intelfb: add vsync interrupt support

[03/05] intelfb: Implement basic interrupt handling

Functions have been added to enable and disable interrupts using the MMIO registers. Currently only pipe A vsync interrupts are enabled.
A generalized vsync accounting struct is defined, with the intent that it can encapsulate per-pipe vsync related info in the future. Currently a single instance is hard-coded.
The interrupt service routine currently only looks for vsync interrupts on pipe A, and increments a counter and wakes up anyone waiting on it.

This implementation is heavily influenced by similar implementations in the atyfb and matroxfb drivers.

Signed-off-by: Eric Hustvedt <ehustvedt@cecropia.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/video/intelfb/intelfb.h b/drivers/video/intelfb/intelfb.h
index cb016fe4d488..dab1f2d764d2 100644
--- a/drivers/video/intelfb/intelfb.h
+++ b/drivers/video/intelfb/intelfb.h
@@ -208,6 +208,11 @@ struct intelfb_heap_data {
         u32 size;    // in bytes
 };
 
+struct intelfb_vsync {
+        wait_queue_head_t wait;
+        unsigned int count;
+};
+
 struct intelfb_info {
         struct fb_info *info;
         struct fb_ops  *fbops;
@@ -271,6 +276,12 @@ struct intelfb_info {
         int fixed_mode;
         int ring_active;
         int flag;
+        unsigned long irq_flags;
+        int open;
+
+        /* vsync */
+        struct intelfb_vsync vsync;
+        spinlock_t int_lock;
 
         /* hw cursor */
         int cursor_on;