blob: b08c26c44bb0e5cd6a2869dea00dea486118a461 [file] [log] [blame]
/*
* linux/arch/parisc/kernel/pdc_console.c
*
* The PDC console is a simple console, which can be used for debugging
* boot related problems on HP PA-RISC machines.
*
* This code uses the ROM (=PDC) based functions to read and write characters
* from and to PDC's boot path.
* Since all character read from that path must be polled, this code never
* can or will be a fully functional linux console.
*/
/* Define EARLY_BOOTUP_DEBUG to debug kernel related boot problems.
* On production kernels EARLY_BOOTUP_DEBUG should be undefined. */
#undef EARLY_BOOTUP_DEBUG
#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/console.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <asm/page.h>
#include <asm/types.h>
#include <asm/system.h>
#include <asm/pdc.h> /* for iodc_call() proto and friends */
static void pdc_console_write(struct console *co, const char *s, unsigned count)
{
while(count--)
pdc_iodc_putc(*s++);
}
void pdc_outc(unsigned char c)
{
pdc_iodc_outc(c);
}
int pdc_console_poll_key(struct console *co)
{
return pdc_iodc_getc();
}
static int pdc_console_setup(struct console *co, char *options)
{
return 0;
}
#if defined(CONFIG_PDC_CONSOLE) || defined(CONFIG_SERIAL_MUX)
#define PDC_CONSOLE_DEVICE pdc_console_device
static kdev_t pdc_console_device (struct console *c)
{
return MKDEV(MUX_MAJOR, 0);
}
#else
#define PDC_CONSOLE_DEVICE NULL
#endif
static struct console pdc_cons = {
name: "ttyB",
write: pdc_console_write,
#warning UPSTREAM 2.4.19 removed the next 4 lines but we did not
read: NULL,
device: PDC_CONSOLE_DEVICE,
unblank: NULL,
setup: pdc_console_setup,
flags: CON_BOOT|CON_PRINTBUFFER|CON_ENABLED,
index: -1,
};
static int pdc_console_initialized;
extern unsigned long con_start; /* kernel/printk.c */
extern unsigned long log_end; /* kernel/printk.c */
static void pdc_console_init_force(void)
{
if (pdc_console_initialized)
return;
++pdc_console_initialized;
/* If the console is duplex then copy the COUT parameters to CIN. */
if (PAGE0->mem_cons.cl_class == CL_DUPLEX)
memcpy(&PAGE0->mem_kbd, &PAGE0->mem_cons, sizeof(PAGE0->mem_cons));
/* register the pdc console */
register_console(&pdc_cons);
}
void pdc_console_init(void)
{
#if defined(EARLY_BOOTUP_DEBUG) || defined(CONFIG_PDC_CONSOLE) || defined(CONFIG_SERIAL_MUX)
pdc_console_init_force();
#endif
#ifdef EARLY_BOOTUP_DEBUG
printk(KERN_INFO "Initialized PDC Console for debugging.\n");
#endif
}
/* Unregister the pdc console with the printk console layer */
void pdc_console_die(void)
{
if (!pdc_console_initialized)
return;
--pdc_console_initialized;
printk(KERN_INFO "Switching from PDC console\n");
/* Don't repeat what we've already printed */
con_start = log_end;
unregister_console(&pdc_cons);
}
/*
* Used for emergencies. Currently only used if an HPMC occurs. If an
* HPMC occurs, it is possible that the current console may not be
* properly initialed after the PDC IO reset. This routine unregisters all
* of the current consoles, reinitializes the pdc console and
* registers it.
*/
void pdc_console_restart(void)
{
struct console *console;
if (pdc_console_initialized)
return;
while ((console = console_drivers) != NULL)
unregister_console(console_drivers);
/* Don't repeat what we've already printed */
con_start = log_end;
/* force registering the pdc console */
pdc_console_init_force();
}