Existing OMAP I2C driver does not support address
length greater than one. Hence this patch is to
add support for 2 byte address read/write.
Signed-off-by: Philip, Avinash <avinashphilip(a)ti.com>
Signed-off-by: Hebbar, Gururaja <gururaja.hebbar(a)ti.com>
Signed-off-by: Patil, Rachna <rachna(a)ti.com>
---
Changes for v2:
Fixed review comments from Heiko Schocher
drivers/i2c/omap24xx_i2c.c | 468 ++++++++++++++++++++++++++++----------------
drivers/i2c/omap24xx_i2c.h | 2 +
2 files changed, 298 insertions(+), 172 deletions(-)
diff --git a/drivers/i2c/omap24xx_i2c.c b/drivers/i2c/omap24xx_i2c.c
index 4ae237a..8116f86 100644
--- a/drivers/i2c/omap24xx_i2c.c
+++ b/drivers/i2c/omap24xx_i2c.c
@@ -29,10 +29,11 @@
DECLARE_GLOBAL_DATA_PTR;
-#define I2C_TIMEOUT 1000
+#define I2C_STAT_TIMEO (1 << 31)
+#define I2C_TIMEOUT 10
-static void wait_for_bb(void);
-static u16 wait_for_pin(void);
+static u32 wait_for_bb(void);
+static u32 wait_for_status_mask(u16 mask);
static void flush_fifo(void);
static struct i2c *i2c_base = (struct i2c *)I2C_DEFAULT_BASE;
@@ -45,7 +46,6 @@ void i2c_init(int speed, int slaveadd)
int psc, fsscll, fssclh;
int hsscll = 0, hssclh = 0;
u32 scll, sclh;
- int timeout = I2C_TIMEOUT;
/* Only handle standard, fast and high speeds */
if ((speed != OMAP_I2C_STANDARD) &&
@@ -107,24 +107,14 @@ void i2c_init(int speed, int slaveadd)
sclh = (unsigned int)fssclh;
}
+ if (gd->flags & GD_FLG_RELOC)
+ bus_initialized[current_bus] = 1;
+
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 */
- udelay(1000);
-
- 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");
- return;
- }
- udelay(1000);
- }
-
- writew(0, &i2c_base->con);
writew(psc, &i2c_base->psc);
writew(scll, &i2c_base->scll);
writew(sclh, &i2c_base->sclh);
@@ -140,81 +130,6 @@ void i2c_init(int speed, int slaveadd)
flush_fifo();
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)
-{
- int i2c_error = 0;
- u16 status;
-
- /* wait until bus not busy */
- wait_for_bb();
-
- /* one byte only */
- writew(1, &i2c_base->cnt);
- /* set slave address */
- 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);
-
- /* 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;
- }
- }
-
- /* 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;
- }
- 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
- writew(I2C_STAT_RRDY, &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);
- return i2c_error;
}
static void flush_fifo(void)
@@ -241,32 +156,42 @@ static void flush_fifo(void)
int i2c_probe(uchar chip)
{
- u16 status;
+ u32 status;
int res = 1; /* default = fail */
if (chip == readw(&i2c_base->oa))
return res;
/* wait until bus not busy */
- wait_for_bb();
+ status = wait_for_bb();
+ /* exit on BUS busy */
+ if (status & I2C_STAT_TIMEO)
+ return res;
/* try to write one byte */
writew(1, &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);
-
- 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);
-
+ writew(I2C_CON_EN | I2C_CON_MST | I2C_CON_STT
+ | I2C_CON_STP, &i2c_base->con);
+ /* enough delay for the NACK bit set */
+ udelay(9000);
+
+ if (!(readw(&i2c_base->stat) & I2C_STAT_NACK)) {
