From 1bfb4b21c7c39295f5535c139f796df1d51ec009 Mon Sep 17 00:00:00 2001 From: Vitja Makarov Date: Wed, 7 May 2008 11:41:26 +0800 Subject: [PATCH] [Blackfin] arch: Support for CPU_FREQ and NOHZ Singed-off-by: Vitja Makarov --- arch/blackfin/kernel/time-ts.c | 10 +++++++--- arch/blackfin/mach-common/cpufreq.c | 24 +++++++++++++++--------- include/asm-blackfin/time.h | 4 ++++ 3 files changed, 26 insertions(+), 12 deletions(-) diff --git a/arch/blackfin/kernel/time-ts.c b/arch/blackfin/kernel/time-ts.c index 4482c47c09..e887efc86c 100644 --- a/arch/blackfin/kernel/time-ts.c +++ b/arch/blackfin/kernel/time-ts.c @@ -60,7 +60,7 @@ static inline unsigned long long cycles_2_ns(cycle_t cyc) static cycle_t read_cycles(void) { - return get_cycles(); + return __bfin_cycles_off + (get_cycles() << __bfin_cycles_mod); } unsigned long long sched_clock(void) @@ -117,7 +117,7 @@ static void bfin_timer_set_mode(enum clock_event_mode mode, break; } case CLOCK_EVT_MODE_ONESHOT: - bfin_write_TSCALE(0); + bfin_write_TSCALE(TIME_SCALE - 1); bfin_write_TCOUNT(0); bfin_write_TCNTL(TMPWR | TMREN); CSYNC(); @@ -183,10 +183,14 @@ irqreturn_t timer_interrupt(int irq, void *dev_id) static int __init bfin_clockevent_init(void) { + unsigned long timer_clk; + + timer_clk = get_cclk() / TIME_SCALE; + setup_irq(IRQ_CORETMR, &bfin_timer_irq); bfin_timer_init(); - clockevent_bfin.mult = div_sc(get_cclk(), NSEC_PER_SEC, clockevent_bfin.shift); + clockevent_bfin.mult = div_sc(timer_clk, NSEC_PER_SEC, clockevent_bfin.shift); clockevent_bfin.max_delta_ns = clockevent_delta2ns(-1, &clockevent_bfin); clockevent_bfin.min_delta_ns = clockevent_delta2ns(100, &clockevent_bfin); clockevents_register_device(&clockevent_bfin); diff --git a/arch/blackfin/mach-common/cpufreq.c b/arch/blackfin/mach-common/cpufreq.c index dd1515e409..75cdad291e 100644 --- a/arch/blackfin/mach-common/cpufreq.c +++ b/arch/blackfin/mach-common/cpufreq.c @@ -62,6 +62,14 @@ static struct bfin_dpm_state { 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 @@ static int bfin_target(struct cpufreq_policy *policy, 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 @@ static int bfin_target(struct cpufreq_policy *policy, 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 @@ static int __init __bfin_cpu_init(struct cpufreq_policy *policy) 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; diff --git a/include/asm-blackfin/time.h b/include/asm-blackfin/time.h index 6e5859b6ea..ddc43ce385 100644 --- a/include/asm-blackfin/time.h +++ b/include/asm-blackfin/time.h @@ -24,6 +24,8 @@ #ifndef CONFIG_CPU_FREQ #define TIME_SCALE 1 +#define __bfin_cycles_off (0) +#define __bfin_cycles_mod (0) #else /* * Blackfin CPU frequency scaling supports max Core Clock 1, 1/2 and 1/4 . @@ -31,6 +33,8 @@ * adjust the Core Timer Presale Register. This way we don't lose time. */ #define TIME_SCALE 4 +extern unsigned long long __bfin_cycles_off; +extern unsigned int __bfin_cycles_mod; #endif #endif -- 2.39.5