diff options
Diffstat (limited to 'cpu/mpc824x/drivers/i2c')
| -rw-r--r-- | cpu/mpc824x/drivers/i2c/i2c1.c | 85 |
1 files changed, 44 insertions, 41 deletions
diff --git a/cpu/mpc824x/drivers/i2c/i2c1.c b/cpu/mpc824x/drivers/i2c/i2c1.c index 7a2eb66656..dc1c97ca0f 100644 --- a/cpu/mpc824x/drivers/i2c/i2c1.c +++ b/cpu/mpc824x/drivers/i2c/i2c1.c @@ -125,10 +125,10 @@ I2C_Status I2C_Initialize (unsigned char addr, * 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 + * 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_RESTART, this is a continuation of existing transaction */ I2C_Status I2C_do_transaction ( I2C_INTERRUPT_MODE en_int, I2C_TRANSACTION_MODE act, @@ -191,12 +191,12 @@ I2C_Status I2C_do_transaction ( I2C_INTERRUPT_MODE en_int, } /* - * 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. + * 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); @@ -231,10 +231,10 @@ I2C_Status I2C_do_transaction ( I2C_INTERRUPT_MODE en_int, * 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 + * 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_RESTART, this is a continuation of existing transaction */ static I2C_Status I2C_do_buffer (I2C_INTERRUPT_MODE en_int, I2C_TRANSACTION_MODE act, @@ -518,9 +518,9 @@ static I2CStatus I2C_Timer_Event (unsigned int eumbbar, * function: I2C_Start * * description: Generate a START signal in the desired mode. - * I2C is the master. + * I2C is the master. * - * Return I2CSUCCESS if no error. + * Return I2CSUCCESS if no error. * * note: ****************************************************/ @@ -594,8 +594,8 @@ static I2CStatus I2C_Start (unsigned int eumbbar, unsigned char slave_addr, /* a * function: I2c_Stop * * description: Generate a STOP signal to terminate the master - * transaction. - * return I2CSUCCESS + * transaction. + * return I2CSUCCESS * **********************************************************/ static I2CStatus I2C_Stop (unsigned int eumbbar) @@ -621,10 +621,10 @@ static I2CStatus I2C_Stop (unsigned int eumbbar) * function: I2C_Master_Xmit * * description: Master sends one byte of data to - * slave target + * slave target * - * return I2CSUCCESS if the byte transmitted. - * Otherwise no-zero + * 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 @@ -669,9 +669,9 @@ static I2CStatus I2C_Master_Xmit (unsigned int eumbbar) * function: I2C_Master_Rcv * * description: master reads one byte data - * from slave source + * from slave source * - * return I2CSUCCESS if no error + * return I2CSUCCESS if no error * * Note: condition must meet when this function is called: * I2CSR(MIF) == 1 && I2CSR(MCF) == 1 && @@ -736,10 +736,10 @@ static I2CStatus I2C_Master_Rcv (unsigned int eumbbar) * function: I2C_Slave_Xmit * * description: Slave sends one byte of data to - * requesting destination + * requesting destination * - * return SUCCESS if the byte transmitted. Otherwise - * No-zero + * 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 @@ -757,12 +757,12 @@ static I2CStatus I2C_Slave_Xmit (unsigned int eumbbar) 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 + * 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; @@ -787,9 +787,9 @@ static I2CStatus I2C_Slave_Xmit (unsigned int eumbbar) * function: I2C_Slave_Rcv * * description: slave reads one byte data - * from master source + * from master source * - * return I2CSUCCESS if no error otherwise non-zero + * return I2CSUCCESS if no error otherwise non-zero * * Note: condition must meet when this function is called: * I2CSR(MIF) == 1 && I2CSR(MCF) == 1 && @@ -834,8 +834,8 @@ static I2CStatus I2C_Slave_Rcv (unsigned int eumbbar) * function: I2C_Init * * description: Initialize I2C unit with desired frequency divider, - * master's listening address, with interrupt enabled - * or disabled. + * master's listening address, with interrupt enabled + * or disabled. * * note: ********************************************************/ @@ -912,7 +912,7 @@ static I2C_STAT I2C_Get_Stat (unsigned int eumbbar) * function: I2c_Set_Ctrl * * description: Change I2C Control bits, - * i.e., write to I2CCR + * i.e., write to I2CCR * ********************************************/ static void I2C_Set_Ctrl (unsigned int eumbbar, I2C_CTRL ctrl) @@ -937,7 +937,7 @@ static void I2C_Set_Ctrl (unsigned int eumbbar, I2C_CTRL ctrl) * function: I2C_Get_Ctrl * * description: Query I2C Control bits, - * i.e., read I2CCR + * i.e., read I2CCR *****************************************/ static I2C_CTRL I2C_Get_Ctrl (unsigned int eumbbar) { @@ -959,7 +959,7 @@ static I2C_CTRL I2C_Get_Ctrl (unsigned int eumbbar) * function: I2C_Slave_Addr * * description: Process slave address phase. - * return I2CSUCCESS if no error + * return I2CSUCCESS if no error * * note: Precondition for calling this function: * I2CSR(MIF) == 1 && @@ -1193,14 +1193,17 @@ int i2c_read (uchar chip, uint addr, int alen, uchar * buffer, int len) int i2c_write (uchar chip, uint addr, int alen, uchar * buffer, int len) { I2CStatus status; - unsigned char dummy_buffer[I2C_RXTX_LEN + 2]; + uchar dummy_buffer[I2C_RXTX_LEN + 2]; + uchar *p; int i; - dummy_buffer[0] = addr & 0xFF; - if (alen == 2) - dummy_buffer[1] = (addr >> 8) & 0xFF; - for (i = 0; i < len; i++) - dummy_buffer[i + alen] = buffer[i]; + p = dummy_buffer; + /* fill in address in big endian order */ + for (i=0; i<alen; ++i) + *p++ = (addr >> (i * 8)) & 0xFF; + /* fill in data */ + 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); |