[linux-block.git] / drivers / video / console / dummycon.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 *  linux/drivers/video/dummycon.c -- A dummy console driver
 *
 *  To be used if there's no other console driver (e.g. for plain VGA text)
 *  available, usually until fbcon takes console over.
 */

#include <linux/types.h>
#include <linux/kdev_t.h>
#include <linux/console.h>
#include <linux/vt_kern.h>
#include <linux/screen_info.h>
#include <linux/init.h>
#include <linux/module.h>

/*
 *  Dummy console driver
 */

#if defined(__arm__)
#define DUMMY_COLUMNS	screen_info.orig_video_cols
#define DUMMY_ROWS	screen_info.orig_video_lines
#else
/* set by Kconfig. Use 80x25 for 640x480 and 160x64 for 1280x1024 */
#define DUMMY_COLUMNS	CONFIG_DUMMY_CONSOLE_COLUMNS
#define DUMMY_ROWS	CONFIG_DUMMY_CONSOLE_ROWS
#endif

#ifdef CONFIG_FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER
/* These are both protected by the console_lock */
static RAW_NOTIFIER_HEAD(dummycon_output_nh);
static bool dummycon_putc_called;

void dummycon_register_output_notifier(struct notifier_block *nb)
{
	raw_notifier_chain_register(&dummycon_output_nh, nb);

	if (dummycon_putc_called)
		nb->notifier_call(nb, 0, NULL);
}

void dummycon_unregister_output_notifier(struct notifier_block *nb)
{
	raw_notifier_chain_unregister(&dummycon_output_nh, nb);
}

static void dummycon_putc(struct vc_data *vc, int c, int ypos, int xpos)
{
	dummycon_putc_called = true;
	raw_notifier_call_chain(&dummycon_output_nh, 0, NULL);
}

static void dummycon_putcs(struct vc_data *vc, const unsigned short *s,
			   int count, int ypos, int xpos)
{
	int i;

	if (!dummycon_putc_called) {
		/* Ignore erases */
		for (i = 0 ; i < count; i++) {
			if (s[i] != vc->vc_video_erase_char)
				break;
		}
		if (i == count)
			return;

		dummycon_putc_called = true;
	}

	raw_notifier_call_chain(&dummycon_output_nh, 0, NULL);
}

static int dummycon_blank(struct vc_data *vc, int blank, int mode_switch)
{
	/* Redraw, so that we get putc(s) for output done while blanked */
	return 1;
}
#else
static void dummycon_putc(struct vc_data *vc, int c, int ypos, int xpos) { }
static void dummycon_putcs(struct vc_data *vc, const unsigned short *s,
			   int count, int ypos, int xpos) { }
static int dummycon_blank(struct vc_data *vc, int blank, int mode_switch)
{
	return 0;
}
#endif

static const char *dummycon_startup(void)
{
    return "dummy device";
}

static void dummycon_init(struct vc_data *vc, int init)
{
    vc->vc_can_do_color = 1;
    if (init) {
	vc->vc_cols = DUMMY_COLUMNS;
	vc->vc_rows = DUMMY_ROWS;
    } else
	vc_resize(vc, DUMMY_COLUMNS, DUMMY_ROWS);
}

static void dummycon_deinit(struct vc_data *vc) { }
static void dummycon_clear(struct vc_data *vc, int sy, int sx, int height,
			   int width) { }
static void dummycon_cursor(struct vc_data *vc, int mode) { }

static bool dummycon_scroll(struct vc_data *vc, unsigned int top,
			    unsigned int bottom, enum con_scroll dir,
			    unsigned int lines)
{
	return false;
}

static int dummycon_switch(struct vc_data *vc)
{
	return 0;
}

static int dummycon_font_set(struct vc_data *vc, struct console_font *font,
			     unsigned int flags)
{
	return 0;
}

static int dummycon_font_default(struct vc_data *vc,
				 struct console_font *font, char *name)
{
	return 0;
}

static int dummycon_font_copy(struct vc_data *vc, int con)
{
	return 0;
}

/*
 *  The console `switch' structure for the dummy console
 *
 *  Most of the operations are dummies.
 */

