/*************************************************************
*
* Copyright @ Motorola, 1999
*
************************************************************/
#include <common.h>
#ifdef CONFIG_HARD_I2C
#include <i2c.h>
#include "i2c_export.h"
#include "i2c.h"
#undef I2CDBG0
#undef DEBUG
/* Define a macro to use an optional application-layer print function, if
* one was passed to the I2C library during initialization. If there was
* no function pointer passed, this protects against calling it. Also define
* the global variable that holds the passed pointer.
*/
#define TIMEOUT (CFG_HZ/4)
#define PRINT if ( app_print ) app_print
static int (*app_print) (char *, ...);
/******************* Internal to I2C Driver *****************/
static unsigned int ByteToXmit = 0;
static unsigned int XmitByte = 0;
static unsigned char *XmitBuf = 0;
static unsigned int XmitBufEmptyStop = 0;
static unsigned int ByteToRcv = 0;
static unsigned int RcvByte = 0;
static unsigned char *RcvBuf = 0;
static unsigned int RcvBufFulStop = 0;
static unsigned int MasterRcvAddress = 0;
/* Set by call to get_eumbbar during I2C_Initialize.
* This could be globally available to the I2C library, but there is
* an advantage to passing it as a parameter: it is already in a register
* and doesn't have to be loaded from memory. Also, that is the way the
* I2C library was already implemented and I don't want to change it without
* a more detailed analysis.
* It is being set as a global variable in I2C_Initialize to hide it from
* the DINK application layer, because it is Kahlua-specific. I think that
* get_eumbbar, load_runtime_reg, and store_runtime_reg should be defined in
* a Kahlua-specific library dealing with the embedded utilities memory block.
* Right now, get_eumbbar is defined in dink32/kahlua.s. The other two are
* defined in dink32/drivers/i2c/i2c2.s.
*/
static unsigned int Global_eumbbar = 0;
extern unsigned int load_runtime_reg (unsigned int eumbbar,
unsigned int reg);
extern unsigned int store_runtime_reg (unsigned int eumbbar,
unsigned int reg, unsigned int val);
/************************** API *****************/
/* Application Program Interface (API) are the calls provided by the I2C
* library to upper layer applications (i.e., DINK) to access the Kahlua
* I2C bus interface. The functions and values that are part of this API
* are declared in i2c_export.h.
*/
/* Initialize I2C unit with the following:
* driver's slave address
* interrupt enabled
* optional pointer to application layer print function
*
* These parameters may be added:
* desired clock rate
* digital filter frequency sampling rate
*
* This function must be called before I2C unit can be used.
*/
I2C_Status I2C_Initialize (unsigned char addr,
I2C_INTERRUPT_MODE en_int,
int (*p) (char *, ...))
{
I2CStatus status;
/* establish the pointer, if there is one, to the application's "printf" */
app_print = p;
/* If this is the first call, get the embedded utilities memory block
* base address. I'm not sure what to do about error handling here:
* if a non-zero value is returned, accept it.
*/
if (Global_eumbbar == 0)
Global_eumbbar = get_eumbbar ();
if (Global_eumbbar == 0) {
PRINT ("I2C_Initialize: can't find EUMBBAR\n");
return I2C_ERROR;
}
/* validate the I2C address */
if (addr & 0x80) {
PRINT ("I2C_Initialize, I2C address invalid: %d 0x%x\n",
(unsigned int) addr, (unsigned int) addr);
return I2C_ERROR;
}
/* Call the internal I2C library function to perform work.
* Accept the default frequency sampling rate (no way to set it currently,
* via I2C_Init) and set the clock frequency to something reasonable.
*/
status = I2C_Init (Global_eumbbar, (unsigned char) 0x31, addr, en_int);
if (status != I2CSUCCESS) {
PRINT ("I2C_Initialize: error in initiation\n");
return I2C_ERROR;
}
/* all is well */
return I2C_SUCCESS;
}
/* Perform the given I2C transaction, only MASTER_XMIT and MASTER_RCV
* are implemented. Both are only in polling mode.
*
* en_int controls interrupt/polling mode
* act is the type of transaction
* i2c_addr is the I2C address of the slave device
* data_addr is the address of the data on the slave device
* len is the length of data to send or receive
* buffer is the address of the data buffer
* stop = I2C_NO_STOP, don't signal STOP at end of transaction
* I2C_STOP, signal STOP at end of transaction
* retry is the timeout retry value, currently ignored
* rsta = I2C_NO_RESTART, this is not continuation of existing transaction
* I2C_RESTART, this is a continuation of existing transaction
*/
I2C_Status I2C_do_transaction ( I2C_INTERRUPT_MODE en_int,
I2C_TRANSACTION_MODE act,
unsigned char i2c_addr,
unsigned char data_addr,
int len,
char *buffer,
I2C_STOP_MODE stop,
int retry, I2C_RESTART_MODE rsta)
{
I2C_Status status;
unsigned char data_addr_buffer[1];
#if 1
/* This is a temporary work-around. The I2C library breaks the protocol
* if it attempts to handle a data transmission in more than one
* transaction, so the data address and the actual data bytes are put
* into a single buffer before sending it to the library internal functions.
