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Forget all the nonsense with C delay loops. 'volatile' on the variable makes bloated code and a volatile, blank asm block inside may or may not be optimized out. Use asm delay loops instead for Coldfire. Radio i2c driver also needs NACK after reading last tuner byte. Get the volatile off the Ondio loops (not needed here now). Maybe this is straightened out now.

Browse source 
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@13725 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Michael Sevakis 2007-06-27 03:11:49 +00:00
parent 1092268614
commit 070417d152
3 changed files with 49 additions and 13 deletions
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38
firmware/drivers/fmradio_i2c.c
View file

@ -80,7 +80,17 @@ int fmradio_i2c_read(unsigned char address, unsigned char* buf, int count)
#endif
/* delay loop to achieve 400kHz at 120MHz CPU frequency */
#define DELAY do { volatile int _x; for(_x=0;_x<22;_x++);} while (0)
#define DELAY \
({ \
int _x_; \
asm volatile ( \
"move.l #21, %[_x_] \r\n" \
"1: \r\n" \
"subq.l #1, %[_x_] \r\n" \
"bhi.b 1b \r\n" \
: [_x_]"=&d"(_x_) \
); \
})
static void fmradio_i2c_start(void)
{
@ -102,8 +112,8 @@ static void fmradio_i2c_stop(void)
SDA_HI;
}
static void fmradio_i2c_ack(void)
/* Generate ACK or NACK */
static void fmradio_i2c_ack(bool nack)
{
/* Here's the deal. The slave is slow, and sometimes needs to wait
before it can receive the acknowledge. Therefore it forces the clock
@ -114,7 +124,11 @@ static void fmradio_i2c_ack(void)
we have to drive the SCL high repeatedly to simulate a pullup. */
SCL_LO; /* Set the clock low */
SDA_LO;
if (nack)
SDA_HI;
else
SDA_LO;
SCL_INPUT; /* Set the clock to input */
while(!SCL) /* and wait for the slave to release it */
@ -248,8 +262,7 @@ int fmradio_i2c_read(int address, unsigned char* buf, int count)
for (i=count; i>0; i--)
{
*buf++ = fmradio_i2c_inb();
if (i != 1)
fmradio_i2c_ack();
fmradio_i2c_ack(i == 1);
}
}
else
@ -275,7 +288,7 @@ int fmradio_i2c_read(int address, unsigned char* buf, int count)
#define SCL (PBDR & 0x0002)
/* arbitrary delay loop */
#define DELAY do { volatile int _x; for(_x=0;_x<20;_x++);} while (0)
#define DELAY do { int _x; for(_x=0;_x<20;_x++);} while (0)
static void fmradio_i2c_start(void)
{
@ -296,7 +309,7 @@ static void fmradio_i2c_stop(void)
}
static void fmradio_i2c_ack(void)
static void fmradio_i2c_ack(bool nack)
{
/* Here's the deal. The slave is slow, and sometimes needs to wait
before it can receive the acknowledge. Therefore it forces the clock
@ -304,7 +317,11 @@ static void fmradio_i2c_ack(void)
high before we release the ack. */
SCL_LO; /* Set the clock low */
SDA_LO;
if (nack)
SDA_HI;
else
SDA_LO;
SCL_INPUT; /* Set the clock to input */
while(!SCL) /* and wait for the slave to release it */
@ -416,8 +433,7 @@ int fmradio_i2c_read(int address, unsigned char* buf, int count)
for (i=count; i>0; i--)
{
*buf++ = fmradio_i2c_inb();
if (i != 1)
fmradio_i2c_ack();
fmradio_i2c_ack(i == 1);
}
}
else

12
firmware/target/coldfire/iriver/h100/adc-h100.c
View file

@ -34,7 +34,17 @@ static unsigned char adcdata[NUM_ADC_CHANNELS];
#define DI_HI or_l(0x00200000, &GPIO_OUT)
/* delay loop */
#define DELAY do { int _x; for(_x=0;_x<10;_x++) asm volatile ("");} while (0)
#define DELAY \
({ \
int _x_; \
asm volatile ( \
"move.l #9, %[_x_] \r\n" \
"1: \r\n" \
"subq.l #1, %[_x_] \r\n" \
"bhi.b 1b \r\n" \
: [_x_]"=&d"(_x_) \
); \
})
unsigned short adc_scan(int channel)
{

12
firmware/target/coldfire/iriver/h100/sw_i2c-h100.c
View file

@ -42,7 +42,17 @@
#define SDA_HI and_l(~0x00002000, &GPIO1_ENABLE)
/* delay loop to achieve 400kHz at 120MHz CPU frequency */
#define DELAY do { volatile int _x; for(_x=0;_x<22;_x++);} while(0)
#define DELAY \
({ \
int _x_; \
asm volatile ( \
"move.l #21, %[_x_] \r\n" \
"1: \r\n" \
"subq.l #1, %[_x_] \r\n" \
"bhi.b 1b \r\n" \
: [_x_]"=&d"(_x_) \
); \
})
void sw_i2c_init(void)
{