1 files changed, 78 insertions, 0 deletions
diff --git a/lib/can2040/can2040.h b/lib/can2040/can2040.h
new file mode 100644
index 00000000..884c3caf
--- /dev/null
+++ b/lib/can2040/can2040.h
@@ -0,0 +1,78 @@
+#ifndef _CAN2040_H
+#define _CAN2040_H
+
+#include <stdint.h> // uint32_t
+
+struct can2040_msg {
+    uint32_t id;
+    uint32_t dlc;
+    union {
+        uint8_t data[8];
+        uint32_t data32[2];
+    };
+};
+
+enum {
+    CAN2040_ID_RTR = 1<<30,
+    CAN2040_ID_EFF = 1<<31,
+};
+
+enum {
+    CAN2040_NOTIFY_RX = 1<<20,
+    CAN2040_NOTIFY_TX = 1<<21,
+    CAN2040_NOTIFY_ERROR = 1<<23,
+};
+struct can2040;
+typedef void (*can2040_rx_cb)(struct can2040 *cd, uint32_t notify
+                              , struct can2040_msg *msg);
+
+void can2040_setup(struct can2040 *cd, uint32_t pio_num);
+void can2040_callback_config(struct can2040 *cd, can2040_rx_cb rx_cb);
+void can2040_start(struct can2040 *cd, uint32_t sys_clock, uint32_t bitrate
+                   , uint32_t gpio_rx, uint32_t gpio_tx);
+void can2040_shutdown(struct can2040 *cd);
+void can2040_pio_irq_handler(struct can2040 *cd);
+int can2040_check_transmit(struct can2040 *cd);
+int can2040_transmit(struct can2040 *cd, struct can2040_msg *msg);
+
+
+/****************************************************************
+ * Internal definitions
+ ****************************************************************/
+
+struct can2040_bitunstuffer {
+    uint32_t stuffed_bits, count_stuff;
+    uint32_t unstuffed_bits, count_unstuff;
+};
+
+struct can2040_transmit {
+    struct can2040_msg msg;
+    uint32_t crc, stuffed_words, stuffed_data[5];
+};
+
+struct can2040 {
+    // Setup
+    uint32_t pio_num;
+    void *pio_hw;
+    uint32_t gpio_rx, gpio_tx;
+    can2040_rx_cb rx_cb;
+
+    // Bit unstuffing
+    struct can2040_bitunstuffer unstuf;
+    uint32_t raw_bit_count;
+
+    // Input data state
+    uint32_t parse_state;
+    uint32_t parse_crc;
+    struct can2040_msg parse_msg;
+
+    // Reporting
+    uint32_t report_state;
+
+    // Transmits
+    uint32_t tx_state;
+    uint32_t tx_pull_pos, tx_push_pos;
+    struct can2040_transmit tx_queue[4];
+};
+
+#endif // can2040.h