* The problem is related to being able to restart a transaction without
* sending the I2C device address or repeating the data address. It may take
* a day or two to sort it all out, so I'll have to get back to it later.
* Look at I2C_Start to see about using some status flags (I'm not sure that
* "stop" and "rsta" are enough to reflect the states, maybe so; but the logic
* in the library is insufficient) to control correct handling of the protocol.
*/
unsigned char dummy_buffer[257];
if (act == I2C_MASTER_XMIT) {
int i;
if (len > 256)
return I2C_ERROR;
for (i = 1; i <= len; i++)
dummy_buffer[i] = buffer[i - 1];
dummy_buffer[0] = data_addr;
status = I2C_do_buffer (en_int, act, i2c_addr, 1 + len,
dummy_buffer, stop, retry, rsta);
if (status != I2C_SUCCESS) {
PRINT ("I2C_do_transaction: can't perform data transfer\n");
return I2C_ERROR;
}
return I2C_SUCCESS;
}
#endif /* end of temp work-around */
/* validate requested transaction type */
if ((act != I2C_MASTER_XMIT) && (act != I2C_MASTER_RCV)) {
PRINT ("I2C_do_transaction, invalid transaction request: %d\n",
act);
return I2C_ERROR;
}
/* range check the I2C address */
if (i2c_addr & 0x80) {
PRINT ("I2C_do_transaction, I2C address out of range: %d 0x%x\n",
(unsigned int) i2c_addr, (unsigned int) i2c_addr);
return I2C_ERROR;
} else {
data_addr_buffer[0] = data_addr;
}
/*
* We first have to contact the slave device and transmit the
* data address. Be careful about the STOP and restart stuff.
* We don't want to signal STOP after sending the data
* address, but this could be a continuation if the
* application didn't release the bus after the previous
* transaction, by not sending a STOP after it.
*/
status = I2C_do_buffer (en_int, I2C_MASTER_XMIT, i2c_addr, 1,
data_addr_buffer, I2C_NO_STOP, retry, rsta);
if (status != I2C_SUCCESS) {
PRINT ("I2C_do_transaction: can't send data address for read\n");
return I2C_ERROR;
}
/* The data transfer will be a continuation. */
rsta = I2C_RESTART;
/* now handle the user data */
status = I2C_do_buffer (en_int, act, i2c_addr, len,
buffer, stop, retry, rsta);
if (status != I2C_SUCCESS) {
PRINT ("I2C_do_transaction: can't perform data transfer\n");
return I2C_ERROR;
}
/* all is well */
return I2C_SUCCESS;
}
/* This function performs the work for I2C_do_transaction. The work is
* split into this function to enable I2C_do_transaction to first transmit
* the data address to the I2C slave device without putting the data address
* into the first byte of the buffer.
*
* en_int controls interrupt/polling mode
* act is the type of transaction
* i2c_addr is the I2C address of the slave device
* len is the length of data to send or receive
* buffer is the address of the data buffer
* stop = I2C_NO_STOP, don't signal STOP at end of transaction
* I2C_STOP, signal STOP at end of transaction
* retry is the timeout retry value, currently ignored
* rsta = I2C_NO_RESTART, this is not continuation of existing transaction
* I2C_RESTART, this is a continuation of existing transaction
*/
static I2C_Status I2C_do_buffer (I2C_INTERRUPT_MODE en_int,
I2C_TRANSACTION_MODE act,
unsigned char i2c_addr,
int len,
unsigned char *buffer,
I2C_STOP_MODE stop,
int retry, I2C_RESTART_MODE rsta)
{
I2CStatus rval;
unsigned int dev_stat;
if (act == I2C_MASTER_RCV) {
/* set up for master-receive transaction */
rval = I2C_get (Global_eumbbar, i2c_addr, buffer, len, stop, rsta);
} else {
/* set up for master-transmit transaction */
rval = I2C_put (Global_eumbbar, i2c_addr, buffer, len, stop, rsta);
}
/* validate the setup */
if (rval != I2CSUCCESS) {
dev_stat = load_runtime_reg (Global_eumbbar, I2CSR);
PRINT ("Error(I2C_do_buffer): control phase, code(0x%08x), status(0x%08x)\n", rval, dev_stat);
I2C_Stop (Global_eumbbar);
return I2C_ERROR;
}
if (en_int == 1) {
/* this should not happen, no interrupt handling yet */
return I2C_SUCCESS;
}
/* this performs the polling action, when the transfer is completed,
* the status returned from I2C_Timer_Event will be I2CBUFFFULL or
* I2CBUFFEMPTY (rcv or xmit), I2CSUCCESS or I2CADDRESS indicates the
* transaction is not yet complete, anything else is an error.
