[PATCH 3/5 2.6.17-rc6-mm2] add vsync interrupt support to intelfb driver

From: Eric Hustvedt <redacted>

[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 <redacted>
Signed-off-by: Dennis Munsie <redacted>
---

drivers/video/intelfb/intelfb.h    |   11 +++
drivers/video/intelfb/intelfbdrv.c |   39 +++++++++++++
drivers/video/intelfb/intelfbhw.c  |   77 +++++++++++++++++++++++++++
drivers/video/intelfb/intelfbhw.h  |    2
4 files changed, 129 insertions(+)

diff -X linux-2.6.17-rc4-hwstam/Documentation/dontdiff -Naurp  
linux-2.6.17-rc4-hwstam/drivers/video/intelfb/intelfb.h linux-2.6.17- 
rc4-interrupt/drivers/video/intelfb/intelfb.h

--- linux-2.6.17-rc4-hwstam/drivers/video/intelfb/intelfb.h	 

2006-06-09 09:43:18.000000000 -0600

+++ linux-2.6.17-rc4-interrupt/drivers/video/intelfb/intelfb.h	 

2006-06-09 10:10:15.000000000 -0600

@@ -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;

@@ -271,7 +276,13 @@ 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;
	int cursor_blanked;
diff -X linux-2.6.17-rc4-hwstam/Documentation/dontdiff -Naurp  
linux-2.6.17-rc4-hwstam/drivers/video/intelfb/intelfbdrv.c  
linux-2.6.17-rc4-interrupt/drivers/video/intelfb/intelfbdrv.c

--- linux-2.6.17-rc4-hwstam/drivers/video/intelfb/intelfbdrv.c	 

2006-06-09 09:41:10.000000000 -0600

+++ linux-2.6.17-rc4-interrupt/drivers/video/intelfb/intelfbdrv.c	 

2006-06-09 10:11:11.000000000 -0600

@@ -137,6 +137,8 @@

static void __devinit get_initial_mode(struct intelfb_info *dinfo);
static void update_dinfo(struct intelfb_info *dinfo,
			 struct fb_var_screeninfo *var);
+static int intelfb_open(struct fb_info *info, int user);
+static int intelfb_release(struct fb_info *info, int user);
static int intelfb_check_var(struct fb_var_screeninfo *var,
			     struct fb_info *info);
static int intelfb_set_par(struct fb_info *info);

@@ -195,6 +197,8 @@ static int num_registered = 0;

/* fb ops */
static struct fb_ops intel_fb_ops = {
	.owner =		THIS_MODULE,
+	.fb_open =              intelfb_open,
+	.fb_release =           intelfb_release,
	.fb_check_var =         intelfb_check_var,
	.fb_set_par =           intelfb_set_par,
	.fb_setcolreg =		intelfb_setcolreg,

@@ -447,6 +451,8 @@ cleanup(struct intelfb_info *dinfo)

	if (!dinfo)
		return;
+	intelfbhw_disable_irq(dinfo);
+
	fb_dealloc_cmap(&dinfo->info->cmap);
	kfree(dinfo->info->pixmap.addr);

@@ -889,6 +895,11 @@ intelfb_pci_register(struct pci_dev *pde

	}
	dinfo->registered = 1;
+	dinfo->open = 0;
+
+	init_waitqueue_head(&dinfo->vsync.wait);
+	spin_lock_init(&dinfo->int_lock);
+	dinfo->irq_flags = 0;
	return 0;

@@ -1189,6 +1200,34 @@ update_dinfo(struct intelfb_info *dinfo,
   ***************************************************************/

static int
+intelfb_open(struct fb_info *info, int user)
+{
+	struct intelfb_info *dinfo = GET_DINFO(info);
+	
+	if (user) {
+		dinfo->open++;
+	}
+	
+	return 0;
+}
+
+static int
+intelfb_release(struct fb_info *info, int user)
+{
+	struct intelfb_info *dinfo = GET_DINFO(info);
+	
+	if (user) {
+		dinfo->open--;
+		msleep(1);
+		if (!dinfo->open) {
+			intelfbhw_disable_irq(dinfo);
+		}
+	}
+	
+	return 0;
+}
+
+static int
intelfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
{
	int change_var = 0;
diff -X linux-2.6.17-rc4-hwstam/Documentation/dontdiff -Naurp  
linux-2.6.17-rc4-hwstam/drivers/video/intelfb/intelfbhw.c  
linux-2.6.17-rc4-interrupt/drivers/video/intelfb/intelfbhw.c

