#include "omap24xx_i2c.h"
+DECLARE_GLOBAL_DATA_PTR;
+
#define I2C_TIMEOUT 1000
-static void wait_for_bb (void);
-static u16 wait_for_pin (void);
+static void wait_for_bb(void);
+static u16 wait_for_pin(void);
static void flush_fifo(void);
-static struct i2c *i2c_base = (struct i2c *)I2C_DEFAULT_BASE;
-
-static unsigned int bus_initialized[I2C_BUS_MAX];
-static unsigned int current_bus;
+/*
+ * For SPL boot some boards need i2c before SDRAM is initialised so force
+ * variables to live in SRAM
+ */
+static struct i2c __attribute__((section (".data"))) *i2c_base =
+ (struct i2c *)I2C_DEFAULT_BASE;
+static unsigned int __attribute__((section (".data"))) bus_initialized[I2C_BUS_MAX] =
+ { [0 ... (I2C_BUS_MAX-1)] = 0 };
+static unsigned int __attribute__((section (".data"))) current_bus = 0;
-void i2c_init (int speed, int slaveadd)
+void i2c_init(int speed, int slaveadd)
{
- DECLARE_GLOBAL_DATA_PTR;
int psc, fsscll, fssclh;
int hsscll = 0, hssclh = 0;
u32 scll, sclh;
fssclh -= I2C_HIGHSPEED_PHASE_ONE_SCLH_TRIM;
if (((fsscll < 0) || (fssclh < 0)) ||
((fsscll > 255) || (fssclh > 255))) {
- printf("Error : I2C initializing first phase clock\n");
+ puts("Error : I2C initializing first phase clock\n");
return;
}
hssclh -= I2C_HIGHSPEED_PHASE_TWO_SCLH_TRIM;
if (((fsscll < 0) || (fssclh < 0)) ||
((fsscll > 255) || (fssclh > 255))) {
- printf("Error : I2C initializing second phase clock\n");
+ puts("Error : I2C initializing second phase clock\n");
return;
}
fssclh -= I2C_FASTSPEED_SCLH_TRIM;
if (((fsscll < 0) || (fssclh < 0)) ||
((fsscll > 255) || (fssclh > 255))) {
- printf("Error : I2C initializing clock\n");
+ puts("Error : I2C initializing clock\n");
return;
}
sclh = (unsigned int)fssclh;
}
- if (readw (&i2c_base->con) & I2C_CON_EN) {
- writew (0, &i2c_base->con);
- udelay (50000);
+ if (readw(&i2c_base->con) & I2C_CON_EN) {
+ writew(0, &i2c_base->con);
+ udelay(50000);
}
writew(0x2, &i2c_base->sysc); /* for ES2 after soft reset */
writew(I2C_CON_EN, &i2c_base->con);
while (!(readw(&i2c_base->syss) & I2C_SYSS_RDONE) && timeout--) {
if (timeout <= 0) {
- printf("ERROR: Timeout in soft-reset\n");
+ puts("ERROR: Timeout in soft-reset\n");
return;
}
udelay(1000);
writew(sclh, &i2c_base->sclh);
/* own address */
- writew (slaveadd, &i2c_base->oa);
- writew (I2C_CON_EN, &i2c_base->con);
+ writew(slaveadd, &i2c_base->oa);
+ writew(I2C_CON_EN, &i2c_base->con);
/* have to enable intrrupts or OMAP i2c module doesn't work */
- writew (I2C_IE_XRDY_IE | I2C_IE_RRDY_IE | I2C_IE_ARDY_IE |
+ writew(I2C_IE_XRDY_IE | I2C_IE_RRDY_IE | I2C_IE_ARDY_IE |
I2C_IE_NACK_IE | I2C_IE_AL_IE, &i2c_base->ie);
- udelay (1000);
+ udelay(1000);
flush_fifo();
- writew (0xFFFF, &i2c_base->stat);
- writew (0, &i2c_base->cnt);
+ writew(0xFFFF, &i2c_base->stat);
+ writew(0, &i2c_base->cnt);
if (gd->flags & GD_FLG_RELOC)
bus_initialized[current_bus] = 1;
}
-static int i2c_read_byte (u8 devaddr, u8 regoffset, u8 * value)
+static int i2c_read_byte(u8 devaddr, u8 regoffset, u8 *value)
{
int i2c_error = 0;
u16 status;
/* wait until bus not busy */
- wait_for_bb ();
+ wait_for_bb();
/* one byte only */
- writew (1, &i2c_base->cnt);
+ writew(1, &i2c_base->cnt);
/* set slave address */
- writew (devaddr, &i2c_base->sa);
+ writew(devaddr, &i2c_base->sa);
/* 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 ();
+ writew(I2C_CON_EN | I2C_CON_MST | I2C_CON_STT |
+ I2C_CON_TRX, &i2c_base->con);
- 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;
}
- } 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);
-
- status = wait_for_pin ();
- if (status & I2C_STAT_RRDY) {
-#if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX) || \
- defined(CONFIG_OMAP44XX)
