drivers/tty/hvc/hvc_console.h

   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
  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
 107 static inline int cpus_are_in_xmon(void)
 108 {
 109         return 0;
 110 }
 111 #endif
 112
 113 #endif // HVC_CONSOLE_H