LXR linux/drivers/tty/hvc/hvc

   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * hvc_console.h
   4 * Copyright (C) 2005 IBM Corporation
   5 *
   6 * Author(s):
   7 *      Ryan S. Arnold <rsa@us.ibm.com>
   8 *
   9 * hvc_console header information:
  10 *      moved here from arch/powerpc/include/asm/hvconsole.h
  11 *      and drivers/char/hvc_console.c
  12 */
  13
  14#ifndef HVC_CONSOLE_H
  15#define HVC_CONSOLE_H
  16#include <linux/kref.h>
  17#include <linux/tty.h>
  18#include <linux/spinlock.h>
  19
  20/*
  21 * This is the max number of console adapters that can/will be found as
  22 * console devices on first stage console init.  Any number beyond this range
  23 * can't be used as a console device but is still a valid tty device.
  24 */
  25#define MAX_NR_HVC_CONSOLES     16
  26
  27/*
  28 * The Linux TTY code does not support dynamic addition of tty derived devices
  29 * so we need to know how many tty devices we might need when space is allocated
  30 * for the tty device.  Since this driver supports hotplug of vty adapters we
  31 * need to make sure we have enough allocated.
  32 */
  33#define HVC_ALLOC_TTY_ADAPTERS  8
  34
  35struct hvc_struct {
  36        struct tty_port port;
  37        spinlock_t lock;
  38        int index;
  39        int do_wakeup;
  40        char *outbuf;
  41        int outbuf_size;
  42        int n_outbuf;
  43        uint32_t vtermno;
  44        const struct hv_ops *ops;
  45        int irq_requested;
  46        int data;
  47        struct winsize ws;
  48        struct work_struct tty_resize;
  49        struct list_head next;
  50        unsigned long flags;
  51};
  52
  53/* implemented by a low level driver */
  54struct hv_ops {
  55        int (*get_chars)(uint32_t vtermno, char *buf, int count);
  56        int (*put_chars)(uint32_t vtermno, const char *buf, int count);
  57
  58        /* Callbacks for notification. Called in open, close and hangup */
  59        int (*notifier_add)(struct hvc_struct *hp, int irq);
  60        void (*notifier_del)(struct hvc_struct *hp, int irq);
  61        void (*notifier_hangup)(struct hvc_struct *hp, int irq);
  62
  63        /* tiocmget/set implementation */
  64        int (*tiocmget)(struct hvc_struct *hp);
  65        int (*tiocmset)(struct hvc_struct *hp, unsigned int set, unsigned int clear);
  66
  67        /* Callbacks to handle tty ports */
  68        void (*dtr_rts)(struct hvc_struct *hp, int raise);
  69};
  70
  71/* Register a vterm and a slot index for use as a console (console_init) */
  72extern int hvc_instantiate(uint32_t vtermno, int index,
  73                           const struct hv_ops *ops);
  74
  75/* register a vterm for hvc tty operation (module_init or hotplug add) */
  76extern struct hvc_struct * hvc_alloc(uint32_t vtermno, int data,
  77                                     const struct hv_ops *ops, int outbuf_size);
  78/* remove a vterm from hvc tty operation (module_exit or hotplug remove) */
  79extern int hvc_remove(struct hvc_struct *hp);
  80
  81/* data available */
  82int hvc_poll(struct hvc_struct *hp);
  83void hvc_kick(void);
  84
  85/* Resize hvc tty terminal window */
  86extern void __hvc_resize(struct hvc_struct *hp, struct winsize ws);
  87
  88static inline void hvc_resize(struct hvc_struct *hp, struct winsize ws)
  89{
  90        unsigned long flags;
  91
  92        spin_lock_irqsave(&hp->lock, flags);
  93        __hvc_resize(hp, ws);
  94        spin_unlock_irqrestore(&hp->lock, flags);
  95}
  96
  97/* default notifier for irq based notification */
  98extern int notifier_add_irq(struct hvc_struct *hp, int data);
  99extern void notifier_del_irq(struct hvc_struct *hp, int data);
 100extern void notifier_hangup_irq(struct hvc_struct *hp, int data);
 101
 102
 103#if defined(CONFIG_XMON) && defined(CONFIG_SMP)
 104#include <asm/xmon.h>
 105#else
 106static inline int cpus_are_in_xmon(void)
 107{
 108        return 0;
 109}
 110#endif
 111
 112#endif // HVC_CONSOLE_H
 113