Merge commit '87ddedd'

1 files changed, 329 insertions, 0 deletions

diff --git a/drivers/i2c/omap24xx_i2c.c b/drivers/i2c/omap24xx_i2c.c
new file mode 100644
index 0000000..7dab786
--- /dev/null
+++ b/drivers/i2c/omap24xx_i2c.c
@@ -0,0 +1,329 @@
+/*
+ * Basic I2C functions
+ *
+ * Copyright (c) 2004 Texas Instruments
+ *
+ * This package is free software;  you can redistribute it and/or
+ * modify it under the terms of the license found in the file
+ * named COPYING that should have accompanied this file.
+ *
+ * THIS PACKAGE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
+ * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * Author: Jian Zhang jzhang@ti.com, Texas Instruments
+ *
+ * Copyright (c) 2003 Wolfgang Denk, wd@denx.de
+ * Rewritten to fit into the current U-Boot framework
+ *
+ * Adapted for OMAP2420 I2C, r-woodruff2@ti.com
+ *
+ */
+
+#include <common.h>
+
+#ifdef CONFIG_DRIVER_OMAP24XX_I2C
+
+#include <asm/arch/i2c.h>
+#include <asm/io.h>
+
+#define inw(a) __raw_readw(a)
+#define outw(a,v) __raw_writew(a,v)
+
+static void wait_for_bb (void);
+static u16 wait_for_pin (void);
+static void flush_fifo(void);
+
+void i2c_init (int speed, int slaveadd)
+{
+	u16 scl;
+
+	outw(0x2, I2C_SYSC); /* for ES2 after soft reset */
+	udelay(1000);
+	outw(0x0, I2C_SYSC); /* will probably self clear but */
+
+	if (inw (I2C_CON) & I2C_CON_EN) {
+		outw (0, I2C_CON);
+		udelay (50000);
+	}
+
+	/* 12Mhz I2C module clock */
+	outw (0, I2C_PSC);
+	speed = speed/1000;		    /* 100 or 400 */
+	scl = ((12000/(speed*2)) - 7);	/* use 7 when PSC = 0 */
+	outw (scl, I2C_SCLL);
+	outw (scl, I2C_SCLH);
+	/* own address */
+	outw (slaveadd, I2C_OA);
+	outw (I2C_CON_EN, I2C_CON);
+
+	/* have to enable intrrupts or OMAP i2c module doesn't work */
+	outw (I2C_IE_XRDY_IE | I2C_IE_RRDY_IE | I2C_IE_ARDY_IE |
+	      I2C_IE_NACK_IE | I2C_IE_AL_IE, I2C_IE);
+	udelay (1000);
+	flush_fifo();
+	outw (0xFFFF, I2C_STAT);
+	outw (0, I2C_CNT);
+}
+
+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 */
+	outw (1, I2C_CNT);
+	/* set slave address */
+	outw (devaddr, I2C_SA);
+	/* no stop bit needed here */
+	outw (I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_TRX, I2C_CON);
+
+	status = wait_for_pin ();
+
+	if (status & I2C_STAT_XRDY) {
+		/* Important: have to use byte access */
+		*(volatile u8 *) (I2C_DATA) = regoffset;
+		udelay (20000);
+		if (inw (I2C_STAT) & I2C_STAT_NACK) {
+			i2c_error = 1;
+		}
+	} else {
+		i2c_error = 1;
+	}
+
+	if (!i2c_error) {
+		/* free bus, otherwise we can't use a combined transction */
+		outw (0, I2C_CON);
+		while (inw (I2C_STAT) || (inw (I2C_CON) & I2C_CON_MST)) {
+			udelay (10000);
+			/* Have to clear pending interrupt to clear I2C_STAT */
+			outw (0xFFFF, I2C_STAT);
+		}
+
+		wait_for_bb ();
+		/* set slave address */
+		outw (devaddr, I2C_SA);
+		/* read one byte from slave */
+		outw (1, I2C_CNT);
+		/* need stop bit here */
+		outw (I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_STP,
+		      I2C_CON);
+
+		status = wait_for_pin ();
+		if (status & I2C_STAT_RRDY) {
+			*value = inw (I2C_DATA);
+			udelay (20000);
+		} else {
+			i2c_error = 1;
+		}
+
+		if (!i2c_error) {
+			outw (I2C_CON_EN, I2C_CON);
+			while (inw (I2C_STAT)
+			       || (inw (I2C_CON) & I2C_CON_MST)) {
+				udelay (10000);
+				outw (0xFFFF, I2C_STAT);
+			}
+		}
+	}
+	flush_fifo();
+	outw (0xFFFF, I2C_STAT);
+	outw (0, I2C_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 */
+	outw (2, I2C_CNT);
