[mirror_ubuntu-zesty-kernel.git] / drivers / input / misc / rotary_encoder.c

/*
 * 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
 *
 * A generic driver for rotary encoders connected to GPIO lines.
 * See file:Documentation/input/rotary-encoder.txt for more information
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/input.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/gpio.h>
#include <linux/rotary_encoder.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/of_gpio.h>
#include <linux/pm.h>

#define DRV_NAME "rotary-encoder"

struct rotary_encoder {
	struct input_dev *input;
	const struct rotary_encoder_platform_data *pdata;

	unsigned int axis;
	unsigned int pos;

	unsigned int irq_a;
	unsigned int irq_b;

	bool armed;
	unsigned char dir;	/* 0 - clockwise, 1 - CCW */

	char last_stable;
};

static int rotary_encoder_get_state(const struct rotary_encoder_platform_data *pdata)
{
	int a = !!gpio_get_value(pdata->gpio_a);
	int b = !!gpio_get_value(pdata->gpio_b);

	a ^= pdata->inverted_a;
	b ^= pdata->inverted_b;

	return ((a << 1) | b);
}

static void rotary_encoder_report_event(struct rotary_encoder *encoder)
{
	const 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->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:
	case 0x2:
		if (encoder->armed)
			encoder->dir = state - 1;
		break;

	case 0x3:
		encoder->armed = true;
		break;
	}

	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 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", },
	{ },
};
MODULE_DEVICE_TABLE(of, rotary_encoder_of_match);

static struct rotary_encoder_platform_data *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;
	int error;

	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_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;
}
#else
static inline struct rotary_encoder_platform_data *
rotary_encoder_parse_dt(struct device *dev)
{
	return NULL;
}
#endif

static int rotary_encoder_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	const struct rotary_encoder_platform_data *pdata = dev_get_platdata(dev);
	struct rotary_encoder *encoder;
	struct input_dev *input;
	irq_handler_t handler;
	int err;

	if (!pdata) {
		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) {
		err = -ENOMEM;
		goto exit_free_mem;
	}

	encoder->input = input;
	encoder->pdata = pdata;

	input->name = pdev->name;
	input->id.bustype = BUS_HOST;
	input->dev.parent = dev;

	if (pdata->relative_axis) {
		input->evbit[0] = BIT_MASK(EV_REL);
		input->relbit[0] = BIT_MASK(pdata->axis);
	} else {
		input->evbit[0] = BIT_MASK(EV_ABS);
		input_set_abs_params(encoder->input,
				     pdata->axis, 0, pdata->steps, 0, 1);
	}

	/* 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_free_mem;
	}

	err = gpio_request_one(pdata->gpio_b, GPIOF_IN, dev_name(dev));
	if (err) {
		dev_err(dev, "unable to request GPIO %d\n", pdata->gpio_b);
		goto exit_free_gpio_a;
	}

	encoder->irq_a = gpio_to_irq(pdata->gpio_a);
	encoder->irq_b = gpio_to_irq(pdata->gpio_b);

	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);
		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,
			  IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
			  DRV_NAME, encoder);
	if (err) {
		dev_err(dev, "unable to request IRQ %d\n", encoder->irq_a);
		goto exit_free_gpio_b;
	}

	err = request_irq(encoder->irq_b, handler,
			  IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
			  DRV_NAME, encoder);
	if (err) {
		dev_err(dev, "unable to request IRQ %d\n", encoder->irq_b);
		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;
	}

	device_init_wakeup(&pdev->dev, pdata->wakeup_source);

	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_free_mem:
	input_free_device(input);
	kfree(encoder);
	if (!dev_get_platdata(&pdev->dev))
		kfree(pdata);

	return err;
}

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);
	gpio_free(pdata->gpio_b);

	input_unregister_device(encoder->input);
	kfree(encoder);

	if (!dev_get_platdata(&pdev->dev))
		kfree(pdata);

	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),
	}
};
module_platform_driver(rotary_encoder_driver);

