[PATCH v2 0/2] ArmPlatformPkg: PL011 Dynamic clock freq Support

[PATCH v2 0/2] ArmPlatformPkg: PL011 Dynamic clock freq Support

[Udit Kumar]

[v2]
   Incorporated review comments of v1

Udit Kumar (2):
  ArmPlatformPkg: PL011 Dynamic clock freq Support
  ArmPlatformPkg: Include PL011UartClock Lib

 ArmPlatformPkg/ArmPlatformPkg.dec                  |  1 +
 ArmPlatformPkg/Include/Library/PL011UartClockLib.h | 32 +++++++++++++++++++
 .../PL011SerialPortLib/PL011SerialPortLib.c        |  5 +--
 .../PL011SerialPortLib/PL011SerialPortLib.inf      |  1 +
 .../Library/PL011UartClockLib/PL011UartClockLib.c  | 29 +++++++++++++++++
 .../PL011UartClockLib/PL011UartClockLib.inf        | 37 ++++++++++++++++++++++
 6 files changed, 103 insertions(+), 2 deletions(-)
 create mode 100644 ArmPlatformPkg/Include/Library/PL011UartClockLib.h
 create mode 100644 ArmPlatformPkg/Library/PL011UartClockLib/PL011UartClockLib.c
 create mode 100644 ArmPlatformPkg/Library/PL011UartClockLib/PL011UartClockLib.inf

-- 
1.9.1

[PATCH 1/2] ArmPlatformPkg: PL011 Dynamic clock freq Support

[Udit Kumar]

Some platform support dynamic clocking, Which is controlled
by some jumper setting or hardware registers.
Result of that PCD PL011UartClkInHz needs to be updated for
frequency change.
This patch implements support for dynamic frequency for
PL011 uart.
This patch implements default lib, which is using Pcd.
Platform which needs dynamic clocking needs implement
PL011UartClockLib

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Udit Kumar <udit.kumar@nxp.com>
---
 ArmPlatformPkg/ArmPlatformPkg.dec                  |  1 +
 ArmPlatformPkg/Include/Library/PL011UartClockLib.h | 32 +++++++++++++++++++
 .../Library/PL011UartClockLib/PL011UartClockLib.c  | 29 +++++++++++++++++
 .../PL011UartClockLib/PL011UartClockLib.inf        | 37 ++++++++++++++++++++++
 4 files changed, 99 insertions(+)
 create mode 100644 ArmPlatformPkg/Include/Library/PL011UartClockLib.h
 create mode 100644 ArmPlatformPkg/Library/PL011UartClockLib/PL011UartClockLib.c
 create mode 100644 ArmPlatformPkg/Library/PL011UartClockLib/PL011UartClockLib.inf

diff --git a/ArmPlatformPkg/ArmPlatformPkg.dec b/ArmPlatformPkg/ArmPlatformPkg.dec
index dff4598..5f67e74 100644
--- a/ArmPlatformPkg/ArmPlatformPkg.dec
+++ b/ArmPlatformPkg/ArmPlatformPkg.dec
@@ -36,6 +36,7 @@
   LcdHwLib|Include/Library/LcdHwLib.h
   LcdPlatformLib|Include/Library/LcdPlatformLib.h
   NorFlashPlatformLib|Include/Library/NorFlashPlatformLib.h
+  PL011UartClockLib|Include/Library/PL011UartClockLib.h
   PL011UartLib|Include/Library/PL011UartLib.h
 
