TILER: Notifier callback mechanism for events

This patch adds a tiler notifier callback mechanism
for events.  This covers file close events.

Signed-off-by: Angela Stegmaier <angelabaker@ti.com>
Signed-off-by: David Sin <davidsin@ti.com>

2 files changed, 52 insertions, 0 deletions

diff --git a/arch/arm/mach-omap2/include/mach/tiler.h b/arch/arm/mach-omap2/include/mach/tiler.h
index 84452bc8944..d72f322696c 100644
--- a/arch/arm/mach-omap2/include/mach/tiler.h
+++ b/arch/arm/mach-omap2/include/mach/tiler.h
@@ -81,6 +81,27 @@ static inline u32 tiler_size(const struct tiler_block_t *b)
         return b->height * tiler_vstride(b);
 }
 
+/* Event types */
+#define TILER_DEVICE_CLOSE      0
+
+/**
+ * Registers a notifier block with TILER driver.
+ *
+ * @param nb            notifier_block
+ *
+ * @return error status
+ */
+s32 tiler_reg_notifier(struct notifier_block *nb);
+
+/**
+ * Un-registers a notifier block with TILER driver.
+ *
+ * @param nb            notifier_block
+ *
+ * @return error status
+ */
+s32 tiler_unreg_notifier(struct notifier_block *nb);
+
 /**
  * Reserves a 1D or 2D TILER block area and memory for the
  * current process with group ID 0.
diff --git a/drivers/media/video/tiler/tiler-iface.c b/drivers/media/video/tiler/tiler-iface.c
index f9c53dd4f32..f7a1be7131e 100644
--- a/drivers/media/video/tiler/tiler-iface.c
+++ b/drivers/media/video/tiler/tiler-iface.c
@@ -46,6 +46,17 @@ MODULE_PARM_DESC(offset_lookup,
 static struct mutex mtx;
 static struct list_head procs;  /* list of process info structs */
 static struct tiler_ops *ops;   /* shared methods and variables */
+static struct blocking_notifier_head notifier;  /* notifier for events */
+
+/*
+ *  Event notification methods
+ *  ==========================================================================
+ */
+
+static s32 tiler_notify_event(int event, void *data)
+{
+        return blocking_notifier_call_chain(&notifier, event, data);
+}
 
 /*
  *  Buffer handling methods
@@ -222,6 +233,9 @@ static void _m_free_process_info(struct process_info *pi)
 
         /* have mutex */
 
+        if (!list_empty(&pi->bufs))
+                tiler_notify_event(TILER_DEVICE_CLOSE, NULL);
+
         /* unregister all buffers */
         list_for_each_entry_safe(_b, _b_, &pi->bufs, by_pid)
                 _m_unregister_buf(_b);
@@ -614,6 +628,7 @@ void tiler_iface_init(struct tiler_ops *tiler)
 
         mutex_init(&mtx);
         INIT_LIST_HEAD(&procs);
+        BLOCKING_INIT_NOTIFIER_HEAD(&notifier);
 }
 
 /*
@@ -621,6 +636,22 @@ void tiler_iface_init(struct tiler_ops *tiler)
  *  ==========================================================================
  */
 
+s32 tiler_reg_notifier(struct notifier_block *nb)
+{
+        if (!nb)
+                return -EINVAL;
+        return blocking_notifier_chain_register(&notifier, nb);
+}
+EXPORT_SYMBOL(tiler_reg_notifier);
+
+s32 tiler_unreg_notifier(struct notifier_block *nb)
+{
+        if (!nb)
+                return -EINVAL;
+        return blocking_notifier_chain_unregister(&notifier, nb);
+}
+EXPORT_SYMBOL(tiler_unreg_notifier);
+
 void tiler_reservex(u32 n, enum tiler_fmt fmt, u32 width, u32 height,
                    u32 align, u32 offs, u32 gid, pid_t pid)
 {