+ res = 0; /* success case */
+ flush_fifo();
+ writew(0xFFFF, &i2c_base->stat);
+ } else {
+ /* failure, clear sources*/
+ writew(0xFFFF, &i2c_base->stat);
+ /* finish up xfer */
+ writew(readw(&i2c_base->con) | I2C_CON_STP, &i2c_base->con);
+ status = wait_for_bb();
+ /* exit on BUS busy */
+ if (status & I2C_STAT_TIMEO)
+ return res;
+ }
flush_fifo();
/* don't allow any more data in... we don't want it. */
writew(0, &i2c_base->cnt);
@@ -276,111 +201,312 @@ int i2c_probe(uchar chip)
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);
+ int i2c_error = 0, i;
+ u32 status;
+
+ if ((alen > 2) || (alen < 0))
+ return 1;
+
+ if (alen < 2) {
+ if (addr + len > 256)
+ return 1;
+ } else if (addr + len > 0xFFFF) {
return 1;
}
- if (addr + len > 256) {
- printf("I2C read: address out of range\n");
+ /* wait until bus not busy */
+ status = wait_for_bb();
+
+ /* exit on BUS busy */
+ if (status & I2C_STAT_TIMEO)
return 1;
+
+ writew((alen & 0xFF), &i2c_base->cnt);
+ /* set slave address */
+ writew(chip, &i2c_base->sa);
+ /* Clear the Tx & Rx FIFOs */
+ writew((readw(&i2c_base->buf) | I2C_RXFIFO_CLEAR |
+ I2C_TXFIFO_CLEAR), &i2c_base->buf);
+ /* no stop bit needed here */
+ writew(I2C_CON_EN | I2C_CON_MST | I2C_CON_TRX |
+ I2C_CON_STT, &i2c_base->con);
+
+ /* wait for Transmit ready condition */
+ status = wait_for_status_mask(I2C_STAT_XRDY | I2C_STAT_NACK);
+
+ if (status & (I2C_STAT_NACK | I2C_STAT_TIMEO))
+ i2c_error = 1;
+
+ if (!i2c_error) {
+ if (status & I2C_STAT_XRDY) {
+ switch (alen) {
+ case 2:
+ /* Send address MSByte */
+#if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX)
+ writew(((addr >> 8) & 0xFF), &i2c_base->data);
+
+ /* Clearing XRDY event */
+ writew((status & I2C_STAT_XRDY),
+ &i2c_base->stat);
+ /* wait for Transmit ready condition */
+ status = wait_for_status_mask(I2C_STAT_XRDY |
+ I2C_STAT_NACK);
+
+ if (status & (I2C_STAT_NACK |
+ I2C_STAT_TIMEO)) {
+ i2c_error = 1;
+ break;
+ }
+#endif
+ case 1:
+#if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX)
+ /* Send address LSByte */
+ writew((addr & 0xFF), &i2c_base->data);
+#else
+ /* Send address Short word */
+ writew((addr & 0xFFFF), &i2c_base->data);
+#endif
+ /* Clearing XRDY event */
+ writew((status & I2C_STAT_XRDY),
+ &i2c_base->stat);
+ /*wait for Transmit ready condition */
+ status = wait_for_status_mask(I2C_STAT_ARDY |
+ I2C_STAT_NACK);
+
+ if (status & (I2C_STAT_NACK |
+ I2C_STAT_TIMEO)) {
+ i2c_error = 1;
+ break;
+ }
+ }
+ } else
+ i2c_error = 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);
- return 1;
+ /* Wait for ARDY to set */
+ status = wait_for_status_mask(I2C_STAT_ARDY | I2C_STAT_NACK
+ | I2C_STAT_AL);
+
+ if (!i2c_error) {
+ /* set slave address */
+ writew(chip, &i2c_base->sa);
+ writew((len & 0xFF), &i2c_base->cnt);
+ /* Clear the Tx & Rx FIFOs */
+ writew((readw(&i2c_base->buf) | I2C_RXFIFO_CLEAR |
+ I2C_TXFIFO_CLEAR), &i2c_base->buf);
+ /* need stop bit here */
+ writew(I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_STP,
+ &i2c_base->con);
+
+ for (i = 0; i < len; i++) {
+ /* wait for Receive condition */
