN 6 // 'n'
-#define MP_RX_PIN 7
-#define MP_PERIPHERAL_MUX 3 // 'n'th group of 2 pins
-#define USARTx SERCOM0 // SERCOM0: tx/rx
-#define MP_PORT_FUNC 0x33 // Sets PMUXE & PMUXO to the Alternative Function.A-H=0-7
-#define MP_RXPO_PAD 3 // RXPO- Receive Data Pinout
-#define MP_TXPO_PAD 2 // TXPO- Tranmit Data Pinout
-#define MP_SERCOMx SERCOM0_ // APBCMASK
-#define MP_SERCOM_GCLK_ID_x_CORE GCLK_CLKCTRL_ID_SERCOM0_CORE // Generic Clock Control
diff --git a/ports/samd/boards/ADAFRUIT_TRINKET_M0/pins.c b/ports/samd/boards/ADAFRUIT_TRINKET_M0/pins.c
index 9fecddb6c..676b4794e 100644
--- a/ports/samd/boards/ADAFRUIT_TRINKET_M0/pins.c
+++ b/ports/samd/boards/ADAFRUIT_TRINKET_M0/pins.c
@@ -27,6 +27,7 @@
  */
 
 #include "modmachine.h"
+#include "sam.h"
 #include "pins.h"
 
 // Ensure Declaration in 'pins.h' reflects # of Pins defined here.
diff --git a/ports/samd/boards/MINISAM_M4/mpconfigboard.h b/ports/samd/boards/MINISAM_M4/mpconfigboard.h
index a65eb54b4..a8f1f9624 100644
--- a/ports/samd/boards/MINISAM_M4/mpconfigboard.h
+++ b/ports/samd/boards/MINISAM_M4/mpconfigboard.h
@@ -14,19 +14,4 @@
 #define MICROPY_HW_FLASH_STORAGE_BYTES      (0x1FFFF)
 #define VFS_BLOCK_SIZE_BYTES                (1536) //
 
-// ASF4 MCU package specific Pin definitions
-#include "samd51g19a.h"
-
-// Please consult the SAM_D51 Datasheet, I/O Multiplexing and Considerations.
-// USART pin assignments: Tx=TX_D1=PA17=SERCOM3/PAD[0], Rx=RX_D0=PA16=SERCOM3/PAD[1]
 #define CPU_FREQ (48000000) // For selecting Baud from clock.
-#define MP_PIN_GRP 0 // A-D=0-3
-#define MP_TX_PIN 17
-#define MP_RX_PIN 16 // 'n'
-#define MP_PERIPHERAL_MUX 8 // 'n'th group of 2 pins
-#define USARTx SERCOM3 //
-#define MP_PORT_FUNC 0x33 // Sets PMUXE & PMUXO to the Alternative Function.A-N=0-13
-#define MP_RXPO_PAD 1 // RXPO- Receive Data Pinout
-#define MP_TXPO_PAD 0 // TXPO- Tranmit Data Pinout
-#define MP_SERCOMx SERCOM3_ // APBCMASK
-#define MP_SERCOM_GCLK_ID_x_CORE SERCOM3_GCLK_ID_CORE
diff --git a/ports/samd/boards/MINISAM_M4/pins.c b/ports/samd/boards/MINISAM_M4/pins.c
index 6cdd840b6..17ed58d3c 100644
--- a/ports/samd/boards/MINISAM_M4/pins.c
+++ b/ports/samd/boards/MINISAM_M4/pins.c
@@ -27,6 +27,7 @@
  */
 
 #include "modmachine.h"
+#include "sam.h"
 #include "pins.h"
 
 // Ensure Declaration in 'pins.h' reflects # of Pins defined here.
diff --git a/ports/samd/boards/SAMD21_XPLAINED_PRO/mpconfigboard.h b/ports/samd/boards/SAMD21_XPLAINED_PRO/mpconfigboard.h
index a7dbf7614..860cb6b97 100644
--- a/ports/samd/boards/SAMD21_XPLAINED_PRO/mpconfigboard.h
+++ b/ports/samd/boards/SAMD21_XPLAINED_PRO/mpconfigboard.h
@@ -9,20 +9,4 @@
 #define MICROPY_HW_FLASH_STORAGE_BYTES      (0xFFFF)
 #define VFS_BLOCK_SIZE_BYTES                (1536) // 24x 64B flash pages;
 
