Some rotary-encoder devices (such as those with detents) are capable of producing a stable event on each step. This commit adds support for this case, by implementing a new interruption handler.
The handler needs only detect the direction of the turn and generate an event according to this detection. Cc: Daniel Mack <[email protected]> Cc: Dmitry Torokhov <[email protected]> Signed-off-by: Ezequiel Garcia <[email protected]> --- drivers/input/misc/rotary_encoder.c | 34 ++++++++++++++++++++++++++++++++++ include/linux/rotary_encoder.h | 1 + 2 files changed, 35 insertions(+) diff --git a/drivers/input/misc/rotary_encoder.c b/drivers/input/misc/rotary_encoder.c index 5b1aff8..8802221 100644 --- a/drivers/input/misc/rotary_encoder.c +++ b/drivers/input/misc/rotary_encoder.c @@ -117,6 +117,37 @@ static irqreturn_t rotary_encoder_irq(int irq, void *dev_id) return IRQ_HANDLED; } +static irqreturn_t rotary_encoder_stepped_irq(int irq, void *dev_id) +{ + struct rotary_encoder *encoder = dev_id; + int state, sum; + + state = rotary_encoder_get_state(encoder->pdata); + + /* + * We encode the previous and the current state, + * in the 'sum' variable and then use a table + * to decide the direction of the turn. + */ + sum = (encoder->last_stable << 2) + state; + switch (sum) { + case 0b1101: + case 0b0100: + case 0b0010: + case 0b1011: + encoder->dir = 0; /* clockwise */ + break; + default: + encoder->dir = 1; + } + + rotary_encoder_report_event(encoder); + + encoder->last_stable = state; + + return IRQ_HANDLED; +} + static irqreturn_t rotary_encoder_half_period_irq(int irq, void *dev_id) { struct rotary_encoder *encoder = dev_id; @@ -254,6 +285,9 @@ static int rotary_encoder_probe(struct platform_device *pdev) if (pdata->half_period) { handler = &rotary_encoder_half_period_irq; encoder->last_stable = rotary_encoder_get_state(pdata); + } else if (pdata->on_each_step) { + handler = &rotary_encoder_stepped_irq; + encoder->last_stable = rotary_encoder_get_state(pdata); } else { handler = &rotary_encoder_irq; } diff --git a/include/linux/rotary_encoder.h b/include/linux/rotary_encoder.h index 3f594dc..499f6f7 100644 --- a/include/linux/rotary_encoder.h +++ b/include/linux/rotary_encoder.h @@ -11,6 +11,7 @@ struct rotary_encoder_platform_data { bool relative_axis; bool rollover; bool half_period; + bool on_each_step; }; #endif /* __ROTARY_ENCODER_H__ */ -- 1.8.1.5 -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
