[PATCH v2 3/3] [ARM] s3c-fb: Added wait for VSYNC support.

Pawel Osciak p.osciak at samsung.com
Thu Sep 3 08:44:51 EDT 2009


Added FBIO_WAITFORVSYNC ioctl that allows sleeping on vsync
waitqueue.

Reviewed-by: Marek Szyprowski <m.szyprowski at samsung.com>
Reviewed-by: Kyungmin Park <kyungmin.park at samsung.com>
Signed-off-by: Pawel Osciak <p.osciak at samsung.com>

---
 drivers/video/s3c-fb.c |  170 +++++++++++++++++++++++++++++++++++++++++++++++-
 1 files changed, 168 insertions(+), 2 deletions(-)

diff --git a/drivers/video/s3c-fb.c b/drivers/video/s3c-fb.c
index 3dd4327..001a1a1 100644
--- a/drivers/video/s3c-fb.c
+++ b/drivers/video/s3c-fb.c
@@ -21,6 +21,8 @@
 #include <linux/clk.h>
 #include <linux/fb.h>
 #include <linux/io.h>
+#include <linux/uaccess.h>
+#include <linux/interrupt.h>
 
 #include <mach/map.h>
 #include <mach/regs-fb.h>
@@ -48,6 +50,13 @@
 	__raw_writel(v, r); } while(0)
 #endif /* FB_S3C_DEBUG_REGWRITE */
 
+/* Bit in irq_flags used to mark that interrupts are activated in device */
+#define S3C_FB_IRQ_ENABLED_BIT	0
+
+#ifndef FBIO_WAITFORVSYNC
+#define FBIO_WAITFORVSYNC _IOW('F', 0x20, __u32)
+#endif
+
 struct s3c_fb;
 
 /**
@@ -59,6 +68,7 @@ struct s3c_fb;
  * @pseudo_palette: For use in TRUECOLOUR modes for entries 0..15/
  * @index: The window number of this window.
  * @palette: The bitfields for changing r/g/b into a hardware palette entry.
+ * @vsync: Vsync handling helper.
  */
 struct s3c_fb_win {
 	struct s3c_fb_pd_win	*windata;
@@ -72,6 +82,16 @@ struct s3c_fb_win {
 };
 
 /**
+ * struct s3c_fb_vsync - vsync information for display.
+ * @vsync_queue: A queue for processes waiting for vsync.
+ * @vsync_count: Vsync interrupt count.
+ */
+struct s3c_fb_vsync {
+	wait_queue_head_t	vsync_queue;
+	unsigned long		vsync_count;
+};
+
+/**
  * struct s3c_fb - overall hardware state of the hardware
  * @dev: The device that we bound to, for printing, etc.
  * @regs_res: The resource we claimed for the IO registers.
@@ -80,6 +100,8 @@ struct s3c_fb_win {
  * @enabled: A bitmask of enabled hardware windows.
  * @pdata: The platform configuration data passed with the device.
  * @windows: The hardware windows that have been claimed.
+ * @irq_no: IRQ number for the device (acquired from platform data).
+ * @vsync_info: VSYNC-related information (count, queues...)
  */
 struct s3c_fb {
 	struct device		*dev;
@@ -87,10 +109,15 @@ struct s3c_fb {
 	struct clk		*bus_clk;
 	void __iomem		*regs;
 
-	unsigned char		 enabled;
+	unsigned char		enabled;
 
 	struct s3c_fb_platdata	*pdata;
 	struct s3c_fb_win	*windows[S3C_FB_MAX_WIN];
+
+	unsigned int		irq_no;
+	unsigned long		irq_flags;
+
+	struct s3c_fb_vsync	vsync_info;
 };
 
 /**
@@ -643,6 +670,103 @@ static int s3c_fb_blank(int blank_mode, struct fb_info *info)
 }
 
