console.c

powerpc内核mpc8241linux系统下char驱动程序

/*
 *  linux/drivers/char/console.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 */

/*
 * Hopefully this will be a rather complete VT102 implementation.
 *
 * Beeping thanks to John T Kohl.
 *
 * Virtual Consoles, Screen Blanking, Screen Dumping, Color, Graphics
 *   Chars, and VT100 enhancements by Peter MacDonald.
 *
 * Copy and paste function by Andrew Haylett,
 *   some enhancements by Alessandro Rubini.
 *
 * Code to check for different video-cards mostly by Galen Hunt,
 * <[e-mail]>
 *
 * Rudimentary ISO 10646/Unicode/UTF-8 character set support by
 * Markus Kuhn, <[e-mail]>.
 *
 * Dynamic allocation of consoles, [e-mail], May 1994
 * Resizing of consoles, aeb, 940926
 *
 * Code for xterm like mouse click reporting by Peter Orbaek 20-Jul-94
 * <[e-mail]>
 *
 * User-defined bell sound, new setterm control sequences and printk
 * redirection by Martin Mares <[e-mail]> 19-Nov-95
 *
 * APM screenblank bug fixed Takashi Manabe <[e-mail]>
 *
 * Merge with the abstract console driver by Geert Uytterhoeven
 * <[e-mail]>, Jan 1997.
 *
 *   Original m68k console driver modifications by
 *
 *     - Arno Griffioen <[e-mail]>
 *     - David Carter <[e-mail]>
 * 
 *   Note that the abstract console driver allows all consoles to be of
 *   potentially different sizes, so the following variables depend on the
 *   current console (currcons):
 *
 *     - video_num_columns
 *     - video_num_lines
 *     - video_size_row
 *     - can_do_color
 *
 *   The abstract console driver provides a generic interface for a text
 *   console. It supports VGA text mode, frame buffer based graphical consoles
 *   and special graphics processors that are only accessible through some
 *   registers (e.g. a TMS340x0 GSP).
 *
 *   The interface to the hardware is specified using a special structure
 *   (struct consw) which contains function pointers to console operations
 *   (see <linux/console.h> for more information).
 *
 * Support for changeable cursor shape
 * by Pavel Machek <[e-mail]>, August 1997
 *
 * Ported to i386 and con_scrolldelta fixed
 * by Emmanuel Marty <[e-mail]>, April 1998
 *
 * Resurrected character buffers in videoram plus lots of other trickery
 * by Martin Mares <[e-mail]>, July 1998
 */

#include <linux/module.h>
#include <linux/sched.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/kd.h>
#include <linux/malloc.h>
#include <linux/major.h>
#include <linux/mm.h>
#include <linux/console.h>
#include <linux/init.h>
#include <linux/vt_kern.h>
#include <linux/selection.h>
#include <linux/console_struct.h>
#include <linux/kbd_kern.h>
#include <linux/consolemap.h>
#include <linux/timer.h>
#include <linux/interrupt.h>
#include <linux/config.h>
#include <linux/version.h>
#include <linux/tqueue.h>
#ifdef CONFIG_APM
#include <linux/apm_bios.h>
#endif

#include <asm/io.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/bitops.h>

#include <asm/linux_logo.h>

#include "console_macros.h"


struct consw *conswitchp = NULL;

/* A bitmap for codes <32. A bit of 1 indicates that the code
 * corresponding to that bit number invokes some special action
 * (such as cursor movement) and should not be displayed as a
 * glyph unless the disp_ctrl mode is explicitly enabled.
 */
#define CTRL_ACTION 0x0d00ff81
#define CTRL_ALWAYS 0x0800f501	/* Cannot be overridden by disp_ctrl */

/*
 * Here is the default bell parameters: 750HZ, 1/8th of a second
 */
#define DEFAULT_BELL_PITCH	750
#define DEFAULT_BELL_DURATION	(HZ/8)

#ifndef MIN
#define MIN(a,b)	((a) < (b) ? (a) : (b))
#endif

static struct tty_struct *console_table[MAX_NR_CONSOLES];
static struct termios *console_termios[MAX_NR_CONSOLES];
static struct termios *console_termios_locked[MAX_NR_CONSOLES];
struct vc vc_cons [MAX_NR_CONSOLES];

