Remove global variable from SerialPortLib because this
module is not necessarily executed in memory.
Cc: Sunil V L <suni...@ventanamicro.com>
Cc: Daniel Schaefer <daniel.schae...@hpe.com>
Signed-off-by: Abner Chang <abner.ch...@hpe.com>
---
.../SiFive/U5SeriesPkg/Include/SifiveU5Uart.h | 1 +
.../Library/SerialIoLib/SerialPortLib.c | 58 +++++++++++++++----
2 files changed, 49 insertions(+), 10 deletions(-)
diff --git a/Platform/SiFive/U5SeriesPkg/Include/SifiveU5Uart.h
b/Platform/SiFive/U5SeriesPkg/Include/SifiveU5Uart.h
index 0ccb98e874..be8dce8c96 100644
--- a/Platform/SiFive/U5SeriesPkg/Include/SifiveU5Uart.h
+++ b/Platform/SiFive/U5SeriesPkg/Include/SifiveU5Uart.h
@@ -10,6 +10,7 @@
#ifndef SIFIVE_U5_SERIES_UART_H_
#define SIFIVE_U5_SERIES_UART_H_
+#include <include/sbi/riscv_io.h>
#include <include/sbi_utils/serial/sifive-uart.h>
#endif
diff --git a/Platform/SiFive/U5SeriesPkg/Library/SerialIoLib/SerialPortLib.c
b/Platform/SiFive/U5SeriesPkg/Library/SerialIoLib/SerialPortLib.c
index 7bc73a0b82..42e5aa7b76 100644
--- a/Platform/SiFive/U5SeriesPkg/Library/SerialIoLib/SerialPortLib.c
+++ b/Platform/SiFive/U5SeriesPkg/Library/SerialIoLib/SerialPortLib.c
@@ -8,6 +8,7 @@
**/
#include <Base.h>
+#include <Library/DebugLib.h>
#include <Library/IoLib.h>
#include <Library/SerialPortLib.h>
#include <Include/SifiveU5Uart.h>
@@ -41,7 +42,7 @@
#define UART_BAUDRATE 115200
#define SYS_CLK FixedPcdGet32(PcdU5PlatformSystemClock)
-BOOLEAN Initiated = FALSE;
+BOOLEAN Initiated = TRUE;
/**
Get value from serial port register.
@@ -55,7 +56,9 @@ UINT32 GetReg (
IN UINT32 RegIndex
)
{
- return MmioRead32 (FixedPcdGet32(PcdU5UartBase) + (RegIndex * 0x4));
+ STATIC volatile UINT32 * const uart = (UINT32 *)FixedPcdGet32(PcdU5UartBase);
+
+ return readl ((volatile void *)(uart + RegIndex));
}
/**
@@ -70,7 +73,9 @@ VOID SetReg (
IN UINT32 Value
)
{
- MmioWrite32 (Value, FixedPcdGet32(PcdU5UartBase) + (RegIndex * 0x4));
+ STATIC volatile UINT32 * const uart = (UINT32 *)FixedPcdGet32(PcdU5UartBase);
+
+ writel (Value, (volatile void *)(uart + RegIndex));
}
/**
@@ -104,7 +109,36 @@ UINT32 SifiveUartGetChar (VOID)
}
return -1;
}
+/**
+ Find minimum divisor divides in_freq to max_target_hz;
+ Based on uart driver n SiFive FSBL.
+
+ f_baud = f_in / (div + 1) => div = (f_in / f_baud) - 1
+ The nearest integer solution requires rounding up as to not exceed
max_target_hz.
+ div = ceil(f_in / f_baud) - 1
+ = floor((f_in - 1 + f_baud) / f_baud) - 1
+ This should not overflow as long as (f_in - 1 + f_baud) does not exceed
+ 2^32 - 1, which is unlikely since we represent frequencies in kHz.
+
+ @param Freq The given clock to UART.
+ @param MaxTargetHZ Target baudrate.
+**/
+UINT32
+UartMinClkDivisor (
+ IN UINT64 Freq,
+ IN UINT64 MaxTargetHZ
+ )
+{
+ UINT64 Quotient;
+
+ Quotient = (Freq + MaxTargetHZ - 1) / (MaxTargetHZ);
+ if (Quotient == 0) {
+ return 0;
+ } else {
+ return Quotient - 1;
+ }
+}
/**
Initialize the serial device hardware.
@@ -116,20 +150,24 @@ UINT32 SifiveUartGetChar (VOID)
@retval RETURN_DEVICE_ERROR The serail device could not be initialized.
**/
-RETURN_STATUS
+EFI_STATUS
EFIAPI
SerialPortInitialize (
VOID
)
{
- if (Initiated) {
- return RETURN_SUCCESS;
+ UINT32 Divisor;
+ UINT32 CurrentDivisor;
+
+ Divisor = UartMinClkDivisor (SYS_CLK / 2, UART_BAUDRATE);
+ if (Divisor == 0) {
+ return EFI_INVALID_PARAMETER;
}
- if (sifive_uart_init (FixedPcdGet32(PcdU5UartBase), SYS_CLK / 2,
UART_BAUDRATE) != 0) {
- return EFI_DEVICE_ERROR;
+ CurrentDivisor = GetReg(UART_REG_DIV);
+ if (Divisor != CurrentDivisor) {
+ sifive_uart_init (FixedPcdGet32(PcdU5UartBase), SYS_CLK / 2,
UART_BAUDRATE);
}
- Initiated = TRUE;
- return RETURN_SUCCESS;
+ return EFI_SUCCESS;
}
/**
--
2.31.1
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