*/
while (rval == I2CSUCCESS || rval == I2CADDRESS) {
int timeval = get_timer (0);
/* poll the device until something happens */
do {
rval = I2C_Timer_Event (Global_eumbbar, 0);
}
while (rval == I2CNOEVENT && get_timer (timeval) < TIMEOUT);
/* check for error condition */
if (rval == I2CSUCCESS ||
rval == I2CBUFFFULL ||
rval == I2CBUFFEMPTY ||
rval == I2CADDRESS) {
; /* do nothing */
} else {
/* report the error condition */
dev_stat = load_runtime_reg (Global_eumbbar, I2CSR);
PRINT ("Error(I2C_do_buffer): code(0x%08x), status(0x%08x)\n",
rval, dev_stat);
return I2C_ERROR;
}
}
/* all is well */
return I2C_SUCCESS;
}
/**
* Note:
*
* In all following functions,
* the caller shall pass the configured embedded utility memory
* block base, EUMBBAR.
**/
/***********************************************************
* function: I2C_put
*
* description:
Send a buffer of data to the intended rcv_addr.
* If stop_flag is set, after the whole buffer
* is sent, generate a STOP signal provided that the
* receiver doesn't signal the STOP in the middle.
* I2C is the master performing transmitting. If
* no STOP signal is generated at the end of current
* transaction, the master can generate a START signal
* to another slave addr.
*
* note: this is master xmit API
*********************************************************/
static I2CStatus I2C_put (unsigned int eumbbar, unsigned char rcv_addr, /* receiver's address */
unsigned char *buffer_ptr, /* pointer of data to be sent */
unsigned int length, /* number of byte of in the buffer */
unsigned int stop_flag, /* 1 - signal STOP when buffer is empty
* 0 - no STOP signal when buffer is empty
*/
unsigned int is_cnt)
{ /* 1 - this is a restart, don't check MBB
* 0 - this is a new start, check MBB
*/
if (buffer_ptr == 0 || length == 0) {
return I2CERROR;
}
#ifdef I2CDBG0
PRINT ("%s(%d): I2C_put\n", __FILE__, __LINE__);
#endif
XmitByte = 0;
ByteToXmit = length;
XmitBuf = buffer_ptr;
XmitBufEmptyStop = stop_flag;
RcvByte = 0;
ByteToRcv = 0;
RcvBuf = 0;
/* we are the master, start transaction */
return I2C_Start (eumbbar, rcv_addr, XMIT, is_cnt);
}
/***********************************************************
* function: I2C_get
*
* description:
* Receive a buffer of data from the desired sender_addr
* If stop_flag is set, when the buffer is full and the
* sender does not signal STOP, generate a STOP signal.
* I2C is the master performing receiving. If no STOP signal
* is generated, the master can generate a START signal
* to another slave addr.
*
* note: this is master receive API
**********************************************************/
static I2CStatus I2C_get (unsigned int eumbbar, unsigned char rcv_from, /* sender's address */
unsigned char *buffer_ptr, /* pointer of receiving buffer */
unsigned int length, /* length of the receiving buffer */
unsigned int stop_flag, /* 1 - signal STOP when buffer is full
* 0 - no STOP signal when buffer is full
*/
unsigned int is_cnt)
{ /* 1 - this is a restart, don't check MBB
* 0 - this is a new start, check MBB
*/
if (buffer_ptr == 0 || length == 0) {
return I2CERROR;
}
#ifdef I2CDBG0
PRINT ("%s(%d): I2C_get\n", __FILE__, __LINE__);
#endif
RcvByte = 0;
ByteToRcv = length;
RcvBuf = buffer_ptr;
RcvBufFulStop = stop_flag;
XmitByte = 0;
ByteToXmit = 0;
XmitBuf = 0;
/* we are the master, start the transaction */
return I2C_Start (eumbbar, rcv_from, RCV, is_cnt);
}
#if 0 /* turn off dead code */
/*********************************************************
* function: I2C_write
*
* description:
* Send a buffer of data to the requiring master.
* If stop_flag is set, after the whole buffer is sent,
* generate a STOP signal provided that the requiring
* receiver doesn't signal the STOP in the middle.
* I2C is the slave performing transmitting.
*
* Note: this is slave xmit API.
*
* due to the current Kahlua design, slave transmitter
* shall not signal STOP since there is no way
* for master to detect it, causing I2C bus hung.
