nios2: remove custom early console implementation

As of commits d8f347ba35cf ("nios2: enable earlycon support"),
0dcc0542 ("serial: altera_jtaguart: add earlycon support") and
4d9d7d89 ("serial: altera_uart: add earlycon support"), the nios2
architecture and the altera_uart/altera_jtaguart drivers support
earlycon. Thus, the custom early console implementation for nios2 is no
longer necessary to get early boot messages. Remove it and rely fully on
earlycon support.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>

arch/nios2/include/asm/prom.h

-/*
- * Copyright Altera Corporation (C) <2015>. All rights reserved
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms and conditions of the GNU General Public License,
- * version 2, as published by the Free Software Foundation.
- *
- * This program is distributed in the hope it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
- * more details.
- *
- * You should have received a copy of the GNU General Public License along with
- * this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-
-#ifndef __ASM_NIOS2_PROM_H__
-#define __ASM_NIOS2_PROM_H__
-
-extern unsigned long __init of_early_console(void);
-
-#endif

arch/nios2/include/asm/setup.h

@@ -30,8 +30,6 @@ extern char fast_handler_end[];
 
 extern void pagetable_init(void);
 
-extern void setup_early_printk(void);
-
 #endif/* __KERNEL__ */
 #endif /* __ASSEMBLY__ */
 

arch/nios2/kernel/Makefile

@@ -20,7 +20,6 @@ obj-y	+= syscall_table.o
 obj-y	+= time.o
 obj-y	+= traps.o
 
-obj-$(CONFIG_EARLY_PRINTK)		+= early_printk.o
 obj-$(CONFIG_KGDB)			+= kgdb.o
 obj-$(CONFIG_MODULES)			+= module.o
 obj-$(CONFIG_NIOS2_ALIGNMENT_TRAP)	+= misaligned.o

arch/nios2/kernel/early_printk.c

-/*
- * Early printk for Nios2.
- *
- * Copyright (C) 2015, Altera Corporation
- * Copyright (C) 2010, Tobias Klauser <tklauser@distanz.ch>
- * Copyright (C) 2009, Wind River Systems Inc
- *   Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com
- *
- * This file is subject to the terms and conditions of the GNU General Public
- * License. See the file "COPYING" in the main directory of this archive
- * for more details.
- */
-
-#include <linux/console.h>
-#include <linux/init.h>
-#include <linux/kernel.h>
-#include <linux/io.h>
-
-#include <asm/prom.h>
-
-static unsigned long base_addr;
-
-#if defined(CONFIG_SERIAL_ALTERA_JTAGUART_CONSOLE)
-
-#define ALTERA_JTAGUART_DATA_REG		0
-#define ALTERA_JTAGUART_CONTROL_REG		4
-#define ALTERA_JTAGUART_CONTROL_WSPACE_MSK	0xFFFF0000
-#define ALTERA_JTAGUART_CONTROL_AC_MSK		0x00000400
-
-#define JUART_GET_CR() \
-	__builtin_ldwio((void *)(base_addr + ALTERA_JTAGUART_CONTROL_REG))
-#define JUART_SET_CR(v) \
-	__builtin_stwio((void *)(base_addr + ALTERA_JTAGUART_CONTROL_REG), v)
-#define JUART_SET_TX(v) \
-	__builtin_stwio((void *)(base_addr + ALTERA_JTAGUART_DATA_REG), v)
-
-static void early_console_write(struct console *con, const char *s, unsigned n)
-{
-	unsigned long status;
-
-	while (n-- && *s) {
-		while (((status = JUART_GET_CR())
-				& ALTERA_JTAGUART_CONTROL_WSPACE_MSK) == 0) {
-#if defined(CONFIG_SERIAL_ALTERA_JTAGUART_CONSOLE_BYPASS)
-			if ((status & ALTERA_JTAGUART_CONTROL_AC_MSK) == 0)
-				return;	/* no connection activity */
-#endif
-		}
-		JUART_SET_TX(*s);
-		s++;
-	}
-}
-
-#elif defined(CONFIG_SERIAL_ALTERA_UART_CONSOLE)
-
-#define ALTERA_UART_TXDATA_REG		4
-#define ALTERA_UART_STATUS_REG		8
-#define ALTERA_UART_STATUS_TRDY		0x0040
-
-#define UART_GET_SR() \
-	__builtin_ldwio((void *)(base_addr + ALTERA_UART_STATUS_REG))
-#define UART_SET_TX(v) \
-	__builtin_stwio((void *)(base_addr + ALTERA_UART_TXDATA_REG), v)
-
-static void early_console_putc(char c)
-{
-	while (!(UART_GET_SR() & ALTERA_UART_STATUS_TRDY))
-		;
-
-	UART_SET_TX(c);
-}
-
-static void early_console_write(struct console *con, const char *s, unsigned n)
-{
-	while (n-- && *s) {
-		early_console_putc(*s);
-		if (*s == '\n')
-			early_console_putc('\r');
-		s++;
-	}
-}
-
-#else
-
-static void early_console_write(struct console *con, const char *s, unsigned n)
-{
-}
-
-#endif
-
-static struct console early_console_prom = {
-	.name	= "early",
-	.write	= early_console_write,
-	.flags	= CON_PRINTBUFFER | CON_BOOT,
-	.index	= -1
-};
-
-void __init setup_early_printk(void)
-{
-#if defined(CONFIG_SERIAL_ALTERA_JTAGUART_CONSOLE) ||	\
-	defined(CONFIG_SERIAL_ALTERA_UART_CONSOLE)
-	base_addr = of_early_console();
-#else
-	base_addr = 0;
-#endif
-
-	if (!base_addr)
-		return;
-
-#if defined(CONFIG_SERIAL_ALTERA_JTAGUART_CONSOLE_BYPASS)
-	/* Clear activity bit so BYPASS doesn't stall if we've used JTAG for
-	 * downloading the kernel. This might cause early data to be lost even
-	 * if the JTAG terminal is running.
-	 */
-	JUART_SET_CR(JUART_GET_CR() | ALTERA_JTAGUART_CONTROL_AC_MSK);
-#endif
-
-	early_console = &early_console_prom;
-	register_console(early_console);
-	pr_info("early_console initialized at 0x%08lx\n", base_addr);
-}

