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audk/ArmPlatformPkg/Drivers/PL011Uart/PL011Uart.c

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/** @file
Serial I/O Port library functions with no library constructor/destructor
Copyright (c) 2008 - 2010, Apple Inc. All rights reserved.<BR>
Copyright (c) 2011 - 2016, ARM Ltd. All rights reserved.<BR>
This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution. The full text of the license may be found at
http://opensource.org/licenses/bsd-license.php
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
**/
#include <Library/DebugLib.h>
#include <Library/IoLib.h>
#include <Library/PcdLib.h>
#include <Drivers/PL011Uart.h>
#define FRACTION_PART_SIZE_IN_BITS 6
#define FRACTION_PART_MASK ((1 << FRACTION_PART_SIZE_IN_BITS) - 1)
//
// EFI_SERIAL_SOFTWARE_LOOPBACK_ENABLE is the only
// control bit that is not supported.
//
STATIC CONST UINT32 mInvalidControlBits = EFI_SERIAL_SOFTWARE_LOOPBACK_ENABLE;
/**
Initialise the serial port to the specified settings.
The serial port is re-configured only if the specified settings
are different from the current settings.
All unspecified settings will be set to the default values.
@param UartBase The base address of the serial device.
@param UartClkInHz The clock in Hz for the serial device.
Ignored if the PCD PL011UartInteger is not 0
@param BaudRate The baud rate of the serial device. If the
baud rate is not supported, the speed will be
reduced to the nearest supported one and the
variable's value will be updated accordingly.
@param ReceiveFifoDepth The number of characters the device will
buffer on input. Value of 0 will use the
device's default FIFO depth.
@param Parity If applicable, this is the EFI_PARITY_TYPE
that is computed or checked as each character
is transmitted or received. If the device
does not support parity, the value is the
default parity value.
@param DataBits The number of data bits in each character.
@param StopBits If applicable, the EFI_STOP_BITS_TYPE number
of stop bits per character.
If the device does not support stop bits, the
value is the default stop bit value.
@retval RETURN_SUCCESS All attributes were set correctly on the
serial device.
@retval RETURN_INVALID_PARAMETER One or more of the attributes has an
unsupported value.
**/
RETURN_STATUS
EFIAPI
PL011UartInitializePort (
IN UINTN UartBase,
IN UINT32 UartClkInHz,
IN OUT UINT64 *BaudRate,
IN OUT UINT32 *ReceiveFifoDepth,
IN OUT EFI_PARITY_TYPE *Parity,
IN OUT UINT8 *DataBits,
IN OUT EFI_STOP_BITS_TYPE *StopBits
)
{
UINT32 LineControl;
UINT32 Divisor;
UINT32 Integer;
UINT32 Fractional;
// The PL011 supports a buffer of 1, 16 or 32 chars. Therefore we can accept
// 1 char buffer as the minimum FIFO size. Because everything can be rounded
// down, there is no maximum FIFO size.
if ((*ReceiveFifoDepth == 0) || (*ReceiveFifoDepth >= 32)) {
// Enable FIFO
LineControl = PL011_UARTLCR_H_FEN;
if (PL011_UARTPID2_VER (MmioRead32 (UartBase + UARTPID2)) > PL011_VER_R1P4)
*ReceiveFifoDepth = 32;
else
*ReceiveFifoDepth = 16;
} else {
// Disable FIFO
LineControl = 0;
// Nothing else to do. 1 byte FIFO is default.
