[PATCH 2/2] MdeModulePkg/SdMmcPciHcDxe: Add function to start SD clock

["Albecki, Mateusz" <mateusz.albecki@intel.com>]

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>
---
 MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdDevice.c    | 11 +++-----
 MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdMmcPciHci.c | 33 ++++++++++++++++++++----
 MdeModulePkg/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.
 
-- 
2.14.1.windows.1

--------------------------------------------------------------------

Intel Technology Poland sp. z o.o.
ul. Slowackiego 173 | 80-298 Gdansk | Sad Rejonowy Gdansk Polnoc | VII Wydzial Gospodarczy Krajowego Rejestru Sadowego - KRS 101882 | NIP 957-07-52-316 | Kapital zakladowy 200.000 PLN.

Ta wiadomosc wraz z zalacznikami jest przeznaczona dla okreslonego adresata i moze zawierac informacje poufne. W razie przypadkowego otrzymania tej wiadomosci, prosimy o powiadomienie nadawcy oraz trwale jej usuniecie; jakiekolwiek
przegladanie lub rozpowszechnianie jest zabronione.
This e-mail and any attachments may contain confidential material for the sole use of the intended recipient(s). If you are not the intended recipient, please contact the sender and delete all copies; any review or distribution by
others is strictly prohibited.