V4L/DVB: ir-core: change duration to be coded as a u32 integer

This patch implements the agreed upon 1:31 integer encoded pulse/duration
struct for ir-core raw decoders. All decoders have been tested after the
change. Comments are welcome.

Signed-off-by: David Härdeman <david@hardeman.nu>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

5 files changed, 271 insertions, 254 deletions

diff --git a/drivers/media/IR/ir-core-priv.h b/drivers/media/IR/ir-core-priv.h
index 8c1f84645eaf..77d0b94ede10 100644
--- a/drivers/media/IR/ir-core-priv.h
+++ b/drivers/media/IR/ir-core-priv.h
@@ -22,7 +22,7 @@
 struct ir_raw_handler {
         struct list_head list;
 
-        int (*decode)(struct input_dev *input_dev, s64 duration);
+        int (*decode)(struct input_dev *input_dev, struct ir_raw_event event);
         int (*raw_register)(struct input_dev *input_dev);
         int (*raw_unregister)(struct input_dev *input_dev);
 };
@@ -36,26 +36,28 @@ struct ir_raw_event_ctrl {
 };
 
 /* macros for IR decoders */
-#define PULSE(units)                            ((units))
-#define SPACE(units)                            (-(units))
-#define IS_RESET(duration)                      ((duration) == 0)
-#define IS_PULSE(duration)                      ((duration) > 0)
-#define IS_SPACE(duration)                      ((duration) < 0)
-#define DURATION(duration)                      (abs((duration)))
-#define IS_TRANSITION(x, y)                     ((x) * (y) < 0)
-#define DECREASE_DURATION(duration, amount)                     \
-        do {                                                    \
-                if (IS_SPACE(duration))                         \
-                        duration += (amount);                   \
-                else if (IS_PULSE(duration))                    \
-                        duration -= (amount);                   \
-        } while (0)
-
-#define TO_UNITS(duration, unit_len)                            \
-        ((int)((duration) > 0 ?                                 \
-                DIV_ROUND_CLOSEST(abs((duration)), (unit_len)) :\
-                -DIV_ROUND_CLOSEST(abs((duration)), (unit_len))))
-#define TO_US(duration)         ((int)TO_UNITS(duration, 1000))
+static inline bool geq_margin(unsigned d1, unsigned d2, unsigned margin) {
+        return d1 > (d2 - margin);
+}
+
+static inline bool eq_margin(unsigned d1, unsigned d2, unsigned margin) {
+        return ((d1 > (d2 - margin)) && (d1 < (d2 + margin)));
+}
+
+static inline bool is_transition(struct ir_raw_event *x, struct ir_raw_event *y) {
+        return x->pulse != y->pulse;
+}
+
+static inline void decrease_duration(struct ir_raw_event *ev, unsigned duration) {
+        if (duration > ev->duration)
+                ev->duration = 0;
+        else
+                ev->duration -= duration;
+}
+
+#define TO_US(duration)                 (((duration) + 500) / 1000)
+#define TO_STR(is_pulse)                ((is_pulse) ? "pulse" : "space")
+#define IS_RESET(ev)                    (ev.duration == 0)
 
 /*
  * Routines from ir-sysfs.c - Meant to be called only internally inside
@@ -70,11 +72,6 @@ void ir_unregister_class(struct input_dev *input_dev);
  */
 int ir_raw_event_register(struct input_dev *input_dev);
 void ir_raw_event_unregister(struct input_dev *input_dev);
-static inline void ir_raw_event_reset(struct input_dev *input_dev)
-{
-        ir_raw_event_store(input_dev, 0);
-        ir_raw_event_handle(input_dev);
-}
 int ir_raw_handler_register(struct ir_raw_handler *ir_raw_handler);
 void ir_raw_handler_unregister(struct ir_raw_handler *ir_raw_handler);
 void ir_raw_init(void);
diff --git a/drivers/media/IR/ir-nec-decoder.c b/drivers/media/IR/ir-nec-decoder.c
index 14609d9580a8..ba79233112ef 100644
--- a/drivers/media/IR/ir-nec-decoder.c
+++ b/drivers/media/IR/ir-nec-decoder.c
@@ -17,13 +17,15 @@
 