+ status = wait_for_status_mask(I2C_STAT_RRDY |
+ I2C_STAT_NACK);
+
+ if (status & (I2C_STAT_NACK | I2C_STAT_TIMEO)) {
+ i2c_error = 1;
+ break;
+ }
+
+ if (status & I2C_STAT_RRDY) {
+#if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX)
+ buffer[i] = readb(&i2c_base->data);
+#else
+ *((u16 *)&buffer[i]) =
+ readw(&i2c_base->data) & 0xFFFF;
+ i++;
+#endif
+ writew((status & I2C_STAT_RRDY),
+ &i2c_base->stat);
+ udelay(1000);
+ } else {
+ i2c_error = 1;
+ }
}
}
+ /* Wait for ARDY to set */
+ status = wait_for_status_mask(I2C_STAT_ARDY | I2C_STAT_NACK
+ | I2C_STAT_AL);
+
+ if (i2c_error) {
+ writew(0, &i2c_base->con);
+ return 1;
+ }
+
+ writew(I2C_CON_EN, &i2c_base->con);
+
+ while (readw(&i2c_base->stat)
+ || (readw(&i2c_base->con) & I2C_CON_MST)) {
+ udelay(10000);
+ writew(0xFFFF, &i2c_base->stat);
+ }
+
+ writew(I2C_CON_EN, &i2c_base->con);
+ flush_fifo();
+ writew(0xFFFF, &i2c_base->stat);
+ writew(0, &i2c_base->cnt);
return 0;
}
int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
{
- int i;
- u16 status;
- int i2c_error = 0;
+ int i, i2c_error = 0;
+ u32 status;
+ u16 writelen;
- if (alen > 1) {
- printf("I2C write: addr len %d not supported\n", alen);
+ if (alen > 2)
return 1;
- }
- if (addr + len > 256) {
- printf("I2C write: address 0x%x + 0x%x out of range\n",
- addr, len);
+ if (alen < 2) {
+ if (addr + len > 256)
+ return 1;
+ } else if (addr + len > 0xFFFF) {
return 1;
}
/* wait until bus not busy */
- wait_for_bb();
+ status = wait_for_bb();
+
+ /* exiting on BUS busy */
+ if (status & I2C_STAT_TIMEO)
+ return 1;
+
+ writelen = (len & 0xFFFF) + alen;
+
+ /* two bytes */
+ writew((writelen & 0xFFFF), &i2c_base->cnt);
+ /* Clear the Tx & Rx FIFOs */
+ writew((readw(&i2c_base->buf) | I2C_RXFIFO_CLEAR |
+ I2C_TXFIFO_CLEAR), &i2c_base->buf);
- /* 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) {
+ /* wait for Transmit ready condition */
+ status = wait_for_status_mask(I2C_STAT_XRDY | I2C_STAT_NACK);
+
+ if (status & (I2C_STAT_NACK | I2C_STAT_TIMEO))
i2c_error = 1;
- printf("error waiting for i2c address ACK (status=0x%x)\n",
- status);
- goto write_exit;
+
+ if (!i2c_error) {
+ if (status & I2C_STAT_XRDY) {
+ switch (alen) {
+#if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX)
+ case 2:
+ /* send out MSB byte */
+ writeb(((addr >> 8) & 0xFF), &i2c_base->data);
+#else
+ writeb((addr & 0xFFFF), &i2c_base->data);
+ break;
+#endif
+ /* Clearing XRDY event */
+ writew((status & I2C_STAT_XRDY),
+ &i2c_base->stat);
+ /*waiting for Transmit ready * condition */
+ status = wait_for_status_mask(I2C_STAT_XRDY |
+ I2C_STAT_NACK);
+
+ if (status & (I2C_STAT_NACK | I2C_STAT_TIMEO)) {
+ i2c_error = 1;
+ break;
+ }
+ case 1:
+#if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX)
+ /* send out MSB byte */
+ writeb((addr & 0xFF), &i2c_base->data);
+#else
+ writew(((buffer[0] << 8) | (addr & 0xFF)),
+ &i2c_base->data);
+#endif
+ }
+
+ /* Clearing XRDY event */
+ writew((status & I2C_STAT_XRDY), &i2c_base->stat);
+ }
+
+ /* waiting for Transmit ready condition */
+ status = wait_for_status_mask(I2C_STAT_XRDY | I2C_STAT_NACK);
