drivers/char/hvc_console.h

   1 /*
   2  * hvc_console.h
   3  * Copyright (C) 2005 IBM Corporation
   4  *
   5  * Author(s):
   6  *      Ryan S. Arnold <rsa@us.ibm.com>
   7  *
   8  * hvc_console header information:
   9  *      moved here from arch/powerpc/include/asm/hvconsole.h
  10  *      and drivers/char/hvc_console.c
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program; if not, write to the Free Software
  24  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  25  */
  26
  27 #ifndef HVC_CONSOLE_H
  28 #define HVC_CONSOLE_H
  29 #include <linux/kref.h>
  30
  31 /*
  32  * This is the max number of console adapters that can/will be found as
  33  * console devices on first stage console init.  Any number beyond this range
  34  * can't be used as a console device but is still a valid tty device.
  35  */
  36 #define MAX_NR_HVC_CONSOLES     16
  37
  38 /*
  39  * The Linux TTY code does not support dynamic addition of tty derived devices
  40  * so we need to know how many tty devices we might need when space is allocated
  41  * for the tty device.  Since this driver supports hotplug of vty adapters we
  42  * need to make sure we have enough allocated.
  43  */
  44 #define HVC_ALLOC_TTY_ADAPTERS  8
  45
  46 struct hvc_struct {
  47         spinlock_t lock;
  48         int index;
  49         struct tty_struct *tty;
  50         unsigned int count;
  51         int do_wakeup;
  52         char *outbuf;
  53         int outbuf_size;
  54         int n_outbuf;
  55         uint32_t vtermno;
  56         struct hv_ops *ops;
  57         int irq_requested;
  58         int data;
  59         struct list_head next;
  60         struct kref kref; /* ref count & hvc_struct lifetime */
  61 };
  62
  63 /* implemented by a low level driver */
  64 struct hv_ops {
  65         int (*get_chars)(uint32_t vtermno, char *buf, int count);
  66         int (*put_chars)(uint32_t vtermno, const char *buf, int count);
  67
  68         /* Callbacks for notification. Called in open and close */
  69         int (*notifier_add)(struct hvc_struct *hp, int irq);
  70         void (*notifier_del)(struct hvc_struct *hp, int irq);
  71 };
  72
  73 /* Register a vterm and a slot index for use as a console (console_init) */
  74 extern int hvc_instantiate(uint32_t vtermno, int index, struct hv_ops *ops);
  75
  76 /* register a vterm for hvc tty operation (module_init or hotplug add) */
  77 extern struct hvc_struct * __devinit hvc_alloc(uint32_t vtermno, int data,
  78                                 struct hv_ops *ops, int outbuf_size);
  79 /* remove a vterm from hvc tty operation (module_exit or hotplug remove) */
  80 extern int __devexit hvc_remove(struct hvc_struct *hp);
  81
  82 /* data available */
  83 int hvc_poll(struct hvc_struct *hp);
  84 void hvc_kick(void);
  85
  86 /* default notifier for irq based notification */
  87 extern int notifier_add_irq(struct hvc_struct *hp, int data);
  88 extern void notifier_del_irq(struct hvc_struct *hp, int data);
  89
  90
  91 #if defined(CONFIG_XMON) && defined(CONFIG_SMP)
  92 #include <asm/xmon.h>
  93 #else
  94 static inline int cpus_are_in_xmon(void)
  95 {
  96         return 0;
  97 }
  98 #endif
  99
 100 #endif // HVC_CONSOLE_H