Whitebox
/
u-boot
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Merge branch 'master' of git://git.denx.de/u-boot-i2c

Browse Source
master
Wolfgang Denk 15 years ago
parent d9d47d18e8 fbad355562
commit b76335178e
1 changed files with 117 additions and 92 deletions
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Show Stats Download Patch File Download Diff File
  1. 209
      drivers/i2c/omap24xx_i2c.c

209
drivers/i2c/omap24xx_i2c.c
Unescape View File

@ -27,7 +27,7 @@
#include "omap24xx_i2c.h"
#define I2C_TIMEOUT 10
#define I2C_TIMEOUT 1000
static void wait_for_bb (void);
static u16 wait_for_pin (void);
@ -159,58 +159,56 @@ static int i2c_read_byte (u8 devaddr, u8 regoffset, u8 * value)
/* no stop bit needed here */
writew (I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_TRX, &i2c_base->con);
status = wait_for_pin ();
if (status & I2C_STAT_XRDY) {
/* Important: have to use byte access */
writeb (regoffset, &i2c_base->data);
udelay (20000);
if (readw (&i2c_base->stat) & I2C_STAT_NACK) {
/* send register offset */
while (1) {
status = wait_for_pin();
if (status == 0 || status & I2C_STAT_NACK) {
i2c_error = 1;
goto read_exit;
}
if (status & I2C_STAT_XRDY) {
/* Important: have to use byte access */
writeb(regoffset, &i2c_base->data);
writew(I2C_STAT_XRDY, &i2c_base->stat);
}
if (status & I2C_STAT_ARDY) {
writew(I2C_STAT_ARDY, &i2c_base->stat);
break;
}
} else {
i2c_error = 1;
}
if (!i2c_error) {
writew (I2C_CON_EN, &i2c_base->con);
while (readw(&i2c_base->stat) &
(I2C_STAT_XRDY | I2C_STAT_ARDY)) {
udelay (10000);
/* Have to clear pending interrupt to clear I2C_STAT */
writew (0xFFFF, &i2c_base->stat);
/* set slave address */
writew(devaddr, &i2c_base->sa);
/* read one byte from slave */
writew(1, &i2c_base->cnt);
/* need stop bit here */
writew(I2C_CON_EN | I2C_CON_MST |
I2C_CON_STT | I2C_CON_STP,
&i2c_base->con);
/* receive data */
while (1) {
status = wait_for_pin();
if (status == 0 || status & I2C_STAT_NACK) {
i2c_error = 1;
goto read_exit;
}
/* set slave address */
writew (devaddr, &i2c_base->sa);
/* read one byte from slave */
writew (1, &i2c_base->cnt);
/* need stop bit here */
writew (I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_STP,
&i2c_base->con);
status = wait_for_pin ();
if (status & I2C_STAT_RRDY) {
#if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX) || \
defined(CONFIG_OMAP44XX)
*value = readb (&i2c_base->data);
*value = readb(&i2c_base->data);
#else
*value = readw (&i2c_base->data);
*value = readw(&i2c_base->data);
#endif
udelay (20000);
} else {
i2c_error = 1;
writew(I2C_STAT_RRDY, &i2c_base->stat);
}
if (!i2c_error) {
writew (I2C_CON_EN, &i2c_base->con);
while (readw (&i2c_base->stat) &
(I2C_STAT_RRDY | I2C_STAT_ARDY)) {
udelay (10000);
writew (0xFFFF, &i2c_base->stat);
}
if (status & I2C_STAT_ARDY) {
writew(I2C_STAT_ARDY, &i2c_base->stat);
break;
}
}
read_exit:
flush_fifo();
writew (0xFFFF, &i2c_base->stat);
writew (0, &i2c_base->cnt);
@ -220,7 +218,7 @@ static int i2c_read_byte (u8 devaddr, u8 regoffset, u8 * value)
static int i2c_write_byte (u8 devaddr, u8 regoffset, u8 value)
{
int i2c_error = 0;
u16 status, stat;
u16 status;
/* wait until bus not busy */
wait_for_bb ();
@ -233,49 +231,55 @@ static int i2c_write_byte (u8 devaddr, u8 regoffset, u8 value)
writew (I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_TRX |
I2C_CON_STP, &i2c_base->con);
/* wait until state change */
status = wait_for_pin ();
if (status & I2C_STAT_XRDY) {
#if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX) || \
defined(CONFIG_OMAP44XX)
/* send out 1 byte */
writeb (regoffset, &i2c_base->data);
writew (I2C_STAT_XRDY, &i2c_base->stat);
status = wait_for_pin ();
if ((status & I2C_STAT_XRDY)) {
/* send out next 1 byte */
writeb (value, &i2c_base->data);
writew (I2C_STAT_XRDY, &i2c_base->stat);
} else {
while (1) {
