diff options
Diffstat (limited to 'drivers/input/misc/rotary_encoder.c')
| -rw-r--r-- | drivers/input/misc/rotary_encoder.c | 119 |
1 files changed, 83 insertions, 36 deletions
diff --git a/drivers/input/misc/rotary_encoder.c b/drivers/input/misc/rotary_encoder.c index 7e64d01da2be..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 * @@ -38,52 +39,66 @@ struct rotary_encoder { bool armed; unsigned char dir; /* 0 - clockwise, 1 - CCW */ + + char last_stable; }; -static irqreturn_t rotary_encoder_irq(int irq, void *dev_id) +static int rotary_encoder_get_state(struct rotary_encoder_platform_data *pdata) { - struct rotary_encoder *encoder = dev_id; - struct rotary_encoder_platform_data *pdata = encoder->pdata; int a = !!gpio_get_value(pdata->gpio_a); int b = !!gpio_get_value(pdata->gpio_b); - int state; a ^= pdata->inverted_a; b ^= pdata->inverted_b; - state = (a << 1) | b; - switch (state) { + return ((a << 1) | b); +} - case 0x0: - if (!encoder->armed) - break; +static void rotary_encoder_report_event(struct rotary_encoder *encoder) +{ + struct rotary_encoder_platform_data *pdata = encoder->pdata; - if (pdata->relative_axis) { - input_report_rel(encoder->input, pdata->axis, - encoder->dir ? -1 : 1); - } else { - unsigned int pos = encoder->pos; - - if (encoder->dir) { - /* turning counter-clockwise */ - if (pdata->rollover) - pos += pdata->steps; - if (pos) - pos--; - } else { - /* turning clockwise */ - if (pdata->rollover || pos < pdata->steps) - pos++; - } + if (pdata->relative_axis) { + input_report_rel(encoder->input, + pdata->axis, encoder->dir ? -1 : 1); + } else { + unsigned int pos = encoder->pos; + + if (encoder->dir) { + /* turning counter-clockwise */ if (pdata->rollover) - pos %= pdata->steps; - encoder->pos = pos; - input_report_abs(encoder->input, pdata->axis, - encoder->pos); + pos += pdata->steps; + if (pos) + pos--; + } else { + /* turning clockwise */ + if (pdata->rollover || pos < pdata->steps) + pos++; } - input_sync(encoder->input); - encoder->armed = false; + if (pdata->rollover) + pos %= pdata->steps; + + encoder->pos = pos; + input_report_abs(encoder->input, pdata->axis, encoder->pos); + } + + input_sync(encoder->input); +} + +static irqreturn_t rotary_encoder_irq(int irq, void *dev_id) +{ + struct rotary_encoder *encoder = dev_id; + int state; + + state = rotary_encoder_get_state(encoder->pdata); + + switch (state) { + case 0x0: + if (encoder->armed) { + rotary_encoder_report_event(encoder); + encoder->armed = false; + } break; case 0x1: @@ -100,11 +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) { @@ -175,7 +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) { @@ -184,7 +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) { @@ -252,6 +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"); - |