[edk2-devel] [edk2-platforms][PATCH v2 1/1] Platform/RaspberryPi: Fix mini UART clock divisor calculation

[Ard Biesheuvel]

On Thu, 8 Apr 2021 at 11:47, Pete Batard <pete at akeo.ie> wrote:
>
> On 2021.04.06 15:04, Mario Bălănică wrote:
> > The VPU clock divisor has changed in this commit:
> > https://github.com/raspberrypi/firmware/commit/1e5456a,
> > thus breaking the mini UART clock divisor calculation on the Pi 4.
> >
> > Fix this by reading the core clock from the mailbox instead.
> >
> > Signed-off-by: Mario Bălănică <mariobalanica02 at gmail.com>
> > ---
> >   Platform/RaspberryPi/Library/DualSerialPortLib/DualSerialPortLib.c   | 15 +++------------
> >   Platform/RaspberryPi/Library/PlatformLib/AArch64/RaspberryPiHelper.S |  4 ----
> >   Platform/RaspberryPi/RPi4/RPi4.dsc                                   |  6 ++++--
> >   3 files changed, 7 insertions(+), 18 deletions(-)
> >
> > diff --git a/Platform/RaspberryPi/Library/DualSerialPortLib/DualSerialPortLib.c b/Platform/RaspberryPi/Library/DualSerialPortLib/DualSerialPortLib.c
> > index 5e83bbf022eb..d2f983bf0a9f 100644
> > --- a/Platform/RaspberryPi/Library/DualSerialPortLib/DualSerialPortLib.c
> > +++ b/Platform/RaspberryPi/Library/DualSerialPortLib/DualSerialPortLib.c
> > @@ -34,25 +34,16 @@ SerialPortGetDivisor (
> >     UINT32  SerialBaudRate
> >
> >   )
> >
> >   {
> >
> > -  UINT64              BaseClockRate;
> >
> > +  UINT32              BaseClockRate;
> >
> >     UINT32              Divisor;
> >
> >
> >
> > -  //
> >
> > -  // On the Raspberry Pi, the clock to use for the 16650-compatible UART
> >
> > -  // is the base clock divided by the 12.12 fixed point VPU clock divisor.
> >
> > -  //
> >
> > -  BaseClockRate = (UINT64)PcdGet32 (PcdSerialClockRate);
> >
> > -#if (RPI_MODEL == 4)
> >
> > -  Divisor = MmioRead32(BCM2836_CM_BASE + BCM2836_CM_VPU_CLOCK_DIVISOR) & 0xFFFFFF;
> >
> > -  if (Divisor != 0)
> >
> > -    BaseClockRate = (BaseClockRate << 12) / Divisor;
> >
> > -#endif
> >
> > +  BaseClockRate = PcdGet32 (PcdSerialClockRate);
> >
> >
> >
> >     //
> >
> >     // As per the BCM2xxx datasheets:
> >
> >     // baudrate = system_clock_freq / (8 * (divisor + 1)).
> >
> >     //
> >
> > -  Divisor = (UINT32)BaseClockRate / (SerialBaudRate * 8);
> >
> > +  Divisor = BaseClockRate / (SerialBaudRate * 8);
> >
> >     if (Divisor != 0) {
> >
> >       Divisor--;
> >
> >     }
> >
> > diff --git a/Platform/RaspberryPi/Library/PlatformLib/AArch64/RaspberryPiHelper.S b/Platform/RaspberryPi/Library/PlatformLib/AArch64/RaspberryPiHelper.S
> > index 58351e4fb8cc..7008aaf8aa4c 100644
> > --- a/Platform/RaspberryPi/Library/PlatformLib/AArch64/RaspberryPiHelper.S
> > +++ b/Platform/RaspberryPi/Library/PlatformLib/AArch64/RaspberryPiHelper.S
> > @@ -85,13 +85,11 @@ ASM_FUNC (ArmPlatformPeiBootAction)
> >       adr     x2, mBoardRevision
> >
> >       str     w0, [x2]
