From f68cb23c1469eee7ea6c28191dedcfef114d1495 Mon Sep 17 00:00:00 2001
From: "Albecki, Mateusz" <mateusz.albecki@intel.com>
Date: Sat, 21 Dec 2019 01:13:12 +0800
Subject: [PATCH] MdeModulePkg/SdMmcPciHcDxe: Add function to start SD clock

In SD card voltage switch flow we used to redo the
entire internal clock setup after voltage switch.
Since internal clock has already been setup this
is wasting time on polling the internal clock stable.
This commit changes it to only start the SD clock.

Cc: Hao A Wu <hao.a.wu@intel.com>
Cc: Marcin Wojtas <mw@semihalf.com>
Cc: Zhichao Gao <zhichao.gao@intel.com>
Cc: Liming Gao <liming.gao@intel.com>

Signed-off-by: Mateusz Albecki <mateusz.albecki@intel.com>
Tested-by: Marcin Wojtas <mw@semihalf.com>
Tested-by: Hao A Wu <hao.a.wu@intel.com>
Reviewed-by: Hao A Wu <hao.a.wu@intel.com>
---
 MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdDevice.c | 11 +++----
 .../Bus/Pci/SdMmcPciHcDxe/SdMmcPciHci.c       | 33 ++++++++++++++++---
 .../Bus/Pci/SdMmcPciHcDxe/SdMmcPciHci.h       | 15 +++++++++
 3 files changed, 47 insertions(+), 12 deletions(-)

diff --git a/MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdDevice.c b/MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdDevice.c
index d63dc54e8c..b630daab76 100644
--- a/MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdDevice.c
+++ b/MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdDevice.c
@@ -1327,13 +1327,10 @@ SdCardIdentification (
         goto Error;
       }
 
-      //
-      // Restart the clock with first time parameters.
-      // NOTE: it is not required to actually restart the clock
-      // and go through internal clock setup again. Some time
-      // could be saved if we simply started the SD clock.
-      //
-      SdMmcHcClockSupply (Private, Slot, 0, TRUE, 400);
+      Status = SdMmcHcStartSdClock (PciIo, Slot);
+      if (EFI_ERROR (Status)) {
+        goto Error;
+      }
 
       gBS->Stall (1000);
 
diff --git a/MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdMmcPciHci.c b/MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdMmcPciHci.c
index f667264c5e..e7f2fac69b 100644
--- a/MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdMmcPciHci.c
+++ b/MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdMmcPciHci.c
@@ -758,6 +758,30 @@ SdMmcHcStopClock (
   return Status;
 }
 
+/**
+  Start the SD clock.
+
+  @param[in] PciIo  The PCI IO protocol instance.
+  @param[in] Slot   The slot number.
+
+  @retval EFI_SUCCESS  Succeeded to start the SD clock.
+  @rtval  Others       Failed to start the SD clock.
+**/
+EFI_STATUS
+SdMmcHcStartSdClock (
+  IN EFI_PCI_IO_PROTOCOL  *PciIo,
+  IN UINT8                Slot
+  )
+{
+  UINT16                    ClockCtrl;
+
+  //
+  // Set SD Clock Enable in the Clock Control register to 1
+  //
+  ClockCtrl = BIT2;
+  return SdMmcHcOrMmio (PciIo, Slot, SD_MMC_HC_CLOCK_CTRL, sizeof (ClockCtrl), &ClockCtrl);
+}
+
 /**
   SD/MMC card clock supply.
 
@@ -879,11 +903,10 @@ SdMmcHcClockSupply (
     return Status;
   }
 
-  //
-  // Set SD Clock Enable in the Clock Control register to 1
-  //
-  ClockCtrl = BIT2;
-  Status = SdMmcHcOrMmio (PciIo, Slot, SD_MMC_HC_CLOCK_CTRL, sizeof (ClockCtrl), &ClockCtrl);
+  Status = SdMmcHcStartSdClock (PciIo, Slot);
+  if (EFI_ERROR (Status)) {
+    return Status;
+  }
 
   //
   // We don't notify the platform on first time setup to avoid changing
diff --git a/MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdMmcPciHci.h b/MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdMmcPciHci.h
index 826e851b04..4753bb6864 100644
--- a/MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdMmcPciHci.h
+++ b/MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdMmcPciHci.h
@@ -478,6 +478,21 @@ SdMmcHcStopClock (
   IN UINT8                  Slot
   );
 
+/**
+  Start the SD clock.
+
+  @param[in] PciIo  The PCI IO protocol instance.
+  @param[in] Slot   The slot number.
+
+  @retval EFI_SUCCESS  Succeeded to start the SD clock.
+  @rtval  Others       Failed to start the SD clock.
+**/
+EFI_STATUS
+SdMmcHcStartSdClock (
+  IN EFI_PCI_IO_PROTOCOL  *PciIo,
+  IN UINT8                Slot
+  );
+
 /**
   SD/MMC bus power control.
 
-- 
2.39.2