Initial revision

1 files changed, 315 insertions, 0 deletions

diff --git a/board/evb64260/i2c.c b/board/evb64260/i2c.c
new file mode 100644
index 0000000..22cb809
--- /dev/null
+++ b/board/evb64260/i2c.c
@@ -0,0 +1,315 @@
+#include <common.h>
+#include <mpc8xx.h>
+#include <malloc.h>
+#include <galileo/gt64260R.h>
+#include <galileo/core.h>
+
+#define MAX_I2C_RETRYS	    10
+#define I2C_DELAY	    1000  /* Should be at least the # of MHz of Tclk */
+#undef	DEBUG_I2C
+
+#ifdef DEBUG_I2C
+#define DP(x) x
+#else
+#define DP(x)
+#endif
+
+/* Assuming that there is only one master on the bus (us) */
+
+static void
+i2c_init(int speed, int slaveaddr)
+{
+	unsigned int n, m, freq, margin, power;
+	unsigned int actualFreq, actualN=0, actualM=0;
+	unsigned int control, status;
+	unsigned int minMargin = 0xffffffff;
+	unsigned int tclk = 125000000;
+
+	DP(puts("i2c_init\n"));
+
+	for(n = 0 ; n < 8 ; n++)
+	{
+		for(m = 0 ; m < 16 ; m++)
+		{
+			power = 2<<n; /* power = 2^(n+1) */
+			freq = tclk/(10*(m+1)*power);
+			if (speed > freq)
+				margin = speed - freq;
+			else
+				margin = freq - speed;
+			if(margin < minMargin)
+			{
+				minMargin   = margin;
+				actualFreq  = freq;
+				actualN	    = n;
+				actualM	    = m;
+			}
+		}
+	}
+
+	DP(puts("setup i2c bus\n"));
+
+	/* Setup bus */
+
+	GT_REG_WRITE(I2C_SOFT_RESET, 0);
+
+	DP(puts("udelay...\n"));
+
+	udelay(I2C_DELAY);
+
+	DP(puts("set baudrate\n"));
+
+	GT_REG_WRITE(I2C_STATUS_BAUDE_RATE, (actualM << 3) | actualN);
+	GT_REG_WRITE(I2C_CONTROL, (0x1 << 2) | (0x1 << 6));
+
+	udelay(I2C_DELAY * 10);
+
+	DP(puts("read control, baudrate\n"));
+
+	GT_REG_READ(I2C_STATUS_BAUDE_RATE, &status);
+	GT_REG_READ(I2C_CONTROL, &control);
+}
+
+static uchar
+i2c_start(void)
+{
+	unsigned int control, status;
+	int count = 0;
+
+	DP(puts("i2c_start\n"));
+
+	/* Set the start bit */
+
+	GT_REG_READ(I2C_CONTROL, &control);
+	control |= (0x1 << 5);
+	GT_REG_WRITE(I2C_CONTROL, control);
+
+	GT_REG_READ(I2C_STATUS_BAUDE_RATE, &status);
+
+	count = 0;
+	while ((status & 0xff) != 0x08) {
+		udelay(I2C_DELAY);
+		if (count > 20) {
+			GT_REG_WRITE(I2C_CONTROL, (0x1 << 4)); /*stop*/
+			return (status);
+		}
+		GT_REG_READ(I2C_STATUS_BAUDE_RATE, &status);
+		count++;
+	}
+
+	return (0);
+}
+
+static uchar
+i2c_select_device(uchar dev_addr, uchar read, int ten_bit)
+{
+	unsigned int status, data, bits = 7;
+	int count = 0;
+
+	DP(puts("i2c_select_device\n"));
+
+	/* Output slave address */
+
+	if (ten_bit) {
+		bits = 10;
+	}
+
+	data = (dev_addr << 1);
+	/* set the read bit */
+	data |= read;
+	GT_REG_WRITE(I2C_DATA, data);
+	/* assert the address */
+	RESET_REG_BITS(I2C_CONTROL, BIT3);
+
+	udelay(I2C_DELAY);
+
+	GT_REG_READ(I2C_STATUS_BAUDE_RATE, &status);
+	count = 0;
+	while (((status & 0xff) != 0x40) && ((status & 0xff) != 0x18)) {
+		udelay(I2C_DELAY);
+		if (count > 20) {
+			GT_REG_WRITE(I2C_CONTROL, (0x1 << 4)); /*stop*/
+			return(status);
+		}
+		GT_REG_READ(I2C_STATUS_BAUDE_RATE, &status);
+		count++;
+	}
+
+	if (bits == 10) {
+		printf("10 bit I2C addressing not yet implemented\n");
+		return (0xff);
+	}
+
+	return (0);
+}
+
+static uchar
+i2c_get_data(uchar* return_data, int len) {
+
+	unsigned int data, status;
