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authorBenjamin Herrenschmidt <benh@kernel.crashing.org>2007-12-21 15:39:26 +1100
committerJosh Boyer <jwboyer@linux.vnet.ibm.com>2007-12-23 13:13:03 -0600
commit9dae8afdf212d39bc7c25f1b1ca9b10f10f6beaa (patch)
tree12721945adf3a3fc01ba292e1756af4826a7eed3 /arch
parent69c0785112921a43739495a68f459fde88a9bbd8 (diff)
[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 <benh@kernel.crashing.org> Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/powerpc/Kconfig.debug13
-rw-r--r--arch/powerpc/kernel/misc_32.S39
-rw-r--r--arch/powerpc/kernel/udbg.c3
-rw-r--r--arch/powerpc/kernel/udbg_16550.c33
-rw-r--r--arch/powerpc/platforms/Kconfig.cputype1
5 files changed, 89 insertions, 0 deletions
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"