-// ASF4 MCU package specific Pin definitions
-#include "samd21j18a.h"
-
-// Please consult the SAM_D21 Datasheet, I/O Multiplexing and Considerations.
-// USART pin assignments: (This board has 3 USARTS brought out to the pins. See https://docs.zephyrproject.org/1.14.1/boards/arm/atsamd21_xpro/doc/index.html#serial-port )
-// Tx=PA10=SERCOM0/PAD[2], Rx=PA11=SERCOM0/PAD[3]
 #define CPU_FREQ (48000000) // For selecting Baud from clock.
-#define MP_PIN_GRP 1 // A=0, B=1
-#define MP_TX_PIN 10 // 'n'
-#define MP_RX_PIN 11
-#define MP_PERIPHERAL_MUX 5 // 'n'th group of 2 pins
-#define USARTx SERCOM0 // SERCOM0: tx/rx
-#define MP_PORT_FUNC 0x22 // Sets PMUXE & PMUXO to the Alternative Function.(A-H=0-7)
-#define MP_RXPO_PAD 3 // RXPO- Receive Data Pinout
-#define MP_TXPO_PAD 2 // TXPO- Tranmit Data Pinout
-#define MP_SERCOMx SERCOM0_ // APBCMASK
-#define MP_SERCOM_GCLK_ID_x_CORE GCLK_CLKCTRL_ID_SERCOM0_CORE // Generic Clock Control
diff --git a/ports/samd/boards/SAMD21_XPLAINED_PRO/pins.c b/ports/samd/boards/SAMD21_XPLAINED_PRO/pins.c
index 2a2d50eb4..35718ea7f 100644
--- a/ports/samd/boards/SAMD21_XPLAINED_PRO/pins.c
+++ b/ports/samd/boards/SAMD21_XPLAINED_PRO/pins.c
@@ -27,6 +27,7 @@
  */
 
 #include "modmachine.h"
+#include "sam.h"
 #include "pins.h"
 
 // Ensure Declaration in 'pins.h' reflects # of Pins defined here.
diff --git a/ports/samd/boards/SEEED_WIO_TERMINAL/mpconfigboard.h b/ports/samd/boards/SEEED_WIO_TERMINAL/mpconfigboard.h
index 290bd802b..bb0f1c828 100644
--- a/ports/samd/boards/SEEED_WIO_TERMINAL/mpconfigboard.h
+++ b/ports/samd/boards/SEEED_WIO_TERMINAL/mpconfigboard.h
@@ -14,19 +14,4 @@
 #define MICROPY_HW_FLASH_STORAGE_BYTES      (0x1FFFF)
 #define VFS_BLOCK_SIZE_BYTES                (1536) // 24x 64B flash pages;
 
-// ASF4 MCU package specific Pin definitions
-#include "samd51p19a.h"
-
-// Please consult the SAM_D51 Datasheet, I/O Multiplexing and Considerations.
-// WIO_Terminal USART pin assignments: Tx=BCM14=PB27=SERCOM2/PAD[0], Rx=BCM15=PB26=SERCOM2/PAD[1]
 #define CPU_FREQ (48000000) // For selecting Baud from clock.
-#define MP_PIN_GRP 1 // A-D=0-3
-#define MP_TX_PIN 27
-#define MP_RX_PIN 26 // 'n'
-#define MP_PERIPHERAL_MUX 13 // 'n'th group of 2 pins
-#define USARTx SERCOM2 //
-#define MP_PORT_FUNC 0x22 // Sets PMUXE & PMUXO to the Alternative Function.A-N=0-13
-#define MP_RXPO_PAD 1 // RXPO- Receive Data Pinout
-#define MP_TXPO_PAD 0 // TXPO- Tranmit Data Pinout
-#define MP_SERCOMx SERCOM2_ // APBCMASK
-#define MP_SERCOM_GCLK_ID_x_CORE SERCOM2_GCLK_ID_CORE
diff --git a/ports/samd/boards/SEEED_WIO_TERMINAL/pins.c b/ports/samd/boards/SEEED_WIO_TERMINAL/pins.c
index 9862552fa..d7833416d 100644
--- a/ports/samd/boards/SEEED_WIO_TERMINAL/pins.c
+++ b/ports/samd/boards/SEEED_WIO_TERMINAL/pins.c
@@ -27,6 +27,7 @@
  */
 
