From d4102f68dceb36fa8f07af9fa3d24b0da9f173bf Mon Sep 17 00:00:00 2001
From: Jun Nie <jun.nie@linaro.org>
Date: Wed, 5 Jul 2017 16:27:07 +0800
Subject: EmbeddedPkg/DwEmmcDxe: limit max clock for platform

Some boards may have max clock limitation. Add a Pcd to notify
driver.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jun Nie <jun.nie@linaro.org>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
---
 EmbeddedPkg/Drivers/DwEmmcDxe/DwEmmcDxe.c   | 4 ++++
 EmbeddedPkg/Drivers/DwEmmcDxe/DwEmmcDxe.inf | 1 +
 2 files changed, 5 insertions(+)

(limited to 'EmbeddedPkg/Drivers')

diff --git a/EmbeddedPkg/Drivers/DwEmmcDxe/DwEmmcDxe.c b/EmbeddedPkg/Drivers/DwEmmcDxe/DwEmmcDxe.c
index fe23d113ee..bb26b69fd1 100644
--- a/EmbeddedPkg/Drivers/DwEmmcDxe/DwEmmcDxe.c
+++ b/EmbeddedPkg/Drivers/DwEmmcDxe/DwEmmcDxe.c
@@ -560,6 +560,10 @@ DwEmmcSetIos (
   EFI_STATUS Status = EFI_SUCCESS;
   UINT32    Data;
 
+  if ((PcdGet32 (PcdDwEmmcDxeMaxClockFreqInHz) != 0) &&
+      (BusClockFreq > PcdGet32 (PcdDwEmmcDxeMaxClockFreqInHz))) {
+    return EFI_UNSUPPORTED;
+  }
   if (TimingMode != EMMCBACKWARD) {
     Data = MmioRead32 (DWEMMC_UHSREG);
     switch (TimingMode) {
diff --git a/EmbeddedPkg/Drivers/DwEmmcDxe/DwEmmcDxe.inf b/EmbeddedPkg/Drivers/DwEmmcDxe/DwEmmcDxe.inf
index e3c8313bc5..99b4f990f6 100644
--- a/EmbeddedPkg/Drivers/DwEmmcDxe/DwEmmcDxe.inf
+++ b/EmbeddedPkg/Drivers/DwEmmcDxe/DwEmmcDxe.inf
@@ -48,6 +48,7 @@
 [Pcd]
   gEmbeddedTokenSpaceGuid.PcdDwEmmcDxeBaseAddress
   gEmbeddedTokenSpaceGuid.PcdDwEmmcDxeClockFrequencyInHz
+  gEmbeddedTokenSpaceGuid.PcdDwEmmcDxeMaxClockFreqInHz
 
 [Depex]
   TRUE
-- 
cgit