 #define NEC_NBITS               32
 #define NEC_UNIT                562500  /* ns */
-#define NEC_HEADER_PULSE        PULSE(16)
-#define NECX_HEADER_PULSE       PULSE(8) /* Less common NEC variant */
-#define NEC_HEADER_SPACE        SPACE(8)
-#define NEC_REPEAT_SPACE        SPACE(4)
-#define NEC_BIT_PULSE           PULSE(1)
-#define NEC_BIT_0_SPACE         SPACE(1)
-#define NEC_BIT_1_SPACE         SPACE(3)
+#define NEC_HEADER_PULSE        (16 * NEC_UNIT)
+#define NECX_HEADER_PULSE       (8  * NEC_UNIT) /* Less common NEC variant */
+#define NEC_HEADER_SPACE        (8  * NEC_UNIT)
+#define NEC_REPEAT_SPACE        (8  * NEC_UNIT)
+#define NEC_BIT_PULSE           (1  * NEC_UNIT)
+#define NEC_BIT_0_SPACE         (1  * NEC_UNIT)
+#define NEC_BIT_1_SPACE         (3  * NEC_UNIT)
+#define NEC_TRAILER_PULSE       (1  * NEC_UNIT)
+#define NEC_TRAILER_SPACE       (10 * NEC_UNIT) /* even longer in reality */
 
 /* Used to register nec_decoder clients */
 static LIST_HEAD(decoder_list);
@@ -119,15 +121,14 @@ static struct attribute_group decoder_attribute_group = {
 /**
  * ir_nec_decode() - Decode one NEC pulse or space
  * @input_dev:  the struct input_dev descriptor of the device
- * @duration:   duration in ns of pulse/space
+ * @duration:   the struct ir_raw_event descriptor of the pulse/space
  *
  * This function returns -EINVAL if the pulse violates the state machine
  */
-static int ir_nec_decode(struct input_dev *input_dev, s64 duration)
+static int ir_nec_decode(struct input_dev *input_dev, struct ir_raw_event ev)
 {
         struct decoder_data *data;
         struct ir_input_dev *ir_dev = input_get_drvdata(input_dev);
-        int u;
         u32 scancode;
         u8 address, not_address, command, not_command;
 
@@ -138,59 +139,88 @@ static int ir_nec_decode(struct input_dev *input_dev, s64 duration)
         if (!data->enabled)
                 return 0;
 
-        if (IS_RESET(duration)) {
+        if (IS_RESET(ev)) {
                 data->state = STATE_INACTIVE;
                 return 0;
         }
 
-        u = TO_UNITS(duration, NEC_UNIT);
-        if (DURATION(u) == 0)
-                goto out;
-
-        IR_dprintk(2, "NEC decode started at state %d (%i units, %ius)\n",
-                   data->state, u, TO_US(duration));
+        IR_dprintk(2, "NEC decode started at state %d (%uus %s)\n",
+                   data->state, TO_US(ev.duration), TO_STR(ev.pulse));
 
         switch (data->state) {
 
         case STATE_INACTIVE:
-                if (u == NEC_HEADER_PULSE || u == NECX_HEADER_PULSE) {
-                        data->count = 0;
-                        data->state = STATE_HEADER_SPACE;
-                }
+                if (!ev.pulse)
+                        break;
+
+                if (!eq_margin(ev.duration, NEC_HEADER_PULSE, NEC_UNIT / 2) &&
+                    !eq_margin(ev.duration, NECX_HEADER_PULSE, NEC_UNIT / 2))
+                        break;
+
+                data->count = 0;
+                data->state = STATE_HEADER_SPACE;
                 return 0;
 
         case STATE_HEADER_SPACE:
-                if (u == NEC_HEADER_SPACE) {
+                if (ev.pulse)
+                        break;
+
+                if (eq_margin(ev.duration, NEC_HEADER_SPACE, NEC_UNIT / 2)) {
                         data->state = STATE_BIT_PULSE;
                         return 0;
-                } else if (u == NEC_REPEAT_SPACE) {
+                } else if (eq_margin(ev.duration, NEC_REPEAT_SPACE, NEC_UNIT / 2)) {
                         ir_repeat(input_dev);
                         IR_dprintk(1, "Repeat last key\n");
                         data->state = STATE_TRAILER_PULSE;
                         return 0;
                 }
+
                 break;
 
