Factoring of jtag_examine_chain for maintainability:

- Factor initial chain examination check into new static helper.

git-svn-id: svn://svn.berlios.de/openocd/trunk@2084 b42882b7-edfa-0310-969c-e2dbd0fdcd60

diff --git a/src/jtag/jtag.c b/src/jtag/jtag.c
index a3d86adead05ad03ce3f0216aee72c1ea7a18597..03462d6bada297c48ce4073778b4ecd6442a4bf3 100644 (file)
--- a/src/jtag/jtag.c
+++ b/src/jtag/jtag.c
@@ -963,32 +963,41 @@ static int jtag_examine_chain_execute(u8 *idcode_buffer, unsigned num_idcode)
        return jtag_execute_queue();
 }
 
+static bool jtag_examine_chain_check(u8 *idcodes, unsigned count)
+{
+       u8 zero_check = 0x0;
+       u8 one_check = 0xff;
+
+       for (unsigned i = 0; i < count * 4; i++)
+       {
+               zero_check |= idcodes[i];
+               one_check &= idcodes[i];
+       }
+
+       /* if there wasn't a single non-zero bit or if all bits were one,
+        * the scan is not valid */
+       if (zero_check == 0x00 || one_check == 0xff)
+       {
+               LOG_ERROR("JTAG communication failure: check connection, "
+                       "JTAG interface, target power etc.");
+               return false;
+       }
+       return true;
+}
+
 /* Try to examine chain layout according to IEEE 1149.1 §12
  */
 static int jtag_examine_chain(void)
 {
        jtag_tap_t *tap;
        u8 idcode_buffer[JTAG_MAX_CHAIN_SIZE * 4];
-       int i;
        int bit_count;
        int device_count = 0;
-       u8 zero_check = 0x0;
-       u8 one_check = 0xff;
 
        jtag_examine_chain_execute(idcode_buffer, JTAG_MAX_CHAIN_SIZE);
 
-       for (i = 0; i < JTAG_MAX_CHAIN_SIZE * 4; i++)
-       {
-               zero_check |= idcode_buffer[i];
-               one_check &= idcode_buffer[i];
-       }
-
-       /* if there wasn't a single non-zero bit or if all bits were one, the scan isn't valid */
-       if ((zero_check == 0x00) || (one_check == 0xff))
-       {
-               LOG_ERROR("JTAG communication failure, check connection, JTAG interface, target power etc.");
+       if (!jtag_examine_chain_check(idcode_buffer, JTAG_MAX_CHAIN_SIZE))
                return ERROR_JTAG_INIT_FAILED;
-       }
 
        /* point at the 1st tap */
        tap = jtag_tap_next_enabled(NULL);