kernel/include/linux/console.h

/*
 *  linux/include/linux/console.h
 *
 *  Copyright (C) 1993        Hamish Macdonald
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file COPYING in the main directory of this archive
 * for more details.
 *
 * Changed:
 * 10-Mar-94: Arno Griffioen: Conversion for vt100 emulator port from PC LINUX
 */

#ifndef _LINUX_CONSOLE_H_
#define _LINUX_CONSOLE_H_ 1

#include <linux/atomic.h>
#include <linux/types.h>

struct vc_data;
struct console_font_op;
struct console_font;
struct module;
struct tty_struct;
struct notifier_block;

/*
 * this is what the terminal answers to a ESC-Z or csi0c query.
 */
#define VT100ID "\033[?1;2c"
#define VT102ID "\033[?6c"

enum con_scroll {
	SM_UP,
	SM_DOWN,
};

/**
 * struct consw - callbacks for consoles
 *
 * @con_scroll: move lines from @top to @bottom in direction @dir by @lines.
 *		Return true if no generic handling should be done.
 *		Invoked by csi_M and printing to the console.
 * @con_set_palette: sets the palette of the console to @table (optional)
 * @con_scrolldelta: the contents of the console should be scrolled by @lines.
 *		     Invoked by user. (optional)
 */
struct consw {
	struct module *owner;
	const char *(*con_startup)(void);
	void	(*con_init)(struct vc_data *vc, int init);
	void	(*con_deinit)(struct vc_data *vc);
	void	(*con_clear)(struct vc_data *vc, int sy, int sx, int height,
			int width);
	void	(*con_putc)(struct vc_data *vc, int c, int ypos, int xpos);
	void	(*con_putcs)(struct vc_data *vc, const unsigned short *s,
			int count, int ypos, int xpos);
	void	(*con_cursor)(struct vc_data *vc, int mode);
	bool	(*con_scroll)(struct vc_data *vc, unsigned int top,
			unsigned int bottom, enum con_scroll dir,
			unsigned int lines);
	int	(*con_switch)(struct vc_data *vc);
	int	(*con_blank)(struct vc_data *vc, int blank, int mode_switch);
	int	(*con_font_set)(struct vc_data *vc, struct console_font *font,
			unsigned int flags);
	int	(*con_font_get)(struct vc_data *vc, struct console_font *font);
	int	(*con_font_default)(struct vc_data *vc,
			struct console_font *font, char *name);
	int	(*con_font_copy)(struct vc_data *vc, int con);
	int     (*con_resize)(struct vc_data *vc, unsigned int width,
			unsigned int height, unsigned int user);
	void	(*con_set_palette)(struct vc_data *vc,
			const unsigned char *table);
	void	(*con_scrolldelta)(struct vc_data *vc, int lines);
	int	(*con_set_origin)(struct vc_data *vc);
	void	(*con_save_screen)(struct vc_data *vc);
	u8	(*con_build_attr)(struct vc_data *vc, u8 color, u8 intensity,
			u8 blink, u8 underline, u8 reverse, u8 italic);
	void	(*con_invert_region)(struct vc_data *vc, u16 *p, int count);
	u16    *(*con_screen_pos)(struct vc_data *vc, int offset);
	unsigned long (*con_getxy)(struct vc_data *vc, unsigned long position,
			int *px, int *py);
	/*
	 * Flush the video console driver's scrollback buffer
	 */
	void	(*con_flush_scrollback)(struct vc_data *vc);
	/*
	 * Prepare the console for the debugger.  This includes, but is not
	 * limited to, unblanking the console, loading an appropriate
	 * palette, and allowing debugger generated output.
	 */
	int	(*con_debug_enter)(struct vc_data *vc);
	/*
	 * Restore the console to its pre-debug state as closely as possible.
	 */
	int	(*con_debug_leave)(struct vc_data *vc);
};

extern const struct consw *conswitchp;

extern const struct consw dummy_con;	/* dummy console buffer */
extern const struct consw vga_con;	/* VGA text console */
extern const struct consw newport_con;	/* SGI Newport console  */
extern const struct consw prom_con;	/* SPARC PROM console */

int con_is_bound(const struct consw *csw);
int do_unregister_con_driver(const struct consw *csw);
int do_take_over_console(const struct consw *sw, int first, int last, int deflt);
void give_up_console(const struct consw *sw);
#ifdef CONFIG_HW_CONSOLE
int con_debug_enter(struct vc_data *vc);
int con_debug_leave(void);
#else
static inline int con_debug_enter(struct vc_data *vc)
{
	return 0;
}
static inline int con_debug_leave(void)
{
	return 0;
}
#endif

