diff options
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/input/misc/rotary_encoder.c | 156 |
1 files changed, 64 insertions, 92 deletions
diff --git a/drivers/input/misc/rotary_encoder.c b/drivers/input/misc/rotary_encoder.c index 5a4e1d69c4af..96c486de49e0 100644 --- a/drivers/input/misc/rotary_encoder.c +++ b/drivers/input/misc/rotary_encoder.c @@ -40,35 +40,42 @@ struct rotary_encoder { unsigned int pos; - struct gpio_desc *gpio_a; - struct gpio_desc *gpio_b; + struct gpio_descs *gpios; - unsigned int irq_a; - unsigned int irq_b; + unsigned int *irq; bool armed; - unsigned char dir; /* 0 - clockwise, 1 - CCW */ + signed char dir; /* 1 - clockwise, -1 - CCW */ - char last_stable; + unsigned last_stable; }; -static int rotary_encoder_get_state(struct rotary_encoder *encoder) +static unsigned rotary_encoder_get_state(struct rotary_encoder *encoder) { - int a = !!gpiod_get_value_cansleep(encoder->gpio_a); - int b = !!gpiod_get_value_cansleep(encoder->gpio_b); + int i; + unsigned ret = 0; - return ((a << 1) | b); + for (i = 0; i < encoder->gpios->ndescs; ++i) { + int val = gpiod_get_value_cansleep(encoder->gpios->desc[i]); + /* convert from gray encoding to normal */ + if (ret & 1) + val = !val; + + ret = ret << 1 | val; + } + + return ret & 3; } static void rotary_encoder_report_event(struct rotary_encoder *encoder) { if (encoder->relative_axis) { input_report_rel(encoder->input, - encoder->axis, encoder->dir ? -1 : 1); + encoder->axis, encoder->dir); } else { unsigned int pos = encoder->pos; - if (encoder->dir) { + if (encoder->dir < 0) { /* turning counter-clockwise */ if (encoder->rollover) pos += encoder->steps; @@ -93,7 +100,7 @@ static void rotary_encoder_report_event(struct rotary_encoder *encoder) static irqreturn_t rotary_encoder_irq(int irq, void *dev_id) { struct rotary_encoder *encoder = dev_id; - int state; + unsigned state; mutex_lock(&encoder->access_mutex); @@ -108,12 +115,12 @@ static irqreturn_t rotary_encoder_irq(int irq, void *dev_id) break; case 0x1: - case 0x2: + case 0x3: if (encoder->armed) - encoder->dir = state - 1; + encoder->dir = 2 - state; break; - case 0x3: + case 0x2: encoder->armed = true; break; } @@ -126,25 +133,19 @@ static irqreturn_t rotary_encoder_irq(int irq, void *dev_id) static irqreturn_t rotary_encoder_half_period_irq(int irq, void *dev_id) { struct rotary_encoder *encoder = dev_id; - int state; + unsigned int state; mutex_lock(&encoder->access_mutex); state = rotary_encoder_get_state(encoder); - switch (state) { - case 0x00: - case 0x03: + if (state & 1) { + encoder->dir = ((encoder->last_stable - state + 1) % 4) - 1; + } else { 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; } mutex_unlock(&encoder->access_mutex); @@ -155,46 +156,18 @@ static irqreturn_t rotary_encoder_half_period_irq(int irq, void *dev_id) static irqreturn_t rotary_encoder_quarter_period_irq(int irq, void *dev_id) { struct rotary_encoder *encoder = dev_id; - unsigned char sum; - int state; + unsigned int state; mutex_lock(&encoder->access_mutex); state = rotary_encoder_get_state(encoder); - /* - * 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; - - case 0x13: - case 0x01: - case 0x20: - case 0x32: - encoder->dir = 1; /* counter-clockwise */ - break; - - default: - /* - * Ignore all other values. This covers the case when the - * state didn't change (a spurious interrupt) and the - * cases where the state changed by two steps, making it - * impossible to tell the direction. - * - * In either case, don't report any event and save the - * state for later. - */ + if ((encoder->last_stable + 1) % 4 == state) + encoder->dir = 1; + else if (encoder->last_stable == (state + 1) % 4) + encoder->dir = -1; + else goto out; - } rotary_encoder_report_event(encoder); @@ -212,6 +185,7 @@ static int rotary_encoder_probe(struct platform_device *pdev) struct input_dev *input; irq_handler_t handler; u32 steps_per_period; + unsigned int i; int err; encoder = devm_kzalloc(dev, sizeof(struct rotary_encoder), GFP_KERNEL); @@ -243,24 +217,16 @@ static int rotary_encoder_probe(struct platform_device *pdev) encoder->relative_axis = device_property_read_bool(dev, "rotary-encoder,relative-axis"); - encoder->gpio_a = devm_gpiod_get_index(dev, NULL, 0, GPIOD_IN); - if (IS_ERR(encoder->gpio_a)) { - err = PTR_ERR(encoder->gpio_a); - dev_err(dev, "unable to get GPIO at index 0: %d\n", err); - return err; + encoder->gpios = devm_gpiod_get_array(dev, NULL, GPIOD_IN); + if (IS_ERR(encoder->gpios)) { + dev_err(dev, "unable to get gpios\n"); + return PTR_ERR(encoder->gpios); } - - encoder->irq_a = gpiod_to_irq(encoder->gpio_a); - - encoder->gpio_b = devm_gpiod_get_index(dev, NULL, 1, GPIOD_IN); - if (IS_ERR(encoder->gpio_b)) { - err = PTR_ERR(encoder->gpio_b); - dev_err(dev, "unable to get GPIO at index 1: %d\n", err); - return err; + if (encoder->gpios->ndescs < 2) { + dev_err(dev, "not enough gpios found\n"); + return -EINVAL; } - encoder->irq_b = gpiod_to_irq(encoder->gpio_b); - input = devm_input_allocate_device(dev); if (!input) return -ENOMEM; @@ -277,7 +243,7 @@ static int rotary_encoder_probe(struct platform_device *pdev) input_set_abs_params(input, encoder->axis, 0, encoder->steps, 0, 1); - switch (steps_per_period) { + switch (steps_per_period >> (encoder->gpios->ndescs - 2)) { case 4: handler = &rotary_encoder_quarter_period_irq; encoder->last_stable = rotary_encoder_get_state(encoder); @@ -295,22 +261,26 @@ static int rotary_encoder_probe(struct platform_device *pdev) return -EINVAL; } - err = devm_request_threaded_irq(dev, encoder->irq_a, NULL, handler, - IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | - IRQF_ONESHOT, - DRV_NAME, encoder); - if (err) { - dev_err(dev, "unable to request IRQ %d\n", encoder->irq_a); - return err; - } + encoder->irq = + devm_kzalloc(dev, + sizeof(*encoder->irq) * encoder->gpios->ndescs, + GFP_KERNEL); + if (!encoder->irq) + return -ENOMEM; - err = devm_request_threaded_irq(dev, encoder->irq_b, NULL, handler, + for (i = 0; i < encoder->gpios->ndescs; ++i) { + encoder->irq[i] = gpiod_to_irq(encoder->gpios->desc[i]); + + err = devm_request_threaded_irq(dev, encoder->irq[i], + NULL, handler, IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT, DRV_NAME, encoder); - if (err) { - dev_err(dev, "unable to request IRQ %d\n", encoder->irq_b); - return err; + if (err) { + dev_err(dev, "unable to request IRQ %d (gpio#%d)\n", + encoder->irq[i], i); + return err; + } } err = input_register_device(input); @@ -330,10 +300,11 @@ static int rotary_encoder_probe(struct platform_device *pdev) static int __maybe_unused rotary_encoder_suspend(struct device *dev) { struct rotary_encoder *encoder = dev_get_drvdata(dev); + unsigned int i; if (device_may_wakeup(dev)) { - enable_irq_wake(encoder->irq_a); - enable_irq_wake(encoder->irq_b); + for (i = 0; i < encoder->gpios->ndescs; ++i) + enable_irq_wake(encoder->irq[i]); } return 0; @@ -342,10 +313,11 @@ static int __maybe_unused rotary_encoder_suspend(struct device *dev) static int __maybe_unused rotary_encoder_resume(struct device *dev) { struct rotary_encoder *encoder = dev_get_drvdata(dev); + unsigned int i; if (device_may_wakeup(dev)) { - disable_irq_wake(encoder->irq_a); - disable_irq_wake(encoder->irq_b); + for (i = 0; i < encoder->gpios->ndescs; ++i) + disable_irq_wake(encoder->irq[i]); } return 0; |