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Changed the delay loop to run faster and more accurate. Made the internal functions 'static'.

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git-svn-id: svn://svn.rockbox.org/rockbox/trunk@11894 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Steve Gotthardt 2007-01-04 03:31:03 +00:00
parent 23b722d4a9
commit 2aa3e3f63c
1 changed files with 20 additions and 12 deletions
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32
firmware/target/arm/gigabeat/meg-fx/i2c-meg-fx.c
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@ -27,52 +27,52 @@
#include "string.h" #include "string.h"
#include "generic_i2c.h" #include "generic_i2c.h"
void i2c_sda_output(void) static void i2c_sda_output(void)
{ {
GPECON |= (1 << 30); GPECON |= (1 << 30);
} }
void i2c_sda_input(void) static void i2c_sda_input(void)
{ {
GPECON &= ~(3 << 30); GPECON &= ~(3 << 30);
} }
void i2c_sda_lo(void) static void i2c_sda_lo(void)
{ {
GPEDAT &= ~(1 << 15); GPEDAT &= ~(1 << 15);
} }
void i2c_sda_hi(void) static void i2c_sda_hi(void)
{ {
GPEDAT |= (1 << 15); GPEDAT |= (1 << 15);
} }
int i2c_sda(void) static int i2c_sda(void)
{ {
return GPEDAT & (1 << 15); return GPEDAT & (1 << 15);
} }
void i2c_scl_output(void) static void i2c_scl_output(void)
{ {
GPECON |= (1 << 28); GPECON |= (1 << 28);
} }
void i2c_scl_input(void) static void i2c_scl_input(void)
{ {
GPECON &= ~(3 << 28); GPECON &= ~(3 << 28);
} }
void i2c_scl_lo(void) static void i2c_scl_lo(void)
{ {
GPEDAT &= ~(1 << 14); GPEDAT &= ~(1 << 14);
} }
int i2c_scl(void) static int i2c_scl(void)
{ {
return GPEDAT & (1 << 14); return GPEDAT & (1 << 14);
} }
void i2c_scl_hi(void) static void i2c_scl_hi(void)
{ {
i2c_scl_input(); i2c_scl_input();
while(!i2c_scl()); while(!i2c_scl());
@ -80,9 +80,17 @@ void i2c_scl_hi(void)
i2c_scl_output(); i2c_scl_output();
} }
void i2c_delay(void)
static void i2c_delay(void)
{ {
do { int _x; for(_x=0;_x<2000;_x++);} while (0); volatile int _x;
/* The i2c can clock at 500KHz: 2uS period -> 1uS half period */
/* At 300Mhz - if loop takes 10 cycles @ 3.3nS each -> 1uS / 33nS -> 30 */
for (_x=0; _x<30; _x++)
{
/* burn CPU cycles */
}
} }
struct i2c_interface s3c2440_i2c = { struct i2c_interface s3c2440_i2c = {