zy1000: print out khz correctly in response to setting JTAG speed

Calculate printout based on same core routines.

Signed-off-by: Øyvind Harboe <oyvind.harboe@zylin.com>

diff --git a/src/jtag/zy1000/zy1000.c b/src/jtag/zy1000/zy1000.c
index 28c65b6e56658e9312e1ca3ca642b71a0dcdbc05..23f2fdd79ba775a7eae1f9821037ceb58cc8c8d7 100644 (file)
--- a/src/jtag/zy1000/zy1000.c
+++ b/src/jtag/zy1000/zy1000.c
@@ -1,4 +1,4 @@
-/***************************************************************************
+'n/***************************************************************************
  *   Copyright (C) 2007-2010 by Øyvind Harboe                              *
  *                                                                         *
  *   This program is free software; you can redistribute it and/or modify  *
@@ -84,7 +84,33 @@ static int zy1000_khz(int khz, int *jtag_speed)
        }
        else
        {
-               *jtag_speed = 64000/khz;
+               int speed;
+               /* Round speed up to nearest divisor.
+                *
+                * E.g. 16000kHz
+                * (64000 + 15999) / 16000 = 4
+                * (4 + 1) / 2 = 2
+                * 2 * 2 = 4
+                *
+                * 64000 / 4 = 16000
+                *
+                * E.g. 15999
+                * (64000 + 15998) / 15999 = 5
+                * (5 + 1) / 2 = 3
+                * 3 * 2 = 6
+                *
+                * 64000 / 6 = 10666
+                *
+                */
+               speed = (64000 + (khz -1)) / khz;
+               speed = (speed + 1 ) / 2;
+               speed *= 2;
+               if (speed > 8190)
+               {
+                       /* maximum dividend */
+                       speed = 8190;
+               }
+               *jtag_speed = speed;
        }
        return ERROR_OK;
 }
@@ -243,9 +269,12 @@ int zy1000_speed(int speed)
                        return ERROR_INVALID_ARGUMENTS;
                }
 
-               LOG_USER("jtag_speed %d => JTAG clk=%f", speed, 64.0/(float)speed);
+               int khz;
+               speed &= ~1;
+               zy1000_speed_div(speed, &khz);
+               LOG_USER("jtag_speed %d => JTAG clk=%d kHz", speed, khz);
                ZY1000_POKE(ZY1000_JTAG_BASE + 0x14, 0x100);
-               ZY1000_POKE(ZY1000_JTAG_BASE + 0x1c, speed&~1);
+               ZY1000_POKE(ZY1000_JTAG_BASE + 0x1c, speed);
        }
        return ERROR_OK;
 }