         case STATE_BIT_PULSE:
-                if (u == NEC_BIT_PULSE) {
-                        data->state = STATE_BIT_SPACE;
-                        return 0;
-                }
-                break;
+                if (!ev.pulse)
+                        break;
+
+                if (!eq_margin(ev.duration, NEC_BIT_PULSE, NEC_UNIT / 2))
+                        break;
+
+                data->state = STATE_BIT_SPACE;
+                return 0;
 
         case STATE_BIT_SPACE:
-                if (u != NEC_BIT_0_SPACE && u != NEC_BIT_1_SPACE)
+                if (ev.pulse)
                         break;
 
                 data->nec_bits <<= 1;
-                if (u == NEC_BIT_1_SPACE)
+                if (eq_margin(ev.duration, NEC_BIT_1_SPACE, NEC_UNIT / 2))
                         data->nec_bits |= 1;
+                else if (!eq_margin(ev.duration, NEC_BIT_0_SPACE, NEC_UNIT / 2))
+                        break;
                 data->count++;
 
-                if (data->count != NEC_NBITS) {
+                if (data->count == NEC_NBITS)
+                        data->state = STATE_TRAILER_PULSE;
+                else
                         data->state = STATE_BIT_PULSE;
-                        return 0;
-                }
+
+                return 0;
+
+        case STATE_TRAILER_PULSE:
+                if (!ev.pulse)
+                        break;
+
+                if (!eq_margin(ev.duration, NEC_TRAILER_PULSE, NEC_UNIT / 2))
+                        break;
+
+                data->state = STATE_TRAILER_SPACE;
+                return 0;
+
+        case STATE_TRAILER_SPACE:
+                if (ev.pulse)
+                        break;
+
+                if (!geq_margin(ev.duration, NEC_TRAILER_SPACE, NEC_UNIT / 2))
+                        break;
 
                 address     = bitrev8((data->nec_bits >> 24) & 0xff);
                 not_address = bitrev8((data->nec_bits >> 16) & 0xff);
@@ -210,34 +240,18 @@ static int ir_nec_decode(struct input_dev *input_dev, s64 duration)
                                    command;
                         IR_dprintk(1, "NEC (Ext) scancode 0x%06x\n", scancode);
                 } else {
-                        /* normal NEC */
+                        /* Normal NEC */
                         scancode = address << 8 | command;
                         IR_dprintk(1, "NEC scancode 0x%04x\n", scancode);
                 }
 
                 ir_keydown(input_dev, scancode, 0);
-                data->state = STATE_TRAILER_PULSE;
+                data->state = STATE_INACTIVE;
                 return 0;
-
-        case STATE_TRAILER_PULSE:
-                if (u > 0) {
-                        data->state = STATE_TRAILER_SPACE;
-                        return 0;
-                }
-                break;
-
-        case STATE_TRAILER_SPACE:
-                if (u < 0) {
-                        data->state = STATE_INACTIVE;
-                        return 0;
-                }
-
-                break;
         }
 
-out:
-        IR_dprintk(1, "NEC decode failed at state %d (%i units, %ius)\n",
-                   data->state, u, TO_US(duration));
+        IR_dprintk(1, "NEC decode failed at state %d (%uus %s)\n",
+                   data->state, TO_US(ev.duration), TO_STR(ev.pulse));
         data->state = STATE_INACTIVE;
         return -EINVAL;
 }
diff --git a/drivers/media/IR/ir-raw-event.c b/drivers/media/IR/ir-raw-event.c
index 674442b2f0a8..59f173c45b9d 100644
--- a/drivers/media/IR/ir-raw-event.c
+++ b/drivers/media/IR/ir-raw-event.c
@@ -57,12 +57,12 @@ static struct work_struct wq_load;
 
 static void ir_raw_event_work(struct work_struct *work)
 {
-        s64 d;
+        struct ir_raw_event ev;
         struct ir_raw_event_ctrl *raw =
                 container_of(work, struct ir_raw_event_ctrl, rx_work);
 