status = wait_for_pin();
if (status == 0 || status & I2C_STAT_NACK) {
i2c_error = 1;
goto write_exit;
}
if (status & I2C_STAT_XRDY) {
#if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX) || \
defined(CONFIG_OMAP44XX)
/* send register offset */
writeb(regoffset, &i2c_base->data);
writew(I2C_STAT_XRDY, &i2c_base->stat);
while (1) {
status = wait_for_pin();
if (status == 0 || status & I2C_STAT_NACK) {
i2c_error = 1;
goto write_exit;
}
if (status & I2C_STAT_XRDY) {
/* send data */
writeb(value, &i2c_base->data);
writew(I2C_STAT_XRDY, &i2c_base->stat);
}
if (status & I2C_STAT_ARDY) {
writew(I2C_STAT_ARDY, &i2c_base->stat);
break;
}
}
break;
#else
/* send out two bytes */
writew ((value << 8) + regoffset, &i2c_base->data);
/* send out two bytes */
writew((value << 8) + regoffset, &i2c_base->data);
writew(I2C_STAT_XRDY, &i2c_base->stat);
#endif
/* must have enough delay to allow BB bit to go low */
udelay (50000);
if (readw (&i2c_base->stat) & I2C_STAT_NACK) {
i2c_error = 1;
}
} else {
i2c_error = 1;
if (status & I2C_STAT_ARDY) {
writew(I2C_STAT_ARDY, &i2c_base->stat);
break;
}
}
if (!i2c_error) {
int eout = 200;
wait_for_bb();
writew (I2C_CON_EN, &i2c_base->con);
while ((stat = readw (&i2c_base->stat)) || (readw (&i2c_base->con) & I2C_CON_MST)) {
udelay (1000);
/* have to read to clear intrrupt */
writew (0xFFFF, &i2c_base->stat);
if(--eout == 0) /* better leave with error than hang */
break;
}
}
status = readw(&i2c_base->stat);
if (status & I2C_STAT_NACK)
i2c_error = 1;
write_exit:
flush_fifo();
writew (0xFFFF, &i2c_base->stat);
writew (0, &i2c_base->cnt);
@ -306,6 +310,7 @@ static void flush_fifo(void)
int i2c_probe (uchar chip)
{
u16 status;
int res = 1; /* default = fail */
if (chip == readw (&i2c_base->oa)) {
@ -321,19 +326,37 @@ int i2c_probe (uchar chip)
writew (chip, &i2c_base->sa);
/* stop bit needed here */
writew (I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_STP, &i2c_base->con);
/* enough delay for the NACK bit set */
udelay (50000);
if (!(readw (&i2c_base->stat) & I2C_STAT_NACK)) {
res = 0; /* success case */
flush_fifo();
writew(0xFFFF, &i2c_base->stat);
} else {
writew(0xFFFF, &i2c_base->stat); /* failue, clear sources*/
writew (readw (&i2c_base->con) | I2C_CON_STP, &i2c_base->con); /* finish up xfer */
udelay(20000);
wait_for_bb ();
while (1) {
status = wait_for_pin();
if (status == 0) {
res = 1;
goto probe_exit;
}
if (status & I2C_STAT_NACK) {
res = 1;
writew(0xff, &i2c_base->stat);
writew (readw (&i2c_base->con) | I2C_CON_STP, &i2c_base->con);
wait_for_bb ();
break;
}
if (status & I2C_STAT_ARDY) {
writew(I2C_STAT_ARDY, &i2c_base->stat);
break;
}
if (status & I2C_STAT_RRDY) {
res = 0;
#if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX) || \
defined(CONFIG_OMAP44XX)
readb(&i2c_base->data);
#else
readw(&i2c_base->data);
#endif
writew(I2C_STAT_RRDY, &i2c_base->stat);
}
}
probe_exit:
flush_fifo();
writew (0, &i2c_base->cnt); /* don't allow any more data in...we don't want it.*/
writew(0xFFFF, &i2c_base->stat);
@ -392,13 +415,13 @@ int i2c_write (uchar chip, uint addr, int alen, uchar * buffer, int len)
static void wait_for_bb (void)
{
int timeout = 10;
int timeout = I2C_TIMEOUT;
u16 stat;
writew(0xFFFF, &i2c_base->stat); /* clear current interruts...*/
while ((stat = readw (&i2c_base->stat) & I2C_STAT_BB) && timeout--) {
writew (stat, &i2c_base->stat);
udelay (50000);
udelay(1000);
}
if (timeout <= 0) {
@ -411,7 +434,7 @@ static void wait_for_bb (void)
static u16 wait_for_pin (void)
{
u16 status;
int timeout = 10;
int timeout = I2C_TIMEOUT;
do {
udelay (1000);
@ -424,8 +447,10 @@ static u16 wait_for_pin (void)
if (timeout <= 0) {
printf ("timed out in wait_for_pin: I2C_STAT=%x\n",
readw (&i2c_base->stat));
writew(0xFFFF, &i2c_base->stat);
}
writew(0xFFFF, &i2c_base->stat);
status = 0;
}
return status;
}

Write Preview
Loading…
Cancel
Save