#ifndef VT_SINGLE_DRIVER
static struct consw *con_driver_map[MAX_NR_CONSOLES];
#endif

static int con_open(struct tty_struct *, struct file *);
static void vc_init(unsigned int console, unsigned int rows,
		    unsigned int cols, int do_clear);
static void blank_screen(void);
static void gotoxy(int currcons, int new_x, int new_y);
static void save_cur(int currcons);
static void reset_terminal(int currcons, int do_clear);
static void con_flush_chars(struct tty_struct *tty);
static void set_vesa_blanking(unsigned long arg);
static void set_cursor(int currcons);
static void hide_cursor(int currcons);

static int printable = 0;		/* Is console ready for printing? */

int do_poke_blanked_console = 0;
int console_blanked = 0;

static int vesa_blank_mode = 0; /* 0:none 1:suspendV 2:suspendH 3:powerdown */
static int blankinterval = 10*60*HZ;
static int vesa_off_interval = 0;

/*
 * fg_console is the current virtual console,
 * last_console is the last used one,
 * want_console is the console we want to switch to,
 * kmsg_redirect is the console for kernel messages,
 */
int fg_console = 0;
int last_console = 0;
int want_console = -1;
int kmsg_redirect = 0;

/*
 * For each existing display, we have a pointer to console currently visible
 * on that display, allowing consoles other than fg_console to be refreshed
 * appropriately. Unless the low-level driver supplies its own display_fg
 * variable, we use this one for the "master display".
 */
static struct vc_data *master_display_fg = NULL;

/*
 * Unfortunately, we need to delay tty echo when we're currently writing to the
 * console since the code is (and always was) not re-entrant, so we insert
 * all filp requests to con_task_queue instead of tq_timer and run it from
 * the console_bh.
 */
DECLARE_TASK_QUEUE(con_task_queue);

/*
 * For the same reason, we defer scrollback to the console_bh.
 */
static int scrollback_delta = 0;

/*
 *	Low-Level Functions
 */

#define IS_FG (currcons == fg_console)
#define IS_VISIBLE CON_IS_VISIBLE(vc_cons[currcons].d)

#ifdef VT_BUF_VRAM_ONLY
#define DO_UPDATE 0
#else
#define DO_UPDATE IS_VISIBLE
#endif

static inline unsigned short *screenpos(int currcons, int offset, int viewed)
{
	unsigned short *p;
	
	if (!viewed)
		p = (unsigned short *)(origin + offset);
	else if (!sw->con_screen_pos)
		p = (unsigned short *)(visible_origin + offset);
	else
		p = sw->con_screen_pos(vc_cons[currcons].d, offset);
	return p;
}

static inline void scrolldelta(int lines)
{
	scrollback_delta += lines;
	mark_bh(CONSOLE_BH);
}

static void scrup(int currcons, unsigned int t, unsigned int b, int nr)
{
	unsigned short *d, *s;

	if (t+nr >= b)
		nr = b - t - 1;
	if (b > video_num_lines || t >= b || nr < 1)
		return;
	if (IS_VISIBLE && sw->con_scroll(vc_cons[currcons].d, t, b, SM_UP, nr))
		return;
	d = (unsigned short *) (origin+video_size_row*t);
	s = (unsigned short *) (origin+video_size_row*(t+nr));
	scr_memcpyw(d, s, (b-t-nr) * video_size_row);
	scr_memsetw(d + (b-t-nr) * video_num_columns, video_erase_char, video_size_row*nr);
}

static void
scrdown(int currcons, unsigned int t, unsigned int b, int nr)
{
	unsigned short *s;
	unsigned int step;

	if (t+nr >= b)
		nr = b - t - 1;
	if (b > video_num_lines || t >= b || nr < 1)
		return;
	if (IS_VISIBLE && sw->con_scroll(vc_cons[currcons].d, t, b, SM_DOWN, nr))
		return;
	s = (unsigned short *) (origin+video_size_row*t);
	step = video_num_columns * nr;
	scr_memmovew(s + step, s, (b-t-nr)*video_size_row);
	scr_memsetw(s, video_erase_char, 2*step);
}

static void do_update_region(int currcons, unsigned long start, int count)
{
#ifndef VT_BUF_VRAM_ONLY
	unsigned int xx, yy, offset;
	u16 *p;