-        while (kfifo_out(&raw->kfifo, &d, sizeof(d)) == sizeof(d))
-                RUN_DECODER(decode, raw->input_dev, d);
+        while (kfifo_out(&raw->kfifo, &ev, sizeof(ev)) == sizeof(ev))
+                RUN_DECODER(decode, raw->input_dev, ev);
 }
 
 int ir_raw_event_register(struct input_dev *input_dev)
@@ -114,21 +114,21 @@ void ir_raw_event_unregister(struct input_dev *input_dev)
 /**
  * ir_raw_event_store() - pass a pulse/space duration to the raw ir decoders
  * @input_dev:  the struct input_dev device descriptor
- * @duration:   duration of the pulse or space in ns
+ * @ev:         the struct ir_raw_event descriptor of the pulse/space
  *
  * This routine (which may be called from an interrupt context) stores a
  * pulse/space duration for the raw ir decoding state machines. Pulses are
  * signalled as positive values and spaces as negative values. A zero value
  * will reset the decoding state machines.
  */
-int ir_raw_event_store(struct input_dev *input_dev, s64 duration)
+int ir_raw_event_store(struct input_dev *input_dev, struct ir_raw_event *ev)
 {
         struct ir_input_dev *ir = input_get_drvdata(input_dev);
 
         if (!ir->raw)
                 return -EINVAL;
 
-        if (kfifo_in(&ir->raw->kfifo, &duration, sizeof(duration)) != sizeof(duration))
+        if (kfifo_in(&ir->raw->kfifo, ev, sizeof(*ev)) != sizeof(*ev))
                 return -ENOMEM;
 
         return 0;
@@ -151,6 +151,7 @@ int ir_raw_event_store_edge(struct input_dev *input_dev, enum raw_event_type typ
         struct ir_input_dev     *ir = input_get_drvdata(input_dev);
         ktime_t                 now;
         s64                     delta; /* ns */
+        struct ir_raw_event     ev;
         int                     rc = 0;
 
         if (!ir->raw)
@@ -163,16 +164,21 @@ int ir_raw_event_store_edge(struct input_dev *input_dev, enum raw_event_type typ
          * being called for the first time, note that delta can't
          * possibly be negative.
          */
-        if (delta > NSEC_PER_SEC || !ir->raw->last_type)
+        ev.duration = 0;
+        if (delta > IR_MAX_DURATION || !ir->raw->last_type)
                 type |= IR_START_EVENT;
+        else
+                ev.duration = delta;
 
         if (type & IR_START_EVENT)
                 ir_raw_event_reset(input_dev);
-        else if (ir->raw->last_type & IR_SPACE)
-                rc = ir_raw_event_store(input_dev, -delta);
-        else if (ir->raw->last_type & IR_PULSE)
-                rc = ir_raw_event_store(input_dev, delta);
-        else
+        else if (ir->raw->last_type & IR_SPACE) {
+                ev.pulse = false;
+                rc = ir_raw_event_store(input_dev, &ev);
+        } else if (ir->raw->last_type & IR_PULSE) {
+                ev.pulse = true;
+                rc = ir_raw_event_store(input_dev, &ev);
+        } else
                 return 0;
 
         ir->raw->last_event = now;
diff --git a/drivers/media/IR/ir-rc5-decoder.c b/drivers/media/IR/ir-rc5-decoder.c
index dd5a4d5f25fd..23cdb1b1a3bc 100644
--- a/drivers/media/IR/ir-rc5-decoder.c
+++ b/drivers/media/IR/ir-rc5-decoder.c
@@ -25,8 +25,10 @@
 #define RC5_NBITS               14
 #define RC5X_NBITS              20
 #define CHECK_RC5X_NBITS        8
-#define RC5X_SPACE              SPACE(4)
 #define RC5_UNIT                888888 /* ns */
+#define RC5_BIT_START           (1 * RC5_UNIT)
+#define RC5_BIT_END             (1 * RC5_UNIT)
+#define RC5X_SPACE              (4 * RC5_UNIT)
 
 /* Used to register rc5_decoder clients */
 static LIST_HEAD(decoder_list);
@@ -48,7 +50,7 @@ struct decoder_data {
         /* State machine control */
         enum rc5_state          state;
         u32                     rc5_bits;
-        int                     last_unit;
+        struct ir_raw_event     prev_ev;
         unsigned                count;
         unsigned                wanted_bits;
 };
@@ -124,17 +126,16 @@ static struct attribute_group decoder_attribute_group = {
 /**
  * ir_rc5_decode() - Decode one RC-5 pulse or space
  * @input_dev:  the struct input_dev descriptor of the device
- * @duration:   duration of pulse/space in ns
+ * @ev:         the struct ir_raw_event descriptor of the pulse/space
  *
  * This function returns -EINVAL if the pulse violates the state machine
  */
-static int ir_rc5_decode(struct input_dev *input_dev, s64 duration)
+static int ir_rc5_decode(struct input_dev *input_dev, struct ir_raw_event ev)
 {
         struct decoder_data *data;
         struct ir_input_dev *ir_dev = input_get_drvdata(input_dev);
         u8 toggle;
         u32 scancode;
-        int u;
 
