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 be6817261c8..8053e3b8427 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 15a0f192d41..411976d10f8 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 d0c18db4c0d..43094e7eccf 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
  *