*
* For the above reason, the stop_flag is always
* set, i.e., 0.
*
* programmer shall use the timer on Kahlua to
* control the interval of data byte at the
* master side.
*******************************************************/
static I2CStatus I2C_write (unsigned int eumbbar, unsigned char *buffer_ptr, /* pointer of data to be sent */
unsigned int length, /* number of byte of in the buffer */
unsigned int stop_flag)
{ /* 1 - signal STOP when buffer is empty
* 0 - no STOP signal when buffer is empty
*/
if (buffer_ptr == 0 || length == 0) {
return I2CERROR;
}
XmitByte = 0;
ByteToXmit = length;
XmitBuf = buffer_ptr;
XmitBufEmptyStop = 0; /* in order to avoid bus hung, ignored the user's stop_flag */
RcvByte = 0;
ByteToRcv = 0;
RcvBuf = 0;
/* we are the slave, just wait for being called, or pull */
/* I2C_Timer_Event( eumbbar ); */
}
/******************************************************
* function: I2C_read
*
* description:
* Receive a buffer of data from the sending master.
* If stop_flag is set, when the buffer is full and the
* sender does not signal STOP, generate a STOP signal.
* I2C is the slave performing receiving.
*
* note: this is slave receive API
****************************************************/
static I2CStatus I2C_read (unsigned int eumbbar, unsigned char *buffer_ptr, /* pointer of receiving buffer */
unsigned int length, /* length of the receiving buffer */
unsigned int stop_flag)
{ /* 1 - signal STOP when buffer is full
* 0 - no STOP signal when buffer is full
*/
if (buffer_ptr == 0 || length == 0) {
return I2CERROR;
}
RcvByte = 0;
ByteToRcv = length;
RcvBuf = buffer_ptr;
RcvBufFulStop = stop_flag;
XmitByte = 0;
ByteToXmit = 0;
XmitBuf = 0;
/* wait for master to call us, or poll */
/* I2C_Timer_Event( eumbbar ); */
}
#endif /* turn off dead code */
/*********************************************************
* function: I2c_Timer_Event
*
* description:
* if interrupt is not used, this is the timer event handler.
* After each fixed time interval, this function can be called
* to check the I2C status and call appropriate function to
* handle the status event.
********************************************************/
static I2CStatus I2C_Timer_Event (unsigned int eumbbar,
I2CStatus (*handler) (unsigned int))
{
I2C_STAT stat;
#ifdef I2CDBG0
PRINT ("%s(%d): I2C_Timer_Event\n", __FILE__, __LINE__);
#endif
stat = I2C_Get_Stat (eumbbar);
if (stat.mif == 1) {
if (handler == 0) {
return I2C_ISR (eumbbar);
} else {
return (*handler) (eumbbar);
}
}
return I2CNOEVENT;
}
/****************** Device I/O function *****************/
/******************************************************
* function: I2C_Start
*
* description: Generate a START signal in the desired mode.
* I2C is the master.
*
* Return I2CSUCCESS if no error.
*
* note:
****************************************************/
static I2CStatus I2C_Start (unsigned int eumbbar, unsigned char slave_addr, /* address of the receiver */
I2C_MODE mode, /* XMIT(1) - put (write)
* RCV(0) - get (read)
*/
unsigned int is_cnt)
{ /* 1 - this is a restart, don't check MBB
* 0 - this is a new start
*/
unsigned int tmp = 0;
I2C_STAT stat;
I2C_CTRL ctrl;
#ifdef I2CDBG0
PRINT ("%s(%d): I2C_Start addr 0x%x mode %d cnt %d\n", __FILE__,
__LINE__, slave_addr, mode, is_cnt);
#endif
ctrl = I2C_Get_Ctrl (eumbbar);
/* first make sure I2C has been initialized */
if (ctrl.men == 0) {
return I2CERROR;
}
/* next make sure bus is idle */
stat = I2C_Get_Stat (eumbbar);
if (is_cnt == 0 && stat.mbb == 1) {
/* sorry, we lost */
return I2CBUSBUSY;
} else if (is_cnt == 1 && stat.mif == 1 && stat.mal == 0) {
/* sorry, we lost the bus */
return I2CALOSS;
}
/* OK, I2C is enabled and we have the bus */
/* prepare to write the slave address */
ctrl.msta = 1;
ctrl.mtx = 1;
ctrl.txak = 0;
ctrl.rsta = is_cnt; /* set the repeat start bit */
I2C_Set_Ctrl (eumbbar, ctrl);
/* write the slave address and xmit/rcv mode bit */
tmp = load_runtime_reg (eumbbar, I2CDR);
tmp = (tmp & 0xffffff00) |
((slave_addr & 0x007f) << 1) |
(mode == XMIT ? 0x0 : 0x1);
store_runtime_reg (eumbbar, I2CDR, tmp);
if (mode == RCV) {
MasterRcvAddress = 1;
} else {
MasterRcvAddress = 0;
}
#ifdef I2CDBG0
PRINT ("%s(%d): I2C_Start exit\n", __FILE__, __LINE__);
#endif
/* wait for the interrupt or poll */
return I2CSUCCESS;
}
/***********************************************************
* function: I2c_Stop
*
* description: Generate a STOP signal to terminate the master
* transaction.
