From b74270d7ccee16d14bfd0ec2ce4fbcf897f51698 Mon Sep 17 00:00:00 2001
From: Michael Gernoth <michael@gernoth.net>
Date: Fri, 21 Jun 2013 11:18:12 +0200
Subject: [PATCH] handle errata 1, add timeouts in rx

---
 culfw/culfw-asksin-fix.diff | 69 ++++++++++++++++++++++++++++---------
 1 file changed, 52 insertions(+), 17 deletions(-)

diff --git a/culfw/culfw-asksin-fix.diff b/culfw/culfw-asksin-fix.diff
index 795ff41..bbe630f 100644
--- a/culfw/culfw-asksin-fix.diff
+++ b/culfw/culfw-asksin-fix.diff
@@ -19,7 +19,7 @@ Index: clib/rf_asksin.c
       0x0B, 0x06,
       0x0D, 0x21,
       0x0E, 0x65,
-@@ -26,18 +26,21 @@
+@@ -26,18 +26,22 @@
       0x11, 0x93,
       0x12, 0x03,
       0x15, 0x34,
@@ -39,12 +39,13 @@ Index: clib/rf_asksin.c
 +     0x3e, 0xc3
  };
  
-+static inline uint8_t read_cc1100_rxbytes();
++static inline uint8_t read_cc1100_rxbytes(void);
++static inline void rf_asksin_reset_rx(void);
 +
  void
  rf_asksin_init(void)
  {
-@@ -56,20 +59,30 @@
+@@ -56,20 +60,44 @@
    my_delay_us(100);
  
    // load configuration
@@ -67,7 +68,8 @@ Index: clib/rf_asksin.c
  }
  
 +// Workaround for CC1101 Errata 3
-+static inline uint8_t read_cc1100_rxbytes()
++static inline uint8_t
++read_cc1100_rxbytes(void)
 +{
 +  uint8_t rxbytes, rxbytes2;
 +  
@@ -77,11 +79,24 @@ Index: clib/rf_asksin.c
 +
 +  return rxbytes;
 +}
++
++static inline void
++rf_asksin_reset_rx(void)
++{
++  ccStrobe( CC1100_SFRX  );
++  ccStrobe( CC1100_SIDLE );
++  ccStrobe( CC1100_SNOP  );
++
++  while (read_cc1100_rxbytes() & 0x7f)
++    cc1100_readReg(CC1100_RXFIFO);
++
++  ccStrobe( CC1100_SRX   );
++}
 +
  void
  rf_asksin_task(void)
  {
-@@ -77,18 +90,30 @@
+@@ -77,18 +105,41 @@
    uint8_t dec[MAX_ASKSIN_MSG];
    uint8_t rssi;
    uint8_t l;
@@ -102,25 +117,37 @@ Index: clib/rf_asksin.c
 +    rxfifo_cnt &= 0x7f;
 +
      enc[0] = cc1100_readReg( CC1100_RXFIFO ) & 0x7f; // read len
++    rxfifo_cnt--;
  
-     if (enc[0]>=MAX_ASKSIN_MSG)
-          enc[0] = MAX_ASKSIN_MSG-1;
+-    if (enc[0]>=MAX_ASKSIN_MSG)
+-         enc[0] = MAX_ASKSIN_MSG-1;
 -    
++    if (enc[0] >= MAX_ASKSIN_MSG) {
++      // Something went horribly wrong, out of sync?
++      rf_asksin_reset_rx();
++      return;
++    }
 +
-+    while ((enc[0] + 2) < (rxfifo_cnt - 1)) { // Wait for more data
++    l = 50;
++    while (l-- && ((enc[0] + 2) < rxfifo_cnt)) { // Wait for more data
 +      my_delay_ms(1);
-+      rxfifo_cnt = (read_cc1100_rxbytes() & 0x7f) + 1;
++      rxfifo_cnt = (read_cc1100_rxbytes() & 0x7f);
++    }
++
++    if (!l) {
++      // Not enough data received, out of sync?
++      rf_asksin_reset_rx();
++      return;
 +    }
 +
      CC1100_ASSERT;
      cc1100_sendbyte( CC1100_READ_BURST | CC1100_RXFIFO );
      
-@@ -97,13 +122,12 @@
+@@ -97,14 +148,19 @@
      }
      
      rssi = cc1100_sendbyte( 0 );
 -    
-+    l = cc1100_sendbyte( 0 );
 +
      CC1100_DEASSERT;
  
@@ -128,12 +155,20 @@ Index: clib/rf_asksin.c
 -    ccStrobe( CC1100_SIDLE );
 -    ccStrobe( CC1100_SNOP  );
 -    ccStrobe( CC1100_SRX   );
++    // We must not read the last byte from the RX fifo while RX is in progress (Errata 1)
++    while (((read_cc1100_rxbytes() & 0x7f) == 1) && (cc1100_readReg(CC1100_PKTSTATUS) & (1 << 3))) {
++      my_delay_ms(1);
++    }
+ 
++    l = cc1100_readReg(CC1100_RXFIFO);
++
 +    if (!(l & 0x80)) // CRC not ok
 +      continue;
- 
++
      dec[0] = enc[0];
      dec[1] = (~enc[1]) ^ 0x89;
-@@ -113,7 +137,6 @@
+     
+@@ -113,7 +169,6 @@
      
      dec[l] = enc[l] ^ dec[2];
      
@@ -141,7 +176,7 @@ Index: clib/rf_asksin.c
      if (tx_report & REP_BINTIME) {
        
        DC('a');
-@@ -131,26 +154,17 @@
+@@ -131,26 +186,17 @@
        
        DNL();
      }
@@ -177,7 +212,7 @@ Index: clib/rf_asksin.c
  }
  
  void
-@@ -173,20 +187,7 @@
+@@ -173,20 +219,7 @@
      my_delay_ms(3);             // 3ms: Found by trial and error
    }
  
@@ -198,7 +233,7 @@ Index: clib/rf_asksin.c
    enc[0] = dec[0];
    enc[1] = (~dec[1]) ^ 0x89;
  
-@@ -195,6 +196,15 @@
+@@ -195,6 +228,15 @@
    
    enc[l] = dec[l] ^ dec[2];
  
@@ -214,7 +249,7 @@ Index: clib/rf_asksin.c
    // send
    CC1100_ASSERT;
    cc1100_sendbyte(CC1100_WRITE_BURST | CC1100_TXFIFO);
-@@ -205,12 +215,17 @@
+@@ -205,12 +247,17 @@
  
    CC1100_DEASSERT;
  
-- 
2.39.5