diff options
Diffstat (limited to 'ArmPlatformPkg/Drivers/PL011Uart/PL011Uart.c')
| -rw-r--r-- | ArmPlatformPkg/Drivers/PL011Uart/PL011Uart.c | 25 |
1 files changed, 19 insertions, 6 deletions
diff --git a/ArmPlatformPkg/Drivers/PL011Uart/PL011Uart.c b/ArmPlatformPkg/Drivers/PL011Uart/PL011Uart.c index db15a8b32..3c283fdf3 100644 --- a/ArmPlatformPkg/Drivers/PL011Uart/PL011Uart.c +++ b/ArmPlatformPkg/Drivers/PL011Uart/PL011Uart.c @@ -35,6 +35,8 @@ STATIC CONST UINT32 mInvalidControlBits = EFI_SERIAL_SOFTWARE_LOOPBACK_ENABLE; 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
@@ -63,6 +65,7 @@ RETURN_STATUS EFIAPI
PL011UartInitializePort (
IN UINTN UartBase,
+ IN UINT32 UartClkInHz,
IN OUT UINT64 *BaudRate,
IN OUT UINT32 *ReceiveFifoDepth,
IN OUT EFI_PARITY_TYPE *Parity,
@@ -72,6 +75,8 @@ PL011UartInitializePort ( {
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
@@ -168,19 +173,27 @@ PL011UartInitializePort ( // If PL011 Integer value has been defined then always ignore the BAUD rate
if (FixedPcdGet32 (PL011UartInteger) != 0) {
- MmioWrite32 (UartBase + UARTIBRD, FixedPcdGet32 (PL011UartInteger));
- MmioWrite32 (UartBase + UARTFBRD, FixedPcdGet32 (PL011UartFractional));
+ 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);
- ASSERT (*BaudRate != 0);
+ if (*BaudRate == 0) {
+ return RETURN_INVALID_PARAMETER;
+ }
+ }
+ if (0 == UartClkInHz) {
+ return RETURN_INVALID_PARAMETER;
}
- Divisor = (FixedPcdGet32 (PL011UartClkInHz) * 4) / *BaudRate;
- MmioWrite32 (UartBase + UARTIBRD, Divisor >> FRACTION_PART_SIZE_IN_BITS);
- MmioWrite32 (UartBase + UARTFBRD, Divisor & FRACTION_PART_MASK);
+ Divisor = (UartClkInHz * 4) / *BaudRate;
+ Integer = Divisor >> FRACTION_PART_SIZE_IN_BITS;
+ Fractional = Divisor & FRACTION_PART_MASK;
}
+ // 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);
|