Some rotary encoders have a stable state in all output state combinations. Add support for this type of encoder.
Signed-off-by: Sascha Hauer <[email protected]> Cc: Dmitry Torokhov <[email protected]> Cc: Daniel Mack <[email protected]> Cc: [email protected] Cc: [email protected] --- .../devicetree/bindings/input/rotary-encoder.txt | 1 + Documentation/input/rotary-encoder.txt | 9 +++++-- drivers/input/misc/rotary_encoder.c | 30 ++++++++++++++++++++-- include/linux/rotary_encoder.h | 1 + 4 files changed, 37 insertions(+), 4 deletions(-) diff --git a/Documentation/devicetree/bindings/input/rotary-encoder.txt b/Documentation/devicetree/bindings/input/rotary-encoder.txt index 3315495..cbdb29b 100644 --- a/Documentation/devicetree/bindings/input/rotary-encoder.txt +++ b/Documentation/devicetree/bindings/input/rotary-encoder.txt @@ -15,6 +15,7 @@ Optional properties: - rotary-encoder,rollover: Automatic rollove when the rotary value becomes greater than the specified steps or smaller than 0. For absolute axis only. - rotary-encoder,half-period: Makes the driver work on half-period mode. +- rotary-encoder,quarter-period: Makes the driver work on quarter-period mode. See Documentation/input/rotary-encoder.txt for more information. diff --git a/Documentation/input/rotary-encoder.txt b/Documentation/input/rotary-encoder.txt index 92e68bc..0bbff7e 100644 --- a/Documentation/input/rotary-encoder.txt +++ b/Documentation/input/rotary-encoder.txt @@ -9,8 +9,10 @@ peripherals with two wires. The outputs are phase-shifted by 90 degrees and by triggering on falling and rising edges, the turn direction can be determined. -Some encoders have both outputs low in stable states, whereas others also have -a stable state with both outputs high (half-period mode). + +Some encoders have both outputs low in stable states, others also have +a stable state with both outputs high (half-period mode) and some have +a stable state in all steps (quarter-period mode). The phase diagram of these two outputs look like this: @@ -32,6 +34,9 @@ The phase diagram of these two outputs look like this: |<-->| one step (half-period mode) + |<>| + one step (quarter-period mode) + For more information, please see http://en.wikipedia.org/wiki/Rotary_encoder diff --git a/drivers/input/misc/rotary_encoder.c b/drivers/input/misc/rotary_encoder.c index 5b1aff8..264501c 100644 --- a/drivers/input/misc/rotary_encoder.c +++ b/drivers/input/misc/rotary_encoder.c @@ -42,7 +42,7 @@ struct rotary_encoder { bool armed; unsigned char dir; /* 0 - clockwise, 1 - CCW */ - char last_stable; + int last_stable; }; static int rotary_encoder_get_state(const struct rotary_encoder_platform_data *pdata) @@ -117,6 +117,28 @@ static irqreturn_t rotary_encoder_irq(int irq, void *dev_id) return IRQ_HANDLED; } +static irqreturn_t rotary_encoder_quarter_period_irq(int irq, void *dev_id) +{ + struct rotary_encoder *encoder = dev_id; + int state; + static const u8 states[4][4] = { + { -1, 1, 0, -1 }, + { 0, -1, -1, 1 }, + { 1, -1, -1, 0 }, + { -1, 0, 1, -1 }, + }; + + state = rotary_encoder_get_state(encoder->pdata); + + encoder->dir = states[encoder->last_stable][state]; + encoder->last_stable = state; + + if (encoder->dir >= 0) + rotary_encoder_report_event(encoder); + + return IRQ_HANDLED; +} + static irqreturn_t rotary_encoder_half_period_irq(int irq, void *dev_id) { struct rotary_encoder *encoder = dev_id; @@ -180,7 +202,8 @@ static struct rotary_encoder_platform_data *rotary_encoder_parse_dt(struct devic "rotary-encoder,rollover", NULL); pdata->half_period = !!of_get_property(np, "rotary-encoder,half-period", NULL); - + pdata->quarter_period = !!of_get_property(np, + "rotary-encoder,quarter-period", NULL); return pdata; } #else @@ -254,6 +277,9 @@ 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->quarter_period) { + handler = &rotary_encoder_quarter_period_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..fd0a70f 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 quarter_period; }; #endif /* __ROTARY_ENCODER_H__ */ -- 1.8.5.1 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