* return I2CSUCCESS
*
**********************************************************/
static I2CStatus I2C_Stop (unsigned int eumbbar)
{
I2C_CTRL ctrl;
#ifdef I2CDBG0
PRINT ("%s(%d): I2C_Stop enter\n", __FILE__, __LINE__);
#endif
ctrl = I2C_Get_Ctrl (eumbbar);
ctrl.msta = 0;
I2C_Set_Ctrl (eumbbar, ctrl);
#ifdef I2CDBG0
PRINT ("%s(%d): I2C_Stop exit\n", __FILE__, __LINE__);
#endif
return I2CSUCCESS;
}
/****************************************************
* function: I2C_Master_Xmit
*
* description: Master sends one byte of data to
* slave target
*
* return I2CSUCCESS if the byte transmitted.
* Otherwise no-zero
*
* Note: condition must meet when this function is called:
* I2CSR(MIF) == 1 && I2CSR(MCF) == 1 && I2CSR(RXAK) == 0
* I2CCR(MSTA) == 1 && I2CCR(MTX) == 1
*
***************************************************/
static I2CStatus I2C_Master_Xmit (unsigned int eumbbar)
{
unsigned int val;
if (ByteToXmit > 0) {
if (ByteToXmit == XmitByte) {
/* all xmitted */
ByteToXmit = 0;
if (XmitBufEmptyStop == 1) {
I2C_Stop (eumbbar);
}
return I2CBUFFEMPTY;
}
#ifdef I2CDBG0
PRINT ("%s(%d): xmit 0x%02x\n", __FILE__, __LINE__,
*(XmitBuf + XmitByte));
#endif
val = *(XmitBuf + XmitByte);
val &= 0x000000ff;
store_runtime_reg (eumbbar, I2CDR, val);
XmitByte++;
return I2CSUCCESS;
}
return I2CBUFFEMPTY;
}
/***********************************************
* function: I2C_Master_Rcv
*
* description: master reads one byte data
* from slave source
*
* return I2CSUCCESS if no error
*
* Note: condition must meet when this function is called:
* I2CSR(MIF) == 1 && I2CSR(MCF) == 1 &&
* I2CCR(MSTA) == 1 && I2CCR(MTX) == 0
*
***********************************************/
static I2CStatus I2C_Master_Rcv (unsigned int eumbbar)
{
I2C_CTRL ctrl;
unsigned int val;
if (ByteToRcv > 0) {
if (ByteToRcv - RcvByte == 2 && RcvBufFulStop == 1) {
/* master requests more than or equal to 2 bytes
* we are reading 2nd to last byte
*/
/* we need to set I2CCR(TXAK) to generate a STOP */
ctrl = I2C_Get_Ctrl (eumbbar);
ctrl.txak = 1;
I2C_Set_Ctrl (eumbbar, ctrl);
/* Kahlua will automatically generate a STOP
* next time a transaction happens
*/
/* note: the case of master requesting one byte is
* handled in I2C_ISR
*/
}
/* generat a STOP before reading the last byte */
if (RcvByte + 1 == ByteToRcv && RcvBufFulStop == 1) {
I2C_Stop (eumbbar);
}
val = load_runtime_reg (eumbbar, I2CDR);
*(RcvBuf + RcvByte) = val & 0xFF;
#ifdef I2CDBG0
PRINT ("%s(%d): rcv 0x%02x\n", __FILE__, __LINE__,
*(RcvBuf + RcvByte));
#endif
RcvByte++;
if (ByteToRcv == RcvByte) {
ByteToRcv = 0;
return I2CBUFFFULL;
}
return I2CSUCCESS;
}
return I2CBUFFFULL;
}
/****************************************************
* function: I2C_Slave_Xmit
*
* description: Slave sends one byte of data to
* requesting destination
*
* return SUCCESS if the byte transmitted. Otherwise
* No-zero
*
* Note: condition must meet when this function is called:
* I2CSR(MIF) == 1 && I2CSR(MCF) == 1 && I2CSR(RXAK) = 0
* I2CCR(MSTA) == 0 && I2CCR(MTX) == 1
*
***************************************************/
static I2CStatus I2C_Slave_Xmit (unsigned int eumbbar)
{
unsigned int val;
if (ByteToXmit > 0) {
if (ByteToXmit == XmitByte) {
/* no more data to send */
ByteToXmit = 0;
/*
* do not toggle I2CCR(MTX). Doing so will
* cause bus-hung since current Kahlua design
* does not give master a way to detect slave
* stop. It is always a good idea for master
