V4L/DVB: IR: add helper function for hardware with small o/b buffer

Some ir input devices have small buffer, and interrupt the host
each time it is full (or half full)

Add a helper that automaticly handles timeouts, and also
automaticly merges samples of same time (space-space)
Such samples might be placed by hardware because size of
sample in the buffer is small (a byte for example).

Also remove constness from ir_dev_props, because it now contains timeout
settings that driver might want to change

Signed-off-by: Maxim Levitsky <maximlevitsky@gmail.com>
Acked-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

3 files changed, 86 insertions, 1 deletions

diff --git a/drivers/media/IR/ir-core-priv.h b/drivers/media/IR/ir-core-priv.h
index be68172..8053e3b 100644
--- a/drivers/media/IR/ir-core-priv.h
+++ b/drivers/media/IR/ir-core-priv.h
@@ -41,6 +41,7 @@ struct ir_raw_event_ctrl {
 
 	/* raw decoder state follows */
 	struct ir_raw_event prev_ev;
+	struct ir_raw_event this_ev;
 	struct nec_dec {
 		int state;
 		unsigned count;
diff --git a/drivers/media/IR/ir-keytable.c b/drivers/media/IR/ir-keytable.c
index 15a0f19..411976d 100644
--- a/drivers/media/IR/ir-keytable.c
+++ b/drivers/media/IR/ir-keytable.c
@@ -428,7 +428,7 @@ static void ir_close(struct input_dev *input_dev)
  */
 int __ir_input_register(struct input_dev *input_dev,
 		      const struct ir_scancode_table *rc_tab,
-		      const struct ir_dev_props *props,
+		      struct ir_dev_props *props,
 		      const char *driver_name)
 {
 	struct ir_input_dev *ir_dev;
diff --git a/drivers/media/IR/ir-raw-event.c b/drivers/media/IR/ir-raw-event.c
index d0c18db..43094e7 100644
--- a/drivers/media/IR/ir-raw-event.c
+++ b/drivers/media/IR/ir-raw-event.c
@@ -140,6 +140,90 @@ int ir_raw_event_store_edge(struct input_dev *input_dev, enum raw_event_type typ
 EXPORT_SYMBOL_GPL(ir_raw_event_store_edge);
 
 /**
+ * ir_raw_event_store_with_filter() - pass next pulse/space to decoders with some processing
+ * @input_dev:	the struct input_dev device descriptor
+ * @type:	the type of the event that has occurred
+ *
+ * This routine (which may be called from an interrupt context) works
+ * in similiar manner to ir_raw_event_store_edge.
+ * This routine is intended for devices with limited internal buffer
+ * It automerges samples of same type, and handles timeouts
+ */
+int ir_raw_event_store_with_filter(struct input_dev *input_dev,
+						struct ir_raw_event *ev)
+{
+	struct ir_input_dev *ir = input_get_drvdata(input_dev);
+	struct ir_raw_event_ctrl *raw = ir->raw;
+
+	if (!raw || !ir->props)
+		return -EINVAL;
+
+	/* Ignore spaces in idle mode */
+	if (ir->idle && !ev->pulse)
+		return 0;
+	else if (ir->idle)
+		ir_raw_event_set_idle(input_dev, 0);
+
+	if (!raw->this_ev.duration) {
+		raw->this_ev = *ev;
+	} else if (ev->pulse == raw->this_ev.pulse) {
+		raw->this_ev.duration += ev->duration;
+	} else {
+		ir_raw_event_store(input_dev, &raw->this_ev);
+		raw->this_ev = *ev;
+	}
+
+	/* Enter idle mode if nessesary */
+	if (!ev->pulse && ir->props->timeout &&
+		raw->this_ev.duration >= ir->props->timeout)
+		ir_raw_event_set_idle(input_dev, 1);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ir_raw_event_store_with_filter);
+
+void ir_raw_event_set_idle(struct input_dev *input_dev, int idle)
+{
+	struct ir_input_dev *ir = input_get_drvdata(input_dev);
+	struct ir_raw_event_ctrl *raw = ir->raw;
+	ktime_t now;
+	u64 delta;
+
+	if (!ir->props)
+		return;
+
+	if (!ir->raw)
+		goto out;
+
+	if (idle) {
+		IR_dprintk(2, "enter idle mode\n");
+		raw->last_event = ktime_get();
+	} else {
+		IR_dprintk(2, "exit idle mode\n");
+
+		now = ktime_get();
+		delta = ktime_to_ns(ktime_sub(now, ir->raw->last_event));
+
+		WARN_ON(raw->this_ev.pulse);
+
+		raw->this_ev.duration =
+			min(raw->this_ev.duration + delta,
+						(u64)IR_MAX_DURATION);
+
+		ir_raw_event_store(input_dev, &raw->this_ev);
+
+		if (raw->this_ev.duration == IR_MAX_DURATION)
+			ir_raw_event_reset(input_dev);
+
+		raw->this_ev.duration = 0;
+	}
+out:
+	if (ir->props->s_idle)
+		ir->props->s_idle(ir->props->priv, idle);
+	ir->idle = idle;
+}
+EXPORT_SYMBOL_GPL(ir_raw_event_set_idle);
+
+/**
  * ir_raw_event_handle() - schedules the decoding of stored ir data
  * @input_dev:	the struct input_dev device descriptor
  *