         data = get_decoder_data(ir_dev);
         if (!data)
@@ -143,76 +144,65 @@ static int ir_rc5_decode(struct input_dev *input_dev, s64 duration)
         if (!data->enabled)
                 return 0;
 
-        if (IS_RESET(duration)) {
+        if (IS_RESET(ev)) {
                 data->state = STATE_INACTIVE;
                 return 0;
         }
 
-        u = TO_UNITS(duration, RC5_UNIT);
-        if (DURATION(u) == 0)
+        if (!geq_margin(ev.duration, RC5_UNIT, RC5_UNIT / 2))
                 goto out;
 
 again:
-        IR_dprintk(2, "RC5(x) decode started at state %i (%i units, %ius)\n",
-                   data->state, u, TO_US(duration));
+        IR_dprintk(2, "RC5(x) decode started at state %i (%uus %s)\n",
+                   data->state, TO_US(ev.duration), TO_STR(ev.pulse));
 
-        if (DURATION(u) == 0 && data->state != STATE_FINISHED)
+        if (!geq_margin(ev.duration, RC5_UNIT, RC5_UNIT / 2))
                 return 0;
 
         switch (data->state) {
 
         case STATE_INACTIVE:
-                if (IS_PULSE(u)) {
-                        data->state = STATE_BIT_START;
-                        data->count = 1;
-                        /* We just need enough bits to get to STATE_CHECK_RC5X */
-                        data->wanted_bits = RC5X_NBITS;
-                        DECREASE_DURATION(u, 1);
-                        goto again;
-                }
-                break;
+                if (!ev.pulse)
+                        break;
+
+                data->state = STATE_BIT_START;
+                data->count = 1;
+                /* We just need enough bits to get to STATE_CHECK_RC5X */
+                data->wanted_bits = RC5X_NBITS;
+                decrease_duration(&ev, RC5_BIT_START);
+                goto again;
 
         case STATE_BIT_START:
-                if (DURATION(u) == 1) {
-                        data->rc5_bits <<= 1;
-                        if (IS_SPACE(u))
-                                data->rc5_bits |= 1;
-                        data->count++;
-                        data->last_unit = u;
-
-                        /*
-                         * If the last bit is zero, a space will merge
-                         * with the silence after the command.
-                         */
-                        if (IS_PULSE(u) && data->count == data->wanted_bits) {
-                                data->state = STATE_FINISHED;
-                                goto again;
-                        }
-
-                        data->state = STATE_BIT_END;
-                        return 0;
-                }
-                break;
+                if (!eq_margin(ev.duration, RC5_BIT_START, RC5_UNIT / 2))
+                        break;
+
+                data->rc5_bits <<= 1;
+                if (!ev.pulse)
+                        data->rc5_bits |= 1;
+                data->count++;
+                data->prev_ev = ev;
+                data->state = STATE_BIT_END;
+                return 0;
 
         case STATE_BIT_END:
-                if (IS_TRANSITION(u, data->last_unit)) {
-                        if (data->count == data->wanted_bits)
-                                data->state = STATE_FINISHED;
-                        else if (data->count == CHECK_RC5X_NBITS)
-                                data->state = STATE_CHECK_RC5X;
-                        else
-                                data->state = STATE_BIT_START;
-
-                        DECREASE_DURATION(u, 1);
-                        goto again;
-                }
-                break;
+                if (!is_transition(&ev, &data->prev_ev))
+                        break;
+
+                if (data->count == data->wanted_bits)
+                        data->state = STATE_FINISHED;
+                else if (data->count == CHECK_RC5X_NBITS)
+                        data->state = STATE_CHECK_RC5X;
+                else
+                        data->state = STATE_BIT_START;
+
+                decrease_duration(&ev, RC5_BIT_END);
+                goto again;
 
