[Blackfin][PATCH] Add BF537 stamp board support
diff --git a/cpu/bf537/i2c.c b/cpu/bf537/i2c.c
new file mode 100644
index 0000000..3b0d026
--- /dev/null
+++ b/cpu/bf537/i2c.c
@@ -0,0 +1,460 @@
+/****************************************************************
+ * $ID: i2c.c	24 Oct 2006 12:00:00 +0800 $ 			*
+ *								*
+ * Description:							*
+ *								*
+ * Maintainer:  sonicz  <sonic.zhang@analog.com>		*
+ *								*
+ * CopyRight (c)  2006  Analog Device				*
+ * All rights reserved.						*
+ *								*
+ * This file is free software;					*
+ *	you are free to modify and/or redistribute it		*
+ *	under the terms of the GNU General Public Licence (GPL).*
+ *								*
+ ****************************************************************/
+
+#include <common.h>
+
+#ifdef CONFIG_HARD_I2C
+
+#include <asm/blackfin.h>
+#include <i2c.h>
+#include <asm/io.h>
+
+#define bfin_read16(addr) ({ unsigned __v; \
+			__asm__ __volatile__ (\
+			"%0 = w[%1] (z);\n\t"\
+			: "=d"(__v) : "a"(addr)); (unsigned short)__v; })
+
+#define bfin_write16(addr,val) ({\
+			__asm__ __volatile__ (\
+			"w[%0] = %1;\n\t"\
+			: : "a"(addr) , "d"(val) : "memory");})
+
+/* Two-Wire Interface		(0xFFC01400 - 0xFFC014FF) */
+#define bfin_read_TWI_CLKDIV()		bfin_read16(TWI_CLKDIV)
+#define bfin_write_TWI_CLKDIV(val)	bfin_write16(TWI_CLKDIV,val)
+#define bfin_read_TWI_CONTROL()		bfin_read16(TWI_CONTROL)
+#define bfin_write_TWI_CONTROL(val)	bfin_write16(TWI_CONTROL,val)
+#define bfin_read_TWI_SLAVE_CTL()	bfin_read16(TWI_SLAVE_CTL)
+#define bfin_write_TWI_SLAVE_CTL(val)	bfin_write16(TWI_SLAVE_CTL,val)
+#define bfin_read_TWI_SLAVE_STAT()	bfin_read16(TWI_SLAVE_STAT)
+#define bfin_write_TWI_SLAVE_STAT(val)	bfin_write16(TWI_SLAVE_STAT,val)
+#define bfin_read_TWI_SLAVE_ADDR()	bfin_read16(TWI_SLAVE_ADDR)
+#define bfin_write_TWI_SLAVE_ADDR(val)	bfin_write16(TWI_SLAVE_ADDR,val)
+#define bfin_read_TWI_MASTER_CTL()	bfin_read16(TWI_MASTER_CTL)
+#define bfin_write_TWI_MASTER_CTL(val)	bfin_write16(TWI_MASTER_CTL,val)
+#define bfin_read_TWI_MASTER_STAT()	bfin_read16(TWI_MASTER_STAT)
+#define bfin_write_TWI_MASTER_STAT(val)	bfin_write16(TWI_MASTER_STAT,val)
+#define bfin_read_TWI_MASTER_ADDR()	bfin_read16(TWI_MASTER_ADDR)
+#define bfin_write_TWI_MASTER_ADDR(val)	bfin_write16(TWI_MASTER_ADDR,val)
+#define bfin_read_TWI_INT_STAT()	bfin_read16(TWI_INT_STAT)
+#define bfin_write_TWI_INT_STAT(val)	bfin_write16(TWI_INT_STAT,val)
+#define bfin_read_TWI_INT_MASK()	bfin_read16(TWI_INT_MASK)
+#define bfin_write_TWI_INT_MASK(val)	bfin_write16(TWI_INT_MASK,val)
+#define bfin_read_TWI_FIFO_CTL()	bfin_read16(TWI_FIFO_CTL)
+#define bfin_write_TWI_FIFO_CTL(val)	bfin_write16(TWI_FIFO_CTL,val)
+#define bfin_read_TWI_FIFO_STAT()	bfin_read16(TWI_FIFO_STAT)
+#define bfin_write_TWI_FIFO_STAT(val)	bfin_write16(TWI_FIFO_STAT,val)
+#define bfin_read_TWI_XMT_DATA8()	bfin_read16(TWI_XMT_DATA8)
+#define bfin_write_TWI_XMT_DATA8(val)	bfin_write16(TWI_XMT_DATA8,val)
+#define bfin_read_TWI_XMT_DATA16()	bfin_read16(TWI_XMT_DATA16)
+#define bfin_write_TWI_XMT_DATA16(val)	bfin_write16(TWI_XMT_DATA16,val)
+#define bfin_read_TWI_RCV_DATA8()	bfin_read16(TWI_RCV_DATA8)
+#define bfin_write_TWI_RCV_DATA8(val)	bfin_write16(TWI_RCV_DATA8,val)
+#define bfin_read_TWI_RCV_DATA16()	bfin_read16(TWI_RCV_DATA16)
+#define bfin_write_TWI_RCV_DATA16(val)	bfin_write16(TWI_RCV_DATA16,val)
+
+#ifdef DEBUG_I2C
+#define PRINTD(fmt,args...)	do {	\
+	DECLARE_GLOBAL_DATA_PTR;	\
+	if (gd->have_console)		\
+		printf(fmt ,##args);	\
+	} while (0)
+#else
+#define PRINTD(fmt,args...)
