From: Jordan Crouse <[EMAIL PROTECTED]>
Allow drivers to register for notification when the current VT console
switches from KD_TEXT to KD_GRAPHICS mode. Framebuffer drivers in
particular can use the distinction to determine who "owns" the framebuffer
and who should be responsible for saving and restoring registers during
power events.
Signed-off-by: Jordan Crouse <[EMAIL PROTECTED]>
---
drivers/char/vt_ioctl.c | 11 +++++++++++
include/linux/vt_kern.h | 19 +++++++++++++++++++
2 files changed, 30 insertions(+), 0 deletions(-)
diff --git a/drivers/char/vt_ioctl.c b/drivers/char/vt_ioctl.c
index 3a5d301..f301102 100644
--- a/drivers/char/vt_ioctl.c
+++ b/drivers/char/vt_ioctl.c
@@ -37,6 +37,9 @@ #include <linux/selection.h>
static char vt_dont_switch;
extern struct tty_driver *console_driver;
+/* Add a notifier chain to inform drivers of a VT_TEXT/VT_GRAPHICS switch */
+RAW_NOTIFIER_HEAD(console_notifier_list);
+
#define VT_IS_IN_USE(i) (console_driver->ttys[i] &&
console_driver->ttys[i]->count)
#define VT_BUSY(i) (VT_IS_IN_USE(i) || i == fg_console || vc_cons[i].d ==
sel_cons)
@@ -491,6 +494,14 @@ #endif
vc->vc_mode = (unsigned char) arg;
if (console != fg_console)
return 0;
+
+ /* Notify listeners if the current fg_console has switched */
+
+ raw_notifier_call_chain(&console_notifier_list,
+ (arg == KD_TEXT) ?
+ CONSOLE_EVENT_SWITCH_TEXT :
+ CONSOLE_EVENT_SWITCH_GRAPHICS, 0);
+
/*
* explicitly blank/unblank the screen if switching modes
*/
diff --git a/include/linux/vt_kern.h b/include/linux/vt_kern.h
index 37a1a41..d83e89c 100644
--- a/include/linux/vt_kern.h
+++ b/include/linux/vt_kern.h
@@ -91,4 +91,23 @@ struct vt_spawn_console {
};
extern struct vt_spawn_console vt_spawn_con;
+/* A notifier list for console events */
+extern struct raw_notifier_head console_notifier_list;
+
+/* Called when the FG console switches to KD_TEXT mode */
+#define CONSOLE_EVENT_SWITCH_TEXT 0x01
+
+/* Called when the FG console switches to KD_GRAPHICS mode */
+#define CONSOLE_EVENT_SWITCH_GRAPHICS 0x02
+
+static inline int console_event_register(struct notifier_block *n)
+{
+ return raw_notifier_chain_register(&console_notifier_list, n);
+}
+
+static inline int console_event_unregister(struct notifier_block *n)
+{
+ return raw_notifier_chain_unregister(&console_notifier_list, n);
+}
+
#endif /* _VT_KERN_H */
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