         case STATE_CHECK_RC5X:
-                if (IS_SPACE(u) && DURATION(u) >= DURATION(RC5X_SPACE)) {
+                if (!ev.pulse && geq_margin(ev.duration, RC5X_SPACE, RC5_UNIT / 2)) {
                         /* RC5X */
                         data->wanted_bits = RC5X_NBITS;
-                        DECREASE_DURATION(u, DURATION(RC5X_SPACE));
+                        decrease_duration(&ev, RC5X_SPACE);
                 } else {
                         /* RC5 */
                         data->wanted_bits = RC5_NBITS;
@@ -221,6 +211,9 @@ again:
                 goto again;
 
         case STATE_FINISHED:
+                if (ev.pulse)
+                        break;
+
                 if (data->wanted_bits == RC5X_NBITS) {
                         /* RC5X */
                         u8 xdata, command, system;
@@ -253,8 +246,8 @@ again:
         }
 
 out:
-        IR_dprintk(1, "RC5(x) decode failed at state %i (%i units, %ius)\n",
-                   data->state, u, TO_US(duration));
+        IR_dprintk(1, "RC5(x) decode failed at state %i (%uus %s)\n",
+                   data->state, TO_US(ev.duration), TO_STR(ev.pulse));
         data->state = STATE_INACTIVE;
         return -EINVAL;
 }
diff --git a/drivers/media/IR/ir-rc6-decoder.c b/drivers/media/IR/ir-rc6-decoder.c
index ccc5be240f82..2bf479f4f1bc 100644
--- a/drivers/media/IR/ir-rc6-decoder.c
+++ b/drivers/media/IR/ir-rc6-decoder.c
@@ -26,8 +26,12 @@
 #define RC6_0_NBITS             16
 #define RC6_6A_SMALL_NBITS      24
 #define RC6_6A_LARGE_NBITS      32
-#define RC6_PREFIX_PULSE        PULSE(6)
-#define RC6_PREFIX_SPACE        SPACE(2)
+#define RC6_PREFIX_PULSE        (6 * RC6_UNIT)
+#define RC6_PREFIX_SPACE        (2 * RC6_UNIT)
+#define RC6_BIT_START           (1 * RC6_UNIT)
+#define RC6_BIT_END             (1 * RC6_UNIT)
+#define RC6_TOGGLE_START        (2 * RC6_UNIT)
+#define RC6_TOGGLE_END          (2 * RC6_UNIT)
 #define RC6_MODE_MASK           0x07    /* for the header bits */
 #define RC6_STARTBIT_MASK       0x08    /* for the header bits */
 #define RC6_6A_MCE_TOGGLE_MASK  0x8000  /* for the body bits */
@@ -63,7 +67,7 @@ struct decoder_data {
         enum rc6_state          state;
         u8                      header;
         u32                     body;
-        int                     last_unit;
+        struct ir_raw_event     prev_ev;
         bool                    toggle;
         unsigned                count;
         unsigned                wanted_bits;
@@ -152,17 +156,16 @@ static enum rc6_mode rc6_mode(struct decoder_data *data) {
 /**
  * ir_rc6_decode() - Decode one RC6 pulse or space
  * @input_dev:  the struct input_dev descriptor of the device
- * @duration:   duration of pulse/space in ns
+ * @ev:         the struct ir_raw_event descriptor of the pulse/space
  *
  * This function returns -EINVAL if the pulse violates the state machine
  */
-static int ir_rc6_decode(struct input_dev *input_dev, s64 duration)
+static int ir_rc6_decode(struct input_dev *input_dev, struct ir_raw_event ev)
 {
         struct decoder_data *data;
         struct ir_input_dev *ir_dev = input_get_drvdata(input_dev);
         u32 scancode;
         u8 toggle;
-        int u;
 
         data = get_decoder_data(ir_dev);
         if (!data)
@@ -171,140 +174,144 @@ static int ir_rc6_decode(struct input_dev *input_dev, s64 duration)
         if (!data->enabled)
                 return 0;
 
-        if (IS_RESET(duration)) {
+        if (IS_RESET(ev)) {
                 data->state = STATE_INACTIVE;
                 return 0;
         }
 
