From 50f63ba95b36f7cfe0cf82fc1b464945d0e11b4a Mon Sep 17 00:00:00 2001
From: John Rigby <john.rigby@linaro.org>
Date: Thu, 22 Sep 2011 19:50:22 -0600
Subject: SAUCE: Revert "ARMV7: OMAP: Write more than 1 byte at a time in
 i2c_write"

This causes current kernel to fault due to a bug in the omap i2c code.
This can be un-reverted after once the kernel is fixed.

This reverts commit 0607e2b97a907ed3bdf926227e5ad0603a6216ad.
---
 drivers/i2c/omap24xx_i2c.c | 136 ++++++++++++++++++++++++++-------------------
 1 file changed, 78 insertions(+), 58 deletions(-)

diff --git a/drivers/i2c/omap24xx_i2c.c b/drivers/i2c/omap24xx_i2c.c
index 4ae237aa8..7e35f6c11 100644
--- a/drivers/i2c/omap24xx_i2c.c
+++ b/drivers/i2c/omap24xx_i2c.c
@@ -217,6 +217,77 @@ read_exit:
 	return i2c_error;
 }
 
+static int i2c_write_byte (u8 devaddr, u8 regoffset, u8 value)
+{
+	int i2c_error = 0;
+	u16 status;
+
+	/* 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);
+
+	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);
+			writew(I2C_STAT_XRDY, &i2c_base->stat);
+#endif
+		}
+		if (status & I2C_STAT_ARDY) {
+			writew(I2C_STAT_ARDY, &i2c_base->stat);
+			break;
+		}
+	}
+
+	wait_for_bb();
+
+	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);
+	return i2c_error;
+}
+
 static void flush_fifo(void)
 {	u16 stat;
 
@@ -302,77 +373,26 @@ int i2c_read(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 write: 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 write: address 0x%x + 0x%x out of range\n",
-				addr, len);
+		printf ("I2C read: address out of range\n");
 		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++) {
-		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;
+		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;
 		}
 	}
 
-write_exit:
-	flush_fifo();
-	writew(0xFFFF, &i2c_base->stat);
-	return i2c_error;
+	return 0;
 }
 
 static void wait_for_bb(void)
-- 
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