diff options
Diffstat (limited to 'arch/nios2/kernel')
| -rw-r--r-- | arch/nios2/kernel/Makefile | 1 | ||||
| -rw-r--r-- | arch/nios2/kernel/early_printk.c | 118 | ||||
| -rw-r--r-- | arch/nios2/kernel/prom.c | 52 | ||||
| -rw-r--r-- | arch/nios2/kernel/setup.c | 4 |
4 files changed, 174 insertions, 1 deletions
diff --git a/arch/nios2/kernel/Makefile b/arch/nios2/kernel/Makefile index 8ae76823ff93..eaaa894c432f 100644 --- a/arch/nios2/kernel/Makefile +++ b/arch/nios2/kernel/Makefile @@ -20,5 +20,6 @@ obj-y += syscall_table.o obj-y += time.o obj-y += traps.o +obj-$(CONFIG_EARLY_PRINTK) += early_printk.o obj-$(CONFIG_MODULES) += module.o obj-$(CONFIG_NIOS2_ALIGNMENT_TRAP) += misaligned.o diff --git a/arch/nios2/kernel/early_printk.c b/arch/nios2/kernel/early_printk.c new file mode 100644 index 000000000000..c08e4c1486fc --- /dev/null +++ b/arch/nios2/kernel/early_printk.c @@ -0,0 +1,118 @@ +/* + * 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 +# error Neither SERIAL_ALTERA_JTAGUART_CONSOLE nor SERIAL_ALTERA_UART_CONSOLE \ +selected +#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); +} diff --git a/arch/nios2/kernel/prom.c b/arch/nios2/kernel/prom.c index 0522d3378e3f..718dd197909f 100644 --- a/arch/nios2/kernel/prom.c +++ b/arch/nios2/kernel/prom.c @@ -1,7 +1,7 @@ /* * Device tree support * - * Copyright (C) 2013 Altera Corporation + * Copyright (C) 2013, 2015 Altera Corporation * Copyright (C) 2010 Thomas Chou <thomas@wytron.com.tw> * * Based on MIPS support for CONFIG_OF device tree support @@ -30,6 +30,7 @@ #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) @@ -63,3 +64,52 @@ 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 = fdt_translate_address((const void *)initial_boot_params, + 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 */ diff --git a/arch/nios2/kernel/setup.c b/arch/nios2/kernel/setup.c index cb3121f975d4..b101a43d3c5a 100644 --- a/arch/nios2/kernel/setup.c +++ b/arch/nios2/kernel/setup.c @@ -139,6 +139,10 @@ 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; |