 /**
+ * s3c_fb_enable_irq() - enable interrupts in hardware.
+ * @sfb: The base resources for the hardware.
+ */
+static int s3c_fb_enable_irq(struct s3c_fb *sfb)
+{
+	u32	     irq_ctrl_reg;
+	void __iomem *regs = sfb->regs;
+
+	if (!test_and_set_bit(S3C_FB_IRQ_ENABLED_BIT, &sfb->irq_flags)) {
+		/* IRQ was 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);
+	}
+
+	return 0;
+}
+
+/**
+ * s3c_fb_disable_irq() - disable interrupts in hardware.
+ * @sfb: The base resources for the hardware.
+ */
+static int s3c_fb_disable_irq(struct s3c_fb *sfb)
+{
+	u32	     irq_ctrl_reg;
+	void __iomem *regs = sfb->regs;
+
+	if (test_and_clear_bit(S3C_FB_IRQ_ENABLED_BIT, &sfb->irq_flags)) {
+		/* IRQ was 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);
+	}
+
+	return 0;
+}
+
+static irqreturn_t s3c_fb_interrupt(int irq, void *dev_id)
+{
+	u32	      irq_sts_reg;
+	struct s3c_fb *sfb = dev_id;
+	void __iomem  *regs = sfb->regs;
+
+	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.vsync_count++;
+		wake_up_interruptible(&sfb->vsync_info.vsync_queue);
+	}
+
+	/* We support only waiting for VSYNC interrupt for now,
+	 * so it's safe to disable irqs here. */
+	s3c_fb_disable_irq(sfb);
+
+	return IRQ_HANDLED;
+}
+
+/**
+ * s3c_fb_wait_for_vsync() - sleep until next VSYNC interrupt or timeout.
+ * @sfb: The base resources for the hardware.
+ * @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;
+
+	s3c_fb_enable_irq(sfb);
+	count = sfb->vsync_info.vsync_count;
+	ret = wait_event_interruptible_timeout(sfb->vsync_info.vsync_queue,
+				       count != sfb->vsync_info.vsync_count,
+				       HZ / 10);
+	if (ret == 0)
+		return -ETIMEDOUT;
+
+	return 0;
+}
+
+/**
  * s3c_fb_pan_display() - Pan the display.
  *
  * Note, that the offsets can be written to the device at any time, as their
@@ -697,6 +821,27 @@ static int s3c_fb_pan_display(struct fb_var_screeninfo *var,
 	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;
+
+	switch (cmd) {
+	case FBIO_WAITFORVSYNC: {
+		u32 crtc;
+		if (get_user(crtc, (u32 __user *)arg))
+			return -EFAULT;
+
+		return s3c_fb_wait_for_vsync(sfb, crtc);
+		}
+	default:
+		return -ENOTTY;
+	}
+
+	return 0;
+}
+
 static struct fb_ops s3c_fb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_check_var	= s3c_fb_check_var,
@@ -706,6 +851,7 @@ static struct fb_ops s3c_fb_ops = {
 	.fb_fillrect	= cfb_fillrect,
 	.fb_copyarea	= cfb_copyarea,
 	.fb_imageblit	= cfb_imageblit,
+	.fb_ioctl	= s3c_fb_ioctl,
 	.fb_pan_display	= s3c_fb_pan_display,
 };
 
@@ -931,6 +1077,7 @@ static int __devinit s3c_fb_probe(struct platform_device *pdev)
 
 	sfb->dev = dev;
 	sfb->pdata = pd;
+	init_waitqueue_head(&sfb->vsync_info.vsync_queue);
 
 	sfb->bus_clk = clk_get(dev, "lcd");
 	if (IS_ERR(sfb->bus_clk)) {
@@ -962,6 +1109,20 @@ static int __devinit s3c_fb_probe(struct platform_device *pdev)
 		goto err_req_region;
 	}
 
+	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+	if (!res) {
+		dev_err(dev, "failed to acquire irq resource\n");
+		ret = -ENOENT;
+		goto err_ioremap;
+	}
+	sfb->irq_no = res->start;
+	ret = request_irq(sfb->irq_no, s3c_fb_interrupt,
+			  0, "s3c_fb", sfb);
+	if (ret) {
+		dev_err(dev, "irq request failed\n");
+		goto err_ioremap;
+	}
+
 	dev_dbg(dev, "got resources (regs %p), probing windows\n", sfb->regs);
 
 	/* setup gpio and output polarity controls */
@@ -986,7 +1147,7 @@ static int __devinit s3c_fb_probe(struct platform_device *pdev)
 			dev_err(dev, "failed to create window %d\n", win);
 			for (; win >= 0; win--)
 				s3c_fb_release_win(sfb, sfb->windows[win]);
-			goto err_ioremap;
+			goto err_irq;
 		}
 	}
 
@@ -994,6 +1155,9 @@ static int __devinit s3c_fb_probe(struct platform_device *pdev)
 
 	return 0;
 
+err_irq:
+	free_irq(sfb->irq_no, sfb);
+
 err_ioremap:
 	iounmap(sfb->regs);
 
@@ -1026,6 +1190,8 @@ static int __devexit s3c_fb_remove(struct platform_device *pdev)
 		if (sfb->windows[win])
 			s3c_fb_release_win(sfb, sfb->windows[win]);
 
+	free_irq(sfb->irq_no, sfb);
+
 	iounmap(sfb->regs);
 
 	clk_disable(sfb->bus_clk);
-- 
1.6.4.2.253.g0b1fac



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