MODULE_ALIAS("platform:" DRV_NAME);
MODULE_DESCRIPTION("GPIO rotary encoder driver");
MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>, Johan Hovold");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
73969ff0 DM	1	/*
	2	* rotary_encoder.c
	3	*
	4	* (c) 2009 Daniel Mack <daniel@caiaq.de>
e70bdd41	5	* Copyright (C) 2011 Johan Hovold <jhovold@gmail.com>
73969ff0 DM	6	*
	7	* state machine code inspired by code from Tim Ruetz
	8	*
	9	* A generic driver for rotary encoders connected to GPIO lines.
395cf969	10	* See file:Documentation/input/rotary-encoder.txt for more information
73969ff0 DM	11	*
	12	* This program is free software; you can redistribute it and/or modify
	13	* it under the terms of the GNU General Public License version 2 as
	14	* published by the Free Software Foundation.
	15	*/
	16
	17	#include <linux/kernel.h>
	18	#include <linux/module.h>
73969ff0 DM	19	#include <linux/interrupt.h>
	20	#include <linux/input.h>
	21	#include <linux/device.h>
	22	#include <linux/platform_device.h>
	23	#include <linux/gpio.h>
	24	#include <linux/rotary_encoder.h>
5a0e3ad6	25	#include <linux/slab.h>
2e45e539	26	#include <linux/of.h>
80c99bcd DM	27	#include <linux/of_platform.h>
80c99bcd DM	28	#include <linux/of_gpio.h>
47ec6e5a	29	#include <linux/pm.h>
73969ff0 DM	30
	31	#define DRV_NAME "rotary-encoder"
	32
	33	struct rotary_encoder {
73969ff0	34	struct input_dev *input;
ce919537	35	const struct rotary_encoder_platform_data *pdata;
bd3ce655 HS	36
	37	unsigned int axis;
	38	unsigned int pos;
	39
	40	unsigned int irq_a;
	41	unsigned int irq_b;
	42
	43	bool armed;
	44	unsigned char dir; /* 0 - clockwise, 1 - CCW */
e70bdd41 JH	45
e70bdd41 JH	46	char last_stable;
73969ff0 DM	47	};
73969ff0 DM	48
ce919537	49	static int rotary_encoder_get_state(const struct rotary_encoder_platform_data *pdata)
73969ff0	50	{
73969ff0 DM	51	int a = !!gpio_get_value(pdata->gpio_a);
73969ff0 DM	52	int b = !!gpio_get_value(pdata->gpio_b);
73969ff0 DM	53
	54	a ^= pdata->inverted_a;
	55	b ^= pdata->inverted_b;
73969ff0	56
521a8f5c JH	57	return ((a << 1) \| b);
521a8f5c JH	58	}
73969ff0	59
521a8f5c JH	60	static void rotary_encoder_report_event(struct rotary_encoder *encoder)
521a8f5c JH	61	{
ce919537	62	const struct rotary_encoder_platform_data *pdata = encoder->pdata;
73969ff0	63
521a8f5c JH	64	if (pdata->relative_axis) {
	65	input_report_rel(encoder->input,
	66	pdata->axis, encoder->dir ? -1 : 1);
	67	} else {
	68	unsigned int pos = encoder->pos;
	69
	70	if (encoder->dir) {
	71	/* turning counter-clockwise */
bd3ce655	72	if (pdata->rollover)
521a8f5c JH	73	pos += pdata->steps;
	74	if (pos)
	75	pos--;
	76	} else {
	77	/* turning clockwise */
	78	if (pdata->rollover \|\| pos < pdata->steps)
	79	pos++;
73969ff0	80	}
73969ff0	81
521a8f5c JH	82	if (pdata->rollover)
	83	pos %= pdata->steps;
	84
	85	encoder->pos = pos;
	86	input_report_abs(encoder->input, pdata->axis, encoder->pos);
	87	}
	88
	89	input_sync(encoder->input);
	90	}
	91
	92	static irqreturn_t rotary_encoder_irq(int irq, void *dev_id)
