[PATCH 6/9] Platform/RaspberryPi: Add mailbox cmd to control audio amp

["Jeremy Linton" <jeremy.linton@arm.com>]

The lower level firmware can enable/disable a LDO audio
amp, which allows us to mute/unmute audio output while
the firmware is running.

Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
---
 .../Drivers/RpiFirmwareDxe/RpiFirmwareDxe.c        | 62 +++++++++++++++++++++-
 .../RaspberryPi/Include/IndustryStandard/RpiMbox.h |  1 +
 .../RaspberryPi/Include/Protocol/RpiFirmware.h     |  7 +++
 3 files changed, 69 insertions(+), 1 deletion(-)

diff --git a/Platform/RaspberryPi/Drivers/RpiFirmwareDxe/RpiFirmwareDxe.c b/Platform/RaspberryPi/Drivers/RpiFirmwareDxe/RpiFirmwareDxe.c
index d38ffbc7d3..03c1e1708f 100644
--- a/Platform/RaspberryPi/Drivers/RpiFirmwareDxe/RpiFirmwareDxe.c
+++ b/Platform/RaspberryPi/Drivers/RpiFirmwareDxe/RpiFirmwareDxe.c
@@ -1532,6 +1532,65 @@ RpiFirmwareNotifyGpioSetCfg (
   return Status;
 }
 
+#pragma pack()
+typedef struct {
+  UINT32                       State;
+} RPI_FW_SET_LDO_REG_TAG;
+
+typedef struct {
+  RPI_FW_BUFFER_HEAD           BufferHead;
+  RPI_FW_TAG_HEAD              TagHead;
+  RPI_FW_SET_LDO_REG_TAG       TagBody;
+  UINT32                       EndTag;
+} RPI_FW_SET_LDO_REG_CMD;
+#pragma pack()
+
+
+STATIC
+EFI_STATUS
+EFIAPI
+RpiFirmwareSetLdoRegState (
+  IN UINTN State
+  )
+{
+  RPI_FW_SET_LDO_REG_CMD       *Cmd;
+  EFI_STATUS                   Status;
+  UINT32                       Result;
+
+  if (!AcquireSpinLockOrFail (&mMailboxLock)) {
+    DEBUG ((DEBUG_ERROR, "%a: failed to acquire spinlock\n", __FUNCTION__));
+    return EFI_DEVICE_ERROR;
+  }
+
+  DEBUG ((DEBUG_ERROR, "%a: set LDO\n", __FUNCTION__));
+  Cmd = mDmaBuffer;
+  ZeroMem (Cmd, sizeof (*Cmd));
+
+  Cmd->BufferHead.BufferSize  = sizeof (*Cmd);
+  Cmd->BufferHead.Response    = 0;
+  Cmd->TagHead.TagId          = RPI_MBOX_SET_LDO_REGULATOR;
+  Cmd->TagHead.TagSize        = sizeof (Cmd->TagBody);
+  Cmd->TagBody.State          = State;
+
+  Cmd->TagHead.TagValueSize   = 0;
+  Cmd->EndTag                 = 0;
+
+  Status = MailboxTransaction (Cmd->BufferHead.BufferSize, RPI_MBOX_VC_CHANNEL, &Result);
+
+  DEBUG ((DEBUG_ERROR, "%a: set LDO Done\n", __FUNCTION__));
+  if (EFI_ERROR (Status) ||
+      Cmd->BufferHead.Response != RPI_MBOX_RESP_SUCCESS) {
+    DEBUG ((DEBUG_ERROR,
+      "%a: mailbox  transaction error: Status == %r, Response == 0x%x\n",
+      __FUNCTION__, Status, Cmd->BufferHead.Response));
+  }
+
+  ReleaseSpinLock (&mMailboxLock);
+
+  return Status;
+}
+
+
 STATIC RASPBERRY_PI_FIRMWARE_PROTOCOL mRpiFirmwareProtocol = {
   RpiFirmwareSetPowerState,
   RpiFirmwareGetMacAddress,
@@ -1557,7 +1616,8 @@ STATIC RASPBERRY_PI_FIRMWARE_PROTOCOL mRpiFirmwareProtocol = {
   RpiFirmwareNotifyXhciReset,
   RpiFirmwareGetCurrentClockState,
   RpiFirmwareSetClockState,
-  RpiFirmwareNotifyGpioSetCfg
+  RpiFirmwareNotifyGpioSetCfg,
+  RpiFirmwareSetLdoRegState
 };
 
 /**
diff --git a/Platform/RaspberryPi/Include/IndustryStandard/RpiMbox.h b/Platform/RaspberryPi/Include/IndustryStandard/RpiMbox.h
index 551c2b82e5..f36aaafaf8 100644
--- a/Platform/RaspberryPi/Include/IndustryStandard/RpiMbox.h
+++ b/Platform/RaspberryPi/Include/IndustryStandard/RpiMbox.h
@@ -92,6 +92,7 @@
 #define RPI_MBOX_NOTIFY_REBOOT                                0x00030048
 #define RPI_MBOX_GET_POE_HAT_VAL                              0x00030049
 #define RPI_MBOX_SET_POE_HAT_VAL                              0x00030050
+#define RPI_MBOX_SET_LDO_REGULATOR                            0x00030056
 #define RPI_MBOX_NOTIFY_XHCI_RESET                            0x00030058
 
 #define RPI_MBOX_SET_CLOCK_STATE                              0x00038001
diff --git a/Platform/RaspberryPi/Include/Protocol/RpiFirmware.h b/Platform/RaspberryPi/Include/Protocol/RpiFirmware.h
index c48bb6e434..175894e37a 100644
--- a/Platform/RaspberryPi/Include/Protocol/RpiFirmware.h
+++ b/Platform/RaspberryPi/Include/Protocol/RpiFirmware.h
@@ -171,6 +171,12 @@ EFI_STATUS
   UINTN State
   );
 
+typedef
+EFI_STATUS
+(EFIAPI *SET_LDO_REGULATOR) (
+  UINTN State
+  );
+
 typedef struct {
   SET_POWER_STATE        SetPowerState;
   GET_MAC_ADDRESS        GetMacAddress;
@@ -197,6 +203,7 @@ typedef struct {
   GET_CLOCK_STATE        GetClockState;
   SET_CLOCK_STATE        SetClockState;
   GPIO_SET_CFG           SetGpioConfig;
+  SET_LDO_REGULATOR      SetLdoRegState;
 } RASPBERRY_PI_FIRMWARE_PROTOCOL;
 
 extern EFI_GUID gRaspberryPiFirmwareProtocolGuid;
-- 
2.13.7