diff options
| author | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2021-06-18 05:46:32 +0200 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2021-06-21 13:16:31 +0200 |
| commit | 48b545b8018db61ab4978d29c73c16b9fbfad12c (patch) | |
| tree | e0af16bb18cc8c57058e2b27000f14c1f55fc908 | |
| parent | powerpc/xics: Add a native ICS backend for microwatt (diff) | |
| download | linux-48b545b8018db61ab4978d29c73c16b9fbfad12c.tar.xz linux-48b545b8018db61ab4978d29c73c16b9fbfad12c.zip | |
powerpc/microwatt: Use standard 16550 UART for console
This adds support to the Microwatt platform to use the standard
16550-style UART which available in the standalone Microwatt FPGA.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/YMwXGCTzedpQje7r@thinks.paulus.ozlabs.org
| -rw-r--r-- | arch/powerpc/boot/dts/microwatt.dts | 27 | ||||
| -rw-r--r-- | arch/powerpc/kernel/udbg_16550.c | 39 | ||||
| -rw-r--r-- | arch/powerpc/platforms/microwatt/Kconfig | 1 | ||||
| -rw-r--r-- | arch/powerpc/platforms/microwatt/setup.c | 2 |
4 files changed, 63 insertions, 6 deletions
diff --git a/arch/powerpc/boot/dts/microwatt.dts b/arch/powerpc/boot/dts/microwatt.dts index 04e5dd92270e..974abbdda249 100644 --- a/arch/powerpc/boot/dts/microwatt.dts +++ b/arch/powerpc/boot/dts/microwatt.dts @@ -6,6 +6,10 @@ model-name = "microwatt"; compatible = "microwatt-soc"; + aliases { + serial0 = &UART0; + }; + reserved-memory { #size-cells = <0x02>; #address-cells = <0x02>; @@ -89,12 +93,6 @@ }; }; - chosen { - bootargs = ""; - ibm,architecture-vec-5 = [19 00 10 00 00 00 00 00 00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00 40 00 40]; - }; - soc@c0000000 { compatible = "simple-bus"; #address-cells = <1>; @@ -119,5 +117,22 @@ #interrupt-cells = <2>; }; + UART0: serial@2000 { + device_type = "serial"; + compatible = "ns16550"; + reg = <0x2000 0x8>; + clock-frequency = <100000000>; + current-speed = <115200>; + reg-shift = <2>; + fifo-size = <16>; + interrupts = <0x10 0x1>; + }; + }; + + chosen { + bootargs = ""; + ibm,architecture-vec-5 = [19 00 10 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 40 00 40]; + stdout-path = &UART0; }; }; diff --git a/arch/powerpc/kernel/udbg_16550.c b/arch/powerpc/kernel/udbg_16550.c index 9356b60d6030..8513aa49614e 100644 --- a/arch/powerpc/kernel/udbg_16550.c +++ b/arch/powerpc/kernel/udbg_16550.c @@ -296,3 +296,42 @@ void __init udbg_init_40x_realmode(void) } #endif /* CONFIG_PPC_EARLY_DEBUG_40x */ + +#ifdef CONFIG_PPC_EARLY_DEBUG_MICROWATT + +#define UDBG_UART_MW_ADDR ((void __iomem *)0xc0002000) + +static u8 udbg_uart_in_isa300_rm(unsigned int reg) +{ + uint64_t msr = mfmsr(); + uint8_t c; + + mtmsr(msr & ~(MSR_EE|MSR_DR)); + isync(); + eieio(); + c = __raw_rm_readb(UDBG_UART_MW_ADDR + (reg << 2)); + mtmsr(msr); + isync(); + return c; +} + +static void udbg_uart_out_isa300_rm(unsigned int reg, u8 val) +{ + uint64_t msr = mfmsr(); + + mtmsr(msr & ~(MSR_EE|MSR_DR)); + isync(); + eieio(); + __raw_rm_writeb(val, UDBG_UART_MW_ADDR + (reg << 2)); + mtmsr(msr); + isync(); +} + +void __init udbg_init_debug_microwatt(void) +{ + udbg_uart_in = udbg_uart_in_isa300_rm; + udbg_uart_out = udbg_uart_out_isa300_rm; + udbg_use_uart(); +} + +#endif /* CONFIG_PPC_EARLY_DEBUG_MICROWATT */ diff --git a/arch/powerpc/platforms/microwatt/Kconfig b/arch/powerpc/platforms/microwatt/Kconfig index b52c869c0eb8..50ed0cedb5f1 100644 --- a/arch/powerpc/platforms/microwatt/Kconfig +++ b/arch/powerpc/platforms/microwatt/Kconfig @@ -6,6 +6,7 @@ config PPC_MICROWATT select PPC_ICS_NATIVE select PPC_ICP_NATIVE select PPC_NATIVE + select PPC_UDBG_16550 help This option enables support for FPGA-based Microwatt implementations. diff --git a/arch/powerpc/platforms/microwatt/setup.c b/arch/powerpc/platforms/microwatt/setup.c index 1c1b7791fa57..0b02603bdb74 100644 --- a/arch/powerpc/platforms/microwatt/setup.c +++ b/arch/powerpc/platforms/microwatt/setup.c @@ -14,6 +14,7 @@ #include <asm/machdep.h> #include <asm/time.h> #include <asm/xics.h> +#include <asm/udbg.h> static void __init microwatt_init_IRQ(void) { @@ -35,5 +36,6 @@ define_machine(microwatt) { .name = "microwatt", .probe = microwatt_probe, .init_IRQ = microwatt_init_IRQ, + .progress = udbg_progress, .calibrate_decr = generic_calibrate_decr, }; |