- *value = readb (&i2c_base->data);
-#else
- *value = readw (&i2c_base->data);
-#endif
- udelay (20000);
- } else {
- i2c_error = 1;
+ if (status & I2C_STAT_XRDY) {
+ /* Important: have to use byte access */
+ writeb(regoffset, &i2c_base->data);
+ writew(I2C_STAT_XRDY, &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;
}
}
- flush_fifo();
- writew (0xFFFF, &i2c_base->stat);
- writew (0, &i2c_base->cnt);
- return i2c_error;
-}
-static int i2c_write_byte (u8 devaddr, u8 regoffset, u8 value)
-{
- int i2c_error = 0;
- u16 status, stat;
-
- /* wait until bus not busy */
- wait_for_bb ();
-
- /* two bytes */
- writew (2, &i2c_base->cnt);
/* set slave address */
- writew (devaddr, &i2c_base->sa);
- /* stop bit needed here */
- 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 {
+ 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;
}
+ if (status & I2C_STAT_RRDY) {
+#if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX) || \
+ defined(CONFIG_OMAP44XX)
+ *value = readb(&i2c_base->data);
#else
- /* send out two bytes */
- writew ((value << 8) + regoffset, &i2c_base->data);
+ *value = readw(&i2c_base->data);
#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;
+ writew(I2C_STAT_RRDY, &i2c_base->stat);
}
- } else {
- i2c_error = 1;
- }
-
- if (!i2c_error) {
- int eout = 200;
-
- 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;
+ 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);
+ writew(0xFFFF, &i2c_base->stat);
+ writew(0, &i2c_base->cnt);
return i2c_error;
}
/* note: if you try and read data when its not there or ready
* you get a bus error
*/
- while(1){
+ while (1) {
stat = readw(&i2c_base->stat);
- if(stat == I2C_STAT_RRDY){
+ if (stat == I2C_STAT_RRDY) {
#if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX) || \
- defined(CONFIG_OMAP44XX)
+ defined(CONFIG_OMAP44XX)
readb(&i2c_base->data);
#else
readw(&i2c_base->data);
#endif
- writew(I2C_STAT_RRDY,&i2c_base->stat);
+ writew(I2C_STAT_RRDY, &i2c_base->stat);
udelay(1000);
- }else
+ } else
break;
}
}
-int i2c_probe (uchar chip)
+int i2c_probe(uchar chip)
{
+ u16 status;
int res = 1; /* default = fail */
- if (chip == readw (&i2c_base->oa)) {
+ if (chip == readw(&i2c_base->oa))
return res;
- }
/* wait until bus not busy */
- wait_for_bb ();
+ wait_for_bb();
- /* try to read one byte */
- writew (1, &i2c_base->cnt);
+ /* try to write one byte */
+ writew(1, &i2c_base->cnt);
/* set slave address */
- writew (chip, &i2c_base->sa);
+ 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);
+ writew(I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_TRX |
+ I2C_CON_STP, &i2c_base->con);
+
+ status = wait_for_pin();
+
+ /* check for ACK (!NAK) */
+ if (!(status & I2C_STAT_NACK))
+ res = 0;
+
+ /* abort transfer (force idle state) */
+ writew(0, &i2c_base->con);
- 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 ();
- }
flush_fifo();
- writew (0, &i2c_base->cnt); /* don't allow any more data in...we don't want it.*/
+ /* don't allow any more data in... we don't want it. */
+ writew(0, &i2c_base->cnt);
writew(0xFFFF, &i2c_base->stat);
return res;
}
-int i2c_read (uchar chip, uint addr, int alen, uchar * buffer, int len)
+int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
{
int i;
if (alen > 1) {
- printf ("I2C read: addr len %d not supported\n", alen);
+ printf("I2C read: addr len %d not supported\n", alen);
return 1;
}
if (addr + len > 256) {
- printf ("I2C read: address out of range\n");
+ puts("I2C read: address out of range\n");
return 1;
}
for (i = 0; i < len; i++) {
- if (i2c_read_byte (chip, addr + i, &buffer[i])) {
- printf ("I2C read: I/O error\n");
- i2c_init (CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
