+/**
+ * s3c_fb_enable_irq() - enable framebuffer interrupts
+ * @sfb: main hardware state
+ */
+static void s3c_fb_enable_irq(struct s3c_fb *sfb)
+{
+ void __iomem *regs = sfb->regs;
+ u32 irq_ctrl_reg;
+
+ if (!test_and_set_bit(S3C_FB_VSYNC_IRQ_EN, &sfb->irq_flags)) {
+ /* IRQ disabled, enable it */
+ irq_ctrl_reg = readl(regs + VIDINTCON0);
+
+ irq_ctrl_reg |= VIDINTCON0_INT_ENABLE;
+ irq_ctrl_reg |= VIDINTCON0_INT_FRAME;
+
+ irq_ctrl_reg &= ~VIDINTCON0_FRAMESEL0_MASK;
+ irq_ctrl_reg |= VIDINTCON0_FRAMESEL0_VSYNC;
+ irq_ctrl_reg &= ~VIDINTCON0_FRAMESEL1_MASK;
+ irq_ctrl_reg |= VIDINTCON0_FRAMESEL1_NONE;
+
+ writel(irq_ctrl_reg, regs + VIDINTCON0);
+ }
+}
+
+/**
+ * s3c_fb_disable_irq() - disable framebuffer interrupts
+ * @sfb: main hardware state
+ */
+static void s3c_fb_disable_irq(struct s3c_fb *sfb)
+{
+ void __iomem *regs = sfb->regs;
+ u32 irq_ctrl_reg;
+
+ if (test_and_clear_bit(S3C_FB_VSYNC_IRQ_EN, &sfb->irq_flags)) {
+ /* IRQ enabled, disable it */
+ irq_ctrl_reg = readl(regs + VIDINTCON0);
+
+ irq_ctrl_reg &= ~VIDINTCON0_INT_FRAME;
+ irq_ctrl_reg &= ~VIDINTCON0_INT_ENABLE;
+
+ writel(irq_ctrl_reg, regs + VIDINTCON0);
+ }
+}
+
+static irqreturn_t s3c_fb_irq(int irq, void *dev_id)
+{
+ struct s3c_fb *sfb = dev_id;
+ void __iomem *regs = sfb->regs;
+ u32 irq_sts_reg;
+
+ irq_sts_reg = readl(regs + VIDINTCON1);
+
+ if (irq_sts_reg & VIDINTCON1_INT_FRAME) {
+
+ /* VSYNC interrupt, accept it */
+ writel(VIDINTCON1_INT_FRAME, regs + VIDINTCON1);
+
+ sfb->vsync_info.count++;
+ wake_up_interruptible(&sfb->vsync_info.wait);
+ }
+
+ /* We only support waiting for VSYNC for now, so it's safe
+ * to always disable irqs here.
+ */
+ s3c_fb_disable_irq(sfb);
+
+ return IRQ_HANDLED;
+}
+
+/**
+ * s3c_fb_wait_for_vsync() - sleep until next VSYNC interrupt or timeout
+ * @sfb: main hardware state
+ * @crtc: head index.
+ */
+static int s3c_fb_wait_for_vsync(struct s3c_fb *sfb, u32 crtc)
+{
+ unsigned long count;
+ int ret;
+
+ if (crtc != 0)
+ return -ENODEV;
+
+ count = sfb->vsync_info.count;
+ s3c_fb_enable_irq(sfb);
+ ret = wait_event_interruptible_timeout(sfb->vsync_info.wait,
+ count != sfb->vsync_info.count,
+ msecs_to_jiffies(VSYNC_TIMEOUT_MSEC));
+ if (ret == 0)
+ return -ETIMEDOUT;
+
+ return 0;
+}
+
+static int s3c_fb_ioctl(struct fb_info *info, unsigned int cmd,
+ unsigned long arg)
+{
+ struct s3c_fb_win *win = info->par;
+ struct s3c_fb *sfb = win->parent;
+ int ret;
+ u32 crtc;
+
+ switch (cmd) {
+ case FBIO_WAITFORVSYNC:
+ if (get_user(crtc, (u32 __user *)arg)) {
+ ret = -EFAULT;
+ break;
+ }
+
+ ret = s3c_fb_wait_for_vsync(sfb, crtc);
+ break;
+ default:
+ ret = -ENOTTY;
+ }
+
+ return ret;
+}
+