From 71096fc4a8a98d555ff709d628dcbbd9c99c5d96 Mon Sep 17 00:00:00 2001
From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Date: Wed, 1 Nov 2017 13:23:01 +0000
Subject: Silicon/SynQuacer: implement 'clear NVRAM' feature using a DIP switch

Ordinary computers typically have a physical switch or jumper on the
board that allows non-volatile settings to be cleared. Let's implement
the same using DIP switch #1 on block #3, and clear the EFI variable
store if it is set to ON at boot time.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
---
 .../SynQuacerPlatformPeiLib.c                      | 30 +++++++++++++++++++++-
 .../SynQuacerPlatformPeiLib.inf                    |  6 +++++
 2 files changed, 35 insertions(+), 1 deletion(-)

(limited to 'Silicon/Socionext/SynQuacer/Library')

diff --git a/Silicon/Socionext/SynQuacer/Library/SynQuacerPlatformPeiLib/SynQuacerPlatformPeiLib.c b/Silicon/Socionext/SynQuacer/Library/SynQuacerPlatformPeiLib/SynQuacerPlatformPeiLib.c
index 358dd5a91f..e4aec8b091 100644
--- a/Silicon/Socionext/SynQuacer/Library/SynQuacerPlatformPeiLib/SynQuacerPlatformPeiLib.c
+++ b/Silicon/Socionext/SynQuacer/Library/SynQuacerPlatformPeiLib/SynQuacerPlatformPeiLib.c
@@ -21,8 +21,11 @@
 #include <Library/PeiServicesLib.h>
 #include <Platform/DramInfo.h>
 #include <Ppi/DramInfo.h>
+#include <Ppi/EmbeddedGpio.h>
 #include <Ppi/MemoryDiscovered.h>
 
+#define CLEAR_SETTINGS_GPIO_NOT_IMPLEMENTED   MAX_UINT8
+
 STATIC
 CONST DRAM_INFO *mDramInfo = (VOID *)(UINTN)FixedPcdGet64 (PcdDramInfoBase);
 
@@ -103,10 +106,35 @@ PlatformPeim (
   VOID
   )
 {
-  EFI_STATUS      Status;
+  EMBEDDED_GPIO_PPI   *Gpio;
+  EFI_STATUS          Status;
+  UINTN               Value;
+  UINT8               Pin;
 
   ASSERT (mDramInfo->NumRegions > 0);
 
+  Pin = FixedPcdGet8 (PcdClearSettingsGpioPin);
+  if (Pin != CLEAR_SETTINGS_GPIO_NOT_IMPLEMENTED) {
+    Status = PeiServicesLocatePpi (&gEdkiiEmbeddedGpioPpiGuid, 0, NULL,
+               (VOID **)&Gpio);
+    ASSERT_EFI_ERROR (Status);
+
+    Status = Gpio->Set (Gpio, Pin, GPIO_MODE_INPUT);
+    if (EFI_ERROR (Status)) {
+      DEBUG ((DEBUG_WARN, "%a: failed to set GPIO as input - %r\n",
+        __FUNCTION__, Status));
+    } else {
+      Status = Gpio->Get (Gpio, Pin, &Value);
+      if (EFI_ERROR (Status)) {
+        DEBUG ((DEBUG_WARN, "%a: failed to get GPIO state - %r\n",
+          __FUNCTION__, Status));
+      } else if (Value > 0) {
+        DEBUG ((DEBUG_INFO, "%a: clearing NVRAM\n", __FUNCTION__));
+        PeiServicesSetBootMode (BOOT_WITH_DEFAULT_SETTINGS);
+      }
+    }
+  }
+
   //
   // Record the first region into PcdSystemMemoryBase and PcdSystemMemorySize.
   // This is the region we will use for UEFI itself.
diff --git a/Silicon/Socionext/SynQuacer/Library/SynQuacerPlatformPeiLib/SynQuacerPlatformPeiLib.inf b/Silicon/Socionext/SynQuacer/Library/SynQuacerPlatformPeiLib/SynQuacerPlatformPeiLib.inf
index 70eb715d44..a6501fb205 100644
--- a/Silicon/Socionext/SynQuacer/Library/SynQuacerPlatformPeiLib/SynQuacerPlatformPeiLib.inf
+++ b/Silicon/Socionext/SynQuacer/Library/SynQuacerPlatformPeiLib/SynQuacerPlatformPeiLib.inf
@@ -25,6 +25,7 @@
 
 [Packages]
   ArmPkg/ArmPkg.dec
+  EmbeddedPkg/EmbeddedPkg.dec
   MdePkg/MdePkg.dec
   MdeModulePkg/MdeModulePkg.dec
   Silicon/Socionext/SynQuacer/SynQuacer.dec
@@ -40,11 +41,16 @@
 [FixedPcd]
   gArmTokenSpaceGuid.PcdFvBaseAddress
   gArmTokenSpaceGuid.PcdFvSize
+  gSynQuacerTokenSpaceGuid.PcdClearSettingsGpioPin
   gSynQuacerTokenSpaceGuid.PcdDramInfoBase
 
 [Ppis]
+  gEdkiiEmbeddedGpioPpiGuid             ## CONSUMES
   gSynQuacerDramInfoPpiGuid             ## PRODUCES
 
 [Pcd]
   gArmTokenSpaceGuid.PcdSystemMemoryBase
   gArmTokenSpaceGuid.PcdSystemMemorySize
+
+[Depex]
+  gEdkiiEmbeddedGpioPpiGuid
-- 
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