/* cursor */
#define CM_DRAW     (1)
#define CM_ERASE    (2)
#define CM_MOVE     (3)

/*
 * The interface for a console, or any other device that wants to capture
 * console messages (printer driver?)
 *
 * If a console driver is marked CON_BOOT then it will be auto-unregistered
 * when the first real console is registered.  This is for early-printk drivers.
 */

#define CON_PRINTBUFFER	(1)
#define CON_CONSDEV	(2) /* Last on the command line */
#define CON_ENABLED	(4)
#define CON_BOOT	(8)
#define CON_ANYTIME	(16) /* Safe to call when cpu is offline */
#define CON_BRL		(32) /* Used for a braille device */
#define CON_EXTENDED	(64) /* Use the extended output format a la /dev/kmsg */

struct console {
	char	name[16];
	void	(*write)(struct console *, const char *, unsigned);
	int	(*read)(struct console *, char *, unsigned);
	struct tty_driver *(*device)(struct console *, int *);
	void	(*unblank)(void);
	int	(*setup)(struct console *, char *);
	int	(*match)(struct console *, char *name, int idx, char *options);
	short	flags;
	short	index;
	int	cflag;
	void	*data;
	struct	 console *next;
};

/*
 * for_each_console() allows you to iterate on each console
 */
#define for_each_console(con) \
	for (con = console_drivers; con != NULL; con = con->next)

extern int console_set_on_cmdline;
extern struct console *early_console;

enum con_flush_mode {
	CONSOLE_FLUSH_PENDING,
	CONSOLE_REPLAY_ALL,
};

extern int add_preferred_console(char *name, int idx, char *options);
extern void register_console(struct console *);
extern int unregister_console(struct console *);
extern struct console *console_drivers;
extern void console_lock(void);
extern int console_trylock(void);
extern void console_unlock(void);
extern void console_conditional_schedule(void);
extern void console_unblank(void);
extern void console_flush_on_panic(enum con_flush_mode mode);
extern struct tty_driver *console_device(int *);
extern void console_stop(struct console *);
extern void console_start(struct console *);
extern int is_console_locked(void);
extern int braille_register_console(struct console *, int index,
		char *console_options, char *braille_options);
extern int braille_unregister_console(struct console *);
#ifdef CONFIG_TTY
extern void console_sysfs_notify(void);
#else
static inline void console_sysfs_notify(void)
{ }
#endif
extern bool console_suspend_enabled;

/* Suspend and resume console messages over PM events */
extern void suspend_console(void);
extern void resume_console(void);

int mda_console_init(void);
void prom_con_init(void);

void vcs_make_sysfs(int index);
void vcs_remove_sysfs(int index);

/* Some debug stub to catch some of the obvious races in the VT code */
#define WARN_CONSOLE_UNLOCKED()						\
	WARN_ON(!atomic_read(&ignore_console_lock_warning) &&		\
		!is_console_locked() && !oops_in_progress)
/*
 * Increment ignore_console_lock_warning if you need to quiet
 * WARN_CONSOLE_UNLOCKED() for debugging purposes.
 */
extern atomic_t ignore_console_lock_warning;

/* VESA Blanking Levels */
#define VESA_NO_BLANKING        0
#define VESA_VSYNC_SUSPEND      1
#define VESA_HSYNC_SUSPEND      2
#define VESA_POWERDOWN          3

#ifdef CONFIG_VGA_CONSOLE
extern bool vgacon_text_force(void);
#else
static inline bool vgacon_text_force(void) { return false; }
#endif

extern void console_init(void);

/* For deferred console takeover */
void dummycon_register_output_notifier(struct notifier_block *nb);
void dummycon_unregister_output_notifier(struct notifier_block *nb);

#endif /* _LINUX_CONSOLE_H */