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Blackfin: SMP: implement cpu_freq support

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Re-use some of the existing cpu hotplugging code in the process.

Signed-off-by: Graf Yang <graf.yang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
This commit is contained in:
Graf Yang
2010-01-28 10:46:55 +00:00
committed by Mike Frysinger
parent 820b127dae
commit 6f546bc3ac
6 changed files with 70 additions and 34 deletions
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50
arch/blackfin/mach-common/dpmc.c
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@@ -61,17 +61,63 @@ err_out:
}
#ifdef CONFIG_CPU_FREQ
# ifdef CONFIG_SMP
static void bfin_idle_this_cpu(void *info)
{
unsigned long flags = 0;
unsigned long iwr0, iwr1, iwr2;
unsigned int cpu = smp_processor_id();
local_irq_save_hw(flags);
bfin_iwr_set_sup0(&iwr0, &iwr1, &iwr2);
platform_clear_ipi(cpu, IRQ_SUPPLE_0);
SSYNC();
asm("IDLE;");
bfin_iwr_restore(iwr0, iwr1, iwr2);
local_irq_restore_hw(flags);
}
static void bfin_idle_cpu(void)
{
smp_call_function(bfin_idle_this_cpu, NULL, 0);
}
static void bfin_wakeup_cpu(void)
{
unsigned int cpu;
unsigned int this_cpu = smp_processor_id();
cpumask_t mask = cpu_online_map;
cpu_clear(this_cpu, mask);
for_each_cpu_mask(cpu, mask)
platform_send_ipi_cpu(cpu, IRQ_SUPPLE_0);
}
# else
static void bfin_idle_cpu(void) {}
static void bfin_wakeup_cpu(void) {}
# endif
static int
vreg_cpufreq_notifier(struct notifier_block *nb, unsigned long val, void *data)
{
struct cpufreq_freqs *freq = data;
if (freq->cpu != CPUFREQ_CPU)
return 0;
if (val == CPUFREQ_PRECHANGE && freq->old < freq->new) {
bfin_idle_cpu();
bfin_set_vlev(bfin_get_vlev(freq->new));
udelay(pdata->vr_settling_time); /* Wait until Volatge settled */
} else if (val == CPUFREQ_POSTCHANGE && freq->old > freq->new)
bfin_wakeup_cpu();
} else if (val == CPUFREQ_POSTCHANGE && freq->old > freq->new) {
bfin_idle_cpu();
bfin_set_vlev(bfin_get_vlev(freq->new));
bfin_wakeup_cpu();
}
return 0;
}