/* * (C) Copyright 2000 * Wolfgang Denk, DENX Software Engineering, wd@denx.de. * * See file CREDITS for list of people who contributed to this * project. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation; either version 2 of * the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, * MA 02111-1307 USA * * 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 recieved: 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 */ }