* to use timer to prevent the long long
* delays
*/
return I2CBUFFEMPTY;
}
#ifdef I2CDBG
PRINT ("%s(%d): xmit 0x%02x\n", __FILE__, __LINE__,
*(XmitBuf + XmitByte));
#endif
val = *(XmitBuf + XmitByte);
val &= 0x000000ff;
store_runtime_reg (eumbbar, I2CDR, val);
XmitByte++;
return I2CSUCCESS;
}
return I2CBUFFEMPTY;
}
/***********************************************
* function: I2C_Slave_Rcv
*
* description: slave reads one byte data
* from master source
*
* return I2CSUCCESS if no error otherwise non-zero
*
* Note: condition must meet when this function is called:
* I2CSR(MIF) == 1 && I2CSR(MCF) == 1 &&
* I2CCR(MSTA) == 0 && I2CCR(MTX) = 0
*
***********************************************/
static I2CStatus I2C_Slave_Rcv (unsigned int eumbbar)
{
unsigned int val;
I2C_CTRL ctrl;
if (ByteToRcv > 0) {
val = load_runtime_reg (eumbbar, I2CDR);
*(RcvBuf + RcvByte) = val & 0xff;
#ifdef I2CDBG
PRINT ("%s(%d): rcv 0x%02x\n", __FILE__, __LINE__,
*(RcvBuf + RcvByte));
#endif
RcvByte++;
if (ByteToRcv == RcvByte) {
if (RcvBufFulStop == 1) {
/* all done */
ctrl = I2C_Get_Ctrl (eumbbar);
ctrl.txak = 1;
I2C_Set_Ctrl (eumbbar, ctrl);
}
ByteToRcv = 0;
return I2CBUFFFULL;
}
return I2CSUCCESS;
}
return I2CBUFFFULL;
}
/****************** Device Control Function *************/
/*********************************************************
* function: I2C_Init
*
* description: Initialize I2C unit with desired frequency divider,
* master's listening address, with interrupt enabled
* or disabled.
*
* note:
********************************************************/
static I2CStatus I2C_Init (unsigned int eumbbar, unsigned char fdr, /* frequency divider */
unsigned char slave_addr, /* driver's address used for receiving */
unsigned int en_int)
{ /* 1 - enable I2C interrupt
* 0 - disable I2C interrup
*/
I2C_CTRL ctrl;
unsigned int tmp;
#ifdef I2CDBG0
PRINT ("%s(%d): I2C_Init enter\n", __FILE__, __LINE__);
#endif
ctrl = I2C_Get_Ctrl (eumbbar);
/* disable the I2C module before we change everything */
ctrl.men = 0;
I2C_Set_Ctrl (eumbbar, ctrl);
/* set the frequency diver */
tmp = load_runtime_reg (eumbbar, I2CFDR);
tmp = (tmp & 0xffffffc0) | (fdr & 0x3f);
store_runtime_reg (eumbbar, I2CFDR, tmp);
/* Set our listening (slave) address */
tmp = load_runtime_reg (eumbbar, I2CADR);
tmp = (tmp & 0xffffff01) | ((slave_addr & 0x7f) << 1);
store_runtime_reg (eumbbar, I2CADR, tmp);
/* enable I2C with desired interrupt setting */
ctrl.men = 1;
ctrl.mien = en_int & 0x1;
I2C_Set_Ctrl (eumbbar, ctrl);
#ifdef I2CDBG0
PRINT ("%s(%d): I2C_Init exit\n", __FILE__, __LINE__);
#endif
return I2CSUCCESS;
}
/*****************************************
* function I2c_Get_Stat
*
* description: Query I2C Status, i.e., read I2CSR
*
****************************************/
static I2C_STAT I2C_Get_Stat (unsigned int eumbbar)
{
unsigned int temp;
I2C_STAT stat;
temp = load_runtime_reg (eumbbar, I2CSR);
#ifdef I2CDBG0
PRINT ("%s(%d): get stat = 0x%08x\n", __FILE__, __LINE__, temp);
#endif
stat.rsrv0 = (temp & 0xffffff00) >> 8;
stat.mcf = (temp & 0x00000080) >> 7;
stat.maas = (temp & 0x00000040) >> 6;
stat.mbb = (temp & 0x00000020) >> 5;
stat.mal = (temp & 0x00000010) >> 4;
stat.rsrv1 = (temp & 0x00000008) >> 3;
stat.srw = (temp & 0x00000004) >> 2;
stat.mif = (temp & 0x00000002) >> 1;
stat.rxak = (temp & 0x00000001);
return stat;
}
/*********************************************
* function: I2c_Set_Ctrl
*
* description: Change I2C Control bits,