 [Guids.common]
diff --git a/ArmPlatformPkg/Include/Library/PL011UartClockLib.h b/ArmPlatformPkg/Include/Library/PL011UartClockLib.h
new file mode 100644
index 0000000..93813a0
--- /dev/null
+++ b/ArmPlatformPkg/Include/Library/PL011UartClockLib.h
@@ -0,0 +1,32 @@
+/** @file
+*
+*  Copyright 2018 NXP
+*
+*  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.
+*
+**/
+
+#ifndef __PL011CLOCKLIB_H__
+#define __PL011CLOCKLIB_H__
+
+
+/**
+  Return frequency of PL011.
+
+  By default this function returns FixedPcdGet32 (PL011UartClkInHz)
+
+  @return Return frequency of PL011
+
+**/
+UINT32
+ArmPlatformGetPL011ClockFreq (
+  VOID
+  );
+
+#endif
diff --git a/ArmPlatformPkg/Library/PL011UartClockLib/PL011UartClockLib.c b/ArmPlatformPkg/Library/PL011UartClockLib/PL011UartClockLib.c
new file mode 100644
index 0000000..b56af14
--- /dev/null
+++ b/ArmPlatformPkg/Library/PL011UartClockLib/PL011UartClockLib.c
@@ -0,0 +1,29 @@
+/** @file
+*
+*  Copyright 2018 NXP
+*
+*  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/PL011UartClockLib.h>
+
+/**
+  Return clock in for PL011 Uart IP.
+**/
+UINT32
+ArmPlatformGetPL011ClockFreq (
+  VOID
+  )
+{
+  // This function needs to be implemented on platforms which supports
+  // dynamic clocking to avoid re-building of UEFI firmware for PL011
+  // clock change
+  return FixedPcdGet32 (PL011UartClkInHz);
+}
diff --git a/ArmPlatformPkg/Library/PL011UartClockLib/PL011UartClockLib.inf b/ArmPlatformPkg/Library/PL011UartClockLib/PL011UartClockLib.inf
new file mode 100644
index 0000000..5f6f699
--- /dev/null
+++ b/ArmPlatformPkg/Library/PL011UartClockLib/PL011UartClockLib.inf
@@ -0,0 +1,37 @@
+#/* @file
+#  Copyright 2018 NXP
+#
+#  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.
+#
+#*/
+
+[Defines]
+  INF_VERSION                    = 0x0001000A
+  BASE_NAME                      = PL011UartClockLib
+  FILE_GUID                      = af8fef24-afbb-472a-b8b7-13101a79703c
+  MODULE_TYPE                    = BASE
+  VERSION_STRING                 = 1.0
+  LIBRARY_CLASS                  = PL011UartClockLib
+
+[Packages]
+  MdePkg/MdePkg.dec
+  MdeModulePkg/MdeModulePkg.dec
+  ArmPkg/ArmPkg.dec
+  ArmPlatformPkg/ArmPlatformPkg.dec
+
+[LibraryClasses]
+  ArmLib
+  DebugLib
+
+[Sources.common]
+  PL011UartClockLib.c
+
+[FixedPcd]
+  gArmPlatformTokenSpaceGuid.PL011UartClkInHz
+
-- 
1.9.1

[PATCH 2/2] ArmPlatformPkg: Include PL011UartClock Lib

[Udit Kumar]

This patch includes, PL011UartClock lib.

In case of no implemenation of this Clock Lib,
Pcd value will be used for PL011 frequency.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Udit Kumar <udit.kumar@nxp.com>
---
 ArmPlatformPkg/Library/PL011SerialPortLib/PL011SerialPortLib.c   | 5 +++--
 ArmPlatformPkg/Library/PL011SerialPortLib/PL011SerialPortLib.inf | 1 +
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/ArmPlatformPkg/Library/PL011SerialPortLib/PL011SerialPortLib.c b/ArmPlatformPkg/Library/PL011SerialPortLib/PL011SerialPortLib.c
index 6aa8063..c73e8db 100644
--- a/ArmPlatformPkg/Library/PL011SerialPortLib/PL011SerialPortLib.c
+++ b/ArmPlatformPkg/Library/PL011SerialPortLib/PL011SerialPortLib.c
@@ -19,6 +19,7 @@
 
 #include <Library/IoLib.h>
 #include <Library/PcdLib.h>
+#include <Library/PL011UartClockLib.h>
 #include <Library/PL011UartLib.h>
 #include <Library/SerialPortLib.h>
 
