ibmpc: Replace unit16_t recv_data with ringbuf

tmk_core/protocol/ibmpc.c

@@ -46,6 +46,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #include "debug.h"
 #include "timer.h"
 #include "wait.h"
+#include "ringbuf.h"
 
 
 #define WAIT(stat, us, err) do { \
@@ -60,15 +61,11 @@ volatile uint16_t ibmpc_isr_debug = 0;
 volatile uint8_t ibmpc_protocol = IBMPC_PROTOCOL_NO;
 volatile uint8_t ibmpc_error = IBMPC_ERR_NONE;
 
-/* 2-byte buffer for data received from keyboard
+/* buffer for data received from device */
- * buffer states:
+#define RINGBUF_SIZE    16
- *      FFFF: empty
+static uint8_t rbuf[RINGBUF_SIZE];
- *      FFss: one data
+static ringbuf_t rb = {};
- *      sstt: two data
+
- *      eeFF: error
- * where ss, tt and ee are 0x00-0xFE. 0xFF means empty or no data in buffer.
- */
-static volatile uint16_t recv_data = 0xFFFF;
 /* internal state of receiving data */
 static volatile uint16_t isr_state = 0x8000;
 static uint8_t timer_start = 0;
@@ -80,6 +77,7 @@ void ibmpc_host_init(void)
     inhibit();
     IBMPC_INT_INIT();
     IBMPC_INT_OFF();
+    ringbuf_init(&rb, rbuf, RINGBUF_SIZE);
 }
 
 void ibmpc_host_enable(void)
@@ -180,60 +178,19 @@ ERROR:
  */
 int16_t ibmpc_host_recv(void)
 {
-    uint16_t data = 0;
+    int16_t ret = -1;
-    uint8_t ret = 0xFF;
 
-    ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
+    // Enable ISR if buffer was full
-        data = recv_data;
+    if (ringbuf_is_full(&rb)) {
-
-        // remove data from buffer:
-        // FFFF(empty)      -> FFFF
-        // FFss(one data)   -> FFFF
-        // sstt(two data)   -> FFtt
-        // eeFF(errror)     -> FFFF
-        recv_data = data | (((data&0xFF00) == 0xFF00) ? 0x00FF : 0xFF00);
-    }
-
-    if ((data&0x00FF) == 0x00FF) {
-        // error: eeFF
-        switch (data>>8) {
-            case IBMPC_ERR_FF:
-                // 0xFF(Overrun/Error) from keyboard
-                dprintf("!FF! ");
-                ret = 0xFF;
-                break;
-            case IBMPC_ERR_FULL:
-                // buffer overflow
-                dprintf("!OVF! ");
-                ret = 0xFF;
-                break;
-            case 0xFF:
-                // empty: FFFF
-                return -1;
-            default:
-                // other errors
-                dprintf("e%02X ", data>>8);
-                return -1;
-        }
-    } else {
-        if ((data | 0x00FF) != 0xFFFF) {
-            // two data: sstt
-            dprintf("b:%04X ", data);
-            ret = (data>>8);
-        } else {
-            // one data: FFss
-            ret = (data&0x00FF);
-        }
-    }
-
-    // Enable ISR if recv_data is not full
-    if ((recv_data | 0x00FF) == 0xFFFF) {
         ibmpc_host_isr_clear();
         IBMPC_INT_ON();
         idle();
     }
-    //dprintf("i%04X ", ibmpc_isr_debug); ibmpc_isr_debug = 0;
+
-    dprintf("r%02X ", ret);
+    ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
+        ret = ringbuf_get(&rb);
+    }
+    if (ret != -1) dprintf("r%02X ", ret&0xFF);
     return ret;
 }
 
@@ -254,7 +211,7 @@ void ibmpc_host_isr_clear(void)
     ibmpc_protocol = 0;
     ibmpc_error = 0;
     isr_state = 0x8000;
-    recv_data = 0xFFFF;
+    ringbuf_reset(&rb);
 }
 
 #define LO8(w)  (*((uint8_t *)&(w)))
@@ -407,32 +364,19 @@ ISR(IBMPC_INT_VECT)
             break;
     }
 
-ERROR:
-    // error: eeFF
-    recv_data = (ibmpc_error<<8) | 0x00FF;
-    goto CLEAR;
 DONE:
-    if ((isr_state & 0x00FF) == 0x00FF) {
+    // store data
-        // receive error code 0xFF
+    if (!ringbuf_put(&rb, isr_state & 0xFF)) {
-        ibmpc_error = IBMPC_ERR_FF;
-        goto ERROR;
-    }
-    if (HI8(recv_data) != 0xFF && LO8(recv_data) != 0xFF) {
         // buffer overflow
         ibmpc_error = IBMPC_ERR_FULL;
-        goto ERROR;
+
-    }
+        // Disable ISR if buffer is full
-    // store data
-    recv_data = recv_data<<8;
-    recv_data |= isr_state & 0xFF;
-CLEAR:
-    // Disable ISR if recv_data is full
-    if ((recv_data | 0x00FF) != 0xFFFF) {
         IBMPC_INT_OFF();
         // inhibit: clock_lo
         IBMPC_CLOCK_PORT &= ~(1<<IBMPC_CLOCK_BIT);
         IBMPC_CLOCK_DDR  |=  (1<<IBMPC_CLOCK_BIT);
     }
+ERROR:
     // clear for next data
     isr_state = 0x8000;
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