From 80c99bcd28617bd534b6f9489857235ee613c797 Mon Sep 17 00:00:00 2001 From: Daniel Mack Date: Tue, 31 Jul 2012 22:08:50 -0700 Subject: [PATCH] Input: rotary-encoder - add DT bindings This adds devicetree bindings to the rotary encoder driver and some documentation about how to use them. Tested on a PXA3xx platform. Signed-off-by: Daniel Mack Signed-off-by: Dmitry Torokhov --- .../devicetree/bindings/input/rotary-encoder.txt | 36 ++++++++ drivers/input/misc/rotary_encoder.c | 96 ++++++++++++++++++---- 2 files changed, 116 insertions(+), 16 deletions(-) create mode 100644 Documentation/devicetree/bindings/input/rotary-encoder.txt diff --git a/Documentation/devicetree/bindings/input/rotary-encoder.txt b/Documentation/devicetree/bindings/input/rotary-encoder.txt new file mode 100644 index 0000000..3315495 --- /dev/null +++ b/Documentation/devicetree/bindings/input/rotary-encoder.txt @@ -0,0 +1,36 @@ +Rotary encoder DT bindings + +Required properties: +- gpios: a spec for two GPIOs to be used + +Optional properties: +- linux,axis: the input subsystem axis to map to this rotary encoder. + Defaults to 0 (ABS_X / REL_X) +- rotary-encoder,steps: Number of steps in a full turnaround of the + encoder. Only relevant for absolute axis. Defaults to 24 which is a + typical value for such devices. +- rotary-encoder,relative-axis: register a relative axis rather than an + absolute one. Relative axis will only generate +1/-1 events on the input + device, hence no steps need to be passed. +- rotary-encoder,rollover: Automatic rollove when the rotary value becomes + greater than the specified steps or smaller than 0. For absolute axis only. +- rotary-encoder,half-period: Makes the driver work on half-period mode. + +See Documentation/input/rotary-encoder.txt for more information. + +Example: + + rotary@0 { + compatible = "rotary-encoder"; + gpios = <&gpio 19 1>, <&gpio 20 0>; /* GPIO19 is inverted */ + linux,axis = <0>; /* REL_X */ + rotary-encoder,relative-axis; + }; + + rotary@1 { + compatible = "rotary-encoder"; + gpios = <&gpio 21 0>, <&gpio 22 0>; + linux,axis = <1>; /* ABS_Y */ + rotary-encoder,steps = <24>; + rotary-encoder,rollover; + }; diff --git a/drivers/input/misc/rotary_encoder.c b/drivers/input/misc/rotary_encoder.c index ea51265..99a49e4 100644 --- a/drivers/input/misc/rotary_encoder.c +++ b/drivers/input/misc/rotary_encoder.c @@ -24,6 +24,8 @@ #include #include #include +#include +#include #define DRV_NAME "rotary-encoder" @@ -140,6 +142,56 @@ static irqreturn_t rotary_encoder_half_period_irq(int irq, void *dev_id) return IRQ_HANDLED; } +#ifdef CONFIG_OF +static struct of_device_id rotary_encoder_of_match[] = { + { .compatible = "rotary-encoder", }, + { }, +}; +MODULE_DEVICE_TABLE(of, rotary_encoder_of_match); + +static struct rotary_encoder_platform_data * __devinit +rotary_encoder_parse_dt(struct device *dev) +{ + const struct of_device_id *of_id = + of_match_device(rotary_encoder_of_match, dev); + struct device_node *np = dev->of_node; + struct rotary_encoder_platform_data *pdata; + enum of_gpio_flags flags; + + if (!of_id || !np) + return NULL; + + pdata = kzalloc(sizeof(struct rotary_encoder_platform_data), + GFP_KERNEL); + if (!pdata) + return ERR_PTR(-ENOMEM); + + of_property_read_u32(np, "rotary-encoder,steps", &pdata->steps); + of_property_read_u32(np, "linux,axis", &pdata->axis); + + pdata->gpio_a = of_get_gpio_flags(np, 0, &flags); + pdata->inverted_a = flags & OF_GPIO_ACTIVE_LOW; + + 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); + + return pdata; +} +#else +static inline struct rotary_encoder_platform_data * +rotary_encoder_parse_dt(struct device *dev) +{ + return NULL; +} +#endif + static int __devinit rotary_encoder_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; @@ -150,14 +202,19 @@ static int __devinit rotary_encoder_probe(struct platform_device *pdev) int err; if (!pdata) { - dev_err(&pdev->dev, "missing platform data\n"); - return -ENOENT; + pdata = rotary_encoder_parse_dt(dev); + if (IS_ERR(pdata)) + return PTR_ERR(pdata); + + if (!pdata) { + dev_err(dev, "missing platform data\n"); + return -EINVAL; + } } encoder = kzalloc(sizeof(struct rotary_encoder), GFP_KERNEL); input = input_allocate_device(); if (!encoder || !input) { - dev_err(&pdev->dev, "failed to allocate memory for device\n"); err = -ENOMEM; goto exit_free_mem; } @@ -165,10 +222,9 @@ static int __devinit rotary_encoder_probe(struct platform_device *pdev) encoder->input = input; encoder->pdata = pdata; - /* create and register the input driver */ input->name = pdev->name; input->id.bustype = BUS_HOST; - input->dev.parent = &pdev->dev; + input->dev.parent = dev; if (pdata->relative_axis) { input->evbit[0] = BIT_MASK(EV_REL); @@ -179,17 +235,11 @@ static int __devinit rotary_encoder_probe(struct platform_device *pdev) pdata->axis, 0, pdata->steps, 0, 1); } - err = input_register_device(input); - if (err) { - dev_err(dev, "failed to register input device\n"); - goto exit_free_mem; - } - /* request the GPIOs */ err = gpio_request_one(pdata->gpio_a, GPIOF_IN, dev_name(dev)); if (err) { dev_err(dev, "unable to request GPIO %d\n", pdata->gpio_a); - goto exit_unregister_input; + goto exit_free_mem; } err = gpio_request_one(pdata->gpio_b, GPIOF_IN, dev_name(dev)); @@ -225,22 +275,30 @@ static int __devinit rotary_encoder_probe(struct platform_device *pdev) goto exit_free_irq_a; } + err = input_register_device(input); + if (err) { + dev_err(dev, "failed to register input device\n"); + goto exit_free_irq_b; + } + platform_set_drvdata(pdev, encoder); return 0; +exit_free_irq_b: + free_irq(encoder->irq_b, encoder); exit_free_irq_a: free_irq(encoder->irq_a, encoder); exit_free_gpio_b: gpio_free(pdata->gpio_b); exit_free_gpio_a: gpio_free(pdata->gpio_a); -exit_unregister_input: - input_unregister_device(input); - input = NULL; /* so we don't try to free it */ exit_free_mem: input_free_device(input); kfree(encoder); + if (!dev_get_platdata(&pdev->dev)) + kfree(pdata); + return err; } @@ -253,10 +311,15 @@ static int __devexit rotary_encoder_remove(struct platform_device *pdev) free_irq(encoder->irq_b, encoder); gpio_free(pdata->gpio_a); gpio_free(pdata->gpio_b); + input_unregister_device(encoder->input); - platform_set_drvdata(pdev, NULL); kfree(encoder); + if (!dev_get_platdata(&pdev->dev)) + kfree(pdata); + + platform_set_drvdata(pdev, NULL); + return 0; } @@ -266,6 +329,7 @@ static struct platform_driver rotary_encoder_driver = { .driver = { .name = DRV_NAME, .owner = THIS_MODULE, + .of_match_table = of_match_ptr(rotary_encoder_of_match), } }; module_platform_driver(rotary_encoder_driver); -- 2.7.4