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>
diff --git a/drivers/video/intelfb/intelfb.h b/drivers/video/intelfb/intelfb.h
index cb016fe..dab1f2d 100644
--- a/drivers/video/intelfb/intelfb.h
+++ b/drivers/video/intelfb/intelfb.h
@@ -208,6 +208,11 @@
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 @@
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;
diff --git a/drivers/video/intelfb/intelfbdrv.c b/drivers/video/intelfb/intelfbdrv.c
index 0a0a8b1..068c56d 100644
--- a/drivers/video/intelfb/intelfbdrv.c
+++ b/drivers/video/intelfb/intelfbdrv.c
@@ -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 @@
/* 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 @@
if (!dinfo)
return;
+ intelfbhw_disable_irq(dinfo);
+
fb_dealloc_cmap(&dinfo->info->cmap);
kfree(dinfo->info->pixmap.addr);
@@ -889,6 +895,11 @@
}
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 @@
***************************************************************/
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 --git a/drivers/video/intelfb/intelfbhw.c b/drivers/video/intelfb/intelfbhw.c
index 05aded6..1a698a7 100644
--- a/drivers/video/intelfb/intelfbhw.c
+++ b/drivers/video/intelfb/intelfbhw.c
@@ -34,6 +34,7 @@
#include <linux/pci.h>
#include <linux/vmalloc.h>
#include <linux/pagemap.h>
+#include <linux/interrupt.h>
#include <asm/io.h>
@@ -1943,3 +1944,78 @@
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 --git a/drivers/video/intelfb/intelfbhw.h b/drivers/video/intelfb/intelfbhw.h
index 8d2e369..aa0c139 100644
--- a/drivers/video/intelfb/intelfbhw.h
+++ b/drivers/video/intelfb/intelfbhw.h
@@ -561,5 +561,7 @@
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 */