+ if (i2c_read_byte(chip, addr + i, &buffer[i])) {
+ puts("I2C read: I/O error\n");
+ i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
return 1;
}
}
return 0;
}
-int i2c_write (uchar chip, uint addr, int alen, uchar * buffer, int len)
+int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
{
int i;
+ u16 status;
+ int i2c_error = 0;
if (alen > 1) {
- printf ("I2C read: addr len %d not supported\n", alen);
+ printf("I2C write: addr len %d not supported\n", alen);
return 1;
}
if (addr + len > 256) {
- printf ("I2C read: address out of range\n");
+ printf("I2C write: address 0x%x + 0x%x out of range\n",
+ addr, len);
return 1;
}
+ /* wait until bus not busy */
+ wait_for_bb();
+
+ /* start address phase - will write regoffset + len bytes data */
+ /* TODO consider case when !CONFIG_OMAP243X/34XX/44XX */
+ writew(alen + len, &i2c_base->cnt);
+ /* set slave address */
+ writew(chip, &i2c_base->sa);
+ /* stop bit needed here */
+ writew(I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_TRX |
+ I2C_CON_STP, &i2c_base->con);
+
+ /* Send address byte */
+ status = wait_for_pin();
+
+ if (status == 0 || status & I2C_STAT_NACK) {
+ i2c_error = 1;
+ printf("error waiting for i2c address ACK (status=0x%x)\n",
+ status);
+ goto write_exit;
+ }
+
+ if (status & I2C_STAT_XRDY) {
+ writeb(addr & 0xFF, &i2c_base->data);
+ writew(I2C_STAT_XRDY, &i2c_base->stat);
+ } else {
+ i2c_error = 1;
+ printf("i2c bus not ready for transmit (status=0x%x)\n",
+ status);
+ goto write_exit;
+ }
+
+ /* address phase is over, now write data */
for (i = 0; i < len; i++) {
- if (i2c_write_byte (chip, addr + i, buffer[i])) {
- printf ("I2C read: I/O error\n");
- i2c_init (CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
- return 1;
+ status = wait_for_pin();
+
+ if (status == 0 || status & I2C_STAT_NACK) {
+ i2c_error = 1;
+ printf("i2c error waiting for data ACK (status=0x%x)\n",
+ status);
+ goto write_exit;
+ }
+
+ if (status & I2C_STAT_XRDY) {
+ writeb(buffer[i], &i2c_base->data);
+ writew(I2C_STAT_XRDY, &i2c_base->stat);
+ } else {
+ i2c_error = 1;
+ printf("i2c bus not ready for Tx (i=%d)\n", i);
+ goto write_exit;
}
}
- return 0;
+write_exit:
+ flush_fifo();
+ writew(0xFFFF, &i2c_base->stat);
+ return i2c_error;
}
-static void wait_for_bb (void)
+static void wait_for_bb(void)
{
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);
+ writew(0xFFFF, &i2c_base->stat); /* clear current interrupts...*/
+ while ((stat = readw(&i2c_base->stat) & I2C_STAT_BB) && timeout--) {
+ writew(stat, &i2c_base->stat);
udelay(1000);
}
if (timeout <= 0) {
- printf ("timed out in wait_for_bb: I2C_STAT=%x\n",
- readw (&i2c_base->stat));
+ printf("timed out in wait_for_bb: I2C_STAT=%x\n",
+ readw(&i2c_base->stat));
}
writew(0xFFFF, &i2c_base->stat); /* clear delayed stuff*/
}
-static u16 wait_for_pin (void)
+static u16 wait_for_pin(void)
{
u16 status;
int timeout = I2C_TIMEOUT;
do {
- udelay (1000);
- status = readw (&i2c_base->stat);
- } while ( !(status &
+ udelay(1000);
+ status = readw(&i2c_base->stat);
+ } while (!(status &
(I2C_STAT_ROVR | I2C_STAT_XUDF | I2C_STAT_XRDY |
I2C_STAT_RRDY | I2C_STAT_ARDY | I2C_STAT_NACK |
I2C_STAT_AL)) && timeout--);
if (timeout <= 0) {
- printf ("timed out in wait_for_pin: I2C_STAT=%x\n",
- readw (&i2c_base->stat));
+ printf("timed out in wait_for_pin: I2C_STAT=%x\n",
+ readw(&i2c_base->stat));
writew(0xFFFF, &i2c_base->stat);
status = 0;
}
return -1;
}
-#if I2C_BUS_MAX==3
+#if I2C_BUS_MAX == 3
if (bus == 2)
i2c_base = (struct i2c *)I2C_BASE3;
else
current_bus = bus;
- if(!bus_initialized[current_bus])
+ if (!bus_initialized[current_bus])
i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
return 0;