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 int (*flush)(uint32_t vtermno, bool wait);
58
59 /* Callbacks for notification. Called in open, close and hangup */
60 int (*notifier_add)(struct hvc_struct *hp, int irq);
61 void (*notifier_del)(struct hvc_struct *hp, int irq);
62 void (*notifier_hangup)(struct hvc_struct *hp, int irq);
63
64 /* tiocmget/set implementation */
65 int (*tiocmget)(struct hvc_struct *hp);
66 int (*tiocmset)(struct hvc_struct *hp, unsigned int set, unsigned int clear);
67
68 /* Callbacks to handle tty ports */
69 void (*dtr_rts)(struct hvc_struct *hp, int raise);
70};
71
72/* Register a vterm and a slot index for use as a console (console_init) */
73extern int hvc_instantiate(uint32_t vtermno, int index,
74 const struct hv_ops *ops);
75
76/* register a vterm for hvc tty operation (module_init or hotplug add) */
77extern struct hvc_struct * hvc_alloc(uint32_t vtermno, int data,
78 const struct hv_ops *ops, int outbuf_size);
79/* remove a vterm from hvc tty operation (module_exit or hotplug remove) */
80extern int hvc_remove(struct hvc_struct *hp);
81
82/* data available */
83int hvc_poll(struct hvc_struct *hp);
84void hvc_kick(void);
85
86/* Resize hvc tty terminal window */
87extern void __hvc_resize(struct hvc_struct *hp, struct winsize ws);
88
89static inline void hvc_resize(struct hvc_struct *hp, struct winsize ws)
90{
91 unsigned long flags;
92
93 spin_lock_irqsave(&hp->lock, flags);
94 __hvc_resize(hp, ws);
95 spin_unlock_irqrestore(&hp->lock, flags);
96}
97
98/* default notifier for irq based notification */
99extern int notifier_add_irq(struct hvc_struct *hp, int data);
100extern void notifier_del_irq(struct hvc_struct *hp, int data);
101extern void notifier_hangup_irq(struct hvc_struct *hp, int data);
102
103
104#if defined(CONFIG_XMON) && defined(CONFIG_SMP)
105#include <asm/xmon.h>
106#else
107static inline int cpus_are_in_xmon(void)
108{
109 return 0;
110}
111#endif
112
113#endif // HVC_CONSOLE_H
114