Author: Michael Bruck <mbruck@digenius.de>

[openocd] / src / jtag / jtag.c

diff --git a/src/jtag/jtag.c b/src/jtag/jtag.c
index a4f5d51d71384857605d43bc449c8cba51e76bfd..1b503ece5b5b4bb2eddeb19d706b347314ad8e41 100644 (file)
--- a/src/jtag/jtag.c
+++ b/src/jtag/jtag.c
@@ -589,27 +589,33 @@ void jtag_add_ir_scan(int in_num_fields, scan_field_t *in_fields, tap_state_t st
        }
 }
 
+/**
+ * Generate a list of scan fields with one entry for each TAP.
+ *
+ * If the input field list contains an instruction value for a TAP then that is used
+ * otherwise the TAP is set to bypass.
+ *
+ */
 int MINIDRIVER(interface_jtag_add_ir_scan)(int in_num_fields, scan_field_t *in_fields, tap_state_t state)
 {
        jtag_tap_t *tap;
-       int x;
        int nth_tap;
        int scan_size = 0;
 
-       /* allocate memory for a new list member */
-       jtag_command_t * cmd = cmd_queue_alloc(sizeof(jtag_command_t));
-       
+       int num_taps = jtag_NumEnabledTaps();
+
+       jtag_command_t * cmd    = cmd_queue_alloc(sizeof(jtag_command_t));
+       scan_command_t * scan   = cmd_queue_alloc(sizeof(scan_command_t));
+
        jtag_queue_command(cmd);
-       
-       cmd->type = JTAG_SCAN;
 
-       /* allocate memory for ir scan command */
-       cmd->cmd.scan = cmd_queue_alloc(sizeof(scan_command_t));
-       cmd->cmd.scan->ir_scan = true;
-       x = jtag_NumEnabledTaps();
-       cmd->cmd.scan->num_fields = x;  /* one field per device */
-       cmd->cmd.scan->fields = cmd_queue_alloc(x  * sizeof(scan_field_t));
-       cmd->cmd.scan->end_state = state;
+       cmd->type                               = JTAG_SCAN;
+       cmd->cmd.scan                   = scan;
+
+       scan->ir_scan                   = true;
+       scan->num_fields                = num_taps;     /* one field per device */
+       scan->fields                    = cmd_queue_alloc(num_taps  * sizeof(scan_field_t));
+       scan->end_state                 = state;
 
        nth_tap = -1;
        tap = NULL;
@@ -623,12 +629,12 @@ int MINIDRIVER(interface_jtag_add_ir_scan)(int in_num_fields, scan_field_t *in_f
                }
                nth_tap++;
 
-               assert(nth_tap < x );
+               assert(nth_tap < num_taps);
 
-               scan_size = tap->ir_length;
-               cmd->cmd.scan->fields[nth_tap].tap = tap;
-               cmd->cmd.scan->fields[nth_tap].num_bits = scan_size;
-               cmd->cmd.scan->fields[nth_tap].in_value = NULL; /* do not collect input for tap's in bypass */
+               scan_size                                               = tap->ir_length;
+               scan->fields[nth_tap].tap               = tap;
+               scan->fields[nth_tap].num_bits  = scan_size;
+               scan->fields[nth_tap].in_value  = NULL; /* do not collect input for tap's in bypass */
 
                /* search the list */
                for (int j = 0; j < in_num_fields; j++)
@@ -636,8 +642,8 @@ int MINIDRIVER(interface_jtag_add_ir_scan)(int in_num_fields, scan_field_t *in_f
                        if (tap == in_fields[j].tap)
                        {
                                found = 1;
-                               cmd->cmd.scan->fields[nth_tap].in_value = in_fields[j].in_value;
-                               cmd->cmd.scan->fields[nth_tap].out_value = buf_cpy(in_fields[j].out_value, cmd_queue_alloc(CEIL(scan_size, 8)), scan_size);
+                               scan->fields[nth_tap].in_value  = in_fields[j].in_value;
+                               scan->fields[nth_tap].out_value = buf_cpy(in_fields[j].out_value, cmd_queue_alloc(CEIL(scan_size, 8)), scan_size);
 
                                tap->bypass = 0;
                                break;
@@ -647,14 +653,15 @@ int MINIDRIVER(interface_jtag_add_ir_scan)(int in_num_fields, scan_field_t *in_f
                if (!found)
                {
                        /* if a tap isn't listed, set it to BYPASS */
-                       cmd->cmd.scan->fields[nth_tap].out_value = buf_set_ones(cmd_queue_alloc(CEIL(scan_size, 8)), scan_size);
+                       scan->fields[nth_tap].out_value = buf_set_ones(cmd_queue_alloc(CEIL(scan_size, 8)), scan_size);
                        tap->bypass = 1;
                }
 
                /* update device information */
-               buf_cpy(cmd->cmd.scan->fields[nth_tap].out_value, tap->cur_instr, scan_size);
+               buf_cpy(scan->fields[nth_tap].out_value, tap->cur_instr, scan_size);
        }
-       assert(nth_tap == (x-1));
+
+       assert(nth_tap == (num_taps - 1));
 
        return ERROR_OK;
 }