 #include "modmachine.h"
+#include "sam.h"
 #include "pins.h"
 
 // Ensure Declaration in "pins.h" reflects # of Pins defined here.
diff --git a/ports/samd/boards/SEEED_XIAO/mpconfigboard.h b/ports/samd/boards/SEEED_XIAO/mpconfigboard.h
index 6422d7ea0..a2f2a9fb0 100644
--- a/ports/samd/boards/SEEED_XIAO/mpconfigboard.h
+++ b/ports/samd/boards/SEEED_XIAO/mpconfigboard.h
@@ -9,19 +9,4 @@
 #define MICROPY_HW_FLASH_STORAGE_BYTES      (0xFFFF)
 #define VFS_BLOCK_SIZE_BYTES                (1536) // 24x 64B flash pages;
 
-// ASF4 MCU package specific Pin definitions
-#include "samd21g18a.h"
-
-// Please consult the SAM_D21 Datasheet, I/O Multiplexing and Considerations.
-// XIAO_M0 USART pin assignments: Tx=A6=PB8=SERCOM4/PAD[0], Rx=PB9=A7=SERCOM4/PAD[1]
 #define CPU_FREQ (48000000) // For selecting Baud from clock.
-#define MP_PIN_GRP 1 // A=0, B=1
-#define MP_TX_PIN 8 // 'n'
-#define MP_RX_PIN 9
-#define MP_PERIPHERAL_MUX 4 // 'n'th group of 2 pins
-#define USARTx SERCOM4 // SERCOM4:XIAO_M0 tx/rx
-#define MP_PORT_FUNC 0x33 // Sets PMUXE & PMUXO to the Alternative Function.A-H=0-7
-#define MP_RXPO_PAD 1 // RXPO- Receive Data Pinout
-#define MP_TXPO_PAD 0 // TXPO- Tranmit Data Pinout
-#define MP_SERCOMx SERCOM4_ // APBCMASK
-#define MP_SERCOM_GCLK_ID_x_CORE GCLK_CLKCTRL_ID_SERCOM4_CORE // Generic Clock Control
diff --git a/ports/samd/boards/SEEED_XIAO/pins.c b/ports/samd/boards/SEEED_XIAO/pins.c
index 6043913d2..e2f7c264b 100644
--- a/ports/samd/boards/SEEED_XIAO/pins.c
+++ b/ports/samd/boards/SEEED_XIAO/pins.c
@@ -27,6 +27,7 @@
  */
 
 #include "modmachine.h"
+#include "sam.h"
 #include "pins.h"
 
 // Ensure Declaration in 'pins.h' reflects # of Pins defined here.
diff --git a/ports/samd/modmachine.c b/ports/samd/modmachine.c
index 74e357175..1b78b687e 100644
--- a/ports/samd/modmachine.c
+++ b/ports/samd/modmachine.c
@@ -45,9 +45,6 @@
 #define DBL_TAP_MAGIC_LOADER 0xf01669ef
 #define DBL_TAP_MAGIC_RESET 0xf02669ef
 
