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

[Michal Simek <monstr@seznam.cz>]

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
>>
>>
> 
> 
>