CC2420: CC2420_WRITE_RAM with parameterizable ordering + resulting

simplifications

dev/cc2420/cc2420-aes.c

@@ -44,20 +44,6 @@
 
 #define KEYLEN 16
 #define MAX_DATALEN 16
-
-#define CC2420_WRITE_RAM_REV(buffer,adr,count)               \
-  do {                                                       \
-    uint8_t i;                                               \
-    CC2420_SPI_ENABLE();                                     \
-    SPI_WRITE_FAST(0x80 | (adr & 0x7f));                     \
-    SPI_WRITE_FAST((adr >> 1) & 0xc0);                       \
-    for(i = (count); i > 0; i--) {                           \
-      SPI_WRITE_FAST(((uint8_t*)(buffer))[i - 1]);           \
-    }                                                        \
-    SPI_WAITFORTx_ENDED();                                   \
-    CC2420_SPI_DISABLE();                                    \
-  } while(0)
-
 #define MIN(a,b) ((a) < (b)? (a): (b))
 
 /*---------------------------------------------------------------------------*/
@@ -66,10 +52,10 @@ cc2420_aes_set_key(const uint8_t *key, int index)
 {
   switch(index) {
   case 0:
-    CC2420_WRITE_RAM_REV(key, CC2420RAM_KEY0, KEYLEN);
+    CC2420_WRITE_RAM(key, CC2420RAM_KEY0, KEYLEN, CC2420_WRITE_RAM_REVERSE);
     break;
   case 1:
-    CC2420_WRITE_RAM_REV(key, CC2420RAM_KEY1, KEYLEN);
+    CC2420_WRITE_RAM(key, CC2420RAM_KEY1, KEYLEN, CC2420_WRITE_RAM_REVERSE);
     break;
   }
 }
@@ -82,7 +68,7 @@ cipher16(uint8_t *data, int len)
 
   len = MIN(len, MAX_DATALEN);
 
-  CC2420_WRITE_RAM(data, CC2420RAM_SABUF, len);
+  CC2420_WRITE_RAM(data, CC2420RAM_SABUF, len, CC2420_WRITE_RAM_IN_ORDER);
   CC2420_STROBE(CC2420_SAES);
   /* Wait for the encryption to finish */
   do {

dev/cc2420/cc2420.c

@@ -300,9 +300,12 @@ read_ram(uint8_t *buffer, uint16_t adr, uint16_t count)
 }
 /*---------------------------------------------------------------------------*/
 static void
-write_ram(uint8_t *buffer, uint16_t adr, uint16_t count)
+write_ram(const uint8_t *buffer,
+    uint16_t adr,
+    uint16_t count,
+    enum cc2420_write_ram_order order)
 {
-  CC2420_WRITE_RAM(buffer, adr, count);
+  CC2420_WRITE_RAM(buffer, adr, count, order);
 }
 /*---------------------------------------------------------------------------*/
 static void
@@ -541,7 +544,7 @@ cc2420_transmit(unsigned short payload_len)
         if(packetbuf_attr(PACKETBUF_ATTR_PACKET_TYPE) ==
            PACKETBUF_ATTR_PACKET_TYPE_TIMESTAMP) {
           /* Write timestamp to last two bytes of packet in TXFIFO. */
-          write_ram((uint8_t *) &sfd_timestamp, CC2420RAM_TXFIFO + payload_len - 1, 2);
+          write_ram((uint8_t *) &sfd_timestamp, CC2420RAM_TXFIFO + payload_len - 1, 2, CC2420_WRITE_RAM_IN_ORDER);
         }
       }
 
@@ -719,9 +722,6 @@ cc2420_set_pan_addr(unsigned pan,
                     unsigned addr,
                     const uint8_t *ieee_addr)
 {
-  uint16_t f = 0;
-  uint8_t tmp[2];
-
   GET_LOCK();
   
   /*
@@ -729,20 +729,11 @@ cc2420_set_pan_addr(unsigned pan,
    */
   wait_for_status(BV(CC2420_XOSC16M_STABLE));
 
-  tmp[0] = pan & 0xff;
+  write_ram((uint8_t *) &pan, CC2420RAM_PANID, 2, CC2420_WRITE_RAM_IN_ORDER);
-  tmp[1] = pan >> 8;
+  write_ram((uint8_t *) &addr, CC2420RAM_SHORTADDR, 2, CC2420_WRITE_RAM_IN_ORDER);
-  write_ram((uint8_t *) &tmp, CC2420RAM_PANID, 2);
   
-  tmp[0] = addr & 0xff;
-  tmp[1] = addr >> 8;
-  write_ram((uint8_t *) &tmp, CC2420RAM_SHORTADDR, 2);
   if(ieee_addr != NULL) {
-    uint8_t tmp_addr[8];
+    write_ram(ieee_addr, CC2420RAM_IEEEADDR, 8, CC2420_WRITE_RAM_REVERSE);
-    /* LSB first, MSB last for 802.15.4 addresses in CC2420 */
-    for (f = 0; f < 8; f++) {
-      tmp_addr[7 - f] = ieee_addr[f];
-    }
-    write_ram(tmp_addr, CC2420RAM_IEEEADDR, 8);
   }
   RELEASE_LOCK();
 }

dev/cc2420/cc2420.h

@@ -163,16 +163,29 @@ void cc2420_set_cca_threshold(int value);
     CC2420_SPI_DISABLE();                                               \
   } while(0)
 
+enum cc2420_write_ram_order {
+  /* Begin with writing the first given byte */
+  CC2420_WRITE_RAM_IN_ORDER,
+  /* Begin with writing the last given byte */
+  CC2420_WRITE_RAM_REVERSE
+};
+
 /* Write to RAM in the CC2420 */
-#define CC2420_WRITE_RAM(buffer,adr,count)                 \
+#define CC2420_WRITE_RAM(buffer,adr,count,order)             \
   do {                                                       \
     uint8_t i;                                               \
     CC2420_SPI_ENABLE();                                     \
     SPI_WRITE_FAST(0x80 | ((adr) & 0x7f));                   \
     SPI_WRITE_FAST(((adr) >> 1) & 0xc0);                     \
+    if(order == CC2420_WRITE_RAM_IN_ORDER) {                 \
       for(i = 0; i < (count); i++) {                         \
         SPI_WRITE_FAST(((uint8_t*)(buffer))[i]);             \
       }                                                      \
+    } else {                                                 \
+      for(i = (count); i > 0; i--) {                         \
+        SPI_WRITE_FAST(((uint8_t*)(buffer))[i - 1]);         \
+      }                                                      \
+    }                                                        \
     SPI_WAITFORTx_ENDED();                                   \
     CC2420_SPI_DISABLE();                                    \
   } while(0)