@@ -48,7 +49,7 @@ SerialPortInitialize (
 
   return PL011UartInitializePort (
            (UINTN)FixedPcdGet64 (PcdSerialRegisterBase),
-           FixedPcdGet32 (PL011UartClkInHz),
+           ArmPlatformGetPL011ClockFreq(),
            &BaudRate,
            &ReceiveFifoDepth,
            &Parity,
@@ -156,7 +157,7 @@ SerialPortSetAttributes (
 {
   return PL011UartInitializePort (
            (UINTN)FixedPcdGet64 (PcdSerialRegisterBase),
-           FixedPcdGet32 (PL011UartClkInHz),
+           ArmPlatformGetPL011ClockFreq(),
            BaudRate,
            ReceiveFifoDepth,
            Parity,
diff --git a/ArmPlatformPkg/Library/PL011SerialPortLib/PL011SerialPortLib.inf b/ArmPlatformPkg/Library/PL011SerialPortLib/PL011SerialPortLib.inf
index 3683e06..5ce5b2f 100644
--- a/ArmPlatformPkg/Library/PL011SerialPortLib/PL011SerialPortLib.inf
+++ b/ArmPlatformPkg/Library/PL011SerialPortLib/PL011SerialPortLib.inf
@@ -26,6 +26,7 @@
   PL011SerialPortLib.c
 
 [LibraryClasses]
+  PL011UartClockLib
   PL011UartLib
   PcdLib
 
-- 
1.9.1

Re: [PATCH 1/2] ArmPlatformPkg: PL011 Dynamic clock freq Support

[Ard Biesheuvel]

Hello Udit,

Apologies for not bringing this up the first time, but I have some
additional comments. The first time around, I only had a cursory look
because at that point I was still skeptical whether we needed this
library in the first place.

On 5 June 2018 at 19:59, Udit Kumar <udit.kumar@nxp.com> wrote:
> Some platform support dynamic clocking, Which is controlled
> by some jumper setting or hardware registers.
> Result of that PCD PL011UartClkInHz needs to be updated for
> frequency change.
> This patch implements support for dynamic frequency for
> PL011 uart.
> This patch implements default lib, which is using Pcd.
> Platform which needs dynamic clocking needs implement
> PL011UartClockLib
>
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Udit Kumar <udit.kumar@nxp.com>
> ---
>  ArmPlatformPkg/ArmPlatformPkg.dec                  |  1 +
>  ArmPlatformPkg/Include/Library/PL011UartClockLib.h | 32 +++++++++++++++++++
>  .../Library/PL011UartClockLib/PL011UartClockLib.c  | 29 +++++++++++++++++
>  .../PL011UartClockLib/PL011UartClockLib.inf        | 37 ++++++++++++++++++++++

Please add a reference to the new library in the [Components] section
of ArmPlatformPkg.dsc as well, so we can build it standalone.

>  4 files changed, 99 insertions(+)
>  create mode 100644 ArmPlatformPkg/Include/Library/PL011UartClockLib.h
>  create mode 100644 ArmPlatformPkg/Library/PL011UartClockLib/PL011UartClockLib.c
>  create mode 100644 ArmPlatformPkg/Library/PL011UartClockLib/PL011UartClockLib.inf
>
> diff --git a/ArmPlatformPkg/ArmPlatformPkg.dec b/ArmPlatformPkg/ArmPlatformPkg.dec
> index dff4598..5f67e74 100644
> --- a/ArmPlatformPkg/ArmPlatformPkg.dec
> +++ b/ArmPlatformPkg/ArmPlatformPkg.dec
> @@ -36,6 +36,7 @@
>    LcdHwLib|Include/Library/LcdHwLib.h
>    LcdPlatformLib|Include/Library/LcdPlatformLib.h
>    NorFlashPlatformLib|Include/Library/NorFlashPlatformLib.h
> +  PL011UartClockLib|Include/Library/PL011UartClockLib.h
>    PL011UartLib|Include/Library/PL011UartLib.h
>
>  [Guids.common]
> diff --git a/ArmPlatformPkg/Include/Library/PL011UartClockLib.h b/ArmPlatformPkg/Include/Library/PL011UartClockLib.h
> new file mode 100644
> index 0000000..93813a0
> --- /dev/null
> +++ b/ArmPlatformPkg/Include/Library/PL011UartClockLib.h
> @@ -0,0 +1,32 @@
> +/** @file
> +*
> +*  Copyright 2018 NXP
> +*
> +*  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.
> +*
> +**/
> +
> +#ifndef __PL011CLOCKLIB_H__
> +#define __PL011CLOCKLIB_H__

Nit: use __PL011UARTCLOCKLIB_H__ to match the filename.

