Keyboard: Helix serial improvements (#3608)

* add change_reciver2sender()/change_sender2reciver()

This is a change to improve readability.

* txled, rxled off in matrix_init()

* add serial_send_packet() / serial_recive_packet()

This is a change to reduce object size.

* add serial_low() at ISR() top

* add __attribute__((always_inline)) to some functions

* modify serial_send_packet()/serial_recive_packet()

A little, object size reduction.
A little, speedup.

* add debug code to helix/serial.c

* Adjust sampling timing of serial signal being received

* add split_scomm.c/split_scomm.h and change serial.c/serial.h

serial.c was divided into 2 layers, split_scom.c and serial.c.
The upper layer split_scomm.c is called from matrix.c.
The lower layer serial.c accesses the hardware.

* add split_scomm.c/split_scomm.h into helix/rev1

* reduce object size helix/rev2/matrix.c

* remove checksum check, add parity check

* force occur parity error for test

* parity test ok. remove test code

* change some comment & add skip code when buffer_size == 0

* serial.c: multiple types of transaction support

Add 4 bits transaction-type field at packet top.
Select Transaction Descriptor Table entry by transaction-type.

* helix serial master-slave transaction optimize

Using multi-type transaction feature of serial.c, communication contents between master slaves were optimized.

* add debug code for retry

* add comment into each config.h

* fix ISR status drop

* add a debug macro 'debug_retry_chg()'

* reduce led_test size

* remove debug code from helix/serial.c and etc.

* helix:five_rows change TAPPING_TERM value 140

* Improved compatibility with let's split of serial.c. Finish helix/serial.c improvement.

- The difference with the original let's split's serial.c
  - It's high-speed about 4 times.
  - Stable bi-directional data transfer. (Helix need master to slave transfer)
  - serial.h was divided 2 files, serial_config.h and sereial.h
  - With multiple types of transaction support, communication contents can be optimized. (NEW flexible API)

- USE OLD Simple APIs (compatible with let's split serial.c)
  - files :
    - serial_config.h -- hardware configuration (need include by config.h)
    - serial.c/serial.h -- serial communication

- USE NEW flexible APIs. (Support multi-type transaction function.)
  serial.c was divided into 2 layers, split_scom.c and serial.c.
  The upper layer split_scomm.c is called from matrix.c.
  The lower layer serial.c accesses the hardware.
  - files
    - split_scomm.c -- communication buffer is defined in here. call by matrix.c.
    - split_scomm.h -- buffer size is defined in here. include by matrix.c, split_util.c
    - serial_config.h -- hardware configuration (need include by config.h)
      To use the NEW API, specify #define SERIAL_USE_MULTI_TRANSACTION
    - serial.c/serial.h -- serial communication lower layer

- NEW APIs for serial.c / serial.h (The lower layer)
  // 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;

  // initiator is transaction start side
  void soft_serial_initiator_init(SSTD_t *sstd_table);
  // target is interrupt accept side
  void soft_serial_target_init(SSTD_t *sstd_table);
  int soft_serial_transaction(int sstd_index);
  int soft_serial_get_and_clean_target_status(int sstd_index);

- NEW APIs for split_scomm.c / split_scomm.h (The upper layer)
   move from old serial.c the following buffer and functions
     serial_slave_buffer[]
     serial_master_buffer[]
     void serial_master_init(void)
     void serial_slave_init(void)
     int serial_update_buffers(void)
   define SERIAL_xxxxx_BUFFER_LENGTH move from serial_config.h to split_scomm.h

1 files changed, 73 insertions, 0 deletions

diff --git a/keyboards/helix/rev2/split_scomm.c b/keyboards/helix/rev2/split_scomm.c
new file mode 100644
index 0000000000..9719eb22ea
--- /dev/null
+++ b/keyboards/helix/rev2/split_scomm.c
@@ -0,0 +1,73 @@
+#ifdef USE_SERIAL
+#ifdef SERIAL_USE_MULTI_TRANSACTION
+/* --- USE flexible API (using multi-type transaction function) --- */
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <split_scomm.h>
+#include "serial.h"
+#ifdef SERIAL_DEBUG_MODE
+#include <avr/io.h>
+#endif
+
+uint8_t volatile serial_slave_buffer[SERIAL_SLAVE_BUFFER_LENGTH] = {0};
+uint8_t volatile serial_master_buffer[SERIAL_MASTER_BUFFER_LENGTH] = {0};
+uint8_t volatile status_com = 0;
+uint8_t volatile status1 = 0;
+uint8_t slave_buffer_change_count = 0;
+uint8_t s_change_old = 0xff;
+
+SSTD_t transactions[] = {
+#define GET_SLAVE_STATUS 0
+    /* master buffer not changed, only recive slave_buffer_change_count */
+    { (uint8_t *)&status_com,
+      0, NULL,
+      sizeof(slave_buffer_change_count), &slave_buffer_change_count,
+    },
+#define PUT_MASTER_GET_SLAVE_STATUS 1
+    /* master buffer changed need send, and recive slave_buffer_change_count  */
+    { (uint8_t *)&status_com,
+      sizeof(serial_master_buffer), (uint8_t *)serial_master_buffer,
+      sizeof(slave_buffer_change_count), &slave_buffer_change_count,
+    },
+#define GET_SLAVE_BUFFER 2
+    /* recive serial_slave_buffer */
+    { (uint8_t *)&status1,
+      0, NULL,
+      sizeof(serial_slave_buffer), (uint8_t *)serial_slave_buffer
+    }
+};
+
+void serial_master_init(void)
+{
+    soft_serial_initiator_init(transactions);
+}
+
+void serial_slave_init(void)
+{
+    soft_serial_target_init(transactions);
+}
+
+// 0 => no error
+// 1 => slave did not respond
+// 2 => checksum error
+int serial_update_buffers(int master_update)
+{
+    int status;
+    static int need_retry = 0;
+    if( s_change_old != slave_buffer_change_count ) {
+	status = soft_serial_transaction(GET_SLAVE_BUFFER);
+	if( status == TRANSACTION_END )
+	    s_change_old = slave_buffer_change_count;
+    }
+    if( !master_update && !need_retry)
+	status = soft_serial_transaction(GET_SLAVE_STATUS);
+    else
+	status = soft_serial_transaction(PUT_MASTER_GET_SLAVE_STATUS);
+    need_retry = ( status == TRANSACTION_END ) ? 0 : 1;
+    return status;
+}
+
+#endif // SERIAL_USE_MULTI_TRANSACTION
+#endif /* USE_SERIAL */