> >
> >
> >
> > -#if (RPI_MODEL == 3)
> >
> >       run     .Lclkinfo_buffer
> >
> >
> >
> >       ldr     w0, .Lfrequency
> >
> >       adr     x2, _gPcd_BinaryPatch_PcdSerialClockRate
> >
> >       str     w0, [x2]
> >
> > -#endif
> >
> >
> >
> >       ret
> >
> >
> >
> > @@ -135,7 +133,6 @@ ASM_FUNC (ArmPlatformPeiBootAction)
> >       .long   0                           // end tag
> >
> >       .set    .Lrevinfo_size, . - .Lrevinfo_buffer
> >
> >
> >
> > -#if (RPI_MODEL == 3)
> >
> >       .align  4
> >
> >   .Lclkinfo_buffer:
> >
> >       .long   .Lclkinfo_size
> >
> > @@ -148,7 +145,6 @@ ASM_FUNC (ArmPlatformPeiBootAction)
> >       .long   0                           // frequency
> >
> >       .long   0                           // end tag
> >
> >       .set    .Lclkinfo_size, . - .Lclkinfo_buffer
> >
> > -#endif
> >
> >
> >
> >   //UINTN
> >
> >   //ArmPlatformGetPrimaryCoreMpId (
> >
> > diff --git a/Platform/RaspberryPi/RPi4/RPi4.dsc b/Platform/RaspberryPi/RPi4/RPi4.dsc
> > index 2c05c31118d2..ff802d8347ea 100644
> > --- a/Platform/RaspberryPi/RPi4/RPi4.dsc
> > +++ b/Platform/RaspberryPi/RPi4/RPi4.dsc
> > @@ -429,7 +429,6 @@ [PcdsFixedAtBuild.common]
> >     gArmPlatformTokenSpaceGuid.PL011UartClkInHz|48000000
> >
> >     gEfiMdeModulePkgTokenSpaceGuid.PcdSerialUseMmio|TRUE
> >
> >     gEfiMdeModulePkgTokenSpaceGuid.PcdSerialRegisterStride|4
> >
> > -  gEfiMdeModulePkgTokenSpaceGuid.PcdSerialClockRate|1000000000
> >
> >     gEfiMdeModulePkgTokenSpaceGuid.PcdSerialFifoControl|0x27
> >
> >     gEfiMdeModulePkgTokenSpaceGuid.PcdSerialExtendedTxFifoSize|8
> >
> >     gEfiMdePkgTokenSpaceGuid.PcdUartDefaultBaudRate|115200
> >
> > @@ -465,6 +464,9 @@ [PcdsFixedAtBuild.common]
> >     gEfiMdeModulePkgTokenSpaceGuid.PcdFirmwareVendor|L"EDK2"
> >
> >     gEfiMdeModulePkgTokenSpaceGuid.PcdSetNxForStack|TRUE
> >
> >
> >
> > +[PcdsPatchableInModule]
> >
> > +  gEfiMdeModulePkgTokenSpaceGuid.PcdSerialClockRate|500000000
> >
> > +
> >
> >   [PcdsDynamicHii.common.DEFAULT]
> >
> >
> >
> >     #
> >
> > @@ -621,7 +623,7 @@ [Components.common]
> >     MdeModulePkg/Universal/Console/TerminalDxe/TerminalDxe.inf
> >
> >     MdeModulePkg/Universal/SerialDxe/SerialDxe.inf {
> >
> >       <LibraryClasses>
> >
> > -      SerialPortLib|Platform/RaspberryPi/Library/DualSerialPortLib/DualSerialPortLib.inf
> >
> > +      SerialPortLib|Platform/RaspberryPi/Library/DualSerialPortLib/DualSerialPortDxeLib.inf
> >
> >     }
> >
> >     Platform/RaspberryPi/Drivers/DisplayDxe/DisplayDxe.inf
> >
> >     EmbeddedPkg/Drivers/ConsolePrefDxe/ConsolePrefDxe.inf
> >
>
> Reviewed-by: Pete Batard <pete at akeo.ie>
> Tested-by: Pete Batard <pete at akeo.ie>

Thanks Pete.

Could anyone get me a version of this patch that is not whitespace
mangled? This one does not apply with 'git am'


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