--- /dev/null
+/*
+ * (C) Copyright 2000
+ * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ *
+ * Hacked for the DB64360 board by Ingo.Assmus@keymile.com
+ * extra improvments by Brain Waite
+ */
+#include <common.h>
+#include <mpc8xx.h>
+#include <malloc.h>
+#include <i2c.h>
+#include "../include/mv_gen_reg.h"
+#include "../include/core.h"
+
+#define MAX_I2C_RETRYS 10
+#define I2C_DELAY 1000 /* Should be at least the # of MHz of Tclk */
+#undef DEBUG_I2C
+/*#define 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) */
+
+void i2c_init (int speed, int slaveaddr)
+{
+ unsigned int n, m, freq, margin, power;
+ unsigned int actualN = 0, actualM = 0;
+ unsigned int control, status;
+ unsigned int minMargin = 0xffffffff;
+ unsigned int tclk = CONFIG_SYS_TCLK;
+ unsigned int i2cFreq = speed; /* 100000 max. Fast mode not supported */
+
+ DP (puts ("i2c_init\n"));
+/* gtI2cMasterInit */
+ 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 (i2cFreq > freq)
+ margin = i2cFreq - freq;
+ else
+ margin = freq - i2cFreq;
+ if (margin < minMargin) {
+ minMargin = margin;
+ actualN = n;
+ actualM = m;
+ }
+ }
+ }
+
+ DP (puts ("setup i2c bus\n"));
+
+ /* Setup bus */
+/* gtI2cReset */
+ 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)
+{ /* DB64360 checked -> ok */
+ unsigned int control, status;
+ int count = 0;
+
+ DP (puts ("i2c_start\n"));
+
+ /* Set the start bit */
+
+/* gtI2cGenerateStartBit() */
+
+ GT_REG_READ (I2C_CONTROL, &control);
+ control |= (0x1 << 5); /* generate the I2C_START_BIT */
+ 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 = 0;
+ 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;
+ unsigned int temp;
+ unsigned int *temp_ptr = data;
+
+ DP (puts ("i2c_write_data\n"));
+
+ while (len) {
+ temp = (unsigned int) (*temp_ptr);
+ GT_REG_WRITE (I2C_DATA, temp);
+ 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--;
+ temp_ptr++;
+ }
+/* 11-14-2002 Paul Marchese */
+/* Can't have the write issuing a stop command */
+/* it's wrong to have a stop bit in read stream or write stream */
+/* since we don't know if it's really the end of the command */
+/* or whether we have just send the device address + offset */
+/* we will push issuing the stop command off to the original */
+/* calling function */
+ /* set the interrupt bit in the control register */
+ GT_REG_WRITE (I2C_CONTROL, (0x1 << 3));
+ udelay (I2C_DELAY * 10);
+ return (0);
+}
+
+/* 11-14-2002 Paul Marchese */
+/* created this function to get the i2c_write() */
+/* function working properly. */
+/* function to write bytes out on the i2c bus */
+/* this is identical to the function i2c_write_data() */
+/* except that it requires a buffer that is an */
+/* unsigned character array. You can't use */
+/* i2c_write_data() to send an array of unsigned characters */
+/* since the byte of interest ends up on the wrong end of the bus */
+/* aah, the joys of big endian versus little endian! */
+/* */
+/* returns 0 = success */
+/* anything other than zero is failure */
+static uchar i2c_write_byte (unsigned char *data, int len)
+{
+ unsigned int status;
+ int count = 0;
+ unsigned int temp;
+ unsigned char *temp_ptr = data;
+
+ DP (puts ("i2c_write_byte\n"));
+
+ while (len) {
+ /* Set and assert the data */
+ temp = *temp_ptr;
+ GT_REG_WRITE (I2C_DATA, temp);
+ 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--;
+ temp_ptr++;
+ }
+/* Can't have the write issuing a stop command */
+/* it's wrong to have a stop bit in read stream or write stream */
+/* since we don't know if it's really the end of the command */
+/* or whether we have just send the device address + offset */
+/* we will push issuing the stop command off to the original */
+/* calling function */
+/* GT_REG_WRITE(I2C_CONTROL, (0x1 << 3) | (0x1 << 4));
+ GT_REG_WRITE(I2C_CONTROL, (0x1 << 4)); */
+ /* set the interrupt bit in the control register */
+ GT_REG_WRITE (I2C_CONTROL, (0x1 << 3));
+ udelay (I2C_DELAY * 10);
+
+ return (0);
+}
+
+static uchar
+i2c_set_dev_offset (uchar dev_addr, unsigned int offset, int ten_bit,
+ int alen)
+{
+ uchar status;
+ unsigned int table[2];
+
+/* initialize the table of address offset bytes */
+/* utilized for 2 byte address offsets */
+/* NOTE: the order is high byte first! */
+ table[1] = offset & 0xff; /* low byte */
