Platform/RaspberryPi: query firmware for 16550 input clock at boot on…

… RPi3 Query the firmware for the clock rate that is used to drive the 16550 baud clock, so that we can program the correct baud rate. Co-authored-by: Pete Batard <pete@akeo.ie> Co-authored-by: Andrei Warkentin <andrey.warkentin@gmail.com> Co-authored-by: Ard Biesheuvel <ard.biesheuvel@arm.com> Signed-off-by: Pete Batard <pete@akeo.ie> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@arm.com> Reviewed-by: Pete Batard <pete@akeo.ie> Tested-by: Pete Batard <pete@akeo.ie>
tianocore · May 6, 2020 · 043ee2e · 043ee2e
1 parent 3c29ba3
commit 043ee2e
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Showing 4 changed files with 29 additions and 1 deletion.
diff --git a/Platform/RaspberryPi/Library/PlatformLib/AArch64/RaspberryPiHelper.S b/Platform/RaspberryPi/Library/PlatformLib/AArch64/RaspberryPiHelper.S
@@ -3,7 +3,7 @@
  *  Copyright (c) 2020, Andrei Warkentin <andrey.warkentin@gmail.com>
  *  Copyright (c) 2019-2020, Pete Batard <pete@akeo.ie>
  *  Copyright (c) 2016, Linaro Limited. All rights reserved.
- *  Copyright (c) 2011-2013, ARM Limited. All rights reserved.
+ *  Copyright (c) 2011-2020, ARM Limited. All rights reserved.
  *
  *  SPDX-License-Identifier: BSD-2-Clause-Patent
  *
@@ -85,6 +85,14 @@ 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
 
     .align  4
@@ -127,6 +135,21 @@ ASM_FUNC (ArmPlatformPeiBootAction)
     .long   0                           // end tag
     .set    .Lrevinfo_size, . - .Lrevinfo_buffer
 
+#if (RPI_MODEL == 3)
+    .align  4
+.Lclkinfo_buffer:
+    .long   .Lclkinfo_size
+    .long   0x0
+    .long   RPI_MBOX_GET_CLOCK_RATE
+    .long   8                           // buf size
+    .long   4                           // input len
+    .long   4                           // clock id: 0x04 = Core/VPU
+.Lfrequency:
+    .long   0                           // frequency
+    .long   0                           // end tag
+    .set    .Lclkinfo_size, . - .Lclkinfo_buffer
+#endif
+
 //UINTN
 //ArmPlatformGetPrimaryCoreMpId (
 //  VOID

diff --git a/Platform/RaspberryPi/Library/PlatformLib/PlatformLib.inf b/Platform/RaspberryPi/Library/PlatformLib/PlatformLib.inf
@@ -61,5 +61,8 @@
   gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwWorkingSize
   gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwSpareSize
 
+[Pcd]
+  gEfiMdeModulePkgTokenSpaceGuid.PcdSerialClockRate     # RPi3 only
+
 [Ppis]
   gArmMpCoreInfoPpiGuid
diff --git a/Platform/RaspberryPi/RPi3/RPi3.dsc b/Platform/RaspberryPi/RPi3/RPi3.dsc
@@ -230,6 +230,7 @@
 
 [BuildOptions]
   GCC:*_*_*_CC_FLAGS          = -DRPI_MODEL=3
+  GCC:*_*_*_PP_FLAGS          = -DRPI_MODEL=3
   GCC:*_*_*_ASLPP_FLAGS       = -DRPI_MODEL=3
   GCC:*_*_*_ASLCC_FLAGS       = -DRPI_MODEL=3
   GCC:*_*_*_VFRPP_FLAGS       = -DRPI_MODEL=3

diff --git a/Platform/RaspberryPi/RPi4/RPi4.dsc b/Platform/RaspberryPi/RPi4/RPi4.dsc
@@ -238,6 +238,7 @@
 
 [BuildOptions]
   GCC:*_*_*_CC_FLAGS          = -DRPI_MODEL=4
+  GCC:*_*_*_PP_FLAGS          = -DRPI_MODEL=4
   GCC:*_*_*_ASLPP_FLAGS       = -DRPI_MODEL=4
   GCC:*_*_*_ASLCC_FLAGS       = -DRPI_MODEL=4
   GCC:*_*_*_VFRPP_FLAGS       = -DRPI_MODEL=4