*ReceiveFifoDepth = 1;
}
//
// Parity
//
switch (*Parity) {
case DefaultParity:
*Parity = NoParity;
case NoParity:
// Nothing to do. Parity is disabled by default.
break;
case EvenParity:
LineControl |= (PL011_UARTLCR_H_PEN | PL011_UARTLCR_H_EPS);
break;
case OddParity:
LineControl |= PL011_UARTLCR_H_PEN;
break;
case MarkParity:
LineControl |= ( PL011_UARTLCR_H_PEN \
| PL011_UARTLCR_H_SPS \
| PL011_UARTLCR_H_EPS);
break;
case SpaceParity:
LineControl |= (PL011_UARTLCR_H_PEN | PL011_UARTLCR_H_SPS);
break;
default:
return RETURN_INVALID_PARAMETER;
}
//
// Data Bits
//
switch (*DataBits) {
case 0:
*DataBits = 8;
case 8:
LineControl |= PL011_UARTLCR_H_WLEN_8;
break;
case 7:
LineControl |= PL011_UARTLCR_H_WLEN_7;
break;
case 6:
LineControl |= PL011_UARTLCR_H_WLEN_6;
break;
case 5:
LineControl |= PL011_UARTLCR_H_WLEN_5;
break;
default:
return RETURN_INVALID_PARAMETER;
}
//
// Stop Bits
//
switch (*StopBits) {
case DefaultStopBits:
*StopBits = OneStopBit;
case OneStopBit:
// Nothing to do. One stop bit is enabled by default.
break;
case TwoStopBits:
LineControl |= PL011_UARTLCR_H_STP2;
break;
case OneFiveStopBits:
// Only 1 or 2 stop bits are supported
default:
return RETURN_INVALID_PARAMETER;
}
// Don't send the LineControl value to the PL011 yet,
// wait until after the Baud Rate setting.
// This ensures we do not mess up the UART settings halfway through
// in the rare case when there is an error with the Baud Rate.
//
// Baud Rate
//
// If PL011 Integer value has been defined then always ignore the BAUD rate
if (FixedPcdGet32 (PL011UartInteger) != 0) {
Integer = FixedPcdGet32 (PL011UartInteger);
Fractional = FixedPcdGet32 (PL011UartFractional);
} else {
// If BAUD rate is zero then replace it with the system default value
if (*BaudRate == 0) {
*BaudRate = FixedPcdGet32 (PcdSerialBaudRate);
if (*BaudRate == 0) {
return RETURN_INVALID_PARAMETER;
}
}
if (0 == UartClkInHz) {
return RETURN_INVALID_PARAMETER;
}
Divisor = (UartClkInHz * 4) / *BaudRate;
Integer = Divisor >> FRACTION_PART_SIZE_IN_BITS;
Fractional = Divisor & FRACTION_PART_MASK;
}
//
// If PL011 is already initialized, check the current settings
// and re-initialize only if the settings are different.
//
if (((MmioRead32 (UartBase + UARTCR) & PL011_UARTCR_UARTEN) != 0) &&
(MmioRead32 (UartBase + UARTLCR_H) == LineControl) &&
(MmioRead32 (UartBase + UARTIBRD) == Integer) &&
(MmioRead32 (UartBase + UARTFBRD) == Fractional)) {
// Nothing to do - already initialized with correct attributes
return RETURN_SUCCESS;
}
// Wait for the end of transmission
while ((MmioRead32 (UartBase + UARTFR) & PL011_UARTFR_TXFE) == 0);
// Disable UART: "The UARTLCR_H, UARTIBRD, and UARTFBRD registers must not be changed
// when the UART is enabled"
MmioWrite32 (UartBase + UARTCR, 0);
// Set Baud Rate Registers
MmioWrite32 (UartBase + UARTIBRD, Integer);
MmioWrite32 (UartBase + UARTFBRD, Fractional);
// No parity, 1 stop, no fifo, 8 data bits
MmioWrite32 (UartBase + UARTLCR_H, LineControl);
// Clear any pending errors
MmioWrite32 (UartBase + UARTECR, 0);
// Enable Tx, Rx, and UART overall
MmioWrite32 (UartBase + UARTCR,
PL011_UARTCR_RXE | PL011_UARTCR_TXE | PL011_UARTCR_UARTEN);
return RETURN_SUCCESS;
}
/**
Assert or deassert the control signals on a serial port.
The following control signals are set according their bit settings :
. Request to Send
. Data Terminal Ready
@param[in] UartBase UART registers base address
@param[in] Control The following bits are taken into account :
. EFI_SERIAL_REQUEST_TO_SEND : assert/deassert the
"Request To Send" control signal if this bit is
equal to one/zero.
