[U-Boot] [PATCH] Revert "ARM: I2C: I2C Multi byte address support"

Tom Rini trini at ti.com
Mon Feb 20 23:59:09 CET 2012


This reverts commits 2faa76196af4b3e93bcb9e38ed9090cbd3b06db3 and
498cbdfe62a8330f6c89765bdd15e60328a26511.  These have introduced some
large problems on all other platforms and have more changes in them than
the commit message implies.

Cc: Heiko Schocher <hs at denx.de>
Cc: Patil, Rachna <rachna at ti.com>
Signed-off-by: Tom Rini <trini at ti.com>
---
 drivers/i2c/omap24xx_i2c.c |  475 ++++++++++++++++----------------------------
 drivers/i2c/omap24xx_i2c.h |    2 -
 2 files changed, 174 insertions(+), 303 deletions(-)

diff --git a/drivers/i2c/omap24xx_i2c.c b/drivers/i2c/omap24xx_i2c.c
index f06af02..a7ffd95 100644
--- a/drivers/i2c/omap24xx_i2c.c
+++ b/drivers/i2c/omap24xx_i2c.c
@@ -29,11 +29,10 @@
 
 DECLARE_GLOBAL_DATA_PTR;
 
-#define I2C_STAT_TIMEO	(1 << 31)
-#define I2C_TIMEOUT	10
+#define I2C_TIMEOUT	1000
 
-static u32 wait_for_bb(void);
-static u32 wait_for_status_mask(u16 mask);
+static void wait_for_bb(void);
+static u16 wait_for_pin(void);
 static void flush_fifo(void);
 
 /*
@@ -51,6 +50,7 @@ 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) &&
@@ -112,14 +112,24 @@ 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) {
+			puts("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);
@@ -135,6 +145,81 @@ 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)
@@ -147,7 +232,7 @@ static void flush_fifo(void)
 		stat = readw(&i2c_base->stat);
 		if (stat == I2C_STAT_RRDY) {
 #if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX) || \
-	defined(CONFIG_OMAP44XX) || defined(CONFIG_AM33XX)
+	defined(CONFIG_OMAP44XX)
 			readb(&i2c_base->data);
 #else
 			readw(&i2c_base->data);
@@ -161,42 +246,32 @@ static void flush_fifo(void)
 
 int i2c_probe(uchar chip)
 {
-	u32 status;
+	u16 status;
 	int res = 1; /* default = fail */
 
 	if (chip == readw(&i2c_base->oa))
 		return res;
 
 	/* wait until bus not busy */
-	status = wait_for_bb();
-	/* exit on BUS busy */
-	if (status & I2C_STAT_TIMEO)
-		return res;
+	wait_for_bb();
 
 	/* 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_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;
-	}
+	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);
+
 	flush_fifo();
 	/* don't allow any more data in... we don't want it. */
 	writew(0, &i2c_base->cnt);
@@ -206,315 +281,111 @@ int i2c_probe(uchar chip)
 
 int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
 {
-	int i2c_error = 0, i;
-	u32 status;
+	int i;
 
-	if ((alen > 2) || (alen < 0))
-		return 1;
-
-	if (alen < 2) {
-		if (addr + len > 256)
-			return 1;
-	} else if (addr + len > 0xFFFF) {
+	if (alen > 1) {
+		printf("I2C read: addr len %d not supported\n", alen);
 		return 1;
 	}
 
-	/* wait until bus not busy */
-	status = wait_for_bb();
-
-	/* exit on BUS busy */
-	if (status & I2C_STAT_TIMEO)
+	if (addr + len > 256) {
+		puts("I2C read: address out of range\n");
 		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) || \
-			defined(CONFIG_AM33XX)
-				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) || \
-			defined(CONFIG_AM33XX)
-				/* 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;
 	}
 
-	/* 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) || \
-			defined(CONFIG_AM33XX)
-				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;
-			}
+	for (i = 0; i < len; i++) {
+		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;
 		}
 	}
 
