LXR linux/drivers/char/hvc

   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
  48struct 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 */
  68struct 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) */
  79extern 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) */
  83extern 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) */
  86extern int hvc_remove(struct hvc_struct *hp);
  87
  88/* data available */
  89int hvc_poll(struct hvc_struct *hp);
  90void hvc_kick(void);
  91
  92/* Resize hvc tty terminal window */
  93extern void __hvc_resize(struct hvc_struct *hp, struct winsize ws);
  94
  95static 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 */
 105extern int notifier_add_irq(struct hvc_struct *hp, int data);
 106extern void notifier_del_irq(struct hvc_struct *hp, int data);
 107extern 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
 113static inline int cpus_are_in_xmon(void)
 114{
 115        return 0;
 116}
 117#endif
 118
 119#endif // HVC_CONSOLE_H
 120