. EFI_SERIAL_DATA_TERMINAL_READY : assert/deassert
the "Data Terminal Ready" control signal if this
bit is equal to one/zero.
. EFI_SERIAL_HARDWARE_LOOPBACK_ENABLE : enable/disable
the hardware loopback if this bit is equal to
one/zero.
. EFI_SERIAL_SOFTWARE_LOOPBACK_ENABLE : not supported.
. EFI_SERIAL_HARDWARE_FLOW_CONTROL_ENABLE : enable/
disable the hardware flow control based on CTS (Clear
To Send) and RTS (Ready To Send) control signals.
@retval RETURN_SUCCESS The new control bits were set on the device.
@retval RETURN_UNSUPPORTED The device does not support this operation.
**/
RETURN_STATUS
EFIAPI
PL011UartSetControl (
IN UINTN UartBase,
IN UINT32 Control
)
{
UINT32 Bits;
if (Control & (mInvalidControlBits)) {
return RETURN_UNSUPPORTED;
}
Bits = MmioRead32 (UartBase + UARTCR);
if (Control & EFI_SERIAL_REQUEST_TO_SEND) {
Bits |= PL011_UARTCR_RTS;
} else {
Bits &= ~PL011_UARTCR_RTS;
}
if (Control & EFI_SERIAL_DATA_TERMINAL_READY) {
Bits |= PL011_UARTCR_DTR;
} else {
Bits &= ~PL011_UARTCR_DTR;
}
if (Control & EFI_SERIAL_HARDWARE_LOOPBACK_ENABLE) {
Bits |= PL011_UARTCR_LBE;
} else {
Bits &= ~PL011_UARTCR_LBE;
}
if (Control & EFI_SERIAL_HARDWARE_FLOW_CONTROL_ENABLE) {
Bits |= (PL011_UARTCR_CTSEN | PL011_UARTCR_RTSEN);
} else {
Bits &= ~(PL011_UARTCR_CTSEN | PL011_UARTCR_RTSEN);
}
MmioWrite32 (UartBase + UARTCR, Bits);
return RETURN_SUCCESS;
}
/**
Retrieve the status of the control bits on a serial device.
@param[in] UartBase UART registers base address
@param[out] Control Status of the control bits on a serial device :
. EFI_SERIAL_DATA_CLEAR_TO_SEND,
EFI_SERIAL_DATA_SET_READY,
EFI_SERIAL_RING_INDICATE,
EFI_SERIAL_CARRIER_DETECT,
EFI_SERIAL_REQUEST_TO_SEND,
EFI_SERIAL_DATA_TERMINAL_READY
are all related to the DTE (Data Terminal Equipment)
and DCE (Data Communication Equipment) modes of
operation of the serial device.
. EFI_SERIAL_INPUT_BUFFER_EMPTY : equal to one if the
receive buffer is empty, 0 otherwise.
. EFI_SERIAL_OUTPUT_BUFFER_EMPTY : equal to one if the
transmit buffer is empty, 0 otherwise.
. EFI_SERIAL_HARDWARE_LOOPBACK_ENABLE : equal to one if
the hardware loopback is enabled (the ouput feeds the
receive buffer), 0 otherwise.
. EFI_SERIAL_SOFTWARE_LOOPBACK_ENABLE : equal to one if
a loopback is accomplished by software, 0 otherwise.
. EFI_SERIAL_HARDWARE_FLOW_CONTROL_ENABLE : equal to
one if the hardware flow control based on CTS (Clear
To Send) and RTS (Ready To Send) control signals is
enabled, 0 otherwise.
@retval RETURN_SUCCESS The control bits were read from the serial device.
