ARM split - Add uart half duplex transport support (#7987)

* ARM split - Add uart half duplex transport support

* Fix for f103

* initial full duplex pass

* partially remove full duplex

* Correct speeds within driver docs

Co-authored-by: Nick Brassel <nick@tzarc.org>

Co-authored-by: Nick Brassel <nick@tzarc.org>

1 files changed, 62 insertions, 0 deletions

diff --git a/drivers/chibios/serial.h b/drivers/chibios/serial.h
new file mode 100644
index 000000000..0c1857d52
--- /dev/null
+++ b/drivers/chibios/serial.h
@@ -0,0 +1,62 @@
+#pragma once
+
+#include <stdbool.h>
+
+// /////////////////////////////////////////////////////////////////
+// Need Soft Serial defines in config.h
+// /////////////////////////////////////////////////////////////////
+// ex.
+//  #define SOFT_SERIAL_PIN ??   // ?? = D0,D1,D2,D3,E6
+//  OPTIONAL: #define SELECT_SOFT_SERIAL_SPEED ? // ? = 1,2,3,4,5
+//                                               //  1: about 137kbps (default)
+//                                               //  2: about 75kbps
+//                                               //  3: about 39kbps
+//                                               //  4: about 26kbps
+//                                               //  5: about 20kbps
+//
+// //// USE simple API (using signle-type transaction function)
+//   /* nothing */
+// //// USE flexible API (using multi-type transaction function)
+//   #define SERIAL_USE_MULTI_TRANSACTION
+//
+// /////////////////////////////////////////////////////////////////
+
+// Soft Serial Transaction Descriptor
+typedef struct _SSTD_t {
+    uint8_t *status;
+    uint8_t  initiator2target_buffer_size;
+    uint8_t *initiator2target_buffer;
+    uint8_t  target2initiator_buffer_size;
+    uint8_t *target2initiator_buffer;
+} SSTD_t;
+#define TID_LIMIT(table) (sizeof(table) / sizeof(SSTD_t))
+
+// initiator is transaction start side
+void soft_serial_initiator_init(SSTD_t *sstd_table, int sstd_table_size);
+// target is interrupt accept side
+void soft_serial_target_init(SSTD_t *sstd_table, int sstd_table_size);
+
+// initiator result
+#define TRANSACTION_END 0
+#define TRANSACTION_NO_RESPONSE 0x1
+#define TRANSACTION_DATA_ERROR 0x2
+#define TRANSACTION_TYPE_ERROR 0x4
+#ifndef SERIAL_USE_MULTI_TRANSACTION
+int soft_serial_transaction(void);
+#else
+int soft_serial_transaction(int sstd_index);
+#endif
+
+// target status
+// *SSTD_t.status has
+//   initiator:
+//       TRANSACTION_END
+//    or TRANSACTION_NO_RESPONSE
+//    or TRANSACTION_DATA_ERROR
+//   target:
+//       TRANSACTION_DATA_ERROR
+//    or TRANSACTION_ACCEPTED
+#define TRANSACTION_ACCEPTED 0x8
+#ifdef SERIAL_USE_MULTI_TRANSACTION
+int soft_serial_get_and_clean_status(int sstd_index);
+#endif