BayTrail integrates an internal ns15550 compatible UART (PNP0501). Its IRQ is hardwired to IRQ3 in old revision chipset, but in newer revision one IRQ4 is being used for ISA compatibility. Handle this correctly in the ASL file.
Linux does not need this ASL, but Windows need this to correctly discover a COM port existing in the system so that Windows can show it in the 'Device Manager' window, and expose this COM port to any terminal emulation application.
Signed-off-by: Bin Meng bmeng.cn@gmail.com ---
.../include/asm/arch-baytrail/acpi/irqlinks.asl | 4 ++ arch/x86/include/asm/arch-baytrail/acpi/lpc.asl | 60 ++++++++++++++++++++++ 2 files changed, 64 insertions(+)
diff --git a/arch/x86/include/asm/arch-baytrail/acpi/irqlinks.asl b/arch/x86/include/asm/arch-baytrail/acpi/irqlinks.asl index aa72085..0affa23 100644 --- a/arch/x86/include/asm/arch-baytrail/acpi/irqlinks.asl +++ b/arch/x86/include/asm/arch-baytrail/acpi/irqlinks.asl @@ -21,6 +21,10 @@ Scope () PRTF, 8, PRTG, 8, PRTH, 8, + Offset (0x88), + , 3, + UI3E, 1, + UI4E, 1 } }
diff --git a/arch/x86/include/asm/arch-baytrail/acpi/lpc.asl b/arch/x86/include/asm/arch-baytrail/acpi/lpc.asl index 1dca977..385671c 100644 --- a/arch/x86/include/asm/arch-baytrail/acpi/lpc.asl +++ b/arch/x86/include/asm/arch-baytrail/acpi/lpc.asl @@ -14,6 +14,15 @@ Device (LPCB) { Name(_ADR, 0x001f0000)
+ OperationRegion(LPC0, PCI_Config, 0x00, 0x100) + Field(LPC0, AnyAcc, NoLock, Preserve) { + Offset(0x08), + SRID, 8, + Offset(0x80), + C1EN, 1, + Offset(0x84) + } + #include "irqlinks.asl"
/* Firmware Hub */ @@ -81,6 +90,57 @@ Device (LPCB) } }
+ /* Internal UART */ + Device (IURT) + { + Name(_HID, EISAID("PNP0501")) + Name(_UID, 1) + + Method(_STA, 0, Serialized) + { + /* + * TODO: + * + * Need to hide the internal UART depending on whether + * internal UART is enabled or not so that external + * SuperIO UART can be exposed to system. + */ + Store(1, UI3E) + Store(1, UI4E) + Store(1, C1EN) + Return (STA_VISIBLE) + + } + + Method(_DIS, 0, Serialized) + { + Store(0, UI3E) + Store(0, UI4E) + Store(0, C1EN) + } + + Method(_CRS, 0, Serialized) + { + Name(BUF0, ResourceTemplate() + { + IO(Decode16, 0x03f8, 0x03f8, 0x01, 0x08) + IRQNoFlags() { 3 } + }) + + Name(BUF1, ResourceTemplate() + { + IO(Decode16, 0x03f8, 0x03f8, 0x01, 0x08) + IRQNoFlags() { 4 } + }) + + If (LLessEqual(SRID, 0x04)) { + Return (BUF0) + } Else { + Return (BUF1) + } + } + } + /* Real Time Clock */ Device (RTC) {