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-rw-r--r--arch/parisc/kernel/pdc_cons.c141
1 files changed, 134 insertions, 7 deletions
diff --git a/arch/parisc/kernel/pdc_cons.c b/arch/parisc/kernel/pdc_cons.c
index 1ff366c..66d1f17 100644
--- a/arch/parisc/kernel/pdc_cons.c
+++ b/arch/parisc/kernel/pdc_cons.c
@@ -12,6 +12,7 @@
* 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>
*
*
* This program is free software; you can redistribute it and/or modify
@@ -31,12 +32,11 @@
/*
* The PDC console is a simple console, which can be used for debugging
- * boot related problems on HP PA-RISC machines.
+ * 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.
- * 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.
@@ -53,6 +53,7 @@
#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)
{
@@ -85,12 +86,138 @@ static int pdc_console_setup(struct console *co, char *options)
#if defined(CONFIG_PDC_CONSOLE)
#include <linux/vt_kern.h>
+#include <linux/tty_flip.h>
+
+#define PDC_CONS_POLL_DELAY (30 * HZ / 1000)
+
+static struct timer_list pdc_console_timer;
+
+extern struct console * console_drivers;
+
+static int pdc_console_tty_open(struct tty_struct *tty, struct file *filp)
+{
+
+ mod_timer(&pdc_console_timer, jiffies + PDC_CONS_POLL_DELAY);
+
+ return 0;
+}
+
+static void pdc_console_tty_close(struct tty_struct *tty, struct file *filp)
+{
+ if (!tty->count)
+ del_timer(&pdc_console_timer);
+}
+
+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 int pdc_console_tty_write_room(struct tty_struct *tty)
+{
+ return 32768; /* no limit, no buffer used */
+}
+
+static int pdc_console_tty_chars_in_buffer(struct tty_struct *tty)
+{
+ return 0; /* no buffer */
+}
+
+static struct tty_driver *pdc_console_tty_driver;
+
+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,
+ .chars_in_buffer = pdc_console_tty_chars_in_buffer,
+};
+
+static void pdc_console_poll(unsigned long unused)
+{
+
+ int data, count = 0;
+
+ struct tty_struct *tty = pdc_console_tty_driver->ttys[0];
+
+ if (!tty)
+ return;
+
+ while (1) {
+ data = pdc_console_poll_key(NULL);
+ if (data == -1)
+ break;
+ tty_insert_flip_char(tty, data & 0xFF, TTY_NORMAL);
+ count ++;
+ }
+
+ if (count)
+ tty_flip_buffer_push(tty);
+
+ if (tty->count && (pdc_cons.flags & CON_ENABLED))
+ mod_timer(&pdc_console_timer, jiffies + PDC_CONS_POLL_DELAY);
+}
+
+static int __init pdc_console_tty_driver_init(void)
+{
+
+ int err;
+ struct tty_driver *drv;
+
+ /* 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_drivers;
+
+ for (tmp = console_drivers; tmp; tmp = tmp->next)
+ if (tmp == &pdc_cons)
+ break;
+
+ 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;
+
+ drv = alloc_tty_driver(1);
+
+ if (!drv)
+ return -ENOMEM;
+
+ drv->driver_name = "pdc_cons";
+ drv->name = "ttyB";
+ drv->major = MUX_MAJOR;
+ drv->minor_start = 0;
+ drv->type = TTY_DRIVER_TYPE_SYSTEM;
+ drv->init_termios = tty_std_termios;
+ drv->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_RESET_TERMIOS;
+ tty_set_operations(drv, &pdc_console_tty_ops);
+
+ err = tty_register_driver(drv);
+ if (err) {
+ printk(KERN_ERR "Unable to register the PDC console TTY driver\n");
+ return err;
+ }
+
+ pdc_console_tty_driver = drv;
+
+ /* No need to initialize the pdc_console_timer if tty isn't allocated */
+ init_timer(&pdc_console_timer);
+ pdc_console_timer.function = pdc_console_poll;
+
+ return 0;
+}
+
+module_init(pdc_console_tty_driver_init);
static struct tty_driver * pdc_console_device (struct console *c, int *index)
{
- extern struct tty_driver console_driver;
- *index = c->index ? c->index-1 : fg_console;
- return &console_driver;
+ *index = c->index;
+ return pdc_console_tty_driver;
}
#else
#define pdc_console_device NULL
@@ -101,7 +228,7 @@ static struct console pdc_cons = {
.write = pdc_console_write,
.device = pdc_console_device,
.setup = pdc_console_setup,
- .flags = CON_BOOT | CON_PRINTBUFFER | CON_ENABLED,
+ .flags = CON_BOOT | CON_PRINTBUFFER,
.index = -1,
};
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