+#endif
+
+#ifndef CONFIG_TWICLK_KHZ
+#define CONFIG_TWICLK_KHZ	50
+#endif
+
+/* All transfers are described by this data structure */
+struct i2c_msg {
+	u16 addr;		/* slave address */
+	u16 flags;
+#define I2C_M_STOP		0x2
+#define I2C_M_RD		0x1
+	u16 len;		/* msg length */
+	u8 *buf;		/* pointer to msg data */
+};
+
+/**
+ * i2c_reset: - reset the host controller
+ *
+ */
+
+static void i2c_reset(void)
+{
+	/* Disable TWI */
+	bfin_write_TWI_CONTROL(0);
+	sync();
+
+	/* Set TWI internal clock as 10MHz */
+	bfin_write_TWI_CONTROL(((get_sclk() / 1024 / 1024 + 5) / 10) & 0x7F);
+
+	/* Set Twi interface clock as specified */
+	if (CONFIG_TWICLK_KHZ > 400)
+		bfin_write_TWI_CLKDIV(((5 * 1024 / 400) << 8) | ((5 * 1024 /
+						400) & 0xFF));
+	else
+		bfin_write_TWI_CLKDIV(((5 * 1024 /
+					CONFIG_TWICLK_KHZ) << 8) | ((5 * 1024 /
+						CONFIG_TWICLK_KHZ)
+						& 0xFF));
+
+	/* Enable TWI */
+	bfin_write_TWI_CONTROL(bfin_read_TWI_CONTROL() | TWI_ENA);
+	sync();
+}
+
+int wait_for_completion(struct i2c_msg *msg, int timeout_count)
+{
+	unsigned short twi_int_stat;
+	unsigned short mast_stat;
+	int i;
+
+	for (i = 0; i < timeout_count; i++) {
+		twi_int_stat = bfin_read_TWI_INT_STAT();
+		mast_stat = bfin_read_TWI_MASTER_STAT();
+
+		if (XMTSERV & twi_int_stat) {
+			/* Transmit next data */
+			if (msg->len > 0) {
+				bfin_write_TWI_XMT_DATA8(*(msg->buf++));
+				msg->len--;
+			} else if (msg->flags & I2C_M_STOP)
+				bfin_write_TWI_MASTER_CTL
+				    (bfin_read_TWI_MASTER_CTL() | STOP);
+			sync();
+			/* Clear status */
+			bfin_write_TWI_INT_STAT(XMTSERV);
+			sync();
+			i = 0;
+		}
+		if (RCVSERV & twi_int_stat) {
+			if (msg->len > 0) {
+				/* Receive next data */
+				*(msg->buf++) = bfin_read_TWI_RCV_DATA8();
+				msg->len--;
+			} else if (msg->flags & I2C_M_STOP) {
+				bfin_write_TWI_MASTER_CTL
+				    (bfin_read_TWI_MASTER_CTL() | STOP);
+				sync();
+			}
+			/* Clear interrupt source */
+			bfin_write_TWI_INT_STAT(RCVSERV);
+			sync();
+			i = 0;
+		}
+		if (MERR & twi_int_stat) {
+			bfin_write_TWI_INT_STAT(MERR);
+			bfin_write_TWI_INT_MASK(0);
+			bfin_write_TWI_MASTER_STAT(0x3e);
+			bfin_write_TWI_MASTER_CTL(0);
+			sync();
+			/*
+			 * if both err and complete int stats are set,
+			 * return proper results.
+			 */
+			if (MCOMP & twi_int_stat) {
+				bfin_write_TWI_INT_STAT(MCOMP);
+				bfin_write_TWI_INT_MASK(0);
+				bfin_write_TWI_MASTER_CTL(0);
+				sync();
+				/*
+				 * If it is a quick transfer,
+				 * only address bug no data, not an err.