+ table[0] = offset / 0x100; /* high byte */
+
+ 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;
+ }
+/* check the address offset length */
+ if (alen == 0)
+ /* no address offset */
+ return (0);
+ else if (alen == 1) {
+ /* 1 byte address offset */
+ status = i2c_write_data (&offset, 1);
+ if (status) {
+#ifdef DEBUG_I2C
+ printf ("Failed to write data: 0x%02x\n", status);
+#endif
+ return status;
+ }
+ } else if (alen == 2) {
+ /* 2 bytes address offset */
+ status = i2c_write_data (table, 2);
+ if (status) {
+#ifdef DEBUG_I2C
+ printf ("Failed to write data: 0x%02x\n", status);
+#endif
+ return status;
+ }
+ } else {
+ /* address offset unknown or not supported */
+ printf ("Address length offset %d is not supported\n", alen);
+ return 1;
+ }
+ return 0; /* sucessful completion */
+}
+
+int
+i2c_read (uchar dev_addr, unsigned int offset, int alen, uchar * data,
+ int len)
+{
+ uchar status = 0;
+ unsigned int i2cFreq = CONFIG_SYS_I2C_SPEED;
+
+ DP (puts ("i2c_read\n"));
+
+ /* set the i2c frequency */
+ i2c_init (i2cFreq, CONFIG_SYS_I2C_SLAVE);
+
+ 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, offset, 0, alen); /* send the slave address + offset */
+ if (status) {
+#ifdef DEBUG_I2C
+ printf ("Failed to set slave address & offset: 0x%02x\n",
+ status);
+#endif
+ return status;
+ }
+
+ /* set the i2c frequency again */
+ i2c_init (i2cFreq, CONFIG_SYS_I2C_SLAVE);
+
+ 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, 0); /* send the slave address */
+ 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 received: 0x%02x\n", status);
+#endif
+ return status;
+ }
+
+ return 0;
+}
+
+/* 11-14-2002 Paul Marchese */
+/* Function to set the I2C stop bit */
+void i2c_stop (void)
+{
+ GT_REG_WRITE (I2C_CONTROL, (0x1 << 4));
+}
+
+/* 11-14-2002 Paul Marchese */
+/* I2C write function */
+/* dev_addr = device address */
+/* offset = address offset */
+/* alen = length in bytes of the address offset */
+/* data = pointer to buffer to read data into */
+/* len = # of bytes to read */
+/* */
+/* returns 0 = succesful */
+/* anything but zero is failure */
+int
+i2c_write (uchar dev_addr, unsigned int offset, int alen, uchar * data,
+ int len)
+{
+ uchar status = 0;
+ unsigned int i2cFreq = CONFIG_SYS_I2C_SPEED;
+
+ DP (puts ("i2c_write\n"));
+
+ /* set the i2c frequency */
+ i2c_init (i2cFreq, CONFIG_SYS_I2C_SLAVE);
+
+ status = i2c_start (); /* send a start bit */
+
+ if (status) {
+#ifdef DEBUG_I2C
+ printf ("Transaction start failed: 0x%02x\n", status);
+#endif
+ return status;
+ }
+
+ status = i2c_set_dev_offset (dev_addr, offset, 0, alen); /* send the slave address + offset */
+ if (status) {
+#ifdef DEBUG_I2C
+ printf ("Failed to set slave address & offset: 0x%02x\n",
+ status);
+#endif
+ return status;
+ }
+
+
+ status = i2c_write_byte (data, len); /* write the data */
+ if (status) {
+#ifdef DEBUG_I2C
+ printf ("Data not written: 0x%02x\n", status);
+#endif
+ return status;
+ }
+ /* issue a stop bit */
+ i2c_stop ();
+ return 0;
+}
+
+/* 11-14-2002 Paul Marchese */
+/* function to determine if an I2C device is present */
+/* chip = device address of chip to check for */
+/* */
+/* returns 0 = sucessful, the device exists */
+/* anything other than zero is failure, no device */
+int i2c_probe (uchar chip)
+{
+
+ /* We are just looking for an <ACK> back. */
+ /* To see if the device/chip is there */
+
+#ifdef DEBUG_I2C
+ unsigned int i2c_status;
+#endif
+ uchar status = 0;
+ unsigned int i2cFreq = CONFIG_SYS_I2C_SPEED;
+
+ DP (puts ("i2c_probe\n"));
+
+ /* set the i2c frequency */
+ i2c_init (i2cFreq, CONFIG_SYS_I2C_SLAVE);
+
+ status = i2c_start (); /* send a start bit */
+
+ if (status) {
+#ifdef DEBUG_I2C
+ printf ("Transaction start failed: 0x%02x\n", status);
+#endif
+ return (int) status;
+ }
+
+ status = i2c_set_dev_offset (chip, 0, 0, 0); /* send the slave address + no offset */
+ if (status) {
+#ifdef DEBUG_I2C
+ printf ("Failed to set slave address: 0x%02x\n", status);
+#endif
+ return (int) status;
+ }
+#ifdef DEBUG_I2C
+ GT_REG_READ (I2C_STATUS_BAUDE_RATE, &i2c_status);
+ printf ("address %#x returned %#x\n", chip, i2c_status);
+#endif
+ /* issue a stop bit */
+ i2c_stop ();
+ return 0; /* successful completion */
+}
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