ARM: add lolevel debug support for asm9260

Since there is no public documentation, this patch also provide register
offsets for different UART units on this SoC.
Signed-off-by: Oleksij Rempel <linux@rempel-privat.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

arch/arm/Kconfig.debug

@@ -93,6 +93,27 @@ choice
 	prompt "Kernel low-level debugging port"
 	depends on DEBUG_LL
 
+	config DEBUG_ASM9260_UART
+		bool "Kernel low-level debugging via asm9260 UART"
+		depends on MACH_ASM9260
+		help
+		  Say Y here if you want the debug print routines to direct
+		  their output to an UART or USART port on asm9260 based
+		  machines.
+
+		    DEBUG_UART_PHYS | DEBUG_UART_VIRT
+
+		    0x80000000      | 0xf0000000     | UART0
+		    0x80004000      | 0xf0004000     | UART1
+		    0x80008000      | 0xf0008000     | UART2
+		    0x8000c000      | 0xf000c000     | UART3
+		    0x80010000      | 0xf0010000     | UART4
+		    0x80014000      | 0xf0014000     | UART5
+		    0x80018000      | 0xf0018000     | UART6
+		    0x8001c000      | 0xf001c000     | UART7
+		    0x80020000      | 0xf0020000     | UART8
+		    0x80024000      | 0xf0024000     | UART9
+
 	config AT91_DEBUG_LL_DBGU0
 		bool "Kernel low-level debugging on rm9200, 9260/9g20, 9261/9g10 and 9rl"
 		depends on HAVE_AT91_DBGU0
@@ -1144,6 +1165,7 @@ config DEBUG_LL_INCLUDE
 	string
 	default "debug/sa1100.S" if DEBUG_SA1100
 	default "debug/8250.S" if DEBUG_LL_UART_8250 || DEBUG_UART_8250
+	default "debug/asm9260.S" if DEBUG_ASM9260_UART
 	default "debug/clps711x.S" if DEBUG_CLPS711X_UART1 || DEBUG_CLPS711X_UART2
 	default "debug/meson.S" if DEBUG_MESON_UARTAO
 	default "debug/pl01x.S" if DEBUG_LL_UART_PL01X || DEBUG_UART_PL01X
@@ -1248,6 +1270,7 @@ config DEBUG_UART_PHYS
 	default 0x78000000 if DEBUG_CNS3XXX
 	default 0x7c0003f8 if FOOTBRIDGE
 	default 0x78000000 if DEBUG_CNS3XXX
+	default 0x80010000 if DEBUG_ASM9260_UART
 	default 0x80070000 if DEBUG_IMX23_UART
 	default 0x80074000 if DEBUG_IMX28_UART
 	default 0x80230000 if DEBUG_PICOXCELL_UART
@@ -1297,13 +1320,14 @@ config DEBUG_UART_PHYS
 		DEBUG_RCAR_GEN2_SCIF0 || DEBUG_RCAR_GEN2_SCIF2 || \
 		DEBUG_RMOBILE_SCIFA0 || DEBUG_RMOBILE_SCIFA1 || \
 		DEBUG_RMOBILE_SCIFA4 || DEBUG_S3C24XX_UART || \
-		DEBUG_UART_BCM63XX
+		DEBUG_UART_BCM63XX || DEBUG_ASM9260_UART
 
 config DEBUG_UART_VIRT
 	hex "Virtual base address of debug UART"
 	default 0xe0010fe0 if ARCH_RPC
 	default 0xe1000000 if DEBUG_MSM_UART
 	default 0xf0000be0 if ARCH_EBSA110
+	default 0xf0010000 if DEBUG_ASM9260_UART
 	default 0xf01fb000 if DEBUG_NOMADIK_UART
 	default 0xf0201000 if DEBUG_BCM2835
 	default 0xf1000300 if DEBUG_BCM_5301X
@@ -1374,7 +1398,7 @@ config DEBUG_UART_VIRT
 	depends on DEBUG_LL_UART_8250 || DEBUG_LL_UART_PL01X || \
 		DEBUG_UART_8250 || DEBUG_UART_PL01X || DEBUG_MESON_UARTAO || \
 		DEBUG_MSM_UART || DEBUG_QCOM_UARTDM || DEBUG_S3C24XX_UART || \
-		DEBUG_UART_BCM63XX
+		DEBUG_UART_BCM63XX || DEBUG_ASM9260_UART
 
 config DEBUG_UART_8250_SHIFT
 	int "Register offset shift for the 8250 debug UART"

arch/arm/include/debug/asm9260.S

+/* Debugging macro include header
+ *
+ *  Copyright (C) 1994-1999 Russell King
+ *  Moved from linux/arch/arm/kernel/debug.S by Ben Dooks
+ *  Modified for ASM9260 by Oleksij Remepl <linux@rempel-privat.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+		.macro	addruart, rp, rv, tmp
+		ldr	\rp, = CONFIG_DEBUG_UART_PHYS
+		ldr	\rv, = CONFIG_DEBUG_UART_VIRT
+		.endm
+
+		.macro	waituart,rd,rx
+		.endm
+
+		.macro	senduart,rd,rx
+		str	\rd, [\rx, #0x50]	@ TXDATA
+		.endm
+
+		.macro	busyuart,rd,rx
+1002:		ldr	\rd, [\rx, #0x60]	@ STAT
+		tst	\rd, #1 << 27		@ TXEMPTY
+		beq	1002b			@ wait until transmit done
+		.endm