+	/* set slave address */
+	outw (devaddr, I2C_SA);
+	/* stop bit needed here */
+	outw (I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_TRX |
+	      I2C_CON_STP, I2C_CON);
+
+	/* wait until state change */
+	status = wait_for_pin ();
+
+	if (status & I2C_STAT_XRDY) {
+		/* send out two bytes */
+		outw ((value << 8) + regoffset, I2C_DATA);
+		/* must have enough delay to allow BB bit to go low */
+		udelay (50000);
+		if (inw (I2C_STAT) & I2C_STAT_NACK) {
+			i2c_error = 1;
+		}
+	} else {
+		i2c_error = 1;
+	}
+
+	if (!i2c_error) {
+		int eout = 200;
+
+		outw (I2C_CON_EN, I2C_CON);
+		while ((stat = inw (I2C_STAT)) || (inw (I2C_CON) & I2C_CON_MST)) {
+			udelay (1000);
+			/* have to read to clear intrrupt */
+			outw (0xFFFF, I2C_STAT);
+			if(--eout == 0) /* better leave with error than hang */
+				break;
+		}
+	}
+	flush_fifo();
+	outw (0xFFFF, I2C_STAT);
+	outw (0, I2C_CNT);
+	return i2c_error;
+}
+
+static void flush_fifo(void)
+{	u16 stat;
+
+	/* note: if you try and read data when its not there or ready
+	 * you get a bus error
+	 */
+	while(1){
+		stat = inw(I2C_STAT);
+		if(stat == I2C_STAT_RRDY){
+			inw(I2C_DATA);
+			outw(I2C_STAT_RRDY,I2C_STAT);
+			udelay(1000);
+		}else
+			break;
+	}
+}
+
+int i2c_probe (uchar chip)
+{
+	int res = 1; /* default = fail */
+
+	if (chip == inw (I2C_OA)) {
+		return res;
+	}
+
+	/* wait until bus not busy */
+	wait_for_bb ();
+
+	/* try to read one byte */
+	outw (1, I2C_CNT);
+	/* set slave address */
+	outw (chip, I2C_SA);
+	/* stop bit needed here */
+	outw (I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_STP, I2C_CON);
+	/* enough delay for the NACK bit set */
+	udelay (50000);
+
+	if (!(inw (I2C_STAT) & I2C_STAT_NACK)) {
+		res = 0;      /* success case */
+		flush_fifo();
+		outw(0xFFFF, I2C_STAT);
+	} else {
+		outw(0xFFFF, I2C_STAT);	 /* failue, clear sources*/
+		outw (inw (I2C_CON) | I2C_CON_STP, I2C_CON); /* finish up xfer */
+		udelay(20000);
+		wait_for_bb ();
+	}
+	flush_fifo();
+	outw (0, I2C_CNT); /* don't allow any more data in...we don't want it.*/
+	outw(0xFFFF, I2C_STAT);
+	return res;
+}
+
+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);
+		return 1;
+	}
+
+	if (addr + len > 256) {
+		printf ("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 (CFG_I2C_SPEED, CFG_I2C_SLAVE);
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
+int i2c_write (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);
+		return 1;
+	}
+
+	if (addr + len > 256) {
+		printf ("I2C read: address out of range\n");
+		return 1;
+	}
+
+	for (i = 0; i < len; i++) {
+		if (i2c_write_byte (chip, addr + i, buffer[i])) {
+			printf ("I2C read: I/O error\n");
+			i2c_init (CFG_I2C_SPEED, CFG_I2C_SLAVE);
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
+static void wait_for_bb (void)
+{
+	int timeout = 10;
+	u16 stat;
+
+	outw(0xFFFF, I2C_STAT);	 /* clear current interruts...*/
+	while ((stat = inw (I2C_STAT) & I2C_STAT_BB) && timeout--) {
+		outw (stat, I2C_STAT);
+		udelay (50000);
+	}
+
+	if (timeout <= 0) {
+		printf ("timed out in wait_for_bb: I2C_STAT=%x\n",
+			inw (I2C_STAT));
+	}
+	outw(0xFFFF, I2C_STAT);	 /* clear delayed stuff*/
+}
+
+static u16 wait_for_pin (void)
+{
+	u16 status;
+	int timeout = 10;
+
+	do {
+		udelay (1000);
+		status = inw (I2C_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",
+			inw (I2C_STAT));
+			outw(0xFFFF, I2C_STAT);
+}
+	return status;
+}
+
+#endif /* CONFIG_DRIVER_OMAP24XX_I2C */