diff options
| author | David Gibson <david@gibson.dropbear.id.au> | 2007-05-08 06:59:31 +0400 |
|---|---|---|
| committer | Paul Mackerras <paulus@samba.org> | 2007-05-08 08:47:33 +0400 |
| commit | d9b55a03611ff2e2e54fb4e1ad2648d5eb870fa3 (patch) | |
| tree | 5704be539afcd6f29b1f5751476c8b4f53673bff /arch/powerpc/kernel/udbg_16550.c | |
| parent | f6dfc80554b27da11dbb36ebae166b23ec3aa9ca (diff) | |
| download | linux-d9b55a03611ff2e2e54fb4e1ad2648d5eb870fa3.tar.xz | |
[POWERPC] Early serial debug support for PPC44x
This adds support for early serial debugging via the built in
port on IBM/AMCC PowerPC 44x CPUs. It uses a bolted TLB entry in
address space 1 for the UART's mapping, allowing robust debugging both
before and after the initialization of the MMU.
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'arch/powerpc/kernel/udbg_16550.c')
| -rw-r--r-- | arch/powerpc/kernel/udbg_16550.c | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/udbg_16550.c b/arch/powerpc/kernel/udbg_16550.c index a963f657222b..7afab5bcd61a 100644 --- a/arch/powerpc/kernel/udbg_16550.c +++ b/arch/powerpc/kernel/udbg_16550.c @@ -191,3 +191,26 @@ void udbg_init_pas_realmode(void) udbg_getc_poll = NULL; } #endif /* CONFIG_PPC_MAPLE */ + +#ifdef CONFIG_PPC_EARLY_DEBUG_44x +#include <platforms/44x/44x.h> + +static void udbg_44x_as1_putc(char c) +{ + if (udbg_comport) { + while ((as1_readb(&udbg_comport->lsr) & LSR_THRE) == 0) + /* wait for idle */; + as1_writeb(c, &udbg_comport->thr); eieio(); + if (c == '\n') + udbg_44x_as1_putc('\r'); + } +} + +void __init udbg_init_44x_as1(void) +{ + udbg_comport = + (volatile struct NS16550 __iomem *)PPC44x_EARLY_DEBUG_VIRTADDR; + + udbg_putc = udbg_44x_as1_putc; +} +#endif /* CONFIG_PPC_EARLY_DEBUG_44x */ |