// SPDX-License-Identifier: GPL-2.0-or-later
/*
- * PDC Console support - ie use firmware to dump text via boot console
+ * PDC early console support - use PDC firmware to dump text via boot console
*
- * Copyright (C) 1999-2003 Matthew Wilcox <willy at parisc-linux.org>
- * Copyright (C) 2000 Martin K Petersen <mkp at mkp.net>
- * Copyright (C) 2000 John Marvin <jsm at parisc-linux.org>
- * Copyright (C) 2000-2003 Paul Bame <bame at parisc-linux.org>
- * Copyright (C) 2000 Philipp Rumpf <prumpf with tux.org>
- * Copyright (C) 2000 Michael Ang <mang with subcarrier.org>
- * Copyright (C) 2000 Grant Grundler <grundler with parisc-linux.org>
- * Copyright (C) 2001-2002 Ryan Bradetich <rbrad at parisc-linux.org>
- * Copyright (C) 2001 Helge Deller <deller at parisc-linux.org>
- * Copyright (C) 2001 Thomas Bogendoerfer <tsbogend at parisc-linux.org>
- * Copyright (C) 2002 Randolph Chung <tausq with parisc-linux.org>
- * Copyright (C) 2010 Guy Martin <gmsoft at tuxicoman.be>
+ * Copyright (C) 2001-2022 Helge Deller <deller@gmx.de>
*/
-/*
- * The PDC console is a simple console, which can be used for debugging
- * boot related problems on HP PA-RISC machines. It is also useful when no
- * other console works.
- *
- * This code uses the ROM (=PDC) based functions to read and write characters
- * from and to PDC's boot path.
- */
-
-/* Define EARLY_BOOTUP_DEBUG to debug kernel related boot problems.
- * On production kernels EARLY_BOOTUP_DEBUG should be undefined. */
-#define EARLY_BOOTUP_DEBUG
-
-
-#include <linux/kernel.h>
#include <linux/console.h>
-#include <linux/string.h>
#include <linux/init.h>
-#include <linux/major.h>
-#include <linux/tty.h>
+#include <linux/serial_core.h>
+#include <linux/kgdb.h>
#include <asm/page.h> /* for PAGE0 */
#include <asm/pdc.h> /* for iodc_call() proto and friends */
static DEFINE_SPINLOCK(pdc_console_lock);
-static struct console pdc_cons;
static void pdc_console_write(struct console *co, const char *s, unsigned count)
{
spin_unlock_irqrestore(&pdc_console_lock, flags);
}
-int pdc_console_poll_key(struct console *co)
+#ifdef CONFIG_KGDB
+static int kgdb_pdc_read_char(void)
{
int c;
unsigned long flags;
c = pdc_iodc_getc();
spin_unlock_irqrestore(&pdc_console_lock, flags);
- return c;
-}
-
-static int pdc_console_setup(struct console *co, char *options)
-{
- return 0;
-}
-
-#if defined(CONFIG_PDC_CONSOLE)
-#include <linux/vt_kern.h>
-#include <linux/tty_flip.h>
-
-#define PDC_CONS_POLL_DELAY (30 * HZ / 1000)
-
-static void pdc_console_poll(struct timer_list *unused);
-static DEFINE_TIMER(pdc_console_timer, pdc_console_poll);
-static struct tty_port tty_port;
-
-static int pdc_console_tty_open(struct tty_struct *tty, struct file *filp)
-{
- tty_port_tty_set(&tty_port, tty);
- mod_timer(&pdc_console_timer, jiffies + PDC_CONS_POLL_DELAY);
-
- return 0;
+ return (c <= 0) ? NO_POLL_CHAR : c;
}
-static void pdc_console_tty_close(struct tty_struct *tty, struct file *filp)
+static void kgdb_pdc_write_char(u8 chr)
{
- if (tty->count == 1) {
- del_timer_sync(&pdc_console_timer);
- tty_port_tty_set(&tty_port, NULL);
- }
+ if (PAGE0->mem_cons.cl_class != CL_DUPLEX)
+ pdc_console_write(NULL, &chr, 1);
}
-static int pdc_console_tty_write(struct tty_struct *tty, const unsigned char *buf, int count)
-{
- pdc_console_write(NULL, buf, count);
- return count;
-}
-
-static unsigned int pdc_console_tty_write_room(struct tty_struct *tty)
-{
- return 32768; /* no limit, no buffer used */
-}
-
-static const struct tty_operations pdc_console_tty_ops = {
- .open = pdc_console_tty_open,
- .close = pdc_console_tty_close,
- .write = pdc_console_tty_write,
- .write_room = pdc_console_tty_write_room,
+static struct kgdb_io kgdb_pdc_io_ops = {
+ .name = "kgdb_pdc",
+ .read_char = kgdb_pdc_read_char,
+ .write_char = kgdb_pdc_write_char,
};
-
-static void pdc_console_poll(struct timer_list *unused)
-{
- int data, count = 0;
-
- while (1) {
- data = pdc_console_poll_key(NULL);
- if (data == -1)
- break;
- tty_insert_flip_char(&tty_port, data & 0xFF, TTY_NORMAL);
- count ++;
- }
-
- if (count)
- tty_flip_buffer_push(&tty_port);
-
- if (pdc_cons.flags & CON_ENABLED)
- mod_timer(&pdc_console_timer, jiffies + PDC_CONS_POLL_DELAY);
-}
-
-static struct tty_driver *pdc_console_tty_driver;
-
-static int __init pdc_console_tty_driver_init(void)
-{
- struct tty_driver *driver;
- int err;
-
- /* Check if the console driver is still registered.