* i.e., write to I2CCR
*
********************************************/
static void I2C_Set_Ctrl (unsigned int eumbbar, I2C_CTRL ctrl)
{ /* new control value */
unsigned int temp = load_runtime_reg (eumbbar, I2CCR);
temp &= 0xffffff03;
temp |= ((ctrl.men & 0x1) << 7);
temp |= ((ctrl.mien & 0x1) << 6);
temp |= ((ctrl.msta & 0x1) << 5);
temp |= ((ctrl.mtx & 0x1) << 4);
temp |= ((ctrl.txak & 0x1) << 3);
temp |= ((ctrl.rsta & 0x1) << 2);
#ifdef I2CDBG0
PRINT ("%s(%d): set ctrl = 0x%08x\n", __FILE__, __LINE__, temp);
#endif
store_runtime_reg (eumbbar, I2CCR, temp);
}
/*****************************************
* function: I2C_Get_Ctrl
*
* description: Query I2C Control bits,
* i.e., read I2CCR
*****************************************/
static I2C_CTRL I2C_Get_Ctrl (unsigned int eumbbar)
{
union {
I2C_CTRL ctrl;
unsigned int temp;
} s;
s.temp = load_runtime_reg (eumbbar, I2CCR);
#ifdef I2CDBG0
PRINT ("%s(%d): get ctrl = 0x%08x\n", __FILE__, __LINE__, s.temp);
#endif
return s.ctrl;
}
/****************************************
* function: I2C_Slave_Addr
*
* description: Process slave address phase.
* return I2CSUCCESS if no error
*
* note: Precondition for calling this function:
* I2CSR(MIF) == 1 &&
* I2CSR(MAAS) == 1
****************************************/
static I2CStatus I2C_Slave_Addr (unsigned int eumbbar)
{
I2C_STAT stat = I2C_Get_Stat (eumbbar);
I2C_CTRL ctrl = I2C_Get_Ctrl (eumbbar);
if (stat.srw == 1) {
/* we are asked to xmit */
ctrl.mtx = 1;
I2C_Set_Ctrl (eumbbar, ctrl); /* set MTX */
return I2C_Slave_Xmit (eumbbar);
}
/* we are asked to receive data */
ctrl.mtx = 0;
I2C_Set_Ctrl (eumbbar, ctrl);
(void) load_runtime_reg (eumbbar, I2CDR); /* do a fake read to start */
return I2CADDRESS;
}
/***********************************************
* function: I2C_ISR
*
* description: I2C Interrupt service routine
*
* note: Precondition:
* I2CSR(MIF) == 1
**********************************************/
static I2CStatus I2C_ISR (unsigned int eumbbar)
{
I2C_STAT stat;
I2C_CTRL ctrl;
#ifdef I2CDBG0
PRINT ("%s(%d): I2C_ISR\n", __FILE__, __LINE__);
#endif
stat = I2C_Get_Stat (eumbbar);
ctrl = I2C_Get_Ctrl (eumbbar);
/* clear MIF */
stat.mif = 0;
/* Now let see what kind of event this is */
if (stat.mcf == 1) {
/* transfer compete */
/* clear the MIF bit */
I2C_Set_Stat (eumbbar, stat);
if (ctrl.msta == 1) {
/* master */
if (ctrl.mtx == 1) {
/* check if this is the address phase for master receive */
if (MasterRcvAddress == 1) {
/* Yes, it is the address phase of master receive */
ctrl.mtx = 0;
/* now check how much we want to receive */
if (ByteToRcv == 1 && RcvBufFulStop == 1) {
ctrl.txak = 1;
}
I2C_Set_Ctrl (eumbbar, ctrl);
(void) load_runtime_reg (eumbbar, I2CDR); /* fake read first */
MasterRcvAddress = 0;
return I2CADDRESS;
}
/* master xmit */
if (stat.rxak == 0) {
/* slave has acknowledged */
return I2C_Master_Xmit (eumbbar);
}
/* slave has not acknowledged yet, generate a STOP */
if (XmitBufEmptyStop == 1) {
ctrl.msta = 0;
I2C_Set_Ctrl (eumbbar, ctrl);
}
return I2CSUCCESS;
}
/* master receive */
return I2C_Master_Rcv (eumbbar);
}
/* slave */
if (ctrl.mtx == 1) {
/* slave xmit */
if (stat.rxak == 0) {
/* master has acknowledged */
return I2C_Slave_Xmit (eumbbar);
}
/* master has not acknowledged, wait for STOP */
/* do nothing for preventing bus from hung */
return I2CSUCCESS;
}
/* slave rcv */
return I2C_Slave_Rcv (eumbbar);
} else if (stat.maas == 1) {