+
+ if (status & (I2C_STAT_NACK | I2C_STAT_TIMEO))
+ i2c_error = 1;
+
+ if (!i2c_error) {
+ for (i = ((alen > 1) ? 0 : 1); i < len; i++) {
+ if (status & I2C_STAT_XRDY) {
+#if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX)
+ writeb((buffer[i] & 0xFF),
+ &i2c_base->data);
+#else
+ writew((((buffer[i] << 8) |
+ buffer[i + 1]) & 0xFFFF),
+ &i2c_base->data);
+ i++;
+#endif
+ } else
+ i2c_error = 1;
+ /* Clearing XRDY event */
+ writew((status & I2C_STAT_XRDY),
+ &i2c_base->stat);
+ /* waiting for XRDY condition */
+ status = wait_for_status_mask(
+ I2C_STAT_XRDY |
+ I2C_STAT_ARDY |
+ I2C_STAT_NACK);
+ if (status & (I2C_STAT_NACK |
+ I2C_STAT_TIMEO)) {
+ i2c_error = 1;
+ break;
+ }
+ if (status & I2C_STAT_ARDY)
+ break;
+ }
+ }
}
- if (status & I2C_STAT_XRDY) {
- writeb(addr & 0xFF, &i2c_base->data);
- writew(I2C_STAT_XRDY, &i2c_base->stat);
- } else {
+ status = wait_for_status_mask(I2C_STAT_ARDY | I2C_STAT_NACK |
+ I2C_STAT_AL);
+
+ if (status & (I2C_STAT_NACK | I2C_STAT_TIMEO))
i2c_error = 1;
- printf("i2c bus not ready for transmit (status=0x%x)\n",
- status);
- goto write_exit;
+
+ if (i2c_error) {
+ writew(0, &i2c_base->con);
+ return 1;
}
- /* address phase is over, now write data */
- for (i = 0; i < len; i++) {
- 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 (!i2c_error) {
+ int eout = 200;
- 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;
+ writew(I2C_CON_EN, &i2c_base->con);
+ while ((status = 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;
}
}
-write_exit:
flush_fifo();
writew(0xFFFF, &i2c_base->stat);
- return i2c_error;
+ writew(0, &i2c_base->cnt);
+ return 0;
}
-static void wait_for_bb(void)
+static u32 wait_for_bb(void)
{
int timeout = I2C_TIMEOUT;
- u16 stat;
+ u32 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);
@@ -389,30 +515,28 @@ static void wait_for_bb(void)
if (timeout <= 0) {
printf("timed out in wait_for_bb: I2C_STAT=%x\n",
readw(&i2c_base->stat));
+ stat |= I2C_STAT_TIMEO;
}
writew(0xFFFF, &i2c_base->stat); /* clear delayed stuff*/
+ return stat;
}
-static u16 wait_for_pin(void)
+static u32 wait_for_status_mask(u16 mask)
{
- u16 status;
+ u32 status;
int timeout = I2C_TIMEOUT;
do {
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--);
+ } while (!(status & mask) && timeout--);
if (timeout <= 0) {
- printf("timed out in wait_for_pin: I2C_STAT=%x\n",
+ printf("timed out in wait_for_status_mask: I2C_STAT=%x\n",
readw(&i2c_base->stat));
writew(0xFFFF, &i2c_base->stat);
- status = 0;
+ status |= I2C_STAT_TIMEO;
}
-
return status;
}
diff --git a/drivers/i2c/omap24xx_i2c.h b/drivers/i2c/omap24xx_i2c.h
index 1f38c23..9a0b126 100644
--- a/drivers/i2c/omap24xx_i2c.h
+++ b/drivers/i2c/omap24xx_i2c.h
@@ -60,7 +60,9 @@
/* I2C Buffer Configuration Register (I2C_BUF): */
#define I2C_BUF_RDMA_EN (1 << 15) /* Receive DMA channel enable */
+#define I2C_RXFIFO_CLEAR (1 << 14) /* RX FIFO Clear */
#define I2C_BUF_XDMA_EN (1 << 7) /* Transmit DMA channel enable */
+#define I2C_TXFIFO_CLEAR (1 << 6) /* TX FIFO clear */
/* I2C Configuration Register (I2C_CON): */
--
1.7.1