**/
RETURN_STATUS
EFIAPI
PL011UartGetControl (
IN UINTN UartBase,
OUT UINT32 *Control
)
{
UINT32 FlagRegister;
UINT32 ControlRegister;
FlagRegister = MmioRead32 (UartBase + UARTFR);
ControlRegister = MmioRead32 (UartBase + UARTCR);
*Control = 0;
if ((FlagRegister & PL011_UARTFR_CTS) == PL011_UARTFR_CTS) {
*Control |= EFI_SERIAL_CLEAR_TO_SEND;
}
if ((FlagRegister & PL011_UARTFR_DSR) == PL011_UARTFR_DSR) {
*Control |= EFI_SERIAL_DATA_SET_READY;
}
if ((FlagRegister & PL011_UARTFR_RI) == PL011_UARTFR_RI) {
*Control |= EFI_SERIAL_RING_INDICATE;
}
if ((FlagRegister & PL011_UARTFR_DCD) == PL011_UARTFR_DCD) {
*Control |= EFI_SERIAL_CARRIER_DETECT;
}
if ((ControlRegister & PL011_UARTCR_RTS) == PL011_UARTCR_RTS) {
*Control |= EFI_SERIAL_REQUEST_TO_SEND;
}
if ((ControlRegister & PL011_UARTCR_DTR) == PL011_UARTCR_DTR) {
*Control |= EFI_SERIAL_DATA_TERMINAL_READY;
}
if ((FlagRegister & PL011_UARTFR_RXFE) == PL011_UARTFR_RXFE) {
*Control |= EFI_SERIAL_INPUT_BUFFER_EMPTY;
}
if ((FlagRegister & PL011_UARTFR_TXFE) == PL011_UARTFR_TXFE) {
*Control |= EFI_SERIAL_OUTPUT_BUFFER_EMPTY;
}
if ((ControlRegister & (PL011_UARTCR_CTSEN | PL011_UARTCR_RTSEN))
== (PL011_UARTCR_CTSEN | PL011_UARTCR_RTSEN)) {
*Control |= EFI_SERIAL_HARDWARE_FLOW_CONTROL_ENABLE;
}
if ((ControlRegister & PL011_UARTCR_LBE) == PL011_UARTCR_LBE) {
*Control |= EFI_SERIAL_HARDWARE_LOOPBACK_ENABLE;
}
return RETURN_SUCCESS;
}
/**
Write data to serial device.
@param Buffer Point of data buffer which need to be written.
@param NumberOfBytes Number of output bytes which are cached in Buffer.
@retval 0 Write data failed.
@retval !0 Actual number of bytes written to serial device.
**/
UINTN
EFIAPI
PL011UartWrite (
IN UINTN UartBase,
IN UINT8 *Buffer,
IN UINTN NumberOfBytes
)
{
UINT8* CONST Final = &Buffer[NumberOfBytes];
while (Buffer < Final) {
// Wait until UART able to accept another char
while ((MmioRead32 (UartBase + UARTFR) & UART_TX_FULL_FLAG_MASK));
MmioWrite8 (UartBase + UARTDR, *Buffer++);
}
return NumberOfBytes;
}
/**
Read data from serial device and save the data in buffer.
@param Buffer Point of data buffer which need to be written.
@param NumberOfBytes Number of output bytes which are cached in Buffer.
@retval 0 Read data failed.
@retval !0 Actual number of bytes read from serial device.
**/
UINTN
EFIAPI
PL011UartRead (
IN UINTN UartBase,
OUT UINT8 *Buffer,
IN UINTN NumberOfBytes
)
{
UINTN Count;
for (Count = 0; Count < NumberOfBytes; Count++, Buffer++) {
while ((MmioRead32 (UartBase + UARTFR) & UART_RX_EMPTY_FLAG_MASK) != 0);
*Buffer = MmioRead8 (UartBase + UARTDR);
}
return NumberOfBytes;
}
/**
Check to see if any data is available to be read from the debug device.
@retval EFI_SUCCESS At least one byte of data is available to be read
@retval EFI_NOT_READY No data is available to be read
@retval EFI_DEVICE_ERROR The serial device is not functioning properly
**/
BOOLEAN
EFIAPI
PL011UartPoll (
IN UINTN UartBase
)
{
return ((MmioRead32 (UartBase + UARTFR) & UART_RX_EMPTY_FLAG_MASK) == 0);
}
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