> +
> +
> +/**
> +  Return frequency of PL011.
> +

Mention the baud clock?
> +  By default this function returns FixedPcdGet32 (PL011UartClkInHz)
> +

Drop this line please, it is not part of the prototype

> +  @return Return frequency of PL011
> +
> +**/
> +UINT32
> +ArmPlatformGetPL011ClockFreq (

The ArmPlatform prefix is unnecessary here: please use
PL011UartClockGetFreq() instead.

> +  VOID
> +  );
> +
> +#endif
> diff --git a/ArmPlatformPkg/Library/PL011UartClockLib/PL011UartClockLib.c b/ArmPlatformPkg/Library/PL011UartClockLib/PL011UartClockLib.c
> new file mode 100644
> index 0000000..b56af14
> --- /dev/null
> +++ b/ArmPlatformPkg/Library/PL011UartClockLib/PL011UartClockLib.c
> @@ -0,0 +1,29 @@
> +/** @file
> +*
> +*  Copyright 2018 NXP
> +*
> +*  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/PL011UartClockLib.h>
> +
> +/**
> +  Return clock in for PL011 Uart IP.
> +**/
> +UINT32

Please add EFIAPI even if it is defined to an empty string when using GCC/ARM.

> +ArmPlatformGetPL011ClockFreq (
> +  VOID
> +  )
> +{
> +  // This function needs to be implemented on platforms which supports
> +  // dynamic clocking to avoid re-building of UEFI firmware for PL011
> +  // clock change

Please drop this comment, it does not belong here. You can add
something along these lines in the declaration of the library class if
you want, but you can drop it altogether IMO.

> +  return FixedPcdGet32 (PL011UartClkInHz);
> +}
> diff --git a/ArmPlatformPkg/Library/PL011UartClockLib/PL011UartClockLib.inf b/ArmPlatformPkg/Library/PL011UartClockLib/PL011UartClockLib.inf
> new file mode 100644
> index 0000000..5f6f699
> --- /dev/null
> +++ b/ArmPlatformPkg/Library/PL011UartClockLib/PL011UartClockLib.inf
> @@ -0,0 +1,37 @@
> +#/* @file
> +#  Copyright 2018 NXP
> +#
> +#  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.
> +#
> +#*/
> +
> +[Defines]
> +  INF_VERSION                    = 0x0001000A

Please use 0x0001001A

> +  BASE_NAME                      = PL011UartClockLib

EDK2 usually has a BaseXxxLib implementation and does not reuse the
library class name for the base implementation, so I am fine with
this. Leif?


> +  FILE_GUID                      = af8fef24-afbb-472a-b8b7-13101a79703c
> +  MODULE_TYPE                    = BASE
> +  VERSION_STRING                 = 1.0
> +  LIBRARY_CLASS                  = PL011UartClockLib
> +
> +[Packages]
> +  MdePkg/MdePkg.dec
> +  MdeModulePkg/MdeModulePkg.dec

Is this line needed?

> +  ArmPkg/ArmPkg.dec
> +  ArmPlatformPkg/ArmPlatformPkg.dec
> +

Sort alphabetically please.

> +[LibraryClasses]
> +  ArmLib
> +  DebugLib
> +
> +[Sources.common]
> +  PL011UartClockLib.c
> +
> +[FixedPcd]
> +  gArmPlatformTokenSpaceGuid.PL011UartClkInHz
> +
> --
> 1.9.1
>

Re: [PATCH 2/2] ArmPlatformPkg: Include PL011UartClock Lib

[Ard Biesheuvel]

On 5 June 2018 at 19:59, Udit Kumar <udit.kumar@nxp.com> wrote:
> This patch includes, PL011UartClock lib.
>
> In case of no implemenation of this Clock Lib,
> Pcd value will be used for PL011 frequency.
>

Please improve the commit log. You are modifying the code to obtain
the PL011 baud clock frequency from a library instead of a PCD

> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Udit Kumar <udit.kumar@nxp.com>
> ---
>  ArmPlatformPkg/Library/PL011SerialPortLib/PL011SerialPortLib.c   | 5 +++--
>  ArmPlatformPkg/Library/PL011SerialPortLib/PL011SerialPortLib.inf | 1 +
>  2 files changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/ArmPlatformPkg/Library/PL011SerialPortLib/PL011SerialPortLib.c b/ArmPlatformPkg/Library/PL011SerialPortLib/PL011SerialPortLib.c
> index 6aa8063..c73e8db 100644
> --- a/ArmPlatformPkg/Library/PL011SerialPortLib/PL011SerialPortLib.c
> +++ b/ArmPlatformPkg/Library/PL011SerialPortLib/PL011SerialPortLib.c
> @@ -19,6 +19,7 @@
>
>  #include <Library/IoLib.h>
>  #include <Library/PcdLib.h>
> +#include <Library/PL011UartClockLib.h>
>  #include <Library/PL011UartLib.h>
>  #include <Library/SerialPortLib.h>
>
> @@ -48,7 +49,7 @@ SerialPortInitialize (
>
>    return PL011UartInitializePort (
>             (UINTN)FixedPcdGet64 (PcdSerialRegisterBase),
> -           FixedPcdGet32 (PL011UartClkInHz),
> +           ArmPlatformGetPL011ClockFreq(),
>             &BaudRate,
>             &ReceiveFifoDepth,
>             &Parity,
> @@ -156,7 +157,7 @@ SerialPortSetAttributes (
>  {
>    return PL011UartInitializePort (
>             (UINTN)FixedPcdGet64 (PcdSerialRegisterBase),
> -           FixedPcdGet32 (PL011UartClkInHz),
> +           ArmPlatformGetPL011ClockFreq(),
>             BaudRate,
>             ReceiveFifoDepth,
>             Parity,
> diff --git a/ArmPlatformPkg/Library/PL011SerialPortLib/PL011SerialPortLib.inf b/ArmPlatformPkg/Library/PL011SerialPortLib/PL011SerialPortLib.inf
> index 3683e06..5ce5b2f 100644
> --- a/ArmPlatformPkg/Library/PL011SerialPortLib/PL011SerialPortLib.inf
> +++ b/ArmPlatformPkg/Library/PL011SerialPortLib/PL011SerialPortLib.inf
> @@ -26,6 +26,7 @@
>    PL011SerialPortLib.c
>
>  [LibraryClasses]
> +  PL011UartClockLib
>    PL011UartLib
>    PcdLib
>

You need to add a library resolution to
ArmPlatformPkg/ArmPlatformPkg.dsc for this library or you will break
the build.

Re: [PATCH 2/2] ArmPlatformPkg: Include PL011UartClock Lib

[Udit Kumar]

Thanks Ard 

> -----Original Message-----
> From: Ard Biesheuvel [mailto:ard.biesheuvel@linaro.org]
> Sent: Monday, June 11, 2018 3:37 PM
> To: Udit Kumar <udit.kumar@nxp.com>
> Cc: Leif Lindholm <leif.lindholm@linaro.org>; edk2-devel@lists.01.org
> Subject: Re: [PATCH 2/2] ArmPlatformPkg: Include PL011UartClock Lib
> 
> On 5 June 2018 at 19:59, Udit Kumar <udit.kumar@nxp.com> wrote:
> > This patch includes, PL011UartClock lib.
> >
> > In case of no implemenation of this Clock Lib, Pcd value will be used
> > for PL011 frequency.
> >
> 
> Please improve the commit log. You are modifying the code to obtain the
> PL011 baud clock frequency from a library instead of a PCD

