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as3525v2: set_cpu_frequency()

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delay a bit after changing pclk/fclk
tiny refactoring

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@25571 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Rafaël Carré 2010-04-10 20:00:15 +00:00
parent 31959e78d0
commit 07c08a6d89
1 changed files with 14 additions and 8 deletions
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20
firmware/target/arm/as3525/system-as3525.c
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@ -433,35 +433,41 @@ void set_cpu_frequency(long frequency)
#else /* as3525v2 */ #else /* as3525v2 */
void set_cpu_frequency(long frequency) void set_cpu_frequency(long frequency)
{ {
int oldstatus = disable_irq_save();
int delay;
if(frequency == CPUFREQ_MAX) if(frequency == CPUFREQ_MAX)
{ {
int oldstatus = disable_irq_save();
/* Change PCLK while FCLK is low, so it doesn't go too high */ /* Change PCLK while FCLK is low, so it doesn't go too high */
CGU_PERI = (CGU_PERI & ~(0x1F << 2)) | (AS3525_PCLK_DIV0 << 2); CGU_PERI = (CGU_PERI & ~(0x1F << 2)) | (AS3525_PCLK_DIV0 << 2);
delay = 40; while(delay--) ;
CGU_PROC = ((AS3525_FCLK_POSTDIV << 4) | CGU_PROC = ((AS3525_FCLK_POSTDIV << 4) |
(AS3525_FCLK_PREDIV << 2) | (AS3525_FCLK_PREDIV << 2) |
AS3525_FCLK_SEL); AS3525_FCLK_SEL);
restore_irq(oldstatus); delay = 40; while(delay--) ;
cpu_frequency = CPUFREQ_MAX;
} }
else else
{ {
int oldstatus = disable_irq_save(); frequency = CPUFREQ_NORMAL; /* We only have 2 settings */
CGU_PROC = ((AS3525_FCLK_POSTDIV_UNBOOSTED << 4) | CGU_PROC = ((AS3525_FCLK_POSTDIV_UNBOOSTED << 4) |
(AS3525_FCLK_PREDIV << 2) | (AS3525_FCLK_PREDIV << 2) |
AS3525_FCLK_SEL); AS3525_FCLK_SEL);
delay = 40; while(delay--) ;
/* Change PCLK after FCLK is low, so it doesn't go too high */ /* Change PCLK after FCLK is low, so it doesn't go too high */
CGU_PERI = (CGU_PERI & ~(0x1F << 2)) | (AS3525_PCLK_DIV0_UNBOOSTED << 2); CGU_PERI = (CGU_PERI & ~(0x1F << 2)) | (AS3525_PCLK_DIV0_UNBOOSTED << 2);
delay = 40; while(delay--) ;
}
cpu_frequency = frequency;
restore_irq(oldstatus); restore_irq(oldstatus);
cpu_frequency = CPUFREQ_NORMAL;
}
} }
#endif #endif