[Blackfin] arch: Support for CPU_FREQ and NOHZ
Singed-off-by: Vitja Makarov <vitja.makarov@gmail.com>
diff --git a/arch/blackfin/mach-common/cpufreq.c b/arch/blackfin/mach-common/cpufreq.c
index dd1515e..75cdad2 100644
--- a/arch/blackfin/mach-common/cpufreq.c
+++ b/arch/blackfin/mach-common/cpufreq.c
@@ -62,6 +62,14 @@
unsigned int tscale; /* change the divider on the core timer interrupt */
} dpm_state_table[3];
+/*
+ normalized to maximum frequncy offset for CYCLES,
+ used in time-ts cycles clock source, but could be used
+ somewhere also.
+ */
+unsigned long long __bfin_cycles_off;
+unsigned int __bfin_cycles_mod;
+
/**************************************************************************/
static unsigned int bfin_getfreq(unsigned int cpu)
@@ -80,6 +88,7 @@
unsigned int index, plldiv, tscale;
unsigned long flags, cclk_hz;
struct cpufreq_freqs freqs;
+ cycles_t cycles;
if (cpufreq_frequency_table_target(policy, bfin_freq_table,
target_freq, relation, &index))
@@ -101,8 +110,14 @@
bfin_write_PLL_DIV(plldiv);
/* we have to adjust the core timer, because it is using cclk */
bfin_write_TSCALE(tscale);
+ cycles = get_cycles();
SSYNC();
+ cycles += 10; /* ~10 cycles we loose after get_cycles() */
+ __bfin_cycles_off += (cycles << __bfin_cycles_mod) - (cycles << index);
+ __bfin_cycles_mod = index;
local_irq_restore(flags);
+ /* TODO: just test case for cycles clock source, remove later */
+ pr_debug("cpufreq: done\n");
cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
return 0;
@@ -119,15 +134,6 @@
unsigned long cclk, sclk, csel, min_cclk;
int index;
-#ifdef CONFIG_CYCLES_CLOCKSOURCE
-/*
- * Clocksource CYCLES is still CONTINUOUS but not longer with a constant tick rate in case we enable
- * CPU frequency scaling, since CYCLES runs off Core Clock.
- */
- printk(KERN_WARNING "CPU frequency scaling not supported: Clocksource not suitable\n"
- return -ENODEV;
-#endif
-
if (policy->cpu != 0)
return -EINVAL;