On Wed, Jul 2, 2014 at 3:22 PM, patrick.ingram <patrick.ingram@cantada.com> wrote:
We are currently trying to run arm at 1GHz and have the DSP run at 800MHz to
prove out that max through put we can get on a data processing application
with this processor.  I understand this will damage the life of the part but
we are currently in an exercise to learn what is possible.  We are running
Angstrom built using Yocto project on a Overo Firestorm.  Any advice on how
to set the DSP clock frequency for testing would be greatly appreciated.

I believe this should work...


 Index: git/arch/arm/mach-omap2/clock.c
===================================================================
--- git.orig/arch/arm/mach-omap2/clock.c 2014-04-24 22:24:43.763004434 -0500
+++ git/arch/arm/mach-omap2/clock.c 2014-04-25 23:04:48.183903024 -0500
@@ -462,6 +462,7 @@
 {
  struct clk *mpurate_ck;
  int r;
+        struct clk *dpll2_clk;
 
  if (!mpurate)
  return -EINVAL;
@@ -483,6 +484,16 @@
 
  clk_put(mpurate_ck);
 
+ dpll2_clk = clk_get(NULL, "dpll2_ck");
+ r = clk_set_rate(dpll2_clk, 600000000);
+ if (IS_ERR_VALUE(r)) {
+         printk("Couldn't set DSP clock\n");
+ }
+        else {
+ printk("DSP clock set to 600Mhz\n");
+        }
+ omap3_dpll_recalc(dpll2_clk);
+
  return 0;
 }