diff options
author | David Gibson <david@gibson.dropbear.id.au> | 2007-05-08 02:59:31 (GMT) |
---|---|---|
committer | Paul Mackerras <paulus@samba.org> | 2007-05-08 04:47:33 (GMT) |
commit | d9b55a03611ff2e2e54fb4e1ad2648d5eb870fa3 (patch) | |
tree | 5704be539afcd6f29b1f5751476c8b4f53673bff /arch/powerpc/kernel | |
parent | f6dfc80554b27da11dbb36ebae166b23ec3aa9ca (diff) | |
download | linux-fsl-qoriq-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')
-rw-r--r-- | arch/powerpc/kernel/head_44x.S | 34 | ||||
-rw-r--r-- | arch/powerpc/kernel/of_platform.c | 1 | ||||
-rw-r--r-- | arch/powerpc/kernel/udbg.c | 3 | ||||
-rw-r--r-- | arch/powerpc/kernel/udbg_16550.c | 23 |
4 files changed, 39 insertions, 22 deletions
diff --git a/arch/powerpc/kernel/head_44x.S b/arch/powerpc/kernel/head_44x.S index a51026f0..8869596 100644 --- a/arch/powerpc/kernel/head_44x.S +++ b/arch/powerpc/kernel/head_44x.S @@ -172,36 +172,28 @@ skpinv: addi r4,r4,1 /* Increment */ isync 4: -#ifdef CONFIG_SERIAL_TEXT_DEBUG - /* - * Add temporary UART mapping for early debug. - * We can map UART registers wherever we want as long as they don't - * interfere with other system mappings (e.g. with pinned entries). - * For an example of how we handle this - see ocotea.h. --ebs - */ +#ifdef CONFIG_PPC_EARLY_DEBUG_44x + /* Add UART mapping for early debug. */ + /* pageid fields */ - lis r3,UART0_IO_BASE@h - ori r3,r3,PPC44x_TLB_VALID | PPC44x_TLB_4K + lis r3,PPC44x_EARLY_DEBUG_VIRTADDR@h + ori r3,r3,PPC44x_TLB_VALID|PPC44x_TLB_TS|PPC44x_TLB_64K /* xlat fields */ - lis r4,UART0_PHYS_IO_BASE@h /* RPN depends on SoC */ -#ifndef CONFIG_440EP - ori r4,r4,0x0001 /* ERPN is 1 for second 4GB page */ -#endif + lis r4,CONFIG_PPC_EARLY_DEBUG_44x_PHYSLOW@h + ori r4,r4,CONFIG_PPC_EARLY_DEBUG_44x_PHYSHIGH /* attrib fields */ - li r5,0 - ori r5,r5,(PPC44x_TLB_SW | PPC44x_TLB_SR | PPC44x_TLB_I | PPC44x_TLB_G) + li r5,(PPC44x_TLB_SW|PPC44x_TLB_SR|PPC44x_TLB_I|PPC44x_TLB_G) + li r0,62 /* TLB slot 0 */ - li r0,0 /* TLB slot 0 */ - - tlbwe r3,r0,PPC44x_TLB_PAGEID /* Load the pageid fields */ - tlbwe r4,r0,PPC44x_TLB_XLAT /* Load the translation fields */ - tlbwe r5,r0,PPC44x_TLB_ATTRIB /* Load the attrib/access fields */ + tlbwe r3,r0,PPC44x_TLB_PAGEID + tlbwe r4,r0,PPC44x_TLB_XLAT + tlbwe r5,r0,PPC44x_TLB_ATTRIB /* Force context change */ isync -#endif /* CONFIG_SERIAL_TEXT_DEBUG */ +#endif /* CONFIG_PPC_EARLY_DEBUG_44x */ /* Establish the interrupt vector offsets */ SET_IVOR(0, CriticalInput); diff --git a/arch/powerpc/kernel/of_platform.c b/arch/powerpc/kernel/of_platform.c index 908ed79..84c34d9 100644 --- a/arch/powerpc/kernel/of_platform.c +++ b/arch/powerpc/kernel/of_platform.c @@ -29,7 +29,6 @@ #include <asm/ppc-pci.h> #include <asm/atomic.h> - /* * The list of OF IDs below is used for matching bus types in the * system whose devices are to be exposed as of_platform_devices. diff --git a/arch/powerpc/kernel/udbg.c b/arch/powerpc/kernel/udbg.c index 7e09718..7ef97ea 100644 --- a/arch/powerpc/kernel/udbg.c +++ b/arch/powerpc/kernel/udbg.c @@ -51,6 +51,9 @@ void __init udbg_early_init(void) udbg_init_pas_realmode(); #elif defined(CONFIG_BOOTX_TEXT) udbg_init_btext(); +#elif defined(CONFIG_PPC_EARLY_DEBUG_44x) + /* PPC44x debug */ + udbg_init_44x_as1(); #endif } diff --git a/arch/powerpc/kernel/udbg_16550.c b/arch/powerpc/kernel/udbg_16550.c index a963f65..7afab5b 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 */ |