Re: [PATCH v2 1/2] Input: rotary-encoder: Add 'stepped' irq handler
From: Daniel Mack <zonque@gmail.com>
Date: 2013-10-04 13:18:31
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On 04.10.2013 14:53, Ezequiel Garcia wrote:
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.
I think you can squash patch 2/2 into this one. It doesn't make much sense to have a one-liner patch to just update the documenation separately. Other than that, the code looks fine to me. Acked-by: Daniel Mack [off-list ref] Thanks, Daniel
quoted hunk ↗ jump to hunk
Cc: Daniel Mack <zonque@gmail.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar> --- v1->v2: * Add DT property handling * Replace binary representation by hexa-decimal in the sum encoding drivers/input/misc/rotary_encoder.c | 41 +++++++++++++++++++++++++++++++++++++ include/linux/rotary_encoder.h | 1 + 2 files changed, 42 insertions(+)diff --git a/drivers/input/misc/rotary_encoder.c b/drivers/input/misc/rotary_encoder.c index 5b1aff8..6c7a554 100644 --- a/drivers/input/misc/rotary_encoder.c +++ b/drivers/input/misc/rotary_encoder.c@@ -117,6 +117,42 @@ 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; + unsigned char sum; + + state = rotary_encoder_get_state(encoder->pdata); + + /* + * We encode the previous and the current state using a byte. + * The previous state in the MSB nibble, the current state in the LSB + * nibble. Then use a table to decide the direction of the turn. + */ + sum = (encoder->last_stable << 4) + state; + switch (sum) { + case 0x31: + case 0x10: + case 0x02: + case 0x23: + encoder->dir = 0; /* clockwise */ + break; + /* + * TODO: Add the other case, and the illegal values should + * say a WARN (it's a BUG, but we won't stop the kernel for it :) + */ + 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;@@ -180,6 +216,8 @@ 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->on_each_step = !!of_get_property(np, + "rotary-encoder,on-each-step", NULL); return pdata; }@@ -254,6 +292,9 @@ 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__ */