diff options
Diffstat (limited to 'drivers/input/misc/rotary_encoder.c')
| -rw-r--r-- | drivers/input/misc/rotary_encoder.c | 129 |
1 files changed, 120 insertions, 9 deletions
diff --git a/drivers/input/misc/rotary_encoder.c b/drivers/input/misc/rotary_encoder.c index f27f81ee84ed..8aee71986430 100644 --- a/drivers/input/misc/rotary_encoder.c +++ b/drivers/input/misc/rotary_encoder.c @@ -26,6 +26,7 @@ #include <linux/of.h> #include <linux/of_platform.h> #include <linux/of_gpio.h> +#include <linux/pm.h> #define DRV_NAME "rotary-encoder" @@ -142,6 +143,55 @@ static irqreturn_t rotary_encoder_half_period_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; + unsigned char sum; + int state; + + 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; + + 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. + */ + goto out; + } + + rotary_encoder_report_event(encoder); + +out: + encoder->last_stable = state; + return IRQ_HANDLED; +} + #ifdef CONFIG_OF static const struct of_device_id rotary_encoder_of_match[] = { { .compatible = "rotary-encoder", }, @@ -156,6 +206,7 @@ static struct rotary_encoder_platform_data *rotary_encoder_parse_dt(struct devic struct device_node *np = dev->of_node; struct rotary_encoder_platform_data *pdata; enum of_gpio_flags flags; + int error; if (!of_id || !np) return NULL; @@ -174,12 +225,27 @@ static struct rotary_encoder_platform_data *rotary_encoder_parse_dt(struct devic pdata->gpio_b = of_get_gpio_flags(np, 1, &flags); pdata->inverted_b = flags & OF_GPIO_ACTIVE_LOW; - pdata->relative_axis = !!of_get_property(np, - "rotary-encoder,relative-axis", NULL); - pdata->rollover = !!of_get_property(np, - "rotary-encoder,rollover", NULL); - pdata->half_period = !!of_get_property(np, - "rotary-encoder,half-period", NULL); + pdata->relative_axis = + of_property_read_bool(np, "rotary-encoder,relative-axis"); + pdata->rollover = of_property_read_bool(np, "rotary-encoder,rollover"); + + error = of_property_read_u32(np, "rotary-encoder,steps-per-period", + &pdata->steps_per_period); + if (error) { + /* + * The 'half-period' property has been deprecated, you must use + * 'steps-per-period' and set an appropriate value, but we still + * need to parse it to maintain compatibility. + */ + if (of_property_read_bool(np, "rotary-encoder,half-period")) { + pdata->steps_per_period = 2; + } else { + /* Fallback to one step per period behavior */ + pdata->steps_per_period = 1; + } + } + + pdata->wakeup_source = of_property_read_bool(np, "wakeup-source"); return pdata; } @@ -250,12 +316,23 @@ static int rotary_encoder_probe(struct platform_device *pdev) encoder->irq_a = gpio_to_irq(pdata->gpio_a); encoder->irq_b = gpio_to_irq(pdata->gpio_b); - /* request the IRQs */ - if (pdata->half_period) { + switch (pdata->steps_per_period) { + case 4: + handler = &rotary_encoder_quarter_period_irq; + encoder->last_stable = rotary_encoder_get_state(pdata); + break; + case 2: handler = &rotary_encoder_half_period_irq; encoder->last_stable = rotary_encoder_get_state(pdata); - } else { + break; + case 1: handler = &rotary_encoder_irq; + break; + default: + dev_err(dev, "'%d' is not a valid steps-per-period value\n", + pdata->steps_per_period); + err = -EINVAL; + goto exit_free_gpio_b; } err = request_irq(encoder->irq_a, handler, @@ -280,6 +357,8 @@ static int rotary_encoder_probe(struct platform_device *pdev) goto exit_free_irq_b; } + device_init_wakeup(&pdev->dev, pdata->wakeup_source); + platform_set_drvdata(pdev, encoder); return 0; @@ -306,6 +385,8 @@ static int rotary_encoder_remove(struct platform_device *pdev) struct rotary_encoder *encoder = platform_get_drvdata(pdev); const struct rotary_encoder_platform_data *pdata = encoder->pdata; + device_init_wakeup(&pdev->dev, false); + free_irq(encoder->irq_a, encoder); free_irq(encoder->irq_b, encoder); gpio_free(pdata->gpio_a); @@ -320,11 +401,41 @@ static int rotary_encoder_remove(struct platform_device *pdev) return 0; } +#ifdef CONFIG_PM_SLEEP +static int rotary_encoder_suspend(struct device *dev) +{ + struct rotary_encoder *encoder = dev_get_drvdata(dev); + + if (device_may_wakeup(dev)) { + enable_irq_wake(encoder->irq_a); + enable_irq_wake(encoder->irq_b); + } + + return 0; +} + +static int rotary_encoder_resume(struct device *dev) +{ + struct rotary_encoder *encoder = dev_get_drvdata(dev); + + if (device_may_wakeup(dev)) { + disable_irq_wake(encoder->irq_a); + disable_irq_wake(encoder->irq_b); + } + + return 0; +} +#endif + +static SIMPLE_DEV_PM_OPS(rotary_encoder_pm_ops, + rotary_encoder_suspend, rotary_encoder_resume); + static struct platform_driver rotary_encoder_driver = { .probe = rotary_encoder_probe, .remove = rotary_encoder_remove, .driver = { .name = DRV_NAME, + .pm = &rotary_encoder_pm_ops, .of_match_table = of_match_ptr(rotary_encoder_of_match), } }; |