[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>

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

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.

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
 }
 

arch/powerpc/platforms/8xx/Kconfig

@@ -3,6 +3,7 @@ config FADS
 
 config CPM1
 	bool
+	select CPM
 
 choice
 	prompt "8xx Machine Type"

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

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

arch/powerpc/sysdev/cpm_common.c

+/*
+ * 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

include/asm-powerpc/udbg.h

@@ -48,6 +48,7 @@ extern void __init udbg_init_rtas_console(void);
 extern void __init udbg_init_debug_beat(void);
 extern void __init udbg_init_btext(void);
 extern void __init udbg_init_44x_as1(void);
+extern void __init udbg_init_cpm(void);
 
 #endif /* __KERNEL__ */
 #endif /* _ASM_POWERPC_UDBG_H */