b/drivers/input/misc/rotary_encoder.c
@@ -36,8 +36,7 @@ struct rotary_encoder {
unsigned int irq_a;
unsigned int irq_b;
- bool armed;
- unsigned char dir; /* 0 - clockwise, 1 - CCW */
+ int last_state;
};
static irqreturn_t rotary_encoder_irq(int irq, void *dev_id)
@@ -52,51 +51,47 @@ static irqreturn_t rotary_encoder_irq(int irq, void
*dev_id)
b ^= pdata->inverted_b;
state = (a << 1) | b;
- switch (state) {
-
- case 0x0:
- if (!encoder->armed)
- break;
-
- if (pdata->relative_axis) {
- input_report_rel(encoder->input, pdata->axis,
- encoder->dir ? -1 : 1);
- } else {
- unsigned int pos = encoder->pos;
+ if (((state == 0x0) || (state == 0x3)) && ((encoder->last_state ==
0x01) || (encoder->last_state == 0x02))) {
+ int state_exor = state ^ encoder->last_state;
+ int dir = 0;
+ if (state_exor == 0x01) {
+ dir = +1;
+ }
+ else {
+ dir = -1;
+ }
- if (encoder->dir) {
- /* turning counter-clockwise */
- if (pdata->rollover)
- pos += pdata->steps;
- if (pos)
- pos--;
+ if (dir) {
+ if (pdata->relative_axis) {
+ input_report_rel(encoder->input, pdata->axis,
+ dir);
} else {
- /* turning clockwise */
- if (pdata->rollover || pos < pdata->steps)
- pos++;
+ unsigned int pos = encoder->pos;
+
+ if (dir == -1) {
+ /* turning counter-clockwise */
+ if (pdata->rollover)
+ pos += pdata->steps;
+ if (pos)
+ pos--;
+ } else {
+ /* turning clockwise */
+ if (pdata->rollover || pos < pdata->steps)
+ pos++;
+ }
+ if (pdata->rollover)
+ pos %= pdata->steps;
+ encoder->pos = pos;
+ input_report_abs(encoder->input, pdata->axis,
+ encoder->pos);
}
- if (pdata->rollover)
- pos %= pdata->steps;
- encoder->pos = pos;
- input_report_abs(encoder->input, pdata->axis,
- encoder->pos);
+ input_sync(encoder->input);
}
- input_sync(encoder->input);
-
- encoder->armed = false;
- break;
-
- case 0x1:
- case 0x2:
- if (encoder->armed)
- encoder->dir = state - 1;
- break;
-
- case 0x3:
- encoder->armed = true;
- break;
}
+ /* always store the state - even on 00 or 11 */
+ encoder->last_state = state;
+
return IRQ_HANDLED;