remove some unnecessary instructions and function calls. patch from Jesper Karlsson.

platform/msb430/dev/cc1020.c

@@ -178,7 +178,7 @@ cc1020_set_rx(void)
   UBR00 = 0x00;			// No baudrate divider 
   UBR10 = 0x00;			// settings for a spi
   UMCTL0 = 0x00;		// slave.
-  ME1 |= USPIE0;		// Enable USART0 TXD/RXD, disabling does not yield any powersavings
+  ME1 |= URXE0;		// Enable USART0 RXD, disabling does not yield any powersavings
   P3SEL |= 0x0A;		// Select rx line and clk
   UCTL0 &= ~SWRST;		// Clear reset bit
   splx(s);
@@ -233,6 +233,7 @@ cc1020_send(const void *buf, unsigned short len)
 {
   int try;  
   int normal_header = HDRSIZE + len;
+  int i;
   uint16_t rxcrc = 0xFFFF; // For checksum purposes
   
   if(cc1020_state == CC1020_OFF) {
@@ -254,8 +255,7 @@ cc1020_send(const void *buf, unsigned short len)
   rxcrc = crc16_add((uint8_t) (normal_header & 0xff), rxcrc); 
   rxcrc = crc16_add((uint8_t) ((normal_header >> 8)& 0xff), rxcrc);
   
-  int i=0;
+  for(i = 0; i < len; i++) {
-  for(i=0;i<len;i++){
     rxcrc = crc16_add((uint8_t) ((char*)buf)[i], rxcrc);
   }
   
@@ -280,6 +280,7 @@ cc1020_send(const void *buf, unsigned short len)
       }
     }
     if(try == CC1020_CONF_CCA_TIMEOUT) {
+      printf("CCA failed rssi: %d\n", cc1020_get_rssi());
       return -3;
     }
 
@@ -375,7 +376,7 @@ cc1020_off(void)
 uint8_t
 cc1020_get_rssi(void)
 {
-  return cc1020_read_reg(CC1020_RSS);
+  return (cc1020_read_reg(CC1020_RSS) & 0x7F);
 }
 
 uint8_t
@@ -384,12 +385,10 @@ cc1020_get_packet_rssi(void)
   return rssi;
 }
 
-
-
 int
 cc1020_carrier_sense(void)
 {
-  return !!(cc1020_read_reg(CC1020_STATUS) & CARRIER_SENSE);
+  return (cc1020_read_reg(CC1020_STATUS) & CARRIER_SENSE);
 }
 
 PROCESS_THREAD(cc1020_receiver_process, ev, data)
@@ -477,7 +476,7 @@ interrupt(UART0RX_VECTOR) cc1020_rxhandler(void)
     } else {
       return;
     }
-    rssi = cc1020_read_reg(CC1020_RSS);
+    rssi = cc1020_get_rssi();
     CC1020_SET_OPSTATE(CC1020_RX | CC1020_RX_RECEIVING);
   } else if(cc1020_state & CC1020_RX_RECEIVING) {
     if(syncbs == 0) {
@@ -517,18 +516,15 @@ interrupt(UART0RX_VECTOR) cc1020_rxhandler(void)
 static void
 cc1020_write_reg(uint8_t addr, uint8_t adata)
 {
-  unsigned i;
+  unsigned int i;
-  unsigned char data;
+  uint8_t data;
 
-  PSEL_OFF;
   data = addr << 1;
   PSEL_ON;
 
   // Send address bits 
   for(i = 0; i < 7; i++) {
-    nop();
     PCLK_LOW;
-    nop();
     if(data & 0x80) {
       PDI_HIGH;
     } else {
@@ -536,24 +532,20 @@ cc1020_write_reg(uint8_t addr, uint8_t adata)
     }
     data = data << 1;
     PCLK_HIGH;
+    nop();
   }
 
   // Send read/write bit 
   // Ignore bit in data, always use 1 
-  nop();
   PCLK_LOW;
   PDI_HIGH;
-  nop();
   PCLK_HIGH;
   nop();
-  PCLK_LOW;
   data = adata;
 
   // Send data bits 
   for(i = 0; i < 8; i++) {
-    nop();
     PCLK_LOW;
-    nop();
     if(data & 0x80) {
       PDI_HIGH;
     } else {
@@ -561,30 +553,25 @@ cc1020_write_reg(uint8_t addr, uint8_t adata)
     }
     data = data << 1;
     PCLK_HIGH;
+    nop();
   }
 
-  nop();
   PCLK_LOW;
-  nop();
   PSEL_OFF;
 }
 
 static uint8_t
 cc1020_read_reg(uint8_t addr)
 {
-  unsigned i;
+  unsigned int i;
-  unsigned char data = 0;
+  uint8_t data;
 
-  PSEL_OFF;
   data = addr << 1;
   PSEL_ON;
-  nop();
 
   // Send address bits 
   for(i = 0; i < 7; i++) {
-    nop();
     PCLK_LOW;
-    nop();
     if(data & 0x80) {
       PDI_HIGH;
     } else {
@@ -592,14 +579,13 @@ cc1020_read_reg(uint8_t addr)
     }
     data = data << 1;
     PCLK_HIGH;
+    nop();
   }
 
   // Send read/write bit 
   // Ignore bit in data, always use 0 
-  nop();
   PCLK_LOW;
   PDI_LOW;
-  nop();
   PCLK_HIGH;
   nop();
   PCLK_LOW;
@@ -613,11 +599,9 @@ cc1020_read_reg(uint8_t addr)
     if(PDO) {
       data++;
     }
-    nop();
     PCLK_LOW;
   }
 
-  nop();
   PSEL_OFF;
 
   return data;
@@ -697,15 +681,11 @@ cc1020_setupRX(int analog)
   char lock_status;
 
   // Switch into RX, switch to freq. reg A
-  cc1020_write_reg(CC1020_MAIN, 0x11);
+  cc1020_write_reg(CC1020_MAIN, 0x01);
-
-  // Setup bias current adjustment
-  cc1020_write_reg(CC1020_ANALOG, analog);
   MS_DELAY(1);
   lock_status = cc1020_lock();
 
   // Switch RX part of CC1020 on
-  cc1020_write_reg(CC1020_MAIN, 0x01);
   cc1020_write_reg(CC1020_INTERFACE, 0x02);
 
   // Return LOCK status to application
@@ -717,9 +697,6 @@ cc1020_setupTX(int analog)
 {
   char lock_status;
 
-  // Setup bias current adjustment
-  cc1020_write_reg(CC1020_ANALOG, analog);
-
   // Switch into TX, switch to freq. reg B
   cc1020_write_reg(CC1020_MAIN, 0xC1);
   MS_DELAY(1);