- * It is unregistered if the pdc console was not selected as the
- * primary console. */
-
- struct console *tmp;
-
- console_lock();
- for_each_console(tmp)
- if (tmp == &pdc_cons)
- break;
- console_unlock();
-
- if (!tmp) {
- printk(KERN_INFO "PDC console driver not registered anymore, not creating %s\n", pdc_cons.name);
- return -ENODEV;
- }
-
- printk(KERN_INFO "The PDC console driver is still registered, removing CON_BOOT flag\n");
- pdc_cons.flags &= ~CON_BOOT;
-
- driver = tty_alloc_driver(1, TTY_DRIVER_REAL_RAW |
- TTY_DRIVER_RESET_TERMIOS);
- if (IS_ERR(driver))
- return PTR_ERR(driver);
-
- tty_port_init(&tty_port);
-
- driver->driver_name = "pdc_cons";
- driver->name = "ttyB";
- driver->major = MUX_MAJOR;
- driver->minor_start = 0;
- driver->type = TTY_DRIVER_TYPE_SYSTEM;
- driver->init_termios = tty_std_termios;
- tty_set_operations(driver, &pdc_console_tty_ops);
- tty_port_link_device(&tty_port, driver, 0);
-
- err = tty_register_driver(driver);
- if (err) {
- printk(KERN_ERR "Unable to register the PDC console TTY driver\n");
- tty_port_destroy(&tty_port);
- tty_driver_kref_put(driver);
- return err;
- }
-
- pdc_console_tty_driver = driver;
-
- return 0;
-}
-device_initcall(pdc_console_tty_driver_init);
-
-static struct tty_driver * pdc_console_device (struct console *c, int *index)
-{
- *index = c->index;
- return pdc_console_tty_driver;
-}
-#else
-#define pdc_console_device NULL
#endif
-static struct console pdc_cons = {
- .name = "ttyB",
- .write = pdc_console_write,
- .device = pdc_console_device,
- .setup = pdc_console_setup,
- .flags = CON_BOOT | CON_PRINTBUFFER,
- .index = -1,
-};
-
-static int pdc_console_initialized;
-
-static void pdc_console_init_force(void)
+static int __init pdc_earlycon_setup(struct earlycon_device *device,
+ const char *opt)
{
- if (pdc_console_initialized)
- return;
- ++pdc_console_initialized;
-
+ struct console *earlycon_console;
+
/* 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);
-}
+ earlycon_console = device->con;
+ earlycon_console->write = pdc_console_write;
+ device->port.iotype = UPIO_MEM32BE;
-void __init pdc_console_init(void)
-{
-#if defined(EARLY_BOOTUP_DEBUG) || defined(CONFIG_PDC_CONSOLE)
- pdc_console_init_force();
+#ifdef CONFIG_KGDB
+ kgdb_register_io_module(&kgdb_pdc_io_ops);
#endif
-#ifdef EARLY_BOOTUP_DEBUG
- printk(KERN_INFO "Initialized PDC Console for debugging.\n");
-#endif
-}
-
-
-/*
- * 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 initialised 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;
- /* If we've already seen the output, don't bother to print it again */
- if (console_drivers != NULL)
- pdc_cons.flags &= ~CON_PRINTBUFFER;
-
- while ((console = console_drivers) != NULL)
- unregister_console(console_drivers);
-
- /* force registering the pdc console */
- pdc_console_init_force();
+ return 0;
}
+
+EARLYCON_DECLARE(pdc, pdc_earlycon_setup);
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