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Implement udelay() for S5L870x. Exchange sleep() with udelay() during CPU voltage scaling. Voltage scaling was measured stable with 50us delay, to have some headroom we use 100us.

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git-svn-id: svn://svn.rockbox.org/rockbox/trunk@28606 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Andree Buschmann 2010-11-15 21:13:58 +00:00
parent d1302940b9
commit e464656b88
2 changed files with 8 additions and 1 deletions
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3
firmware/target/arm/s5l8700/system-s5l8700.c
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@ -22,6 +22,7 @@
#include "kernel.h" #include "kernel.h"
#include "system.h" #include "system.h"
#include "panic.h" #include "panic.h"
#include "system-target.h"
#ifdef IPOD_NANO2G #ifdef IPOD_NANO2G
#include "storage.h" #include "storage.h"
#include "pmu-target.h" #include "pmu-target.h"
@ -208,7 +209,7 @@ void set_cpu_frequency(long frequency)
/* Vcore = 1.000V */ /* Vcore = 1.000V */
pmu_write(0x1e, 0xf); pmu_write(0x1e, 0xf);
/* Allow for voltage to stabilize */ /* Allow for voltage to stabilize */
sleep(HZ / 100); udelay(100);
/* FCLK_CPU = PLL0, HCLK = PLL0 / 2 */ /* FCLK_CPU = PLL0, HCLK = PLL0 / 2 */
CLKCON = (CLKCON & ~0xFF00FF00) | 0x20003100; CLKCON = (CLKCON & ~0xFF00FF00) | 0x20003100;
/* PCLK = HCLK / 2 */ /* PCLK = HCLK / 2 */

6
firmware/target/arm/s5l8700/system-target.h
View file

@ -38,4 +38,10 @@
#define inw(a) (*(volatile unsigned short *) (a)) #define inw(a) (*(volatile unsigned short *) (a))
#define outw(a,b) (*(volatile unsigned short *) (b) = (a)) #define outw(a,b) (*(volatile unsigned short *) (b) = (a))
static inline void udelay(unsigned usecs)
{
unsigned stop = USEC_TIMER + usecs;
while (TIME_BEFORE(USEC_TIMER, stop));
}
#endif /* SYSTEM_TARGET_H */ #endif /* SYSTEM_TARGET_H */