From: "Irene Park" <ipark@nvidia.com>
To: <devel@edk2.groups.io>
Cc: Irene Park <ipark@nvidia.com>
Subject: [PATCH] ArmPlatformPkg/PL011UartLib: Add PCD for FIFO depth
Date: Fri, 5 Jun 2020 23:23:24 -0400 [thread overview]
Message-ID: <5a94d7db2db04a22baa79c65d42feeea30bf81b8.1591413682.git.ipark@nvidia.com> (raw)
From: Irene Park <ipark@nvidia.com>
PL011UartLib determines its FIFO depth based on the PID2 value but
the register PID2 is not mandatory in the SBSA spec.
This change adds a new 32bit PCD reference to define a FIFO depth and
make PL011UartLib available for the custom UART which is compliant
to the SBSA spec but doesn't support the optional register of PID2.
* Available values for PL011UartFifoDepth: 0, 16, 32
Note that a FIFO depth will be determined based on PID2 when the PCD
reference is set to 0.
Signed-off-by: Irene Park <ipark@nvidia.com>
---
ArmPlatformPkg/ArmPlatformPkg.dec | 2 ++
ArmPlatformPkg/Library/PL011UartLib/PL011UartLib.c | 4 ++++
ArmPlatformPkg/Library/PL011UartLib/PL011UartLib.inf | 1 +
3 files changed, 7 insertions(+)
diff --git a/ArmPlatformPkg/ArmPlatformPkg.dec b/ArmPlatformPkg/ArmPlatformPkg.dec
index 696d636..b4b950f 100644
--- a/ArmPlatformPkg/ArmPlatformPkg.dec
+++ b/ArmPlatformPkg/ArmPlatformPkg.dec
@@ -72,6 +72,8 @@
gArmPlatformTokenSpaceGuid.PL011UartFractional|0|UINT32|0x0000002D
gArmPlatformTokenSpaceGuid.PL011UartInterrupt|0x00000000|UINT32|0x0000002F
gArmPlatformTokenSpaceGuid.PL011UartRegOffsetVariant|0|UINT8|0x0000003E
+ ## FIFO Depth in 0/16/32 (0 to determine FIFO depth based on PID2)
+ gArmPlatformTokenSpaceGuid.PL011UartFifoDepth|0|UINT32|0x0000003F
## PL011 Serial Debug UART
gArmPlatformTokenSpaceGuid.PcdSerialDbgRegisterBase|0x00000000|UINT64|0x00000030
diff --git a/ArmPlatformPkg/Library/PL011UartLib/PL011UartLib.c b/ArmPlatformPkg/Library/PL011UartLib/PL011UartLib.c
index 801990d..1aa6830 100644
--- a/ArmPlatformPkg/Library/PL011UartLib/PL011UartLib.c
+++ b/ArmPlatformPkg/Library/PL011UartLib/PL011UartLib.c
@@ -79,9 +79,13 @@ PL011UartInitializePort (
UINT32 Fractional;
UINT32 HardwareFifoDepth;
+ HardwareFifoDepth = FixedPcdGet8 (PL011UartFifoDepth);
+#if FixedPcdGet8 (PL011UartFifoDepth) == 0
HardwareFifoDepth = (PL011_UARTPID2_VER (MmioRead32 (UartBase + UARTPID2)) \
> PL011_VER_R1P4) \
? 32 : 16 ;
+#endif
+
// The PL011 supports a buffer of 1, 16 or 32 chars. Therefore we can accept
// 1 char buffer as the minimum FIFO size. Because everything can be rounded
// down, there is no maximum FIFO size.
diff --git a/ArmPlatformPkg/Library/PL011UartLib/PL011UartLib.inf b/ArmPlatformPkg/Library/PL011UartLib/PL011UartLib.inf
index d99e89f..3e5efc7 100644
--- a/ArmPlatformPkg/Library/PL011UartLib/PL011UartLib.inf
+++ b/ArmPlatformPkg/Library/PL011UartLib/PL011UartLib.inf
@@ -35,3 +35,4 @@
gArmPlatformTokenSpaceGuid.PL011UartInteger
gArmPlatformTokenSpaceGuid.PL011UartFractional
gArmPlatformTokenSpaceGuid.PL011UartRegOffsetVariant
+ gArmPlatformTokenSpaceGuid.PL011UartFifoDepth
--
2.7.4
next reply other threads:[~2020-06-06 3:23 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-06 3:23 Irene Park [this message]
2020-06-06 3:24 ` [PATCH] ArmPlatformPkg/PL011UartLib: Add PCD for FIFO depth Irene Park
2020-06-08 6:06 ` Irene Park
2020-06-08 8:29 ` [edk2-devel] " Ard Biesheuvel
2020-06-08 14:47 ` Irene Park
2020-06-08 16:44 ` Ard Biesheuvel
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