intelfb: add vsync interrupt support

[04/05] intelfb: implement FBIO_WAITFORVSYNC ioctl

The (unofficial) FBIO_WAITFORVSYNC ioctl is implemented by sleeping on the appropriate waitqueue, as defined in my earlier patch. Currently, only display 0 (aka pipe A) is supported.

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

4 files changed, 51 insertions, 0 deletions

diff --git a/drivers/video/intelfb/intelfb.h b/drivers/video/intelfb/intelfb.h
index dab1f2d764d2..65ac37071a02 100644
--- a/drivers/video/intelfb/intelfb.h
+++ b/drivers/video/intelfb/intelfb.h
@@ -304,6 +304,10 @@ struct intelfb_info {
 
 #define IS_I9XX(dinfo) (((dinfo)->chipset == INTEL_915G)||(dinfo->chipset == INTEL_915GM)||((dinfo)->chipset == INTEL_945G)||(dinfo->chipset==INTEL_945GM))
 
+#ifndef FBIO_WAITFORVSYNC
+#define FBIO_WAITFORVSYNC       _IOW('F', 0x20, __u32)
+#endif
+
 /*** function prototypes ***/
 
 extern int intelfb_var_to_depth(const struct fb_var_screeninfo *var);
diff --git a/drivers/video/intelfb/intelfbdrv.c b/drivers/video/intelfb/intelfbdrv.c
index 068c56d4e652..08f8241bb92a 100644
--- a/drivers/video/intelfb/intelfbdrv.c
+++ b/drivers/video/intelfb/intelfbdrv.c
@@ -1473,6 +1473,19 @@ static int
 intelfb_ioctl(struct fb_info *info, unsigned int cmd, unsigned long arg)
 {
         int retval = 0;
+        struct intelfb_info *dinfo = GET_DINFO(info);
+        u32 pipe = 0;
+
+        switch (cmd) {
+                case FBIO_WAITFORVSYNC:
+                        if (get_user(pipe, (__u32 __user *)arg))
+                                return -EFAULT;
+
+                        retval = intelfbhw_wait_for_vsync(dinfo, pipe);
+                        break;
+                default:
+                        break;
+        }
 
         return retval;
 }
diff --git a/drivers/video/intelfb/intelfbhw.c b/drivers/video/intelfb/intelfbhw.c
index 1a698a7230e0..0f9631c2ad33 100644
--- a/drivers/video/intelfb/intelfbhw.c
+++ b/drivers/video/intelfb/intelfbhw.c
@@ -2019,3 +2019,36 @@ intelfbhw_disable_irq(struct intelfb_info *dinfo) {
                 free_irq(dinfo->pdev->irq, dinfo);
         }
 }
+
+int
+intelfbhw_wait_for_vsync(struct intelfb_info *dinfo, u32 pipe) {
+        struct intelfb_vsync *vsync;
+        unsigned int count;
+        int ret;
+
+        switch (pipe) {
+                case 0:
+                        vsync = &dinfo->vsync;
+                        break;
+                default:
+                        return -ENODEV;
+        }
+
+        ret = intelfbhw_enable_irq(dinfo, 0);
+        if (ret) {
+                return ret;
+        }
+
+        count = vsync->count;
+        ret = wait_event_interruptible_timeout(vsync->wait, count != vsync->count, HZ/10);
+        if (ret < 0) {
+                return ret;
+        }
+        if (ret == 0) {
+                intelfbhw_enable_irq(dinfo, 1);
+                DBG_MSG("wait_for_vsync timed out!\n");
+                return -ETIMEDOUT;
+        }
+
+        return 0;
+}
diff --git a/drivers/video/intelfb/intelfbhw.h b/drivers/video/intelfb/intelfbhw.h
index aa0c139a2301..36980c785e13 100644
--- a/drivers/video/intelfb/intelfbhw.h
+++ b/drivers/video/intelfb/intelfbhw.h
@@ -563,5 +563,6 @@ extern void intelfbhw_cursor_load(struct intelfb_info *dinfo, int width,
 extern void intelfbhw_cursor_reset(struct intelfb_info *dinfo);
 extern int intelfbhw_enable_irq(struct intelfb_info *dinfo, int reenable);
 extern void intelfbhw_disable_irq(struct intelfb_info *dinfo);
+extern int intelfbhw_wait_for_vsync(struct intelfb_info *dinfo, u32 pipe);
 
 #endif /* _INTELFBHW_H */