diff --git a/ports/samd/pin_af.c b/ports/samd/pin_af.c
new file mode 100644
index 0000000000..8c152e0d8b
--- /dev/null
+++ b/ports/samd/pin_af.c
@@ -0,0 +1,125 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2022 Robert Hammelrath
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * This file provides and checks pin capabilities as required
+ * for USART, I2C, SPI, PWM, ADC
+ *
+ */
+
+#include <stdint.h>
+
+#include "py/runtime.h"
+#include "py/misc.h"
+#include "pin_af.h"
+#include "sam.h"
+
+
+extern const uint8_t tcc_channel_count[];
+
+#include PIN_AF_TABLE_C
+
+// Just look for an table entry for a given pin and raise an error
+// in case of no match (which should not happen).
+
+const pin_af_t *get_pin_af_info(int pin_id) {
+    for (int i = 0; i < MP_ARRAY_SIZE(pin_af_table); i++) {
+        if (pin_af_table[i].pin_id == pin_id) { // Pin match
+            return &pin_af_table[i];
+        }
+    }
+    mp_raise_ValueError(MP_ERROR_TEXT("wrong pin"));
+}
+
+// Test, wether the given pin is defined and has signals for sercom.
+// If that applies return the alt_fct and pad_nr.
+// If not, an error will be raised.
+
+sercom_pad_config_t get_sercom_config(int pin_id, uint8_t sercom_nr) {
+    const pin_af_t *pct_ptr = get_pin_af_info(pin_id);
+    if ((pct_ptr->sercom1 >> 4) == sercom_nr) {
+        return (sercom_pad_config_t) {ALT_FCT_SERCOM1, pct_ptr->sercom1 & 0x0f};
+    } else if ((pct_ptr->sercom2 >> 4) == sercom_nr) {
+        return (sercom_pad_config_t) {ALT_FCT_SERCOM2, pct_ptr->sercom2 & 0x0f};
+    } else {
+        mp_raise_ValueError(MP_ERROR_TEXT("wrong serial device"));
+    }
+}
+
+// Test, wether the given pin is defined as ADC.
+// If that applies return the adc instance and channel.
+// If not, an error will be raised.
+
+adc_config_t get_adc_config(int pin_id, int32_t flag) {
+    const pin_af_t *pct_ptr = get_pin_af_info(pin_id);
+    if (pct_ptr->adc0 != 0xff && (flag & (1 << pct_ptr->adc0)) == 0) {
+        return (adc_config_t) {0, pct_ptr->adc0};
+    #if defined(MUC_SAMD51)
+    } else if (pct_ptr->adc1 != 0xff && (flag & (1 << (pct_ptr->adc1 + 16))) == 0) {
+        return (adc_config_t) {1, pct_ptr->adc1};
+    #endif
+    } else {
+        mp_raise_ValueError(MP_ERROR_TEXT("ADC pin used"));
+    }
+}
+
+// Test, wether the given pin is defined and has signals for pwm.
+// If that applies return the alt_fct, tcc number and channel number.
+// If not, an error will be raised.
+// The function either supplies a channel from a wanted device, or
+// tries to provide an unused device, if available.
+
+pwm_config_t get_pwm_config(int pin_id, int wanted_dev, uint8_t device_status[]) {
+    const pin_af_t *pct_ptr = get_pin_af_info(pin_id);
+    uint8_t tcc1 = pct_ptr->tcc1;
+    uint8_t tcc2 = pct_ptr->tcc2;
+
+    if (wanted_dev != -1) {
+        if ((tcc1 >> 4) == wanted_dev) {
+            return (pwm_config_t) {ALT_FCT_TCC1, tcc1};
+        } else if ((tcc2 >> 4) == wanted_dev) {
+            return (pwm_config_t) {ALT_FCT_TCC2, tcc2};
+        } else {
+            mp_raise_ValueError(MP_ERROR_TEXT("wrong device or channel"));
+        }
+    } else {
+        pwm_config_t ret = {};
+        if ((tcc1 >> 4) < TCC_INST_NUM) {
+            ret = (pwm_config_t) {ALT_FCT_TCC1, tcc1};
+            if (tcc2 == 0xff) {
+                return ret;
+            }
+        }
+        if ((tcc2 >> 4) < TCC_INST_NUM) {
+            // if a device in slot 1 is not available or already in use, use the one in slot 2
+            if (tcc1 == 0xff || device_status[(ret.device_channel >> 4)] != 0) {
+                return (pwm_config_t) {ALT_FCT_TCC2, tcc2};
+            } else {
+                return ret;
+            }
+        } else {
+            mp_raise_ValueError(MP_ERROR_TEXT("not a PWM pin"));
+        }
+    }
+}
diff --git a/ports/samd/pin_af.h b/ports/samd/pin_af.h
new file mode 100644
index 0000000000..f9dec6b7da
--- /dev/null
+++ b/ports/samd/pin_af.h
@@ -0,0 +1,90 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2022 Robert Hammelrath
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * This file initialises provides and checks pin capabilities as required
+ * for USART, I2C, SPI, PWM, ADC
+ *
+ */
+
+#if defined(MCU_SAMD21)
+
+typedef struct {
+    uint8_t pin_id;
+    uint8_t eic;
+    uint8_t adc0;
+    uint8_t sercom1;
+    uint8_t sercom2;
+    uint8_t tcc1;
+    uint8_t tcc2;
+} pin_af_t;
+
+#define ALT_FCT_TC        4
+#define ALT_FCT_TCC1      4
+#define ALT_FCT_TCC2      5
+
+#elif defined(MCU_SAMD51)
+
+typedef struct {
+    uint8_t pin_id;
+    uint8_t eic;
+    uint8_t adc0;
+    uint8_t adc1;
+    uint8_t sercom1;
+    uint8_t sercom2;
+    uint8_t tc;
+    uint8_t tcc1;
+    uint8_t tcc2;
+} pin_af_t;
+
+#define ALT_FCT_TC        4
+#define ALT_FCT_TCC1      5
+#define ALT_FCT_TCC2      6
+
+#endif
+
+typedef struct _sercom_pad_config_t {
+    uint8_t alt_fct;
+    uint8_t pad_nr;
+} sercom_pad_config_t;
+
+typedef struct _adc_config_t {
+    uint8_t device;
+    uint8_t channel;
+} adc_config_t;
+
+typedef struct _pwm_config_t {
+    uint8_t alt_fct;
+    uint8_t device_channel;
+} pwm_config_t;
+
+#define ALT_FCT_EIC       0
+#define ALT_FCT_ADC       1
+#define ALT_FCT_SERCOM1   2
+#define ALT_FCT_SERCOM2   3
+
+sercom_pad_config_t get_sercom_config(int pin_id, uint8_t sercom);
+adc_config_t get_adc_config(int pin_id, int32_t flag);
+pwm_config_t get_pwm_config(int pin_id, int wanted_dev, uint8_t used_dev[]);
+const pin_af_t *get_pin_af_info(int pin_id);