This adds devicetree bindings to the rotary encoder driver and some documentation about how to use them. Tested on a PXA3xx platform.
To allow kernel provided data to override DT values, and to avoid touching the pdev->platform_data, a copy of struct rotary_encoder_platform_data is now kept privately in struct rotary_encoder. Signed-off-by: Daniel Mack <[email protected]> --- .../devicetree/bindings/input/rotary-encoder.txt | 37 +++++++ drivers/input/misc/rotary_encoder.c | 101 ++++++++++++++++---- 2 files changed, 120 insertions(+), 18 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..dd1f634 --- /dev/null +++ b/Documentation/devicetree/bindings/input/rotary-encoder.txt @@ -0,0 +1,37 @@ +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 e261ad4..91c661d 100644 --- a/drivers/input/misc/rotary_encoder.c +++ b/drivers/input/misc/rotary_encoder.c @@ -24,12 +24,14 @@ #include <linux/gpio.h> #include <linux/rotary_encoder.h> #include <linux/slab.h> +#include <linux/of_platform.h> +#include <linux/of_gpio.h> #define DRV_NAME "rotary-encoder" struct rotary_encoder { struct input_dev *input; - struct rotary_encoder_platform_data *pdata; + struct rotary_encoder_platform_data pdata; unsigned int axis; unsigned int pos; @@ -56,7 +58,7 @@ static int rotary_encoder_get_state(struct rotary_encoder_platform_data *pdata) static void rotary_encoder_report_event(struct rotary_encoder *encoder) { - struct rotary_encoder_platform_data *pdata = encoder->pdata; + struct rotary_encoder_platform_data *pdata = &encoder->pdata; if (pdata->relative_axis) { input_report_rel(encoder->input, @@ -91,7 +93,7 @@ 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); + state = rotary_encoder_get_state(&encoder->pdata); switch (state) { case 0x0: @@ -120,7 +122,7 @@ 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); + state = rotary_encoder_get_state(&encoder->pdata); switch (state) { case 0x00: @@ -140,35 +142,96 @@ 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 int rotary_encoder_probe_dt(struct platform_device *pdev, + struct rotary_encoder *encoder) +{ + int tmp; + enum of_gpio_flags flags; + struct rotary_encoder_platform_data *pdata = &encoder->pdata; + struct device_node *np = pdev->dev.of_node; + const struct of_device_id *of_id = + of_match_device(rotary_encoder_of_match, &pdev->dev); + + if (!of_id) + return 0; + + if (of_property_read_u32(np, "rotary-encoder,steps", &tmp) == 0) + pdata->steps = tmp; + if (of_property_read_u32(np, "linux,axis", &tmp) == 0) + pdata->axis = tmp; + + 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; + + if (of_get_property(np, "rotary-encoder,relative-axis", NULL)) + pdata->relative_axis = 1; + if (of_get_property(np, "rotary-encoder,rollover", NULL)) + pdata->rollover = 1; + if (of_get_property(np, "rotary-encoder,half-period", NULL)) + pdata->half_period = 1; + + return 1; +} +#else +static inline int rotary_encoder_probe_dt(struct platform_device *) +{ + return 0; +} +#endif + static int __devinit rotary_encoder_probe(struct platform_device *pdev) { - struct rotary_encoder_platform_data *pdata = pdev->dev.platform_data; + struct rotary_encoder_platform_data *pdata; struct rotary_encoder *encoder; struct input_dev *input; struct device *dev = &pdev->dev; irq_handler_t handler; + bool use_of = 0; int err; - if (!pdata) { + encoder = kzalloc(sizeof(struct rotary_encoder), GFP_KERNEL); + if (!encoder) + return -ENOMEM; + + err = rotary_encoder_probe_dt(pdev, encoder); + if (err < 0) + return err; + if (err > 0) + use_of = 1; + + if (!&pdev->dev.platform_data && !use_of) { dev_err(&pdev->dev, "missing platform data\n"); return -ENOENT; } - encoder = kzalloc(sizeof(struct rotary_encoder), GFP_KERNEL); + pdata = &encoder->pdata; + + /* if kernel data was provided, copy it over to our local copy */ + if (pdev->dev.platform_data) + memcpy(pdata, &pdev->dev.platform_data, sizeof(*pdata)); + + /* create and register the input driver */ input = input_allocate_device(); - if (!encoder || !input) { - dev_err(&pdev->dev, "failed to allocate memory for device\n"); + if (!input) { + dev_err(&pdev->dev, "failed to allocate input device\n"); err = -ENOMEM; - goto exit_free_mem; + goto exit_free_encoder; } - 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; + encoder->input = input; if (pdata->relative_axis) { input->evbit[0] = BIT_MASK(EV_REL); @@ -182,7 +245,7 @@ static int __devinit rotary_encoder_probe(struct platform_device *pdev) err = input_register_device(input); if (err) { dev_err(dev, "failed to register input device\n"); - goto exit_free_mem; + goto exit_free_input; } /* request the GPIOs */ @@ -238,8 +301,9 @@ exit_free_gpio_a: exit_unregister_input: input_unregister_device(input); input = NULL; /* so we don't try to free it */ -exit_free_mem: +exit_free_input: input_free_device(input); +exit_free_encoder: kfree(encoder); return err; } @@ -247,7 +311,7 @@ exit_free_mem: static int __devexit rotary_encoder_remove(struct platform_device *pdev) { struct rotary_encoder *encoder = platform_get_drvdata(pdev); - struct rotary_encoder_platform_data *pdata = pdev->dev.platform_data; + struct rotary_encoder_platform_data *pdata = &encoder->pdata; free_irq(encoder->irq_a, encoder); free_irq(encoder->irq_b, encoder); @@ -266,6 +330,7 @@ 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); -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
