From 5fdc0d1af8bcf3a91c04d40e26644fde59aa0cac Mon Sep 17 00:00:00 2001 From: Daniel Palmer Date: Tue, 11 Mar 2025 08:51:19 +0900 Subject: [PATCH] m68k: mvme147: Reinstate early console BugLink: https://bugs.launchpad.net/bugs/2101915 [ Upstream commit 077b33b9e2833ff25050d986178a2c4c4036cbac ] Commit a38eaa07a0ce ("m68k/mvme147: config.c - Remove unused functions"), removed the console functionality for the mvme147 instead of wiring it up to an early console. Put the console write function back and wire it up like mvme16x does so it's possible to see Linux boot on this fine hardware once more. Fixes: a38eaa07a0ce ("m68k/mvme147: config.c - Remove unused functions") Signed-off-by: Daniel Palmer Co-developed-by: Finn Thain Signed-off-by: Finn Thain Reviewed-by: Geert Uytterhoeven Link: https://lore.kernel.org/a82e8f0068a8722996a0ccfe666abb5e0a5c120d.1730850684.git.fthain@linux-m68k.org Signed-off-by: Geert Uytterhoeven Signed-off-by: Sasha Levin Signed-off-by: Koichiro Den Signed-off-by: Stefan Bader --- arch/m68k/kernel/early_printk.c | 5 ++++- arch/m68k/mvme147/config.c | 30 ++++++++++++++++++++++++++++++ arch/m68k/mvme147/mvme147.h | 6 ++++++ 3 files changed, 40 insertions(+), 1 deletion(-) create mode 100644 arch/m68k/mvme147/mvme147.h diff --git a/arch/m68k/kernel/early_printk.c b/arch/m68k/kernel/early_printk.c index 3cc944df04f6..f11ef9f1f56f 100644 --- a/arch/m68k/kernel/early_printk.c +++ b/arch/m68k/kernel/early_printk.c @@ -13,6 +13,7 @@ #include +#include "../mvme147/mvme147.h" #include "../mvme16x/mvme16x.h" asmlinkage void __init debug_cons_nputs(const char *s, unsigned n); @@ -22,7 +23,9 @@ static void __ref debug_cons_write(struct console *c, { #if !(defined(CONFIG_SUN3) || defined(CONFIG_M68000) || \ defined(CONFIG_COLDFIRE)) - if (MACH_IS_MVME16x) + if (MACH_IS_MVME147) + mvme147_scc_write(c, s, n); + else if (MACH_IS_MVME16x) mvme16x_cons_write(c, s, n); else debug_cons_nputs(s, n); diff --git a/arch/m68k/mvme147/config.c b/arch/m68k/mvme147/config.c index 8b5dc07f0811..cc2fb0a83cf0 100644 --- a/arch/m68k/mvme147/config.c +++ b/arch/m68k/mvme147/config.c @@ -32,6 +32,7 @@ #include #include +#include "mvme147.h" static void mvme147_get_model(char *model); extern void mvme147_sched_init(void); @@ -185,3 +186,32 @@ int mvme147_hwclk(int op, struct rtc_time *t) } return 0; } + +static void scc_delay(void) +{ + __asm__ __volatile__ ("nop; nop;"); +} + +static void scc_write(char ch) +{ + do { + scc_delay(); + } while (!(in_8(M147_SCC_A_ADDR) & BIT(2))); + scc_delay(); + out_8(M147_SCC_A_ADDR, 8); + scc_delay(); + out_8(M147_SCC_A_ADDR, ch); +} + +void mvme147_scc_write(struct console *co, const char *str, unsigned int count) +{ + unsigned long flags; + + local_irq_save(flags); + while (count--) { + if (*str == '\n') + scc_write('\r'); + scc_write(*str++); + } + local_irq_restore(flags); +} diff --git a/arch/m68k/mvme147/mvme147.h b/arch/m68k/mvme147/mvme147.h new file mode 100644 index 000000000000..140bc98b0102 --- /dev/null +++ b/arch/m68k/mvme147/mvme147.h @@ -0,0 +1,6 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +struct console; + +/* config.c */ +void mvme147_scc_write(struct console *co, const char *str, unsigned int count);