Ok 
 
> > Contributed-under: TianoCore Contribution Agreement 1.1
> > Signed-off-by: Udit Kumar <udit.kumar@nxp.com>
> > ---
> >  ArmPlatformPkg/Library/PL011SerialPortLib/PL011SerialPortLib.c   | 5
> +++--
> >  ArmPlatformPkg/Library/PL011SerialPortLib/PL011SerialPortLib.inf | 1
> > +
> >  2 files changed, 4 insertions(+), 2 deletions(-)
> >
> > diff --git
> > a/ArmPlatformPkg/Library/PL011SerialPortLib/PL011SerialPortLib.c
> > b/ArmPlatformPkg/Library/PL011SerialPortLib/PL011SerialPortLib.c
> > index 6aa8063..c73e8db 100644
> > --- a/ArmPlatformPkg/Library/PL011SerialPortLib/PL011SerialPortLib.c
> > +++ b/ArmPlatformPkg/Library/PL011SerialPortLib/PL011SerialPortLib.c
> > @@ -19,6 +19,7 @@
> >
> >  #include <Library/IoLib.h>
> >  #include <Library/PcdLib.h>
> > +#include <Library/PL011UartClockLib.h>
> >  #include <Library/PL011UartLib.h>
> >  #include <Library/SerialPortLib.h>
> >
> > @@ -48,7 +49,7 @@ SerialPortInitialize (
> >
> >    return PL011UartInitializePort (
> >             (UINTN)FixedPcdGet64 (PcdSerialRegisterBase),
> > -           FixedPcdGet32 (PL011UartClkInHz),
> > +           ArmPlatformGetPL011ClockFreq(),
> >             &BaudRate,
> >             &ReceiveFifoDepth,
> >             &Parity,
> > @@ -156,7 +157,7 @@ SerialPortSetAttributes (  {
> >    return PL011UartInitializePort (
> >             (UINTN)FixedPcdGet64 (PcdSerialRegisterBase),
> > -           FixedPcdGet32 (PL011UartClkInHz),
> > +           ArmPlatformGetPL011ClockFreq(),
> >             BaudRate,
> >             ReceiveFifoDepth,
> >             Parity,
> > diff --git
> > a/ArmPlatformPkg/Library/PL011SerialPortLib/PL011SerialPortLib.inf
> > b/ArmPlatformPkg/Library/PL011SerialPortLib/PL011SerialPortLib.inf
> > index 3683e06..5ce5b2f 100644
> > --- a/ArmPlatformPkg/Library/PL011SerialPortLib/PL011SerialPortLib.inf
> > +++ b/ArmPlatformPkg/Library/PL011SerialPortLib/PL011SerialPortLib.inf
> > @@ -26,6 +26,7 @@
> >    PL011SerialPortLib.c
> >
> >  [LibraryClasses]
> > +  PL011UartClockLib
> >    PL011UartLib
> >    PcdLib
> >
> 
> You need to add a library resolution to
> ArmPlatformPkg/ArmPlatformPkg.dsc for this library or you will break the
> build.

I will do this, 

FYI,
With update in edk2-platform, my compile was ok for Juno and NXP boards 

Re: [PATCH 1/2] ArmPlatformPkg: PL011 Dynamic clock freq Support

[Udit Kumar]

Thanks for review Ard. 

> -----Original Message-----
> From: Ard Biesheuvel [mailto:ard.biesheuvel@linaro.org]
> Sent: Monday, June 11, 2018 3:35 PM
> To: Udit Kumar <udit.kumar@nxp.com>
> Cc: Leif Lindholm <leif.lindholm@linaro.org>; edk2-devel@lists.01.org
> Subject: Re: [PATCH 1/2] ArmPlatformPkg: PL011 Dynamic clock freq
> Support
> 
> Hello Udit,
> 
> Apologies for not bringing this up the first time, but I have some additional
> comments. The first time around, I only had a cursory look because at that
> point I was still skeptical whether we needed this library in the first place.

I hope, now you agree to have this lib 😊

> On 5 June 2018 at 19:59, Udit Kumar <udit.kumar@nxp.com> wrote:
> > Some platform support dynamic clocking, Which is controlled by some
> > jumper setting or hardware registers.
> > Result of that PCD PL011UartClkInHz needs to be updated for frequency
> > change.
> > This patch implements support for dynamic frequency for
> > PL011 uart.
> > This patch implements default lib, which is using Pcd.
> > Platform which needs dynamic clocking needs implement
> > PL011UartClockLib
> >
> > Contributed-under: TianoCore Contribution Agreement 1.1
> > Signed-off-by: Udit Kumar <udit.kumar@nxp.com>
> > ---
> >  ArmPlatformPkg/ArmPlatformPkg.dec                  |  1 +
> >  ArmPlatformPkg/Include/Library/PL011UartClockLib.h | 32
> > +++++++++++++++++++
> .../Library/PL011UartClockLib/PL011UartClockLib.c  | 29
> +++++++++++++++++
> >  .../PL011UartClockLib/PL011UartClockLib.inf        | 37
> ++++++++++++++++++++++
> 
> Please add a reference to the new library in the [Components] section of
> ArmPlatformPkg.dsc as well, so we can build it standalone.

