Hi,
After reading over MPC85xx specs, I realized that the patch I sent
should use a better macro name. The new function was also a bit
confusing because it had the CLKDIV bits as its argument, instead of
the actual ratio.
Here is a new version of the patch that corrects these issues. Both
macro and function should now be clearer.
The patch is against git commit:
c956717ab25c962ef49d49064dfc73f4edcba1fb
John Ogness
Signed-off-by: John Ogness <[EMAIL PROTECTED]>
Add support for manually setting the CCB:LBC clock ratio.
This patch introduces a new macro CONFIG_LBC_CLOCK_RATIO, whose value
should be set to the desired clock divider. If the macro is not defined,
this patch has no effect. For the MPC85xx boards, the clock divider
defaults to a value of 16.
As an example, the new option can be used in the board config file like
this:
#define CONFIG_LBC_CLOCK_RATIO 4
Signed-off-by: John Ogness <[EMAIL PROTECTED]>
---
diff --git a/cpu/mpc85xx/cpu.c b/cpu/mpc85xx/cpu.c
index 0f72051..0f20c33 100644
--- a/cpu/mpc85xx/cpu.c
+++ b/cpu/mpc85xx/cpu.c
@@ -69,6 +69,31 @@ struct cpu_type *identify_cpu(u32 ver)
return NULL;
}
+#ifdef CONFIG_LBC_CLOCK_RATIO
+void set_lbc_clock_ratio(uint clkratio)
+{
+ volatile ccsr_lbc_t *lbc = (void *)(CFG_MPC85xx_LBC_ADDR);
+ uint lcrr;
+
+ switch (clkratio) {
+ case 4:
+ case 8:
+ case 16:
+ lcrr = lbc->lcrr;
+ lcrr &= ~0xf;
+ lcrr |= (clkratio >> 1);
+ lbc->lcrr = lcrr;
+ lcrr = lbc->lcrr;
+ __asm__ __volatile__ ("isync" : : : "memory");
+ break;
+
+ default:
+ /* invalid CCB:LBC clock ratio */
+ break;
+ }
+}
+#endif
+
int checkcpu (void)
{
sys_info_t sysinfo;
@@ -91,6 +116,10 @@ int checkcpu (void)
major = SVR_MAJ(svr);
minor = SVR_MIN(svr);
+#ifdef CONFIG_LBC_CLOCK_RATIO
+ set_lbc_clock_ratio(CONFIG_LBC_CLOCK_RATIO);
+#endif
+
puts("CPU: ");
cpu = identify_cpu(ver);
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