sam4e8e: Add the SAM4e8e port

This can be flashed to e.g. the duet wifi using bossac. It requires a
later version as is currently included in the klipper repo (1.8
vs. 1.2). Comms are currently via UART0 only, USB serial is still TBD

Signed-off-by: Florian Heilmann <Florian.Heilmann@gmx.net>

src/sam4e8e/gpio.h

@@ -0,0 +1,47 @@
+#ifndef __SAM4E8E_GPIO_H
+#define __SAM4E8E_GPIO_H
+
+#include <stdint.h>
+
+struct gpio_out {
+    uint8_t pin;
+    void *regs;
+    uint32_t bit;
+};
+
+void gpio_set_peripheral(char bank, uint32_t bit, char ptype, uint32_t pull_up);
+struct gpio_out gpio_out_setup(uint8_t pin, uint8_t val);
+void gpio_out_toggle_noirq(struct gpio_out g);
+void gpio_out_toggle(struct gpio_out g);
+void gpio_out_write(struct gpio_out g, uint8_t val);
+
+struct gpio_in {
+    uint8_t pin;
+    void *regs;
+    uint32_t bit;
+};
+
+struct gpio_adc {
+    uint8_t pin;
+    void *afec;
+    uint32_t chan;
+};
+
+struct gpio_in gpio_in_setup(uint8_t pin, int8_t pull_up);
+uint8_t gpio_in_read(struct gpio_in g);
+
+struct gpio_adc gpio_pin_to_afec(uint8_t pin);
+struct gpio_adc gpio_adc_setup(uint8_t pin);
+uint32_t gpio_adc_sample(struct gpio_adc g);
+uint16_t gpio_adc_read(struct gpio_adc g);
+void gpio_adc_cancel_sample(struct gpio_adc g);
+
+struct spi_config {
+    void *sspi;
+    uint32_t cfg;
+};
+struct spi_config spi_setup(uint32_t bus, uint8_t mode, uint32_t rate);
+void spi_transfer(struct spi_config config, uint8_t receive_data
+                  , uint8_t len, uint8_t *data);
+void spi_prepare(struct spi_config config);
+#endif // gpio.h