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/****************************************************************************/
/**
*
* @file xuartns550_format.c
*
* This file contains the data format functions for the 16450/16550 UART driver.
* The data format functions allow the baud rate, number of data bits, number
* of stop bits and parity to be set and retrieved.
*
*
* MODIFICATION HISTORY:
*
* Ver Who Date Changes
* ----- ---- -------- -----------------------------------------------
* 1.00b jhl 03/11/02 Repartitioned driver for smaller files.
* 1.00b rmm 05/15/03 Fixed diab compiler warnings.
* 1.11a sv 03/20/07 Updated to use the new coding guidelines.
* 2.00a ktn 10/20/09 Converted all register accesses to 32 bit access.
* Updated to use HAL Processor APIs. _m is removed from the
* name of all the macro names/definitions.
*
*
*****************************************************************************/
/***************************** Include Files ********************************/
#include "xstatus.h"
#include "xuartns550.h"
#include "xuartns550_i.h"
#include "xil_io.h"
/************************** Constant Definitions ****************************/
/**************************** Type Definitions ******************************/
/***************** Macros (Inline Functions) Definitions ********************/
/************************** Variable Definitions ****************************/
/************************** Function Prototypes *****************************/
/****************************************************************************/
/**
*
* Sets the data format for the specified UART. The data format includes the
* baud rate, number of data bits, number of stop bits, and parity. It is the
* caller's responsibility to ensure that the UART is not sending or receiving
* data when this function is called.
*
* @param InstancePtr is a pointer to the XUartNs550 instance .
* @param FormatPtr is a pointer to a format structure containing the data
* format to be set.
*
* @return
*
* - XST_SUCCESS if the data format was successfully set.
* - XST_UART_BAUD_ERROR indicates the baud rate could not be set
* because of the amount of error with the baud rate and the input
* clock frequency.
* - XST_INVALID_PARAM if one of the parameters was not valid.
*
* @note
*
* The data types in the format type, data bits and parity, are 32 bit fields
* to prevent a compiler warning that is a bug with the GNU PowerPC compiler.
* The asserts in this function will cause a warning if these fields are
* bytes.
*
* The baud rates tested include: 1200, 2400, 4800, 9600, 19200, 38400, 57600
* and 115200.
*
*****************************************************************************/
int XUartNs550_SetDataFormat(XUartNs550 *InstancePtr,
XUartNs550Format *FormatPtr)
{
int Status;
u32 LcrRegister;
Xil_AssertNonvoid(InstancePtr != NULL);
Xil_AssertNonvoid(FormatPtr != NULL);
/*
* Verify the inputs specified are valid and return an error if any
* are not, without setting the data format
*/
if ((FormatPtr->DataBits > XUN_FORMAT_8_BITS) ||
(FormatPtr->Parity > XUN_FORMAT_EVEN_PARITY) ||
((FormatPtr->StopBits != XUN_FORMAT_2_STOP_BIT) &&
(FormatPtr->StopBits != XUN_FORMAT_1_STOP_BIT))) {
return XST_INVALID_PARAM;
}
/*
* Try to set the baud rate and if it's not successful then don't
* continue altering the data format, this is done first to avoid the
* format from being altered when an error occurs
*/
Status = XUartNs550_SetBaudRate(InstancePtr, FormatPtr->BaudRate);
if (Status != XST_SUCCESS) {
return Status;
}
/*
* Read the line control register which contains the parity, length and
* stop bits so they can be updated without affecting any other bits
*/
LcrRegister = XUartNs550_GetLineControlReg(InstancePtr->BaseAddress);
/*
* Set the length of data (8,7,6,5) by first clearing out the bits
* that control it in the register, then set the length in the register
*/
LcrRegister &= ~XUN_LCR_LENGTH_MASK;
LcrRegister |= FormatPtr->DataBits;
/*
* Set the number of stop bits in the line control register, if the
* number of stop bits is not 2, then it must be one which is the bit
* in the register cleared
*/
if (FormatPtr->StopBits == XUN_FORMAT_2_STOP_BIT) {
LcrRegister |= XUN_LCR_2_STOP_BITS;
} else {
LcrRegister &= ~XUN_LCR_2_STOP_BITS;
}
/*
* Set the parity by first clearing out the bits that control it in the
* register, then set the bits in the register, the default is no parity
* after clearing the register bits
*/
LcrRegister &= ~XUN_LCR_PARITY_MASK;
if (FormatPtr->Parity != XUN_FORMAT_NO_PARITY) {
/*
* Some form of parity is specified, set the bit indicating that
* parity is enabled, then setup even or odd, the default is odd
* after clearing the register bits
*/
LcrRegister |= XUN_LCR_ENABLE_PARITY;
if (FormatPtr->Parity == XUN_FORMAT_EVEN_PARITY) {
LcrRegister |= XUN_LCR_EVEN_PARITY;
}
}
/*
* Write the line control register out to save the new data format
* that has been created
*/
XUartNs550_SetLineControlReg(InstancePtr->BaseAddress, LcrRegister);
return XST_SUCCESS;
}
/****************************************************************************/
/**
*
* Gets the data format for the specified UART. The data format includes the
* baud rate, number of data bits, number of stop bits, and parity.
*
* @param InstancePtr is a pointer to the XUartNs550 instance.
* @param FormatPtr is a pointer to a format structure that will contain
* the data format after this call completes.
*
* @return None.
*
* @note None.
*
* @internal
*
* This function gets the state of the hardware rather than returning a state
* that has been stored to ensure that the hardware is correct.
*
*****************************************************************************/
void XUartNs550_GetDataFormat(XUartNs550 *InstancePtr,
XUartNs550Format *FormatPtr)
{
u32 LcrRegister;
Xil_AssertVoid(InstancePtr != NULL);
Xil_AssertVoid(FormatPtr != NULL);
/*
* Assert validates the input arguments
*/
Xil_AssertVoid(InstancePtr != NULL);
Xil_AssertVoid(InstancePtr->IsReady == XIL_COMPONENT_IS_READY);
/*
* Get the baud rate from the instance, this is not retrieved from the
* hardware because it is only kept as a divisor such that it is more
* difficult to get back to the divisor
*/
FormatPtr->BaudRate = InstancePtr->BaudRate;
/*
* Read the line control register which contains the parity, length and
* stop bits so they can be updated without affecting any other bits
*/
LcrRegister = XUartNs550_GetLineControlReg(InstancePtr->BaseAddress);
/*
* Set the length of data (8,7,6,5) by first clearing out the bits
* that control it in the register, then set the length in the register
*/
FormatPtr->DataBits = LcrRegister & XUN_LCR_LENGTH_MASK;
/*
* Set the number of stop bits by first clearing out the bits in that
* control it in the register, then set the bits in the register, the
* default is one stop bit after clearing the register bits
*/
if (LcrRegister & XUN_LCR_2_STOP_BITS) {
FormatPtr->StopBits = XUN_FORMAT_2_STOP_BIT;
} else {
FormatPtr->StopBits = XUN_FORMAT_1_STOP_BIT;
}
/*
* Determine what parity is set from the register and setup the format
* to correspond
*/
if ((LcrRegister & XUN_LCR_ENABLE_PARITY) == 0) {
FormatPtr->Parity = XUN_FORMAT_NO_PARITY;
} else {
/*
* Parity is enables, so determine if it's even or odd and set the
* format to correspond
*/
if (LcrRegister & XUN_LCR_EVEN_PARITY) {
FormatPtr->Parity = XUN_FORMAT_EVEN_PARITY;
} else {
FormatPtr->Parity = XUN_FORMAT_ODD_PARITY;
}
}
}