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| author | Johan Hovold <jhovold@gmail.com> | 2011-05-12 03:35:30 +0400 |
|---|---|---|
| committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2011-05-12 19:28:47 +0400 |
| commit | e70bdd41bd0ead91b4a43e9d656ac1569d7c8779 (patch) | |
| tree | 9518f22417dde4f2b2d2ed3a25af8bc8f4e3814c /drivers/input/misc/rotary_encoder.c | |
| parent | 521a8f5cb79d1017d00d26143227159674e3b79d (diff) | |
| download | linux-e70bdd41bd0ead91b4a43e9d656ac1569d7c8779.tar.xz | |
Input: rotary-encoder - add support for half-period encoders
Add support for encoders that have two detents per input signal period.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Acked-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Diffstat (limited to 'drivers/input/misc/rotary_encoder.c')
| -rw-r--r-- | drivers/input/misc/rotary_encoder.c | 42 |
1 files changed, 39 insertions, 3 deletions
diff --git a/drivers/input/misc/rotary_encoder.c b/drivers/input/misc/rotary_encoder.c index 077b80bdca69..2c8b84dd9dac 100644 --- a/drivers/input/misc/rotary_encoder.c +++ b/drivers/input/misc/rotary_encoder.c @@ -2,6 +2,7 @@ * rotary_encoder.c * * (c) 2009 Daniel Mack <daniel@caiaq.de> + * Copyright (C) 2011 Johan Hovold <jhovold@gmail.com> * * state machine code inspired by code from Tim Ruetz * @@ -38,6 +39,8 @@ struct rotary_encoder { bool armed; unsigned char dir; /* 0 - clockwise, 1 - CCW */ + + char last_stable; }; static int rotary_encoder_get_state(struct rotary_encoder_platform_data *pdata) @@ -112,11 +115,37 @@ static irqreturn_t rotary_encoder_irq(int irq, void *dev_id) return IRQ_HANDLED; } +static irqreturn_t rotary_encoder_half_period_irq(int irq, void *dev_id) +{ + struct rotary_encoder *encoder = dev_id; + int state; + + state = rotary_encoder_get_state(encoder->pdata); + + switch (state) { + case 0x00: + case 0x03: + if (state != encoder->last_stable) { + rotary_encoder_report_event(encoder); + encoder->last_stable = state; + } + break; + + case 0x01: + case 0x02: + encoder->dir = (encoder->last_stable + state) & 0x01; + break; + } + + return IRQ_HANDLED; +} + static int __devinit rotary_encoder_probe(struct platform_device *pdev) { struct rotary_encoder_platform_data *pdata = pdev->dev.platform_data; struct rotary_encoder *encoder; struct input_dev *input; + irq_handler_t handler; int err; if (!pdata) { @@ -187,7 +216,14 @@ static int __devinit rotary_encoder_probe(struct platform_device *pdev) } /* request the IRQs */ - err = request_irq(encoder->irq_a, &rotary_encoder_irq, + if (pdata->half_period) { + handler = &rotary_encoder_half_period_irq; + encoder->last_stable = rotary_encoder_get_state(pdata); + } else { + handler = &rotary_encoder_irq; + } + + err = request_irq(encoder->irq_a, handler, IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING, DRV_NAME, encoder); if (err) { @@ -196,7 +232,7 @@ static int __devinit rotary_encoder_probe(struct platform_device *pdev) goto exit_free_gpio_b; } - err = request_irq(encoder->irq_b, &rotary_encoder_irq, + err = request_irq(encoder->irq_b, handler, IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING, DRV_NAME, encoder); if (err) { @@ -264,5 +300,5 @@ module_exit(rotary_encoder_exit); MODULE_ALIAS("platform:" DRV_NAME); MODULE_DESCRIPTION("GPIO rotary encoder driver"); -MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>"); +MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>, Johan Hovold"); MODULE_LICENSE("GPL v2"); |