+	int count = 0;
+
+	DP(puts("i2c_get_data\n"));
+
+	while (len) {
+
+		/* Get and return the data */
+
+		RESET_REG_BITS(I2C_CONTROL, (0x1 << 3));
+
+		udelay(I2C_DELAY * 5);
+
+		GT_REG_READ(I2C_STATUS_BAUDE_RATE, &status);
+		count++;
+		while ((status & 0xff) != 0x50) {
+			udelay(I2C_DELAY);
+			if(count > 2) {
+				GT_REG_WRITE(I2C_CONTROL, (0x1 << 4)); /*stop*/
+				return 0;
+			}
+			GT_REG_READ(I2C_STATUS_BAUDE_RATE, &status);
+			count++;
+		}
+		GT_REG_READ(I2C_DATA, &data);
+		len--;
+		*return_data = (uchar)data;
+		return_data++;
+	}
+	RESET_REG_BITS(I2C_CONTROL, BIT2|BIT3);
+	while ((status & 0xff) != 0x58) {
+		udelay(I2C_DELAY);
+		if(count > 200) {
+			GT_REG_WRITE(I2C_CONTROL, (0x1 << 4)); /*stop*/
+			return (status);
+		}
+		GT_REG_READ(I2C_STATUS_BAUDE_RATE, &status);
+		count++;
+	}
+	GT_REG_WRITE(I2C_CONTROL, (0x1 << 4)); /* stop */
+
+	return (0);
+}
+
+static uchar
+i2c_write_data(unsigned int data, int len)
+{
+	unsigned int status;
+	int count = 0;
+
+	DP(puts("i2c_write_data\n"));
+
+	if (len > 4)
+		return -1;
+
+	while (len) {
+		/* Set and assert the data */
+
+		GT_REG_WRITE(I2C_DATA, (unsigned int)data);
+		RESET_REG_BITS(I2C_CONTROL, (0x1 << 3));
+
+		udelay(I2C_DELAY);
+
+		GT_REG_READ(I2C_STATUS_BAUDE_RATE, &status);
+		count++;
+		while ((status & 0xff) != 0x28) {
+			udelay(I2C_DELAY);
+			if(count > 20) {
+				GT_REG_WRITE(I2C_CONTROL, (0x1 << 4)); /*stop*/
+				return (status);
+			}
+			GT_REG_READ(I2C_STATUS_BAUDE_RATE, &status);
+			count++;
+		}
+		len--;
+	}
+	GT_REG_WRITE(I2C_CONTROL, (0x1 << 3) | (0x1 << 4));
+	GT_REG_WRITE(I2C_CONTROL, (0x1 << 4));
+
+	udelay(I2C_DELAY * 10);
+
+	return (0);
+}
+
+static uchar
+i2c_set_dev_offset(uchar dev_addr, unsigned int offset, int ten_bit)
+{
+	uchar status;
+
+	DP(puts("i2c_set_dev_offset\n"));
+
+	status = i2c_select_device(dev_addr, 0, ten_bit);
+	if (status) {
+#ifdef DEBUG_I2C
+		printf("Failed to select device setting offset: 0x%02x\n",
+		       status);
+#endif
+		return status;
+	}
+
+	status = i2c_write_data(offset, 1);
+	if (status) {
+#ifdef DEBUG_I2C
+		printf("Failed to write data: 0x%02x\n", status);
+#endif
+		return status;
+	}
+
+	return (0);
+}
+
+uchar
+i2c_read(uchar dev_addr, unsigned int offset, int len, uchar* data,
+	 int ten_bit)
+{
+	uchar status = 0;
+	unsigned int i2cFreq = 400000;
+
+	DP(puts("i2c_read\n"));
+
+	i2c_init(i2cFreq,0);
+
+	status = i2c_start();
+
+	if (status) {
+#ifdef DEBUG_I2C
+		printf("Transaction start failed: 0x%02x\n", status);
+#endif
+		return status;
+	}
+
+	status = i2c_set_dev_offset(dev_addr, 0, 0);
+	if (status) {
+#ifdef DEBUG_I2C
+		printf("Failed to set offset: 0x%02x\n", status);
+#endif
+		return status;
+	}
+
+	i2c_init(i2cFreq,0);
+
+	status = i2c_start();
+	if (status) {
+#ifdef DEBUG_I2C
+		printf("Transaction restart failed: 0x%02x\n", status);
+#endif
+		return status;
+	}
+
+	status = i2c_select_device(dev_addr, 1, ten_bit);
+	if (status) {
+#ifdef DEBUG_I2C
+		printf("Address not acknowledged: 0x%02x\n", status);
+#endif
+		return status;
+	}
+
+	status = i2c_get_data(data, len);
+	if (status) {
+#ifdef DEBUG_I2C
+		printf("Data not recieved: 0x%02x\n", status);
+#endif
+		return status;
+	}
+
+	return 0;
+}