From: Benjamin Herrenschmidt <b...@kernel.crashing.org>
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 <b...@kernel.crashing.org>
Signed-off-by: Paul Mackerras <pau...@ozlabs.org>
---
arch/powerpc/boot/dts/microwatt.dts | 27 ++++++++++++----
arch/powerpc/kernel/udbg_16550.c | 39 ++++++++++++++++++++++++
arch/powerpc/platforms/microwatt/Kconfig | 1 +
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 @@ PowerPC,Microwatt@0 {
};
};
- 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 @@ ICS: interrupt-controller@5000 {
#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,
};
--
2.31.1