-        u =  TO_UNITS(duration, RC6_UNIT);
-        if (DURATION(u) == 0)
+        if (!geq_margin(ev.duration, RC6_UNIT, RC6_UNIT / 2))
                 goto out;
 
 again:
-        IR_dprintk(2, "RC6 decode started at state %i (%i units, %ius)\n",
-                   data->state, u, TO_US(duration));
+        IR_dprintk(2, "RC6 decode started at state %i (%uus %s)\n",
+                   data->state, TO_US(ev.duration), TO_STR(ev.pulse));
 
-        if (DURATION(u) == 0 && data->state != STATE_FINISHED)
+        if (!geq_margin(ev.duration, RC6_UNIT, RC6_UNIT / 2))
                 return 0;
 
         switch (data->state) {
 
         case STATE_INACTIVE:
-                if (u >= RC6_PREFIX_PULSE - 1 && u <= RC6_PREFIX_PULSE + 1) {
-                        data->state = STATE_PREFIX_SPACE;
-                        data->count = 0;
-                        return 0;
-                }
-                break;
+                if (!ev.pulse)
+                        break;
+
+                /* Note: larger margin on first pulse since each RC6_UNIT
+                   is quite short and some hardware takes some time to
+                   adjust to the signal */
+                if (!eq_margin(ev.duration, RC6_PREFIX_PULSE, RC6_UNIT))
+                        break;
+
+                data->state = STATE_PREFIX_SPACE;
+                data->count = 0;
+                return 0;
 
         case STATE_PREFIX_SPACE:
-                if (u == RC6_PREFIX_SPACE) {
-                        data->state = STATE_HEADER_BIT_START;
-                        return 0;
-                }
-                break;
+                if (ev.pulse)
+                        break;
+
+                if (!eq_margin(ev.duration, RC6_PREFIX_SPACE, RC6_UNIT / 2))
+                        break;
+
+                data->state = STATE_HEADER_BIT_START;
+                return 0;
 
         case STATE_HEADER_BIT_START:
-                if (DURATION(u) == 1) {
-                        data->header <<= 1;
-                        if (IS_PULSE(u))
-                                data->header |= 1;
-                        data->count++;
-                        data->last_unit = u;
-                        data->state = STATE_HEADER_BIT_END;
-                        return 0;
-                }
-                break;
+                if (!eq_margin(ev.duration, RC6_BIT_START, RC6_UNIT / 2))
+                        break;
+
+                data->header <<= 1;
+                if (ev.pulse)
+                        data->header |= 1;
+                data->count++;
+                data->prev_ev = ev;
+                data->state = STATE_HEADER_BIT_END;
+                return 0;
 
         case STATE_HEADER_BIT_END:
-                if (IS_TRANSITION(u, data->last_unit)) {
-                        if (data->count == RC6_HEADER_NBITS)
-                                data->state = STATE_TOGGLE_START;
-                        else
-                                data->state = STATE_HEADER_BIT_START;
+                if (!is_transition(&ev, &data->prev_ev))
+                        break;
 
-                        DECREASE_DURATION(u, 1);
-                        goto again;
-                }
-                break;
+                if (data->count == RC6_HEADER_NBITS)
+                        data->state = STATE_TOGGLE_START;
+                else
+                        data->state = STATE_HEADER_BIT_START;
+
+                decrease_duration(&ev, RC6_BIT_END);
+                goto again;
 
         case STATE_TOGGLE_START:
-                if (DURATION(u) == 2) {
-                        data->toggle = IS_PULSE(u);
-                        data->last_unit = u;
-                        data->state = STATE_TOGGLE_END;
-                        return 0;
-                }
-                break;
+                if (!eq_margin(ev.duration, RC6_TOGGLE_START, RC6_UNIT / 2))
+                        break;
+
+                data->toggle = ev.pulse;
+                data->prev_ev = ev;
+                data->state = STATE_TOGGLE_END;
+                return 0;
 
         case STATE_TOGGLE_END:
-                if (IS_TRANSITION(u, data->last_unit) && DURATION(u) >= 2) {
-                        data->state = STATE_BODY_BIT_START;
-                        data->last_unit = u;
-                        DECREASE_DURATION(u, 2);
-                        data->count = 0;
+                if (!is_transition(&ev, &data->prev_ev) ||
+                    !geq_margin(ev.duration, RC6_TOGGLE_END, RC6_UNIT / 2))
+                        break;
 