const struct consw dummy_con = {
	.owner =		THIS_MODULE,
	.con_startup =	dummycon_startup,
	.con_init =		dummycon_init,
	.con_deinit =	dummycon_deinit,
	.con_clear =	dummycon_clear,
	.con_putc =		dummycon_putc,
	.con_putcs =	dummycon_putcs,
	.con_cursor =	dummycon_cursor,
	.con_scroll =	dummycon_scroll,
	.con_switch =	dummycon_switch,
	.con_blank =	dummycon_blank,
	.con_font_set =	dummycon_font_set,
	.con_font_default =	dummycon_font_default,
	.con_font_copy =	dummycon_font_copy,
};
EXPORT_SYMBOL_GPL(dummy_con);
Commit	Line	Data
457c8996	1	// SPDX-License-Identifier: GPL-2.0-only
1da177e4 LT	2	/*
	3	* linux/drivers/video/dummycon.c -- A dummy console driver
	4	*
	5	* To be used if there's no other console driver (e.g. for plain VGA text)
	6	* available, usually until fbcon takes console over.
	7	*/
	8
	9	#include <linux/types.h>
	10	#include <linux/kdev_t.h>
1da177e4 LT	11	#include <linux/console.h>
1da177e4 LT	12	#include <linux/vt_kern.h>
894673ee	13	#include <linux/screen_info.h>
1da177e4 LT	14	#include <linux/init.h>
	15	#include <linux/module.h>
	16
	17	/*
	18	* Dummy console driver
	19	*/
	20
	21	#if defined(__arm__)
3ea33510 PA	22	#define DUMMY_COLUMNS screen_info.orig_video_cols
3ea33510 PA	23	#define DUMMY_ROWS screen_info.orig_video_lines
8f5b1e65	24	#else
1da177e4	25	/* set by Kconfig. Use 80x25 for 640x480 and 160x64 for 1280x1024 */
1da177e4 LT	26	#define DUMMY_COLUMNS CONFIG_DUMMY_CONSOLE_COLUMNS
1da177e4 LT	27	#define DUMMY_ROWS CONFIG_DUMMY_CONSOLE_ROWS
1da177e4 LT	28	#endif
1da177e4 LT	29
83d83beb HG	30	#ifdef CONFIG_FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER
	31	/* These are both protected by the console_lock */
	32	static RAW_NOTIFIER_HEAD(dummycon_output_nh);
	33	static bool dummycon_putc_called;
	34
	35	void dummycon_register_output_notifier(struct notifier_block *nb)
	36	{
	37	raw_notifier_chain_register(&dummycon_output_nh, nb);
	38
	39	if (dummycon_putc_called)
	40	nb->notifier_call(nb, 0, NULL);
	41	}
	42
	43	void dummycon_unregister_output_notifier(struct notifier_block *nb)
	44	{
	45	raw_notifier_chain_unregister(&dummycon_output_nh, nb);
	46	}
	47
	48	static void dummycon_putc(struct vc_data *vc, int c, int ypos, int xpos)
	49	{
	50	dummycon_putc_called = true;
	51	raw_notifier_call_chain(&dummycon_output_nh, 0, NULL);
	52	}
	53
	54	static void dummycon_putcs(struct vc_data vc, const unsigned short s,
	55	int count, int ypos, int xpos)
	56	{
	57	int i;
	58
	59	if (!dummycon_putc_called) {
	60	/* Ignore erases */
	61	for (i = 0 ; i < count; i++) {
	62	if (s[i] != vc->vc_video_erase_char)
	63	break;
	64	}
	65	if (i == count)
	66	return;
	67
	68	dummycon_putc_called = true;
	69	}
	70
	71	raw_notifier_call_chain(&dummycon_output_nh, 0, NULL);
	72	}
	73
	74	static int dummycon_blank(struct vc_data *vc, int blank, int mode_switch)
	75	{
	76	/* Redraw, so that we get putc(s) for output done while blanked */
	77	return 1;
	78	}
	79	#else
	80	static void dummycon_putc(struct vc_data *vc, int c, int ypos, int xpos) { }
	81	static void dummycon_putcs(struct vc_data vc, const unsigned short s,
	82	int count, int ypos, int xpos) { }
	83	static int dummycon_blank(struct vc_data *vc, int blank, int mode_switch)
	84	{
	85	return 0;
	86	}
	87	#endif
	88
1da177e4 LT	89	static const char *dummycon_startup(void)
	90	{
	91	return "dummy device";
	92	}
	93
	94	static void dummycon_init(struct vc_data *vc, int init)
	95	{
	96	vc->vc_can_do_color = 1;
	97	if (init) {
	98	vc->vc_cols = DUMMY_COLUMNS;
	99	vc->vc_rows = DUMMY_ROWS;
	100	} else
	101	vc_resize(vc, DUMMY_COLUMNS, DUMMY_ROWS);
	102	}
	103
c396a5bf KC	104	static void dummycon_deinit(struct vc_data *vc) { }
	105	static void dummycon_clear(struct vc_data *vc, int sy, int sx, int height,
	106	int width) { }
c396a5bf KC	107	static void dummycon_cursor(struct vc_data *vc, int mode) { }
	108
	109	static bool dummycon_scroll(struct vc_data *vc, unsigned int top,
	110	unsigned int bottom, enum con_scroll dir,
	111	unsigned int lines)
	112	{
	113	return false;
	114	}
	115
	116	static int dummycon_switch(struct vc_data *vc)
1da177e4	117	{
c396a5bf	118	return 0;
1da177e4 LT	119	}
1da177e4 LT	120
c396a5bf KC	121	static int dummycon_font_set(struct vc_data vc, struct console_font font,
	122	unsigned int flags)
	123	{
	124	return 0;
	125	}
	126
	127	static int dummycon_font_default(struct vc_data *vc,
	128	struct console_font font, char name)
	129	{
	130	return 0;
	131	}
	132
	133	static int dummycon_font_copy(struct vc_data *vc, int con)
	134	{
	135	return 0;
	136	}
1da177e4 LT	137
	138	/*
	139	* The console `switch' structure for the dummy console
	140	*
	141	* Most of the operations are dummies.
	142	*/
	143
	144	const struct consw dummy_con = {
c396a5bf KC	145	.owner = THIS_MODULE,
	146	.con_startup = dummycon_startup,
	147	.con_init = dummycon_init,
	148	.con_deinit = dummycon_deinit,
	149	.con_clear = dummycon_clear,
	150	.con_putc = dummycon_putc,
	151	.con_putcs = dummycon_putcs,
	152	.con_cursor = dummycon_cursor,
	153	.con_scroll = dummycon_scroll,
	154	.con_switch = dummycon_switch,
	155	.con_blank = dummycon_blank,
	156	.con_font_set = dummycon_font_set,
	157	.con_font_default = dummycon_font_default,
	158	.con_font_copy = dummycon_font_copy,
1da177e4	159	};
a4de0526	160	EXPORT_SYMBOL_GPL(dummy_con);