-MP_DEFINE_CONST_FUN_OBJ_0(machine_uart_init_obj, machine_uart_init);
-MP_DEFINE_CONST_FUN_OBJ_0(machine_uart_deinit_obj, machine_uart_deinit);
-
 STATIC mp_obj_t machine_reset(void) {
     *DBL_TAP_ADDR = DBL_TAP_MAGIC_RESET;
     NVIC_SystemReset();
@@ -119,8 +116,6 @@ STATIC const mp_rom_map_elem_t machine_module_globals_table[] = {
     { MP_ROM_QSTR(MP_QSTR_mem16),               MP_ROM_PTR(&machine_mem16_obj) },
     { MP_ROM_QSTR(MP_QSTR_mem32),               MP_ROM_PTR(&machine_mem32_obj) },
     { MP_ROM_QSTR(MP_QSTR_unique_id),           MP_ROM_PTR(&machine_unique_id_obj) },
-    { MP_ROM_QSTR(MP_QSTR_uart_init),           MP_ROM_PTR(&machine_uart_init_obj) },
-    { MP_ROM_QSTR(MP_QSTR_uart_deinit),         MP_ROM_PTR(&machine_uart_deinit_obj) },
     { MP_ROM_QSTR(MP_QSTR_Pin),                 MP_ROM_PTR(&machine_pin_type) },
     { MP_ROM_QSTR(MP_QSTR_LED),                 MP_ROM_PTR(&machine_led_type) },
 };
diff --git a/ports/samd/modmachine.h b/ports/samd/modmachine.h
index 61bd2f4d2..f7ad2b5e5 100644
--- a/ports/samd/modmachine.h
+++ b/ports/samd/modmachine.h
@@ -31,7 +31,4 @@
 extern const mp_obj_type_t machine_pin_type;
 extern const mp_obj_type_t machine_led_type;
 
-mp_obj_t machine_uart_init(void);
-mp_obj_t machine_uart_deinit(void);
-
 #endif // MICROPY_INCLUDED_SAMD_MODMACHINE_H
diff --git a/ports/samd/mphalport.c b/ports/samd/mphalport.c
index c19d542a8..beade14a6 100644
--- a/ports/samd/mphalport.c
+++ b/ports/samd/mphalport.c
@@ -71,9 +71,6 @@ uintptr_t mp_hal_stdio_poll(uintptr_t poll_flags) {
 
 int mp_hal_stdin_rx_chr(void) {
     for (;;) {
-        if (USARTx->USART.INTFLAG.bit.RXC) {
-            return USARTx->USART.DATA.bit.DATA;
-        }
         if (tud_cdc_connected() && tud_cdc_available()) {
             uint8_t buf[1];
             uint32_t count = tud_cdc_read(buf, sizeof(buf));
@@ -100,9 +97,4 @@ void mp_hal_stdout_tx_strn(const char *str, mp_uint_t len) {
             i += n2;
         }
     }
-    while (len--) {
-        while (!(USARTx->USART.INTFLAG.bit.DRE)) {
-        }
-        USARTx->USART.DATA.bit.DATA = *str++;
-    }
 }
diff --git a/ports/samd/samd_soc.c b/ports/samd/samd_soc.c
index 7f4df1bb1..7a96cbb48 100644
--- a/ports/samd/samd_soc.c
+++ b/ports/samd/samd_soc.c
@@ -35,75 +35,6 @@
 #include "samd_soc.h"
 #include "tusb.h"
 