+				 */
+				if (msg->len == 0 && mast_stat & BUFRDERR)
+					return 0;
+				/*
+				 * If address not acknowledged return -3,
+				 * else return 0.
+				 */
+				else if (!(mast_stat & ANAK))
+					return 0;
+				else
+					return -3;
+			}
+			return -1;
+		}
+		if (MCOMP & twi_int_stat) {
+			bfin_write_TWI_INT_STAT(MCOMP);
+			sync();
+			bfin_write_TWI_INT_MASK(0);
+			bfin_write_TWI_MASTER_CTL(0);
+			sync();
+			return 0;
+		}
+	}
+	if (msg->flags & I2C_M_RD)
+		return -4;
+	else
+		return -2;
+}
+
+/**
+ * i2c_transfer: - Transfer one byte over the i2c bus
+ *
+ * This function can tranfer a byte over the i2c bus in both directions.
+ * It is used by the public API functions.
+ *
+ * @return:	 0: transfer successful
+ *		-1: transfer fail
+ *		-2: transmit timeout
+ *		-3: ACK missing
+ *		-4: receive timeout
+ *		-5: controller not ready
+ */
+int i2c_transfer(struct i2c_msg *msg)
+{
+	int ret = 0;
+	int timeout_count = 10000;
+	int len = msg->len;
+
+	if (!(bfin_read_TWI_CONTROL() & TWI_ENA)) {
+		ret = -5;
+		goto transfer_error;
+	}
+
+	while (bfin_read_TWI_MASTER_STAT() & BUSBUSY) ;
+
+	/* Set Transmit device address */
+	bfin_write_TWI_MASTER_ADDR(msg->addr);
+
+	/*
+	 * FIFO Initiation.
+	 * Data in FIFO should be discarded before start a new operation.
+	 */
+	bfin_write_TWI_FIFO_CTL(0x3);
+	sync();
+	bfin_write_TWI_FIFO_CTL(0);
+	sync();
+
+	if (!(msg->flags & I2C_M_RD)) {
+		/* Transmit first data */
+		if (msg->len > 0) {
+			PRINTD("1 in i2c_transfer: buf=%d, len=%d\n", *msg->buf,
+			       len);
+			bfin_write_TWI_XMT_DATA8(*(msg->buf++));
+			msg->len--;
+			sync();
+		}
+	}
+
+	/* clear int stat */
+	bfin_write_TWI_INT_STAT(MERR | MCOMP | XMTSERV | RCVSERV);
+
+	/* Interrupt mask . Enable XMT, RCV interrupt */
+	bfin_write_TWI_INT_MASK(MCOMP | MERR |
+			((msg->flags & I2C_M_RD) ? RCVSERV : XMTSERV));
+	sync();
+
+	if (len > 0 && len <= 255)
+		bfin_write_TWI_MASTER_CTL((len << 6));
+	else if (msg->len > 255) {
+		bfin_write_TWI_MASTER_CTL((0xff << 6));
+		msg->flags &= I2C_M_STOP;
+	} else
+		bfin_write_TWI_MASTER_CTL(0);
+
+	/* Master enable */
+	bfin_write_TWI_MASTER_CTL(bfin_read_TWI_MASTER_CTL() | MEN |
+			((msg->flags & I2C_M_RD)
+			 ? MDIR : 0) | ((CONFIG_TWICLK_KHZ >
+					 100) ? FAST : 0));
+	sync();
+
+	ret = wait_for_completion(msg, timeout_count);
+	PRINTD("3 in i2c_transfer: ret=%d\n", ret);
+
+transfer_error:
+	switch (ret) {
+	case 1:
+		PRINTD(("i2c_transfer: error: transfer fail\n"));
+		break;
+	case 2:
+		PRINTD(("i2c_transfer: error: transmit timeout\n"));
+		break;
+	case 3:
+		PRINTD(("i2c_transfer: error: ACK missing\n"));
+		break;
+	case 4:
+		PRINTD(("i2c_transfer: error: receive timeout\n"));
+		break;
+	case 5:
+		PRINTD(("i2c_transfer: error: controller not ready\n"));
+		i2c_reset();
+		break;
+	default:
+		break;
+	}
+	return ret;
+
+}
+
+/* ---------------------------------------------------------------------*/
+/* API Functions							*/
+/* ---------------------------------------------------------------------*/
+
+void i2c_init(int speed, int slaveaddr)
+{
+	i2c_reset();
+}
+
+/**
+ * i2c_probe: - Test if a chip answers for a given i2c address
+ *
+ * @chip:	address of the chip which is searched for
+ * @return: 	0 if a chip was found, -1 otherwhise
+ */
+