/* received a call from master */
/* clear the MIF bit */
I2C_Set_Stat (eumbbar, stat);
/* master is calling us, process the address phase */
return I2C_Slave_Addr (eumbbar);
} else {
/* has to be arbitration lost */
stat.mal = 0;
I2C_Set_Stat (eumbbar, stat);
ctrl.msta = 0; /* return to receive mode */
I2C_Set_Ctrl (eumbbar, ctrl);
}
return I2CSUCCESS;
}
/******************************************************
* function: I2C_Set_Stat
*
* description: modify the I2CSR
*
*****************************************************/
static void I2C_Set_Stat (unsigned int eumbbar, I2C_STAT stat)
{
union {
unsigned int val;
I2C_STAT stat;
} s_tmp;
union {
unsigned int val;
I2C_STAT stat;
} s;
s.val = load_runtime_reg (eumbbar, I2CSR);
s.val &= 0xffffff08;
s_tmp.stat = stat;
s.val |= (s_tmp.val & 0xf7);
#ifdef I2CDBG0
PRINT ("%s(%d): set stat = 0x%08x\n", __FILE__, __LINE__, s.val);
#endif
store_runtime_reg (eumbbar, I2CSR, s.val);
}
/******************************************************
* The following are routines to glue the rest of
* U-Boot to the Sandpoint I2C driver.
*****************************************************/
void i2c_init (int speed, int slaveadd)
{
#ifdef CFG_I2C_INIT_BOARD
/*
* call board specific i2c bus reset routine before accessing the
* environment, which might be in a chip on that bus. For details
* about this problem see doc/I2C_Edge_Conditions.
*/
i2c_init_board();
#endif
#ifdef DEBUG
I2C_Initialize (0x7f, 0, (void *) printf);
#else
I2C_Initialize (0x7f, 0, 0);
#endif
}
int i2c_probe (uchar chip)
{
int tmp;
/*
* Try to read the first location of the chip. The underlying
* driver doesn't appear to support sending just the chip address
* and looking for an <ACK> back.
*/
udelay(10000);
return i2c_read (chip, 0, 1, (char *)&tmp, 1);
}
int i2c_read (uchar chip, uint addr, int alen, uchar * buffer, int len)
{
I2CStatus status;
uchar xaddr[4];
if (alen > 0) {
xaddr[0] = (addr >> 24) & 0xFF;
xaddr[1] = (addr >> 16) & 0xFF;
xaddr[2] = (addr >> 8) & 0xFF;
xaddr[3] = addr & 0xFF;
status = I2C_do_buffer (0, I2C_MASTER_XMIT, chip, alen,
&xaddr[4 - alen], I2C_NO_STOP, 1,
I2C_NO_RESTART);
if (status != I2C_SUCCESS) {
PRINT ("i2c_read: can't send data address for read\n");
return 1;
}
}
/* The data transfer will be a continuation. */
status = I2C_do_buffer (0, I2C_MASTER_RCV, chip, len,
buffer, I2C_STOP, 1, (alen > 0 ? I2C_RESTART :
I2C_NO_RESTART));
if (status != I2C_SUCCESS) {
PRINT ("i2c_read: can't perform data transfer\n");
return 1;
}
return 0;
}
int i2c_write (uchar chip, uint addr, int alen, uchar * buffer, int len)
{
I2CStatus status;
uchar dummy_buffer[I2C_RXTX_LEN + 2];
uchar *p;
int i;
/* fill in address in big endian order */
for (i=alen-1; i>=0; --i) {
buffer[i] = addr & 0xFF;
addr >>= 8;
}
/* fill in data */
p = dummy_buffer + alen;
for (i=0; i<len; ++i)
*p++ = *buffer++;
status = I2C_do_buffer (0, I2C_MASTER_XMIT, chip, alen + len,
dummy_buffer, I2C_STOP, 1, I2C_NO_RESTART);
#ifdef CFG_EEPROM_PAGE_WRITE_DELAY_MS
udelay(CFG_EEPROM_PAGE_WRITE_DELAY_MS * 1000);
#endif
if (status != I2C_SUCCESS) {
PRINT ("i2c_write: can't perform data transfer\n");
return 1;
}
return 0;
}
uchar i2c_reg_read (uchar i2c_addr, uchar reg)
{
char buf[1];
i2c_init (0, 0);
i2c_read (i2c_addr, reg, 1, buf, 1);
return (buf[0]);
}
void i2c_reg_write (uchar i2c_addr, uchar reg, uchar val)
{
i2c_init (0, 0);
i2c_write (i2c_addr, reg, 1, &val, 1);
}
#endif /* CONFIG_HARD_I2C */
