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 #include <linux/tty.h>
  31 #include <linux/spinlock.h>
  32
  33 /*
  34  * This is the max number of console adapters that can/will be found as
  35  * console devices on first stage console init.  Any number beyond this range
  36  * can't be used as a console device but is still a valid tty device.
  37  */
  38 #define MAX_NR_HVC_CONSOLES     16
  39
  40 /*
  41  * The Linux TTY code does not support dynamic addition of tty derived devices
  42  * so we need to know how many tty devices we might need when space is allocated
  43  * for the tty device.  Since this driver supports hotplug of vty adapters we
  44  * need to make sure we have enough allocated.
  45  */
  46 #define HVC_ALLOC_TTY_ADAPTERS  8
  47
  48 struct hvc_struct {
  49         spinlock_t lock;
  50         int index;
  51         struct tty_struct *tty;
  52         int count;
  53         int do_wakeup;
  54         char *outbuf;
  55         int outbuf_size;
  56         int n_outbuf;
  57         uint32_t vtermno;
  58         const struct hv_ops *ops;
  59         int irq_requested;
  60         int data;
  61         struct winsize ws;
  62         struct work_struct tty_resize;
  63         struct list_head next;
  64         struct kref kref; /* ref count & hvc_struct lifetime */
  65 };
  66
  67 /* implemented by a low level driver */
  68 struct hv_ops {
  69         int (*get_chars)(uint32_t vtermno, char *buf, int count);
  70         int (*put_chars)(uint32_t vtermno, const char *buf, int count);
  71
  72         /* Callbacks for notification. Called in open, close and hangup */
  73         int (*notifier_add)(struct hvc_struct *hp, int irq);
  74         void (*notifier_del)(struct hvc_struct *hp, int irq);
  75         void (*notifier_hangup)(struct hvc_struct *hp, int irq);
  76 };
  77
  78 /* Register a vterm and a slot index for use as a console (console_init) */
  79 extern int hvc_instantiate(uint32_t vtermno, int index,
  80                            const struct hv_ops *ops);
  81
  82 /* register a vterm for hvc tty operation (module_init or hotplug add) */
  83 extern struct hvc_struct * hvc_alloc(uint32_t vtermno, int data,
  84                                      const struct hv_ops *ops, int outbuf_size);
  85 /* remove a vterm from hvc tty operation (module_exit or hotplug remove) */
  86 extern int hvc_remove(struct hvc_struct *hp);
  87
  88 /* data available */
  89 int hvc_poll(struct hvc_struct *hp);
  90 void hvc_kick(void);
  91
  92 /* Resize hvc tty terminal window */
  93 extern void __hvc_resize(struct hvc_struct *hp, struct winsize ws);
  94
  95 static inline void hvc_resize(struct hvc_struct *hp, struct winsize ws)
  96 {
  97         unsigned long flags;
  98
  99         spin_lock_irqsave(&hp->lock, flags);
 100         __hvc_resize(hp, ws);
 101         spin_unlock_irqrestore(&hp->lock, flags);
 102 }
 103
 104 /* default notifier for irq based notification */
 105 extern int notifier_add_irq(struct hvc_struct *hp, int data);
 106 extern void notifier_del_irq(struct hvc_struct *hp, int data);
 107 extern void notifier_hangup_irq(struct hvc_struct *hp, int data);
 108
 109
 110 #if defined(CONFIG_XMON) && defined(CONFIG_SMP)
 111 #include <asm/xmon.h>
 112 #else
 113 static inline int cpus_are_in_xmon(void)
 114 {
 115         return 0;
 116 }
 117 #endif
 118
 119 #endif // HVC_CONSOLE_H