+int i2c_probe(uchar chip)
+{
+	struct i2c_msg msg;
+	u8 probebuf;
+
+	i2c_reset();
+
+	probebuf = 0;
+	msg.addr = chip;
+	msg.flags = 0;
+	msg.len = 1;
+	msg.buf = &probebuf;
+	if (i2c_transfer(&msg))
+		return -1;
+
+	msg.addr = chip;
+	msg.flags = I2C_M_RD;
+	msg.len = 1;
+	msg.buf = &probebuf;
+	if (i2c_transfer(&msg))
+		return -1;
+
+	return 0;
+}
+
+/**
+ *   i2c_read: - Read multiple bytes from an i2c device
+ *
+ *   chip:    I2C chip address, range 0..127
+ *   addr:    Memory (register) address within the chip
+ *   alen:    Number of bytes to use for addr (typically 1, 2 for larger
+ *		memories, 0 for register type devices with only one
+ *		register)
+ *   buffer:  Where to read/write the data
+ *   len:     How many bytes to read/write
+ *
+ *   Returns: 0 on success, not 0 on failure
+ */
+
+int i2c_read(uchar chip, uint addr, int alen, uchar * buffer, int len)
+{
+	struct i2c_msg msg;
+	u8 addr_bytes[3];	/* lowest...highest byte of data address */
+
+	PRINTD("i2c_read: chip=0x%x, addr=0x%x, alen=0x%x, len=0x%x\n", chip,
+			addr, alen, len);
+
+	if (alen > 0) {
+		addr_bytes[0] = (u8) ((addr >> 0) & 0x000000FF);
+		addr_bytes[1] = (u8) ((addr >> 8) & 0x000000FF);
+		addr_bytes[2] = (u8) ((addr >> 16) & 0x000000FF);
+		msg.addr = chip;
+		msg.flags = 0;
+		msg.len = alen;
+		msg.buf = addr_bytes;
+		if (i2c_transfer(&msg))
+			return -1;
+	}
+
+	/* start read sequence */
+	PRINTD(("i2c_read: start read sequence\n"));
+	msg.addr = chip;
+	msg.flags = I2C_M_RD;
+	msg.len = len;
+	msg.buf = buffer;
+	if (i2c_transfer(&msg))
+		return -1;
+
+	return 0;
+}
+
+/**
+ *   i2c_write: -  Write multiple bytes to an i2c device
+ *
+ *   chip:    I2C chip address, range 0..127
+ *   addr:    Memory (register) address within the chip
+ *   alen:    Number of bytes to use for addr (typically 1, 2 for larger
+ *		memories, 0 for register type devices with only one
+ *		register)
+ *   buffer:  Where to read/write the data
+ *   len:     How many bytes to read/write
+ *
+ *   Returns: 0 on success, not 0 on failure
+ */
+
+int i2c_write(uchar chip, uint addr, int alen, uchar * buffer, int len)
+{
+	struct i2c_msg msg;
+	u8 addr_bytes[3];	/* lowest...highest byte of data address */
+
+	PRINTD
+		("i2c_write: chip=0x%x, addr=0x%x, alen=0x%x, len=0x%x, buf0=0x%x\n",
+		 chip, addr, alen, len, buffer[0]);
+
+	/* chip address write */
+	if (alen > 0) {
+		addr_bytes[0] = (u8) ((addr >> 0) & 0x000000FF);
+		addr_bytes[1] = (u8) ((addr >> 8) & 0x000000FF);
+		addr_bytes[2] = (u8) ((addr >> 16) & 0x000000FF);
+		msg.addr = chip;
+		msg.flags = 0;
+		msg.len = alen;
+		msg.buf = addr_bytes;
+		if (i2c_transfer(&msg))
+			return -1;
+	}
+
+	/* start read sequence */
+	PRINTD(("i2c_write: start write sequence\n"));
+	msg.addr = chip;
+	msg.flags = 0;
+	msg.len = len;
+	msg.buf = buffer;
+	if (i2c_transfer(&msg))
+		return -1;
+
+	return 0;
+
+}
+
+uchar i2c_reg_read(uchar chip, uchar reg)
+{
+	uchar buf;
+
+	PRINTD("i2c_reg_read: chip=0x%02x, reg=0x%02x\n", chip, reg);
+	i2c_read(chip, reg, 0, &buf, 1);
+	return (buf);
+}
+
+void i2c_reg_write(uchar chip, uchar reg, uchar val)
+{
+	PRINTD("i2c_reg_write: chip=0x%02x, reg=0x%02x, val=0x%02x\n", chip,
+			reg, val);
+	i2c_write(chip, reg, 0, &val, 1);
+}
+
+#endif				/* CONFIG_HARD_I2C */