dwcmshc: Fix signaling voltage mismatch

SD cards can only be switched back to 3.3V after a power cycle.

The firmware does not currently implement card power control (and some
boards don't even have a switch to begin with), so we need to ensure
that the card is not initialized before being able to safely change
signaling on the host side. This should only happen after the card is
unplugged.

Signed-off-by: Mario Bălănică <mariobalanica02@gmail.com>

drivers/sd/dwcmshc/dwcmshc.cpp

@@ -1045,6 +1045,10 @@ MshcSlotGetResponse(
         NT_ASSERTMSG("Invalid response type!", FALSE);
     }
 
+    if (Command->Index == SDCMD_SEND_RELATIVE_ADDR) {
+        MshcExtension->CardRca = Response[0] >> 16;
+    }
+
     MSHC_LOG_EXIT(MshcExtension->LogHandle, MshcExtension, "()");
 }
 
@@ -1403,20 +1407,6 @@ MshcResetHost(
     }
 
     if (ResetType == SdResetTypeAll) {
-        // Mask all interrupts, sdport will toggle them as needed.
-        MshcDisableInterrupts(MshcExtension, MSHC_INT_ALL, MSHC_IDINT_ALL);
-
-        // Global interrupt enable
-        MshcWriteRegister(MshcExtension, MSHC_CTRL, MSHC_CTRL_INT_ENABLE);
-
-        // Set the max HW timeout for bus operations.
-        MshcWriteRegister(MshcExtension, MSHC_TMOUT, 0xffffffff);
-
-        //
-        // Bring the slot in its initial state.
-        //
-        MshcSetClock(MshcExtension, 0);
-
         //
         // WORKAROUND:
         // In crashdump mode, sdport will switch to an UHS-I mode
@@ -1425,11 +1415,28 @@ MshcResetHost(
         // for the best...
         //
         if (!gCrashdumpMode) {
+            //
+            // Reset voltages.
+            // We don't trust sdport to always do it when needed.
+            //
             MshcSetVoltage(MshcExtension, SdBusVoltageOff);
             MshcSetSignalingVoltage(MshcExtension, SdSignalingVoltage33);
         }
 
+        // Disable clock
+        MshcSetClock(MshcExtension, 0);
+
+        // Reset bus width
         MshcSetBusWidth(MshcExtension, SdBusWidth1Bit);
+
+        // Mask all interrupts, sdport will toggle them as needed.
+        MshcDisableInterrupts(MshcExtension, MSHC_INT_ALL, MSHC_IDINT_ALL);
+
+        // Global interrupt enable
+        MshcWriteRegister(MshcExtension, MSHC_CTRL, MSHC_CTRL_INT_ENABLE);
+
+        // Set the max HW timeout for bus operations.
+        MshcWriteRegister(MshcExtension, MSHC_TMOUT, 0xffffffff);
     }
 
     // Acknowledge any pending interrupts.
@@ -1494,12 +1501,14 @@ MshcSetVoltage(
         Status = PlatformOperations->SetVoltage(MshcExtension, Voltage);
     }
 
+    MshcExtension->CardPowerControlSupported = NT_SUCCESS(Status);
+
     //
     // Wait 10ms for regulator to stabilize.
     //
     SdPortWait(10000);
 
-    return Status;
+    return STATUS_SUCCESS;
 }
 
 _Use_decl_annotations_
@@ -1707,11 +1716,37 @@ MshcSetSignalingVoltage(
 
     switch (Voltage) {
     case SdSignalingVoltage33:
+        //
+        // The card should've been power cycled for its signaling level to
+        // return to 3.3V. If the platform does not support power control and the
+        // card was already initialized at 1.8V, it's unsafe to change voltage here.
+        // Stay at the current level, since sdport will not switch to 1.8V again
+        // if the card responds with S18A = 0 to ACMD41.
+        //
+        if ((MshcExtension->SignalingVoltage == SdSignalingVoltage18) &&
+            !MshcExtension->CardPowerControlSupported) {
+            //
+            // Issue SEND_STATUS. If it fails, the card was either removed
+            // or isn't actually initialized yet (RCA won't match -> timeout).
+            // We will allow the voltage switch only in this case.
+            //
+            ULONG StatusRegister = 0;
+            Status = MshcSendStatusCommand(MshcExtension, &StatusRegister);
+            if (NT_SUCCESS(Status)) {
+                MSHC_LOG_WARN(
+                    MshcExtension->LogHandle,
+                    MshcExtension,
+                    "Not changing signaling for current card - power control unsupported!");
+                return STATUS_SUCCESS;
+            }
+        }
         Switch18v = FALSE;
         break;
+
     case SdSignalingVoltage18:
         Switch18v = TRUE;
         break;
+
     default:
         NT_ASSERTMSG("Invalid signaling voltage!", FALSE);
         return STATUS_INVALID_PARAMETER;
@@ -1798,6 +1833,10 @@ MshcSetSignalingVoltage(
         MshcEnableGlobalInterrupt(MshcExtension, TRUE);
     }
 