	93	{
	94	struct rotary_encoder *encoder = dev_id;
	95	int state;
	96
	97	state = rotary_encoder_get_state(encoder->pdata);
	98
	99	switch (state) {
	100	case 0x0:
	101	if (encoder->armed) {
	102	rotary_encoder_report_event(encoder);
	103	encoder->armed = false;
	104	}
73969ff0 DM	105	break;
	106
	107	case 0x1:
	108	case 0x2:
	109	if (encoder->armed)
	110	encoder->dir = state - 1;
	111	break;
	112
	113	case 0x3:
bd3ce655	114	encoder->armed = true;
73969ff0 DM	115	break;
	116	}
	117
	118	return IRQ_HANDLED;
	119	}
	120
e70bdd41 JH	121	static irqreturn_t rotary_encoder_half_period_irq(int irq, void *dev_id)
	122	{
	123	struct rotary_encoder *encoder = dev_id;
	124	int state;
	125
	126	state = rotary_encoder_get_state(encoder->pdata);
	127
	128	switch (state) {
	129	case 0x00:
	130	case 0x03:
	131	if (state != encoder->last_stable) {
	132	rotary_encoder_report_event(encoder);
	133	encoder->last_stable = state;
	134	}
	135	break;
	136
	137	case 0x01:
	138	case 0x02:
	139	encoder->dir = (encoder->last_stable + state) & 0x01;
	140	break;
	141	}
	142
	143	return IRQ_HANDLED;
	144	}
	145
3a341a4c EG	146	static irqreturn_t rotary_encoder_quarter_period_irq(int irq, void *dev_id)
	147	{
	148	struct rotary_encoder *encoder = dev_id;
	149	unsigned char sum;
	150	int state;
	151
	152	state = rotary_encoder_get_state(encoder->pdata);
	153
	154	/*
	155	* We encode the previous and the current state using a byte.
	156	* The previous state in the MSB nibble, the current state in the LSB
	157	* nibble. Then use a table to decide the direction of the turn.
	158	*/
	159	sum = (encoder->last_stable << 4) + state;
	160	switch (sum) {
	161	case 0x31:
	162	case 0x10:
	163	case 0x02:
	164	case 0x23:
	165	encoder->dir = 0; /* clockwise */
	166	break;
	167
	168	case 0x13:
	169	case 0x01:
	170	case 0x20:
	171	case 0x32:
	172	encoder->dir = 1; /* counter-clockwise */
	173	break;
	174
	175	default:
	176	/*
	177	* Ignore all other values. This covers the case when the
	178	* state didn't change (a spurious interrupt) and the
	179	* cases where the state changed by two steps, making it
	180	* impossible to tell the direction.
	181	*
	182	* In either case, don't report any event and save the
	183	* state for later.
	184	*/
	185	goto out;
	186	}
	187
	188	rotary_encoder_report_event(encoder);
	189
	190	out:
	191	encoder->last_stable = state;
	192	return IRQ_HANDLED;
	193	}
	194
80c99bcd	195	#ifdef CONFIG_OF
5f155ee1	196	static const struct of_device_id rotary_encoder_of_match[] = {
80c99bcd DM	197	{ .compatible = "rotary-encoder", },
	198	{ },
	199	};
	200	MODULE_DEVICE_TABLE(of, rotary_encoder_of_match);
	201
5298cc4c	202	static struct rotary_encoder_platform_data rotary_encoder_parse_dt(struct device dev)
80c99bcd DM	203	{
	204	const struct of_device_id *of_id =
	205	of_match_device(rotary_encoder_of_match, dev);
	206	struct device_node *np = dev->of_node;
	207	struct rotary_encoder_platform_data *pdata;
	208	enum of_gpio_flags flags;
3a341a4c	209	int error;
80c99bcd DM	210