-                        if (!(data->header & RC6_STARTBIT_MASK)) {
-                                IR_dprintk(1, "RC6 invalid start bit\n");
-                                break;
-                        }
+                if (!(data->header & RC6_STARTBIT_MASK)) {
+                        IR_dprintk(1, "RC6 invalid start bit\n");
+                        break;
+                }
 
-                        switch (rc6_mode(data)) {
-                        case RC6_MODE_0:
-                                data->wanted_bits = RC6_0_NBITS;
-                                break;
-                        case RC6_MODE_6A:
-                                /* This might look weird, but we basically
-                                   check the value of the first body bit to
-                                   determine the number of bits in mode 6A */
-                                if ((DURATION(u) == 0 && IS_SPACE(data->last_unit)) || DURATION(u) > 0)
-                                        data->wanted_bits = RC6_6A_LARGE_NBITS;
-                                else
-                                        data->wanted_bits = RC6_6A_SMALL_NBITS;
-                                break;
-                        default:
-                                IR_dprintk(1, "RC6 unknown mode\n");
-                                goto out;
-                        }
-                        goto again;
+                data->state = STATE_BODY_BIT_START;
+                data->prev_ev = ev;
+                decrease_duration(&ev, RC6_TOGGLE_END);
+                data->count = 0;
+
+                switch (rc6_mode(data)) {
+                case RC6_MODE_0:
+                        data->wanted_bits = RC6_0_NBITS;
+                        break;
+                case RC6_MODE_6A:
+                        /* This might look weird, but we basically
+                           check the value of the first body bit to
+                           determine the number of bits in mode 6A */
+                        if ((!ev.pulse && !geq_margin(ev.duration, RC6_UNIT, RC6_UNIT / 2)) ||
+                            geq_margin(ev.duration, RC6_UNIT, RC6_UNIT / 2))
+                                data->wanted_bits = RC6_6A_LARGE_NBITS;
+                        else
+                                data->wanted_bits = RC6_6A_SMALL_NBITS;
+                        break;
+                default:
+                        IR_dprintk(1, "RC6 unknown mode\n");
+                        goto out;
                 }
-                break;
+                goto again;
 
         case STATE_BODY_BIT_START:
-                if (DURATION(u) == 1) {
-                        data->body <<= 1;
-                        if (IS_PULSE(u))
-                                data->body |= 1;
-                        data->count++;
-                        data->last_unit = u;
-
-                        /*
-                         * If the last bit is one, a space will merge
-                         * with the silence after the command.
-                         */
-                        if (IS_PULSE(u) && data->count == data->wanted_bits) {
-                                data->state = STATE_FINISHED;
-                                goto again;
-                        }
+                if (!eq_margin(ev.duration, RC6_BIT_START, RC6_UNIT / 2))
+                        break;
 
-                        data->state = STATE_BODY_BIT_END;
-                        return 0;
-                }
-                break;
+                data->body <<= 1;
+                if (ev.pulse)
+                        data->body |= 1;
+                data->count++;
+                data->prev_ev = ev;
+
+                data->state = STATE_BODY_BIT_END;
+                return 0;
 
         case STATE_BODY_BIT_END:
-                if (IS_TRANSITION(u, data->last_unit)) {
-                        if (data->count == data->wanted_bits)
-                                data->state = STATE_FINISHED;
-                        else
-                                data->state = STATE_BODY_BIT_START;
+                if (!is_transition(&ev, &data->prev_ev))
+                        break;
 
-                        DECREASE_DURATION(u, 1);
-                        goto again;
-                }
-                break;
+                if (data->count == data->wanted_bits)
+                        data->state = STATE_FINISHED;
+                else
+                        data->state = STATE_BODY_BIT_START;
+
+                decrease_duration(&ev, RC6_BIT_END);
+                goto again;
 
         case STATE_FINISHED:
+                if (ev.pulse)
+                        break;
+
                 switch (rc6_mode(data)) {
                 case RC6_MODE_0:
                         scancode = data->body & 0xffff;
@@ -335,8 +342,8 @@ again:
         }
 
 out:
-        IR_dprintk(1, "RC6 decode failed at state %i (%i units, %ius)\n",
-                   data->state, u, TO_US(duration));
+        IR_dprintk(1, "RC6 decode failed at state %i (%uus %s)\n",
+                   data->state, TO_US(ev.duration), TO_STR(ev.pulse));
         data->state = STATE_INACTIVE;
         return -EINVAL;
 }