From 9dae8afdf212d39bc7c25f1b1ca9b10f10f6beaa Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Fri, 21 Dec 2007 15:39:26 +1100 Subject: [POWERPC] 4xx: Add early udbg support for 40x processors This adds some basic real mode based early udbg support for 40x in order to debug things more easily Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Josh Boyer --- arch/powerpc/Kconfig.debug | 13 ++++++++++++ arch/powerpc/kernel/misc_32.S | 39 ++++++++++++++++++++++++++++++++++ arch/powerpc/kernel/udbg.c | 3 +++ arch/powerpc/kernel/udbg_16550.c | 33 ++++++++++++++++++++++++++++ arch/powerpc/platforms/Kconfig.cputype | 1 + 5 files changed, 89 insertions(+) (limited to 'arch') diff --git a/arch/powerpc/Kconfig.debug b/arch/powerpc/Kconfig.debug index d20ccf5f2ca..179a453f7e0 100644 --- a/arch/powerpc/Kconfig.debug +++ b/arch/powerpc/Kconfig.debug @@ -227,6 +227,14 @@ config PPC_EARLY_DEBUG_44x Select this to enable early debugging for IBM 44x chips via the inbuilt serial port. +config PPC_EARLY_DEBUG_40x + bool "Early serial debugging for IBM/AMCC 40x CPUs" + depends on 40x + help + Select this to enable early debugging for IBM 40x chips via the + inbuilt serial port. This works on chips with a 16550 compatible + UART. Xilinx chips with uartlite cannot use this option. + config PPC_EARLY_DEBUG_CPM bool "Early serial debugging for Freescale CPM-based serial ports" depends on SERIAL_CPM @@ -248,6 +256,11 @@ config PPC_EARLY_DEBUG_44x_PHYSHIGH depends on PPC_EARLY_DEBUG_44x default "0x1" +config PPC_EARLY_DEBUG_40x_PHYSADDR + hex "Early debug UART physical address" + depends on PPC_EARLY_DEBUG_40x + default "0xef600300" + config PPC_EARLY_DEBUG_CPM_ADDR hex "CPM UART early debug transmit descriptor address" depends on PPC_EARLY_DEBUG_CPM diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S index ea1137851a4..be09f0d2d90 100644 --- a/arch/powerpc/kernel/misc_32.S +++ b/arch/powerpc/kernel/misc_32.S @@ -206,6 +206,45 @@ _GLOBAL(_nmask_and_or_msr) isync blr /* Done */ +#ifdef CONFIG_40x + +/* + * Do an IO access in real mode + */ +_GLOBAL(real_readb) + mfmsr r7 + ori r0,r7,MSR_DR + xori r0,r0,MSR_DR + sync + mtmsr r0 + sync + isync + lbz r3,0(r3) + sync + mtmsr r7 + sync + isync + blr + + /* + * Do an IO access in real mode + */ +_GLOBAL(real_writeb) + mfmsr r7 + ori r0,r7,MSR_DR + xori r0,r0,MSR_DR + sync + mtmsr r0 + sync + isync + stb r3,0(r4) + sync + mtmsr r7 + sync + isync + blr + +#endif /* CONFIG_40x */ /* * Flush MMU TLB diff --git a/arch/powerpc/kernel/udbg.c b/arch/powerpc/kernel/udbg.c index eba148f2a31..7aad6203e41 100644 --- a/arch/powerpc/kernel/udbg.c +++ b/arch/powerpc/kernel/udbg.c @@ -54,6 +54,9 @@ void __init udbg_early_init(void) #elif defined(CONFIG_PPC_EARLY_DEBUG_44x) /* PPC44x debug */ udbg_init_44x_as1(); +#elif defined(CONFIG_PPC_EARLY_DEBUG_40x) + /* PPC40x debug */ + udbg_init_40x_realmode(); #elif defined(CONFIG_PPC_EARLY_DEBUG_CPM) udbg_init_cpm(); #endif diff --git a/arch/powerpc/kernel/udbg_16550.c b/arch/powerpc/kernel/udbg_16550.c index df740eae77b..cb01ebc5938 100644 --- a/arch/powerpc/kernel/udbg_16550.c +++ b/arch/powerpc/kernel/udbg_16550.c @@ -225,3 +225,36 @@ void __init udbg_init_44x_as1(void) udbg_getc = udbg_44x_as1_getc; } #endif /* CONFIG_PPC_EARLY_DEBUG_44x */ + +#ifdef CONFIG_PPC_EARLY_DEBUG_40x +static void udbg_40x_real_putc(char c) +{ + if (udbg_comport) { + while ((real_readb(&udbg_comport->lsr) & LSR_THRE) == 0) + /* wait for idle */; + real_writeb(c, &udbg_comport->thr); eieio(); + if (c == '\n') + udbg_40x_real_putc('\r'); + } +} + +static int udbg_40x_real_getc(void) +{ + if (udbg_comport) { + while ((real_readb(&udbg_comport->lsr) & LSR_DR) == 0) + ; /* wait for char */ + return real_readb(&udbg_comport->rbr); + } + return -1; +} + +void __init udbg_init_40x_realmode(void) +{ + udbg_comport = (struct NS16550 __iomem *) + CONFIG_PPC_EARLY_DEBUG_40x_PHYSADDR; + + udbg_putc = udbg_40x_real_putc; + udbg_getc = udbg_40x_real_getc; + udbg_getc_poll = NULL; +} +#endif /* CONFIG_PPC_EARLY_DEBUG_40x */ diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype index 99684ea606a..c3ee0b58d53 100644 --- a/arch/powerpc/platforms/Kconfig.cputype +++ b/arch/powerpc/platforms/Kconfig.cputype @@ -43,6 +43,7 @@ config 40x bool "AMCC 40x" select PPC_DCR_NATIVE select WANT_DEVICE_TREE + select PPC_UDBG_16550 config 44x bool "AMCC 44x" -- cgit v1.2.3