Ok 
 
> >  4 files changed, 99 insertions(+)
> >  create mode 100644
> ArmPlatformPkg/Include/Library/PL011UartClockLib.h
> >  create mode 100644
> > ArmPlatformPkg/Library/PL011UartClockLib/PL011UartClockLib.c
> >  create mode 100644
> > ArmPlatformPkg/Library/PL011UartClockLib/PL011UartClockLib.inf
> >
> > diff --git a/ArmPlatformPkg/ArmPlatformPkg.dec
> > b/ArmPlatformPkg/ArmPlatformPkg.dec
> > index dff4598..5f67e74 100644
> > --- a/ArmPlatformPkg/ArmPlatformPkg.dec
> > +++ b/ArmPlatformPkg/ArmPlatformPkg.dec
> > @@ -36,6 +36,7 @@
> >    LcdHwLib|Include/Library/LcdHwLib.h
> >    LcdPlatformLib|Include/Library/LcdPlatformLib.h
> >    NorFlashPlatformLib|Include/Library/NorFlashPlatformLib.h
> > +  PL011UartClockLib|Include/Library/PL011UartClockLib.h
> >    PL011UartLib|Include/Library/PL011UartLib.h
> >
> >  [Guids.common]
> > diff --git a/ArmPlatformPkg/Include/Library/PL011UartClockLib.h
> > b/ArmPlatformPkg/Include/Library/PL011UartClockLib.h
> > new file mode 100644
> > index 0000000..93813a0
> > --- /dev/null
> > +++ b/ArmPlatformPkg/Include/Library/PL011UartClockLib.h
> > @@ -0,0 +1,32 @@
> > +/** @file
> > +*
> > +*  Copyright 2018 NXP
> > +*
> > +*  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
> > +*
> >
> +https://emea01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fo
> pe
> > +nsource.org%2Flicenses%2Fbsd-
> license.php&data=02%7C01%7Cudit.kumar%40
> >
> +nxp.com%7C2ac27eb60055478ac37d08d5cf82d550%7C686ea1d3bc2b4c
> 6fa92cd99c
> >
> +5c301635%7C0%7C0%7C636643083195138179&sdata=C%2F2MhK2ZA6
> XPmC5c8byWlK3
> > +xAC6rFmLYofPKlj6M7%2FI%3D&reserved=0
> > +*
> > +*  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS
> IS"
> > +BASIS,
> > +*  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER
> EXPRESS OR IMPLIED.
> > +*
> > +**/
> > +
> > +#ifndef __PL011CLOCKLIB_H__
> > +#define __PL011CLOCKLIB_H__
> 
> Nit: use __PL011UARTCLOCKLIB_H__ to match the filename.

My miss, thanks  will do in v3
 
> > +
> > +
> > +/**
> > +  Return frequency of PL011.
> > +
> 
> Mention the baud clock?

Sure 
> > +  By default this function returns FixedPcdGet32 (PL011UartClkInHz)
> > +
> 
> Drop this line please, it is not part of the prototype

Ok 
 
> > +  @return Return frequency of PL011
> > +
> > +**/
> > +UINT32
> > +ArmPlatformGetPL011ClockFreq (
> 
> The ArmPlatform prefix is unnecessary here: please use
> PL011UartClockGetFreq() instead.