+    if (NT_SUCCESS(Status)) {
+        MshcExtension->SignalingVoltage = Voltage;
+    }
+
     return Status;
 }
 
@@ -2820,6 +2859,39 @@ MshcSendStopCommand(
     return MshcIssueRequestSynchronously(MshcExtension, &Request, 1000000, FALSE);
 }
 
+_Use_decl_annotations_
+NTSTATUS
+MshcSendStatusCommand(
+    _In_ PMSHC_EXTENSION MshcExtension,
+    _Out_ PULONG StatusRegister
+    )
+{
+    NTSTATUS Status;
+    SDPORT_REQUEST Request;
+
+    RtlZeroMemory(&Request, sizeof(Request));
+
+    Request.Command.Index = SDCMD_SEND_STATUS;
+    Request.Command.Class = SdCommandClassStandard;
+    Request.Command.ResponseType = SdResponseTypeR1;
+    Request.Command.TransferType = SdTransferTypeNone;
+    Request.Command.Argument = MshcExtension->CardRca << 16;
+
+    //
+    // Send the command.
+    //
+    Request.Type = SdRequestTypeCommandNoTransfer;
+
+    Status = MshcIssueRequestSynchronously(MshcExtension, &Request, 50000, TRUE);
+    if (!NT_SUCCESS(Status)) {
+        return Status;
+    }
+
+    MshcSlotGetResponse(MshcExtension, &Request.Command, StatusRegister);
+
+    return Status;
+}
+
 _Use_decl_annotations_
 NTSTATUS
 MshcSendTuningCommand(

drivers/sd/dwcmshc/dwcmshc.h

@@ -429,8 +429,10 @@ typedef struct _MSHC_IDMAC_DESCRIPTOR {
 // Standard SD/MMC commands
 //
 #define SDCMD_GO_IDLE_STATE             0
+#define SDCMD_SEND_RELATIVE_ADDR        3
 #define SDCMD_VOLTAGE_SWITCH            11
 #define SDCMD_STOP_TRANSMISSION         12
+#define SDCMD_SEND_STATUS               13
 #define SDCMD_GO_INACTIVE_STATE         15
 #define SDCMD_SEND_TUNING_BLOCK         19
 #define SDCMD_EMMC_SEND_TUNING_BLOCK    21
@@ -544,6 +546,9 @@ struct _MSHC_EXTENSION {
     // Current bus configuration
     //
     BOOLEAN CardInitialized;
+    BOOLEAN CardPowerControlSupported;
+    USHORT CardRca;
+    SDPORT_SIGNALING_VOLTAGE SignalingVoltage;
     SDPORT_BUS_SPEED BusSpeed;
     SDPORT_BUS_WIDTH BusWidth;
     ULONG BusFrequencyKhz;
@@ -821,6 +826,13 @@ MshcSendStopCommand(
     _In_ PMSHC_EXTENSION MshcExtension
     );
 
+_IRQL_requires_max_(APC_LEVEL)
+NTSTATUS
+MshcSendStatusCommand(
+    _In_ PMSHC_EXTENSION MshcExtension,
+    _Out_ PULONG StatusRegister
+    );
+
 _IRQL_requires_max_(APC_LEVEL)
 NTSTATUS
 MshcSendTuningCommand(

drivers/sd/dwcmshc/rockchip_ops.cpp

@@ -126,7 +126,7 @@ MshcRockchipSetVoltage(
             Status);
     }
 
-    return STATUS_SUCCESS;
+    return Status;
 }
 
 NTSTATUS
@@ -150,7 +150,7 @@ MshcRockchipSetSignalingVoltage(
             Status);
     }
 
-    return STATUS_SUCCESS;
+    return Status;
 }
 
 NTSTATUS