[POWERPC] Add early debug console for CPM serial ports.

This code assumes that the ports have been previously set up, with
buffers in DPRAM.

Signed-off-by: Scott Wood <scottwood@freescale.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

7 files changed, 91 insertions, 0 deletions

diff --git a/arch/powerpc/Kconfig.debug b/arch/powerpc/Kconfig.debug
index c38bc2237057..f4e5d22312a0 100644
--- a/arch/powerpc/Kconfig.debug
+++ b/arch/powerpc/Kconfig.debug
@@ -221,6 +221,15 @@ config PPC_EARLY_DEBUG_44x
           Select this to enable early debugging for IBM 44x chips via the
           inbuilt serial port.
 
+config PPC_EARLY_DEBUG_CPM
+        bool "Early serial debugging for Freescale CPM-based serial ports"
+        depends on SERIAL_CPM
+        select PIN_TLB if PPC_8xx
+        help
+          Select this to enable early debugging for Freescale chips
+          using a CPM-based serial port.  This assumes that the bootwrapper
+          has run, and set up the CPM in a particular way.
+
 endchoice
 
 config PPC_EARLY_DEBUG_44x_PHYSLOW
@@ -233,4 +242,16 @@ config PPC_EARLY_DEBUG_44x_PHYSHIGH
         depends PPC_EARLY_DEBUG_44x
         default "0x1"
 
+config PPC_EARLY_DEBUG_CPM_ADDR
+        hex "CPM UART early debug transmit descriptor address"
+        depends on PPC_EARLY_DEBUG_CPM
+        default "0xfa202808" if PPC_EP88XC
+        default "0xf0000808" if CPM2
+        default "0xff002808" if CPM1
+        help
+          This specifies the address of the transmit descriptor
+          used for early debug output.  Because it is needed before
+          platform probing is done, all platforms selected must
+          share the same address.
+
 endmenu
diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S
index c86c626cf156..d83f04e5a599 100644
--- a/arch/powerpc/kernel/head_32.S
+++ b/arch/powerpc/kernel/head_32.S
@@ -149,6 +149,9 @@ __after_mmu_off:
 #if defined(CONFIG_BOOTX_TEXT)
         bl      setup_disp_bat
 #endif
+#ifdef CONFIG_PPC_EARLY_DEBUG_CPM
+        bl      setup_cpm_bat
+#endif
 
 /*
  * Call setup_cpu for CPU 0 and initialize 6xx Idle
@@ -1245,6 +1248,19 @@ setup_disp_bat:
         blr
 #endif /* CONFIG_BOOTX_TEXT */
 
+#ifdef CONFIG_PPC_EARLY_DEBUG_CPM
+setup_cpm_bat:
+        lis     r8, 0xf000
+        ori     r8, r8, 0x002a
+        mtspr   SPRN_DBAT1L, r8
+
+        lis     r11, 0xf000
+        ori     r11, r11, (BL_1M << 2) | 2
+        mtspr   SPRN_DBAT1U, r11
+
+        blr
+#endif
+
 #ifdef CONFIG_8260
 /* Jump into the system reset for the rom.
  * We first disable the MMU, and then jump to the ROM reset address.
diff --git a/arch/powerpc/kernel/udbg.c b/arch/powerpc/kernel/udbg.c
index 0f9b4eadfbcb..d723070c9a33 100644
--- a/arch/powerpc/kernel/udbg.c
+++ b/arch/powerpc/kernel/udbg.c
@@ -54,6 +54,8 @@ 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_CPM)
+        udbg_init_cpm();
 #endif
 }
 
diff --git a/arch/powerpc/platforms/8xx/Kconfig b/arch/powerpc/platforms/8xx/Kconfig
index 39bb8c5ebe70..8ecd01ad0de8 100644
--- a/arch/powerpc/platforms/8xx/Kconfig
+++ b/arch/powerpc/platforms/8xx/Kconfig
@@ -3,6 +3,7 @@ config FADS
 
 config CPM1
         bool
+        select CPM
 
 choice
         prompt "8xx Machine Type"
diff --git a/arch/powerpc/platforms/Kconfig b/arch/powerpc/platforms/Kconfig
index 8a62ca533b30..cc6013ffc29a 100644
--- a/arch/powerpc/platforms/Kconfig
+++ b/arch/powerpc/platforms/Kconfig
@@ -273,6 +273,7 @@ config QUICC_ENGINE
 config CPM2
         bool
         default n
+        select CPM
         help
           The CPM2 (Communications Processor Module) is a coprocessor on
           embedded CPUs made by Freescale.  Selecting this option means that
@@ -309,4 +310,7 @@ config FSL_ULI1575
           Freescale reference boards. The boards all use the ULI in pretty
           much the same way.
 
+config CPM
+        bool
+
 endmenu
diff --git a/arch/powerpc/sysdev/Makefile b/arch/powerpc/sysdev/Makefile
index 592c17ea713d..52e93bca10ca 100644
--- a/arch/powerpc/sysdev/Makefile
+++ b/arch/powerpc/sysdev/Makefile
@@ -31,6 +31,7 @@ endif
 
 # Temporary hack until we have migrated to asm-powerpc
 ifeq ($(ARCH),powerpc)
+obj-$(CONFIG_CPM)               += cpm_common.o
 obj-$(CONFIG_CPM2)              += cpm2_common.o cpm2_pic.o
 obj-$(CONFIG_8xx)               += mpc8xx_pic.o commproc.o
 obj-$(CONFIG_UCODE_PATCH)       += micropatch.o
diff --git a/arch/powerpc/sysdev/cpm_common.c b/arch/powerpc/sysdev/cpm_common.c
new file mode 100644
index 000000000000..9daa6ac67676
--- /dev/null
+++ b/arch/powerpc/sysdev/cpm_common.c
@@ -0,0 +1,46 @@
+/*
+ * Common CPM code
+ *
+ * Author: Scott Wood <scottwood@freescale.com>
+ *
+ * Copyright 2007 Freescale Semiconductor, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/init.h>
+#include <asm/udbg.h>
+#include <asm/io.h>
+#include <asm/system.h>
+#include <mm/mmu_decl.h>
+
+#ifdef CONFIG_PPC_EARLY_DEBUG_CPM
+static u32 __iomem *cpm_udbg_txdesc =
+        (u32 __iomem __force *)CONFIG_PPC_EARLY_DEBUG_CPM_ADDR;
+
+static void udbg_putc_cpm(char c)
+{
+        u8 __iomem *txbuf = (u8 __iomem __force *)in_be32(&cpm_udbg_txdesc[1]);
+
+        if (c == '\n')
+                udbg_putc('\r');
+
+        while (in_be32(&cpm_udbg_txdesc[0]) & 0x80000000)
+                ;
+
+        out_8(txbuf, c);
+        out_be32(&cpm_udbg_txdesc[0], 0xa0000001);
+}
+
+void __init udbg_init_cpm(void)
+{
+        if (cpm_udbg_txdesc) {
+#ifdef CONFIG_CPM2
+                setbat(1, 0xf0000000, 0xf0000000, 1024*1024, _PAGE_IO);
+#endif
+                udbg_putc = udbg_putc_cpm;
+        }
+}
+#endif