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>

4 files changed, 106 insertions, 4 deletions

diff --git a/drivers/media/IR/ir-core-priv.h b/drivers/media/IR/ir-core-priv.h
index be6817261c8f..8053e3b84272 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 15a0f192d413..411976d10f83 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 d0c18db4c0d3..43094e7eccfa 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
  *
diff --git a/include/media/ir-core.h b/include/media/ir-core.h
index 197d05aa83dc..a781045aeed5 100644
--- a/include/media/ir-core.h
+++ b/include/media/ir-core.h
@@ -41,6 +41,9 @@ enum rc_driver_type {
  *      anything with it. Yet, as the same keycode table can be used with other
  *      devices, a mask is provided to allow its usage. Drivers should generally
  *      leave this field in blank
+ * @timeout: optional time after which device stops sending data
+ * @min_timeout: minimum timeout supported by device
+ * @max_timeout: maximum timeout supported by device
  * @priv: driver-specific data, to be used on the callbacks
  * @change_protocol: allow changing the protocol used on hardware decoders
  * @open: callback to allow drivers to enable polling/irq when IR input device
@@ -50,11 +53,19 @@ enum rc_driver_type {
  * @s_tx_mask: set transmitter mask (for devices with multiple tx outputs)
  * @s_tx_carrier: set transmit carrier frequency
  * @tx_ir: transmit IR
+ * @s_idle: optional: enable/disable hardware idle mode, upon which,
+ *      device doesn't interrupt host untill it sees IR data
  */
 struct ir_dev_props {
         enum rc_driver_type     driver_type;
         unsigned long           allowed_protos;
         u32                     scanmask;
+
+        u32                     timeout;
+        u32                     min_timeout;
+        u32                     max_timeout;
+
+
         void                    *priv;
         int                     (*change_protocol)(void *priv, u64 ir_type);
         int                     (*open)(void *priv);
@@ -62,6 +73,7 @@ struct ir_dev_props {
         int                     (*s_tx_mask)(void *priv, u32 mask);
         int                     (*s_tx_carrier)(void *priv, u32 carrier);
         int                     (*tx_ir)(void *priv, int *txbuf, u32 n);
+        void                    (*s_idle)(void *priv, int enable);
 };
 
 struct ir_input_dev {
@@ -69,9 +81,10 @@ struct ir_input_dev {
         char                            *driver_name;   /* Name of the driver module */
         struct ir_scancode_table        rc_tab;         /* scan/key table */
         unsigned long                   devno;          /* device number */
-        const struct ir_dev_props       *props;         /* Device properties */
+        struct ir_dev_props             *props;         /* Device properties */
         struct ir_raw_event_ctrl        *raw;           /* for raw pulse/space events */
         struct input_dev                *input_dev;     /* the input device associated with this device */
+        bool                            idle;
 
         /* key info - needed by IR keycode handlers */
         spinlock_t                      keylock;        /* protects the below members */
@@ -95,12 +108,12 @@ enum raw_event_type {
 /* From ir-keytable.c */
 int __ir_input_register(struct input_dev *dev,
                       const struct ir_scancode_table *ir_codes,
-                      const struct ir_dev_props *props,
+                      struct ir_dev_props *props,
                       const char *driver_name);
 
 static inline int ir_input_register(struct input_dev *dev,
                       const char *map_name,
-                      const struct ir_dev_props *props,
+                      struct ir_dev_props *props,
                       const char *driver_name) {
         struct ir_scancode_table *ir_codes;
         struct ir_input_dev *ir_dev;
@@ -148,6 +161,10 @@ struct ir_raw_event {
 void ir_raw_event_handle(struct input_dev *input_dev);
 int ir_raw_event_store(struct input_dev *input_dev, struct ir_raw_event *ev);
 int ir_raw_event_store_edge(struct input_dev *input_dev, enum raw_event_type type);
+int ir_raw_event_store_with_filter(struct input_dev *input_dev,
+                                struct ir_raw_event *ev);
+void ir_raw_event_set_idle(struct input_dev *input_dev, int idle);
+
 static inline void ir_raw_event_reset(struct input_dev *input_dev)
 {
         struct ir_raw_event ev = { .pulse = false, .duration = 0 };