Re: [PATCH 18/56] microblaze_v2: early_printk support

Michal Simek
2008-05-05T20:09:22Z

I added it to future plan on wiki.

M

> On Sun, May 4, 2008 at 5:41 AM, <monstr@seznam.cz> wrote:
>> From: Michal Simek <monstr@monstr.eu>
>>
>>
>> Signed-off-by: Michal Simek <monstr@monstr.eu>
>
> I'm not opposed to this as is, but longer term will you be getting the
> base address out of the device tree instead of from
> CONFIG_EARLY_PRINTK_UARTLITE_ADDRESS?
>
> Cheers,
> g.
>
>> ---
>> arch/microblaze/kernel/early_printk.c | 115 +++++++++++++++++++++++++++++++++
>> 1 files changed, 115 insertions(+), 0 deletions(-)
>> create mode 100644 arch/microblaze/kernel/early_printk.c
>>
>> diff --git a/arch/microblaze/kernel/early_printk.c b/arch/microblaze/kernel/early_printk.c
>> new file mode 100644
>> index 0000000..0f533ff
>> --- /dev/null
>> +++ b/arch/microblaze/kernel/early_printk.c
>> @@ -0,0 +1,115 @@
>> +/*
>> + * arch/microblaze/kernel/early_printk.c
>> + *
>> + * Copyright (C) 2007 Michal Simek <monstr@monstr.eu>
>> + * Copyright (C) 2003-2006 Yasushi SHOJI <yashi@atmark-techno.com>
>> + *
>> + * Early printk support for Microblaze.
>> + *
>> + * Once we got some system without uart light, we need to refactor.
>> + */
>> +
>> +#include <linux/console.h>
>> +#include <linux/kernel.h>
>> +#include <linux/init.h>
>> +#include <linux/string.h>
>> +#include <linux/tty.h>
>> +#include <asm/io.h>
>> +#include <asm/processor.h>
>> +#include <asm/fcntl.h>
>> +#include <asm/setup.h>
>> +
>> +#ifdef CONFIG_EARLY_PRINTK
>> +#define BASE_ADDR ((unsigned char *)CONFIG_EARLY_PRINTK_UARTLITE_ADDRESS)
>> +
>> +#define RX_FIFO BASE_ADDR
>> +#define TX_FIFO ((unsigned long *)(BASE_ADDR + 4))
>> +#define STATUS ((unsigned long *)(BASE_ADDR + 8))
>> +#define CONTROL ((unsigned long *)(BASE_ADDR + 12))
>> +
>> +static void early_printk_putc(char c)
>> +{
>> + while (ioread32(STATUS) & (1<<3));
>> + iowrite32((c & 0xff), TX_FIFO);
>> +}
>> +
>> +static void early_printk_write(struct console *unused,
>> + const char *s, unsigned n)
>> +{
>> + while (*s && n-- > 0) {
>> + early_printk_putc(*s);
>> + if (*s == '\n')
>> + early_printk_putc('\r');
>> + s++;
>> + }
>> +}
>> +
>> +static struct console early_serial_console = {
>> + .name = "earlyser",
>> + .write = early_printk_write,
>> + .flags = CON_PRINTBUFFER,
>> + .index = -1,
>> +};
>> +
>> +/* Direct interface for emergencies */
>> +static struct console *early_console = &early_serial_console;
>> +static int early_console_initialized;
>> +
>> +void early_printk(const char *fmt, ...)
>> +{
>> + char buf[512];
>> + int n;
>> + va_list ap;
>> +
>> + if (early_console_initialized) {
>> + va_start(ap, fmt);
>> + n = vscnprintf(buf, 512, fmt, ap);
>> + early_console->write(early_console, buf, n);
>> + va_end(ap);
>> + }
>> +}
>> +
>> +static int __initdata keep_early;
>> +
>> +int __init setup_early_printk(char *opt)
>> +{
>> + char *space;
>> + char buf[256];
>> +
>> + if (early_console_initialized)
>> + return 1;
>> +
>> + strlcpy(buf, opt, sizeof(buf));
>> + space = strchr(buf, ' ');
>> + if (space)
>> + *space = 0;
>> +
>> + if (strstr(buf, "keep"))
>> + keep_early = 1;
>> +
>> + early_console = &early_serial_console;
>> + early_console_initialized = 1;
>> + register_console(early_console);
>> + return 0;
>> +}
>> +#if 0
>> +static void __init disable_early_printk(void)
>> +{
>> + if (!early_console_initialized || !early_console)
>> + return;
>> + if (!keep_early) {
>> + printk(KERN_INFO "disabling early console\n");
>> + unregister_console(early_console);
>> + early_console_initialized = 0;
>> + } else
>> + printk(KERN_INFO "keeping early console\n");
>> +}
>> +#endif
>> +
>> +__setup("earlyprintk=", setup_early_printk);
>> +
>> +#else
>> +void early_printk(const char *fmt, ...)
>> +{
>> +}
>> +#endif
>> --
>> 1.5.4.GIT
>>
>>
>
>
>