	p = (u16 *) start;
	if (!sw->con_getxy) {
		offset = (start - origin) / 2;
		xx = offset % video_num_columns;
		yy = offset / video_num_columns;
	} else {
		int nxx, nyy;
		start = sw->con_getxy(vc_cons[currcons].d, start, &nxx, &nyy);
		xx = nxx; yy = nyy;
	}
	for(;;) {
		u16 attrib = scr_readw(p) & 0xff00;
		int startx = xx;
		u16 *q = p;
		while (xx < video_num_columns && count) {
			if (attrib != (scr_readw(p) & 0xff00)) {
				if (p > q)
					sw->con_putcs(vc_cons[currcons].d, q, p-q, yy, startx);
				startx = xx;
				q = p;
				attrib = scr_readw(p) & 0xff00;
			}
			p++;
			xx++;
			count--;
		}
		if (p > q)
			sw->con_putcs(vc_cons[currcons].d, q, p-q, yy, startx);
		if (!count)
			break;
		xx = 0;
		yy++;
		if (sw->con_getxy) {
			p = (u16 *)start;
			start = sw->con_getxy(vc_cons[currcons].d, start, NULL, NULL);
		}
	}
#endif
}

void update_region(int currcons, unsigned long start, int count)
{
	if (DO_UPDATE) {
		hide_cursor(currcons);
		do_update_region(currcons, start, count);
		set_cursor(currcons);
	}
}

/* Structure of attributes is hardware-dependent */

static u8 build_attr(int currcons, u8 _color, u8 _intensity, u8 _blink, u8 _underline, u8 _reverse)
{
	if (sw->con_build_attr)
		return sw->con_build_attr(vc_cons[currcons].d, _color, _intensity, _blink, _underline, _reverse);

#ifndef VT_BUF_VRAM_ONLY
/*
 * ++roman: I completely changed the attribute format for monochrome
 * mode (!can_do_color). The formerly used MDA (monochrome display
 * adapter) format didn't allow the combination of certain effects.
 * Now the attribute is just a bit vector:
 *  Bit 0..1: intensity (0..2)
 *  Bit 2   : underline
 *  Bit 3   : reverse
 *  Bit 7   : blink
 */
	{
	u8 a = color;
	if (!can_do_color)
		return _intensity |
		       (_underline ? 4 : 0) |
		       (_reverse ? 8 : 0) |
		       (_blink ? 0x80 : 0);
	if (_underline)
		a = (a & 0xf0) | ulcolor;
	else if (_intensity == 0)
		a = (a & 0xf0) | halfcolor;
	if (_reverse)
		a = ((a) & 0x88) | ((((a) >> 4) | ((a) << 4)) & 0x77);
	if (_blink)
		a ^= 0x80;
	if (_intensity == 2)
		a ^= 0x08;
	if (hi_font_mask == 0x100)
		a <<= 1;
	return a;
	}
#else
	return 0;
#endif
}

static void update_attr(int currcons)
{
	attr = build_attr(currcons, color, intensity, blink, underline, reverse ^ decscnm);
	video_erase_char = (build_attr(currcons, color, 1, 0, 0, decscnm) << 8) | ' ';
}

/* Note: inverting the screen twice should revert to the original state */

void invert_screen(int currcons, int offset, int count, int viewed)
{
	unsigned short *p;

	count /= 2;
	p = screenpos(currcons, offset, viewed);
	if (sw->con_invert_region)
		sw->con_invert_region(vc_cons[currcons].d, p, count);
#ifndef VT_BUF_VRAM_ONLY
	else {
		u16 *q = p;
		int cnt = count;

		if (!can_do_color) {
			while (cnt--) *q++ ^= 0x0800;
		} else if (hi_font_mask == 0x100) {
			while (cnt--) {
				u16 a = *q;
				a = ((a) & 0x11ff) | (((a) & 0xe000) >> 4) | (((a) & 0x0e00) << 4);
				*q++ = a;
			}
		} else {
			while (cnt--) {
				u16 a = *q;
				a = ((a) & 0x88ff) | (((a) & 0x7000) >> 4) | (((a) & 0x0700) << 4);
				*q++ = a;
			}
		}
	}
#endif
	if (DO_UPDATE)
		do_update_region(currcons, (unsigned long) p, count);
}

