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>

1 files changed, 114 insertions, 107 deletions

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;
 }