Ok 
 
> > +  VOID
> > +  );
> > +
> > +#endif
> > diff --git
> > a/ArmPlatformPkg/Library/PL011UartClockLib/PL011UartClockLib.c
> > b/ArmPlatformPkg/Library/PL011UartClockLib/PL011UartClockLib.c
> > new file mode 100644
> > index 0000000..b56af14
> > --- /dev/null
> > +++ b/ArmPlatformPkg/Library/PL011UartClockLib/PL011UartClockLib.c
> > @@ -0,0 +1,29 @@
> > +/** @file
> > +*
> > +*  Copyright 2018 NXP
> > +*
> > +*  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
> > +*
> >
> +https://emea01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fo
> pe
> > +nsource.org%2Flicenses%2Fbsd-
> license.php&data=02%7C01%7Cudit.kumar%40
> >
> +nxp.com%7C2ac27eb60055478ac37d08d5cf82d550%7C686ea1d3bc2b4c
> 6fa92cd99c
> >
> +5c301635%7C0%7C0%7C636643083195138179&sdata=C%2F2MhK2ZA6
> XPmC5c8byWlK3
> > +xAC6rFmLYofPKlj6M7%2FI%3D&reserved=0
> > +*
> > +*  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/PL011UartClockLib.h>
> > +
> > +/**
> > +  Return clock in for PL011 Uart IP.
> > +**/
> > +UINT32
> 
> Please add EFIAPI even if it is defined to an empty string when using
> GCC/ARM.

Ok 
 
> > +ArmPlatformGetPL011ClockFreq (
> > +  VOID
> > +  )
> > +{
> > +  // This function needs to be implemented on platforms which
> > +supports
> > +  // dynamic clocking to avoid re-building of UEFI firmware for PL011
> > +  // clock change
> 
> Please drop this comment, it does not belong here. You can add something
> along these lines in the declaration of the library class if you want, but you
> can drop it altogether IMO.

Ok, I will move to lib class declaration 
 
> > +  return FixedPcdGet32 (PL011UartClkInHz); }
> > diff --git
> > a/ArmPlatformPkg/Library/PL011UartClockLib/PL011UartClockLib.inf
> > b/ArmPlatformPkg/Library/PL011UartClockLib/PL011UartClockLib.inf
> > new file mode 100644
> > index 0000000..5f6f699
> > --- /dev/null
> > +++ b/ArmPlatformPkg/Library/PL011UartClockLib/PL011UartClockLib.inf
> > @@ -0,0 +1,37 @@
> > +#/* @file
> > +#  Copyright 2018 NXP
> > +#
> > +#  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 #
> >
> +https://emea01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fo
> pe
> > +nsource.org%2Flicenses%2Fbsd-
> license.php&data=02%7C01%7Cudit.kumar%40
> >
> +nxp.com%7C2ac27eb60055478ac37d08d5cf82d550%7C686ea1d3bc2b4c
> 6fa92cd99c
> >
> +5c301635%7C0%7C0%7C636643083195138179&sdata=C%2F2MhK2ZA6
> XPmC5c8byWlK3
> > +xAC6rFmLYofPKlj6M7%2FI%3D&reserved=0
> > +#
> > +#  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS
> IS"
> > +BASIS, #  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND,
> EITHER EXPRESS OR IMPLIED.
> > +#
> > +#*/
> > +
> > +[Defines]
> > +  INF_VERSION                    = 0x0001000A
> 
> Please use 0x0001001A
> 
Ok 

> > +  BASE_NAME                      = PL011UartClockLib
> 
> EDK2 usually has a BaseXxxLib implementation and does not reuse the
> library class name for the base implementation, so I am fine with this. Leif?
> 
> 
> > +  FILE_GUID                      = af8fef24-afbb-472a-b8b7-13101a79703c
> > +  MODULE_TYPE                    = BASE
> > +  VERSION_STRING                 = 1.0
> > +  LIBRARY_CLASS                  = PL011UartClockLib
> > +
> > +[Packages]
> > +  MdePkg/MdePkg.dec
> > +  MdeModulePkg/MdeModulePkg.dec
> 
> Is this line needed?

May be not , 
copy-paste mistake  

> 
> > +  ArmPkg/ArmPkg.dec
> > +  ArmPlatformPkg/ArmPlatformPkg.dec
> > +
> 
> Sort alphabetically please.

Ok 
 
> > +[LibraryClasses]
> > +  ArmLib
> > +  DebugLib
> > +
> > +[Sources.common]
> > +  PL011UartClockLib.c
> > +
> > +[FixedPcd]
> > +  gArmPlatformTokenSpaceGuid.PL011UartClkInHz
> > +
> > --
> > 1.9.1
> >