/* used by selection: complement pointer position */
void complement_pos(int currcons, int offset)
{
	static unsigned short *p = NULL;
	static unsigned short old = 0;
	static unsigned short oldx = 0, oldy = 0;

	if (p) {
		scr_writew(old, p);
		if (DO_UPDATE)
			sw->con_putc(vc_cons[currcons].d, old, oldy, oldx);
	}
	if (offset == -1)
		p = NULL;
	else {
		unsigned short new;
		p = screenpos(currcons, offset, 1);
		old = scr_readw(p);
		new = old ^ complement_mask;
		scr_writew(new, p);
		if (DO_UPDATE) {
			oldx = (offset >> 1) % video_num_columns;
			oldy = (offset >> 1) / video_num_columns;
			sw->con_putc(vc_cons[currcons].d, new, oldy, oldx);
		}
	}
}

static void insert_char(int currcons, unsigned int nr)
{
	unsigned short *p, *q = (unsigned short *) pos;

	p = q + video_num_columns - nr - x;
	while (--p >= q)
		scr_writew(scr_readw(p), p + nr);
	scr_memsetw(q, video_erase_char, nr*2);
	need_wrap = 0;
	if (DO_UPDATE) {
		unsigned short oldattr = attr;
		sw->con_bmove(vc_cons[currcons].d,y,x,y,x+nr,1,
			      video_num_columns-x-nr);
		attr = video_erase_char >> 8;
		while (nr--)
			sw->con_putc(vc_cons[currcons].d,
				     video_erase_char,y,x+nr);
		attr = oldattr;
	}
}

static void delete_char(int currcons, unsigned int nr)
{
	unsigned int i = x;
	unsigned short *p = (unsigned short *) pos;

	while (++i <= video_num_columns - nr) {
		scr_writew(scr_readw(p+nr), p);
		p++;
	}
	scr_memsetw(p, video_erase_char, nr*2);
	need_wrap = 0;
	if (DO_UPDATE) {
		unsigned short oldattr = attr;
		sw->con_bmove(vc_cons[currcons].d, y, x+nr, y, x, 1,
			      video_num_columns-x-nr);
		attr = video_erase_char >> 8;
		while (nr--)
			sw->con_putc(vc_cons[currcons].d,
				     video_erase_char, y,
				     video_num_columns-1-nr);
		attr = oldattr;
	}
}

static int softcursor_original;

static void add_softcursor(int currcons)
{
	int i = scr_readw((u16 *) pos);
	u32 type = cursor_type;

	if (! (type & 0x10)) return;
	if (softcursor_original != -1) return;
	softcursor_original = i;
	i |= ((type >> 8) & 0xff00 );
	i ^= ((type) & 0xff00 );
	if ((type & 0x20) && ((softcursor_original & 0x7000) == (i & 0x7000))) i ^= 0x7000;
	if ((type & 0x40) && ((i & 0x700) == ((i & 0x7000) >> 4))) i ^= 0x0700;
	scr_writew(i, (u16 *) pos);
	if (DO_UPDATE)
		sw->con_putc(vc_cons[currcons].d, i, y, x);
}

static void hide_cursor(int currcons)
{
	if (currcons == sel_cons)
		clear_selection();
	if (softcursor_original != -1) {
		scr_writew(softcursor_original,(u16 *) pos);
		if (DO_UPDATE)
			sw->con_putc(vc_cons[currcons].d, softcursor_original, y, x);
		softcursor_original = -1;
	}
	sw->con_cursor(vc_cons[currcons].d,CM_ERASE);
}

static void set_cursor(int currcons)
{
    if (!IS_FG || console_blanked || vcmode == KD_GRAPHICS)
	return;
    if (deccm) {
	if (currcons == sel_cons)
		clear_selection();
	add_softcursor(currcons);
	if ((cursor_type & 0x0f) != 1)
	    sw->con_cursor(vc_cons[currcons].d,CM_DRAW);
    } else
	hide_cursor(currcons);
}

static void set_origin(int currcons)
{
	if (!IS_VISIBLE ||
	    !sw->con_set_origin ||
	    !sw->con_set_origin(vc_cons[currcons].d))
		origin = (unsigned long) screenbuf;
	visible_origin = origin;
	scr_end = origin + screenbuf_size;
	pos = origin + video_size_row*y + 2*x;
}

static inline void save_screen(int currcons)
{
	if (sw->con_save_screen)
		sw->con_save_screen(vc_cons[currcons].d);
}

/*
 *	Redrawing of screen
 */

void redraw_screen(int new_console, int is_switch)
{
	int redraw = 1;
	int currcons, old_console;
	static int lock = 0;

	if (lock)
		return;
	if (!vc_cons_allocated(new_console)) {
		/* strange ... */
		printk("redraw_screen: tty %d not allocated ??\n", new_console+1);
		return;
	}