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
35 struct 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 */
54 struct 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) */
73 extern 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) */
77 extern 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) */
80 extern int 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 /* Resize hvc tty terminal window */
87 extern void __hvc_resize(struct hvc_struct *hp, struct winsize ws);
88
hvc_resize(struct hvc_struct * hp,struct winsize ws)89 static 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 */
99 extern int notifier_add_irq(struct hvc_struct *hp, int data);
100 extern void notifier_del_irq(struct hvc_struct *hp, int data);
101 extern 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
cpus_are_in_xmon(void)107 static inline int cpus_are_in_xmon(void)
108 {
109 return 0;
110 }
111 #endif
112
113 #endif // HVC_CONSOLE_H
114
