Simplify data types, now that I believe that 'frames' will always be rather short

diff --git a/armsrc/legicrf.c b/armsrc/legicrf.c
index ae56dcb5f605ac76881810aed0e0c7c57e476dee..6a40b037cf63eb3c6cfa1f19fd4cb2df557bc5f6 100644 (file)
--- a/armsrc/legicrf.c
+++ b/armsrc/legicrf.c
@@ -8,21 +8,23 @@
 
 #include "apps.h"
 #include "legicrf.h"
+#include "unistd.h"
+#include "stdint.h"
 
 static struct legic_frame {
-       int num_bytes;
-       int num_bits;
-       char data[10];
+       int bits;
+       uint16_t data;
 } current_frame;
 
-static char queries[][4] = {
+static struct legic_frame queries[] = {
                {7, 0x55}, /* 1010 101 */
 };
-static char responses[][4] = {
+
+static struct legic_frame responses[] = {
                {6, 0x3b}, /* 1101 11 */
 };
 
-static void frame_send(char *response, int num_bytes, int num_bits)
+static void frame_send(uint16_t response, int bits)
 {
 #if 0
        /* Use the SSC to send a response. 8-bit transfers, LSBit first, 100us per bit */
@@ -36,9 +38,10 @@ static void frame_send(char *response, int num_bytes, int num_bits)
        while(AT91C_BASE_TC1->TC_CV < 490) ;
        
        int i;
-       for(i=0; i<(num_bytes*8+num_bits); i++) {
+       for(i=0; i<bits; i++) {
                int nextbit = AT91C_BASE_TC1->TC_CV + 150;
-               int bit = response[i/8] & (1<<(i%8));
+               int bit = response & 1;
+               response = response >> 1;
                if(bit) 
                        AT91C_BASE_PIOA->PIO_SODR = GPIO_SSC_DOUT;
                else
@@ -49,20 +52,21 @@ static void frame_send(char *response, int num_bytes, int num_bits)
 #endif
 }
 
-static void frame_respond(struct legic_frame *f)
+static void frame_respond(struct legic_frame const * const f)
 {
        LED_D_ON();
-       int bitcount = f->num_bytes*8+f->num_bits;
-       int i, r=-1;
+       int i;
+       struct legic_frame *r = NULL;
+       
        for(i=0; i<sizeof(queries)/sizeof(queries[0]); i++) {
-               if(bitcount == queries[i][0] && f->data[0] == queries[i][1] && f->data[1] == queries[i][2]) {
-                       r = i;
+               if(f->bits == queries[i].bits && f->data == queries[i].data) {
+                       r = &responses[i];
                        break;
                }
        }
        
-       if(r != -1) {
-               frame_send(&responses[r][1], responses[r][0]/8, responses[r][0]%8);
+       if(r != NULL) {
+               frame_send(r->data, r->bits);
                LED_A_ON();
        } else {
                LED_A_OFF();
@@ -71,26 +75,22 @@ static void frame_respond(struct legic_frame *f)
        LED_D_OFF();
 }
 
-static void frame_append_bit(struct legic_frame *f, int bit)
+static void frame_append_bit(struct legic_frame * const f, int bit)
 {
-       if(f->num_bytes >= (int)sizeof(f->data))
+       if(f->bits >= 15)
                return; /* Overflow, won't happen */
-       f->data[f->num_bytes] |= (bit<<f->num_bits);
-       f->num_bits++;
-       if(f->num_bits > 7) {
-               f->num_bits = 0;
-               f->num_bytes++;
-       }
+       f->data |= (bit<<f->bits);
+       f->bits++;
 }
 
-static int frame_is_empty(struct legic_frame *f)
+static int frame_is_empty(struct legic_frame const * const f)
 {
-       return( (f->num_bytes*8 + f->num_bits) <= 4 );
+       return( f->bits <= 4 );
 }
 
-static void frame_handle(struct legic_frame *f)
+static void frame_handle(struct legic_frame const * const f)
 {
-       if(f->num_bytes == 0 && f->num_bits == 6) {
+       if(f->bits == 6) {
                /* Short path */
                return;
        }
@@ -99,13 +99,10 @@ static void frame_handle(struct legic_frame *f)
        }
 }
 
-static void frame_clean(struct legic_frame *f)
+static void frame_clean(struct legic_frame * const f)
 {
-       if(!frame_is_empty(f)) 
-               /* memset(f->data, 0, sizeof(f->data)); */
-               f->data[0] = f->data[1] = 0;
-       f->num_bits = 0;
-       f->num_bytes = 0;
+       f->data = 0;
+       f->bits = 0;
 }
 
 static void emit(int bit)