-// "MP" macros defined in "boards/$(BOARD)/mpconfigboard.h"
-mp_obj_t machine_uart_init(void) {
-    // Firstly, assign alternate function SERCOM PADs to GPIO pins.
-    PORT->Group[MP_PIN_GRP].PINCFG[MP_TX_PIN].bit.PMUXEN = 1; // Enable
-    PORT->Group[MP_PIN_GRP].PINCFG[MP_RX_PIN].bit.PMUXEN = 1; // Enable
-    PORT->Group[MP_PIN_GRP].PMUX[MP_PERIPHERAL_MUX].reg = MP_PORT_FUNC; // Sets PMUXE & PMUXO in 1 hit.
-    uint32_t rxpo = MP_RXPO_PAD; // 1=Pad1,3=Pad3 Rx data
-    uint32_t txpo = MP_TXPO_PAD; // 0=pad0,1=Pad2 Tx data
-
-    // Initialise the clocks
-    #if defined(MCU_SAMD21)
-    PM->APBCMASK.bit.MP_SERCOMx = 1; // Enable synchronous clock
-    GCLK->CLKCTRL.reg = GCLK_CLKCTRL_CLKEN | GCLK_CLKCTRL_GEN_GCLK0 | MP_SERCOM_GCLK_ID_x_CORE; // Select multiplexer generic clock source and enable.
-    // Wait while it updates synchronously.
-    while (GCLK->STATUS.bit.SYNCBUSY) {
-    }
-    #elif defined(MCU_SAMD51)
-    GCLK->PCHCTRL[MP_SERCOM_GCLK_ID_x_CORE].reg = GCLK_PCHCTRL_CHEN | GCLK_PCHCTRL_GEN_GCLK0;
-    MCLK->APBBMASK.bit.MP_SERCOMx = 1;
-    #endif
-
-    // Setup the Peripheral.
-    // Reset (clear) the peripheral registers.
-    while (USARTx->USART.SYNCBUSY.bit.SWRST) {
-    }
-    USARTx->USART.CTRLA.bit.SWRST = 1; // Reset all Registers, disable peripheral
-    while (USARTx->USART.SYNCBUSY.bit.SWRST) {
-    }
-
-    // Set the register bits as needed
-    // (CMODE (async),CHSIZE (8),FORM (no parity),SBMODE (1 stop) already 0).
-    USARTx->USART.CTRLA.reg =   // USARTx = SERCOMx set in "boards/$(BOARD)/mpconfigboard.h"
-        SERCOM_USART_CTRLA_DORD // Data order
-        | SERCOM_USART_CTRLA_RXPO(rxpo) // Set Pad#
-        | SERCOM_USART_CTRLA_TXPO(txpo) // Set Pad#
-        | SERCOM_USART_CTRLA_MODE(1) // USART with internal clock
-    ;
-    USARTx->USART.CTRLB.reg = SERCOM_USART_CTRLB_RXEN | SERCOM_USART_CTRLB_TXEN; // Enable Rx & Tx
-    while (USARTx->USART.SYNCBUSY.bit.CTRLB) {
-    }
-
-    // Baud rate is clock dependant.
-    #if CPU_FREQ == 8000000
-    uint32_t baud = 50437; // 115200 baud; 65536*(1 - 16 * 115200/8e6)
-    #elif CPU_FREQ == 48000000
-    uint32_t baud = 63019; // 115200 baud; 65536*(1 - 16 * 115200/48e6)
-    #elif CPU_FREQ == 120000000
-    uint32_t baud = 64529; // 115200 baud; 65536*(1 - 16 * 115200/120e6)
-    #endif
-    USARTx->USART.BAUD.bit.BAUD = baud; // Set Baud
-    USARTx->USART.CTRLA.bit.ENABLE = 1; // Enable the peripheral
-    // Wait for the Registers to update.
-    while (USARTx->USART.SYNCBUSY.bit.ENABLE) {
-    }
-
-    return mp_const_none;
-}
-
-// Disconnect SERCOM from GPIO pins. (Can't SWRST, as that will totally kill USART).
-mp_obj_t machine_uart_deinit(void) {
-    // Reset
-    printf("Disabling the Alt-Funct, releasing the USART pins for GPIO... \n");
-    PORT->Group[MP_PIN_GRP].PINCFG[MP_TX_PIN].bit.PMUXEN = 0; // Disable
-    PORT->Group[MP_PIN_GRP].PINCFG[MP_RX_PIN].bit.PMUXEN = 0; // Disable
-
-    return mp_const_none;
-}
-
-
 static void usb_init(void) {
     // Init USB clock
     #if defined(MCU_SAMD21)
@@ -168,6 +99,5 @@ void samd_init(void) {
     #endif
 
     SysTick_Config(CPU_FREQ / 1000);
-    machine_uart_init();
     usb_init();
 }