--- linux-2.6.17-rc4-hwstam/drivers/video/intelfb/intelfbhw.c	 

2006-06-09 09:43:18.000000000 -0600

+++ linux-2.6.17-rc4-interrupt/drivers/video/intelfb/intelfbhw.c	 

2006-06-13 12:15:13.000000000 -0600

@@ -34,6 +34,7 @@

#include <linux/pci.h>
#include <linux/vmalloc.h>
#include <linux/pagemap.h>
+#include <linux/interrupt.h>
#include <asm/io.h>

@@ -1991,3 +1992,79 @@ intelfbhw_cursor_reset(struct intelfb_in

		addr += 16;
	}
}
+
+static irqreturn_t
+intelfbhw_irq(int irq, void *dev_id, struct pt_regs *fp) {
+	int handled = 0;
+	u16 tmp;
+	struct intelfb_info *dinfo = (struct intelfb_info *)dev_id;
+
+	spin_lock(&dinfo->int_lock);
+	
+	tmp = INREG16(IIR);
+	tmp &= VSYNC_PIPE_A_INTERRUPT;
+	
+	if (tmp == 0) {
+		spin_unlock(&dinfo->int_lock);
+		return IRQ_RETVAL(handled);
+	}
+	
+	OUTREG16(IIR, tmp);
+
+	if (tmp & VSYNC_PIPE_A_INTERRUPT) {
+		dinfo->vsync.count++;
+		wake_up_interruptible(&dinfo->vsync.wait);
+		handled = 1;
+	}
+
+	spin_unlock(&dinfo->int_lock);
+	
+	return IRQ_RETVAL(handled);
+}
+
+int
+intelfbhw_enable_irq(struct intelfb_info *dinfo, int reenable) {
+	
+	if (!test_and_set_bit(0, &dinfo->irq_flags)) {
+		if (request_irq(dinfo->pdev->irq, intelfbhw_irq,
+				SA_SHIRQ, "intelfb", dinfo)) {
+			clear_bit(0, &dinfo->irq_flags);
+			return -EINVAL;
+		}
+		
+		spin_lock_irq(&dinfo->int_lock);
+		OUTREG16(HWSTAM, 0xfffe);
+		OUTREG16(IMR, 0x0);
+		OUTREG16(IER, VSYNC_PIPE_A_INTERRUPT);
+		spin_unlock_irq(&dinfo->int_lock);
+	} else if (reenable) {
+		u16 ier;
+
+		spin_lock_irq(&dinfo->int_lock);
+		ier = INREG16(IER);
+		if ((ier & VSYNC_PIPE_A_INTERRUPT)) {
+			DBG_MSG("someone disabled the IRQ [%08X]\n", ier);
+			OUTREG(IER, VSYNC_PIPE_A_INTERRUPT);
+		}
+		spin_unlock_irq(&dinfo->int_lock);
+	}
+	return 0;
+}
+
+void
+intelfbhw_disable_irq(struct intelfb_info *dinfo) {
+	u16 tmp;
+
+	if (test_and_clear_bit(0, &dinfo->irq_flags)) {
+		spin_lock_irq(&dinfo->int_lock);
+		OUTREG16(HWSTAM, 0xffff);
+		OUTREG16(IMR, 0xffff);
+		OUTREG16(IER, 0x0);
+		
+		tmp = INREG16(IIR);
+		OUTREG16(IIR, tmp);
+		spin_unlock_irq(&dinfo->int_lock);
+	
+		free_irq(dinfo->pdev->irq, dinfo);
+	}
+}
diff -X linux-2.6.17-rc4-hwstam/Documentation/dontdiff -Naurp  
linux-2.6.17-rc4-hwstam/drivers/video/intelfb/intelfbhw.h  
linux-2.6.17-rc4-interrupt/drivers/video/intelfb/intelfbhw.h

--- linux-2.6.17-rc4-hwstam/drivers/video/intelfb/intelfbhw.h	 

2006-06-09 10:04:37.000000000 -0600

+++ linux-2.6.17-rc4-interrupt/drivers/video/intelfb/intelfbhw.h	 

2006-06-09 10:17:51.000000000 -0600

@@ -561,5 +561,7 @@ extern void intelfbhw_cursor_setcolor(st

extern void intelfbhw_cursor_load(struct intelfb_info *dinfo, int width,
				  int height, u8 *data);
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);
#endif /* _INTELFBHW_H */