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 	/* tiocmget/set implementation */
78 	int (*tiocmget)(struct hvc_struct *hp);
79 	int (*tiocmset)(struct hvc_struct *hp, unsigned int set, unsigned int clear);
80 };
81 
82 /* Register a vterm and a slot index for use as a console (console_init) */
83 extern int hvc_instantiate(uint32_t vtermno, int index,
84 			   const struct hv_ops *ops);
85 
86 /* register a vterm for hvc tty operation (module_init or hotplug add) */
87 extern struct hvc_struct * hvc_alloc(uint32_t vtermno, int data,
88 				     const struct hv_ops *ops, int outbuf_size);
89 /* remove a vterm from hvc tty operation (module_exit or hotplug remove) */
90 extern int hvc_remove(struct hvc_struct *hp);
91 
92 /* data available */
93 int hvc_poll(struct hvc_struct *hp);
94 void hvc_kick(void);
95 
96 /* Resize hvc tty terminal window */
97 extern void __hvc_resize(struct hvc_struct *hp, struct winsize ws);
98 
hvc_resize(struct hvc_struct * hp,struct winsize ws)99 static inline void hvc_resize(struct hvc_struct *hp, struct winsize ws)
100 {
101 	unsigned long flags;
102 
103 	spin_lock_irqsave(&hp->lock, flags);
104 	__hvc_resize(hp, ws);
105 	spin_unlock_irqrestore(&hp->lock, flags);
106 }
107 
108 /* default notifier for irq based notification */
109 extern int notifier_add_irq(struct hvc_struct *hp, int data);
110 extern void notifier_del_irq(struct hvc_struct *hp, int data);
111 extern void notifier_hangup_irq(struct hvc_struct *hp, int data);
112 
113 
114 #if defined(CONFIG_XMON) && defined(CONFIG_SMP)
115 #include <asm/xmon.h>
116 #else
cpus_are_in_xmon(void)117 static inline int cpus_are_in_xmon(void)
118 {
119 	return 0;
120 }
121 #endif
122 
123 #endif // HVC_CONSOLE_H
124