arch/nios2/kernel/prom.c

@@ -30,7 +30,6 @@
 #include <linux/of_fdt.h>
 #include <linux/io.h>
 
-#include <asm/prom.h>
 #include <asm/sections.h>
 
 void __init early_init_dt_add_memory_arch(u64 base, u64 size)
@@ -71,51 +70,3 @@ void __init early_init_devtree(void *params)
 
 	early_init_dt_scan(params);
 }
-
-#ifdef CONFIG_EARLY_PRINTK
-static int __init early_init_dt_scan_serial(unsigned long node,
-			const char *uname, int depth, void *data)
-{
-	u64 *addr64 = (u64 *) data;
-	const char *p;
-
-	/* only consider serial nodes */
-	if (strncmp(uname, "serial", 6) != 0)
-		return 0;
-
-	p = of_get_flat_dt_prop(node, "compatible", NULL);
-	if (!p)
-		return 0;
-
-	/*
-	 * We found an altera_jtaguart but it wasn't configured for console, so
-	 * skip it.
-	 */
-#ifndef CONFIG_SERIAL_ALTERA_JTAGUART_CONSOLE
-	if (strncmp(p, "altr,juart", 10) == 0)
-		return 0;
-#endif
-
-	/*
-	 * Same for altera_uart.
-	 */
-#ifndef CONFIG_SERIAL_ALTERA_UART_CONSOLE
-	if (strncmp(p, "altr,uart", 9) == 0)
-		return 0;
-#endif
-
-	*addr64 = of_flat_dt_translate_address(node);
-
-	return *addr64 == OF_BAD_ADDR ? 0 : 1;
-}
-
-unsigned long __init of_early_console(void)
-{
-	u64 base = 0;
-
-	if (of_scan_flat_dt(early_init_dt_scan_serial, &base))
-		return (u32)ioremap(base, 32);
-	else
-		return 0;
-}
-#endif /* CONFIG_EARLY_PRINTK */

arch/nios2/kernel/setup.c

@@ -147,10 +147,6 @@ void __init setup_arch(char **cmdline_p)
 
 	console_verbose();
 
-#ifdef CONFIG_EARLY_PRINTK
-	setup_early_printk();
-#endif
-
 	memory_start = PAGE_ALIGN((unsigned long)__pa(_end));
 	memory_end = (unsigned long) CONFIG_NIOS2_MEM_BASE + memory_size;