-	/* 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 > 2)
+	if (alen > 1) {
+		printf("I2C write: addr len %d not supported\n", alen);
 		return 1;
+	}
 
-	if (alen < 2) {
-		if (addr + len > 256)
-			return 1;
-	} else if (addr + len > 0xFFFF) {
+	if (addr + len > 256) {
+		printf("I2C write: address 0x%x + 0x%x out of range\n",
+				addr, len);
 		return 1;
 	}
 
 	/* wait until bus not busy */
-	status = wait_for_bb();
+	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);
 
-	/* wait for Transmit ready condition */
-	status = wait_for_status_mask(I2C_STAT_XRDY | I2C_STAT_NACK);
+	/* Send address byte */
+	status = wait_for_pin();
 
-	if (status & (I2C_STAT_NACK | I2C_STAT_TIMEO))
+	if (status == 0 || status & I2C_STAT_NACK) {
 		i2c_error = 1;
-
-	if (!i2c_error) {
-		if (status & I2C_STAT_XRDY) {
-			switch (alen) {
-#if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX) || \
-			defined(CONFIG_AM33XX)
-			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) || \
-			defined(CONFIG_AM33XX)
-				/* 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) || \
-				defined(CONFIG_AM33XX)
-					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;
-			}
-		}
+		printf("error waiting for i2c address ACK (status=0x%x)\n",
+		      status);
+		goto write_exit;
 	}
 
-	status = wait_for_status_mask(I2C_STAT_ARDY | I2C_STAT_NACK |
-				I2C_STAT_AL);
-
-	if (status & (I2C_STAT_NACK | I2C_STAT_TIMEO))
+	if (status & I2C_STAT_XRDY) {
+		writeb(addr & 0xFF, &i2c_base->data);
+		writew(I2C_STAT_XRDY, &i2c_base->stat);
+	} else {
 		i2c_error = 1;
-
-	if (i2c_error) {
-		writew(0, &i2c_base->con);
-		return 1;
+		printf("i2c bus not ready for transmit (status=0x%x)\n",
+		      status);
+		goto write_exit;
 	}
 
-	if (!i2c_error) {
-		int eout = 200;
+	/* address phase is over, now write data */
+	for (i = 0; i < len; i++) {
+		status = wait_for_pin();
 
-		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;
+		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;
 		}
 	}
 
+write_exit:
 	flush_fifo();
 	writew(0xFFFF, &i2c_base->stat);
-	writew(0, &i2c_base->cnt);
-	return 0;
+	return i2c_error;
 }
 
-static u32 wait_for_bb(void)
+static void wait_for_bb(void)
 {
 	int timeout = I2C_TIMEOUT;
-	u32 stat;
+	u16 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);
@@ -523,28 +394,30 @@ static u32 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 u32 wait_for_status_mask(u16 mask)
+static u16 wait_for_pin(void)
 {
-	u32 status;
+	u16 status;
 	int timeout = I2C_TIMEOUT;
 
 	do {
 		udelay(1000);
 		status = readw(&i2c_base->stat);
-	} while (!(status & mask) && timeout--);
+	} 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_status_mask: I2C_STAT=%x\n",
+		printf("timed out in wait_for_pin: I2C_STAT=%x\n",
 			readw(&i2c_base->stat));
 		writew(0xFFFF, &i2c_base->stat);
-		status |= I2C_STAT_TIMEO;
+		status = 0;
 	}
+
 	return status;
 }
 
diff --git a/drivers/i2c/omap24xx_i2c.h b/drivers/i2c/omap24xx_i2c.h
index 9a0b126..1f38c23 100644
--- a/drivers/i2c/omap24xx_i2c.h
+++ b/drivers/i2c/omap24xx_i2c.h
@@ -60,9 +60,7 @@
 /* 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): */
 
-- 
1.7.0.4



More information about the U-Boot mailing list