linux/drivers/video/console/dummycon.c
Jiri Slaby (SUSE) 77e110936a tty: vt: make types around consw::con_blank() bool
Both the mode_switch parameter and the return value (a redraw needed)
are true/false. So switch them to bool, so that users won't return
-Eerrors or anything else.

And document the hook.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: linux-parisc@vger.kernel.org
Tested-by: Helge Deller <deller@gmx.de> # parisc STI console
Link: https://lore.kernel.org/r/20240122110401.7289-36-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-27 18:08:54 -08:00

152 lines
3.7 KiB
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(CONFIG_ARCH_FOOTBRIDGE) && defined(CONFIG_VGA_CONSOLE)
#include <asm/vga.h>
#define DUMMY_COLUMNS vgacon_screen_info.orig_video_cols
#define DUMMY_ROWS vgacon_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)
{
WARN_CONSOLE_UNLOCKED();
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)
{
WARN_CONSOLE_UNLOCKED();
raw_notifier_chain_unregister(&dummycon_output_nh, nb);
}
static void dummycon_putc(struct vc_data *vc, u16 c, unsigned int y,
unsigned int x)
{
WARN_CONSOLE_UNLOCKED();
dummycon_putc_called = true;
raw_notifier_call_chain(&dummycon_output_nh, 0, NULL);
}
static void dummycon_putcs(struct vc_data *vc, const u16 *s, unsigned int count,
unsigned int ypos, unsigned int xpos)
{
unsigned 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 bool dummycon_blank(struct vc_data *vc, enum vesa_blank_mode blank,
bool mode_switch)
{
/* Redraw, so that we get putc(s) for output done while blanked */
return true;
}
#else
static void dummycon_putc(struct vc_data *vc, u16 c, unsigned int y,
unsigned int x) { }
static void dummycon_putcs(struct vc_data *vc, const u16 *s, unsigned int count,
unsigned int ypos, unsigned int xpos) { }
static bool dummycon_blank(struct vc_data *vc, enum vesa_blank_mode blank,
bool mode_switch)
{
return false;
}
#endif
static const char *dummycon_startup(void)
{
return "dummy device";
}
static void dummycon_init(struct vc_data *vc, bool 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, unsigned int sy, unsigned int sx,
unsigned int width) { }
static void dummycon_cursor(struct vc_data *vc, bool enable) { }
static bool dummycon_scroll(struct vc_data *vc, unsigned int top,
unsigned int bottom, enum con_scroll dir,
unsigned int lines)
{
return false;
}
static bool dummycon_switch(struct vc_data *vc)
{
return false;
}
/*
* 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,
};
EXPORT_SYMBOL_GPL(dummy_con);