	211	if (!of_id \|\| !np)
	212	return NULL;
	213
	214	pdata = kzalloc(sizeof(struct rotary_encoder_platform_data),
	215	GFP_KERNEL);
	216	if (!pdata)
	217	return ERR_PTR(-ENOMEM);
	218
	219	of_property_read_u32(np, "rotary-encoder,steps", &pdata->steps);
	220	of_property_read_u32(np, "linux,axis", &pdata->axis);
	221
	222	pdata->gpio_a = of_get_gpio_flags(np, 0, &flags);
	223	pdata->inverted_a = flags & OF_GPIO_ACTIVE_LOW;
	224
	225	pdata->gpio_b = of_get_gpio_flags(np, 1, &flags);
	226	pdata->inverted_b = flags & OF_GPIO_ACTIVE_LOW;
	227
648b15cb BG	228	pdata->relative_axis =
	229	of_property_read_bool(np, "rotary-encoder,relative-axis");
	230	pdata->rollover = of_property_read_bool(np, "rotary-encoder,rollover");
3a341a4c EG	231
	232	error = of_property_read_u32(np, "rotary-encoder,steps-per-period",
	233	&pdata->steps_per_period);
	234	if (error) {
	235	/*
	236	* The 'half-period' property has been deprecated, you must use
	237	* 'steps-per-period' and set an appropriate value, but we still
	238	* need to parse it to maintain compatibility.
	239	*/
	240	if (of_property_read_bool(np, "rotary-encoder,half-period")) {
	241	pdata->steps_per_period = 2;
	242	} else {
	243	/* Fallback to one step per period behavior */
	244	pdata->steps_per_period = 1;
	245	}
	246	}
	247
648b15cb	248	pdata->wakeup_source = of_property_read_bool(np, "wakeup-source");
80c99bcd DM	249
	250	return pdata;
	251	}
	252	#else
	253	static inline struct rotary_encoder_platform_data *
	254	rotary_encoder_parse_dt(struct device *dev)
	255	{
	256	return NULL;
	257	}
	258	#endif
	259
5298cc4c	260	static int rotary_encoder_probe(struct platform_device *pdev)
73969ff0	261	{
ce919537 DT	262	struct device *dev = &pdev->dev;
ce919537 DT	263	const struct rotary_encoder_platform_data *pdata = dev_get_platdata(dev);
73969ff0 DM	264	struct rotary_encoder *encoder;
73969ff0 DM	265	struct input_dev *input;
e70bdd41	266	irq_handler_t handler;
73969ff0 DM	267	int err;
73969ff0 DM	268
06ee3d3c	269	if (!pdata) {
80c99bcd DM	270	pdata = rotary_encoder_parse_dt(dev);
	271	if (IS_ERR(pdata))
	272	return PTR_ERR(pdata);
	273
	274	if (!pdata) {
	275	dev_err(dev, "missing platform data\n");
	276	return -EINVAL;
	277	}
73969ff0 DM	278	}
	279
	280	encoder = kzalloc(sizeof(struct rotary_encoder), GFP_KERNEL);
	281	input = input_allocate_device();
	282	if (!encoder \|\| !input) {
73969ff0 DM	283	err = -ENOMEM;
	284	goto exit_free_mem;
	285	}
	286
	287	encoder->input = input;
	288	encoder->pdata = pdata;
73969ff0	289
73969ff0 DM	290	input->name = pdev->name;
73969ff0 DM	291	input->id.bustype = BUS_HOST;
80c99bcd	292	input->dev.parent = dev;
bd3ce655 HS	293
	294	if (pdata->relative_axis) {
	295	input->evbit[0] = BIT_MASK(EV_REL);
	296	input->relbit[0] = BIT_MASK(pdata->axis);
	297	} else {
	298	input->evbit[0] = BIT_MASK(EV_ABS);
	299	input_set_abs_params(encoder->input,
	300	pdata->axis, 0, pdata->steps, 0, 1);
	301	}
73969ff0	302
73969ff0	303	/* request the GPIOs */
429a34d7	304	err = gpio_request_one(pdata->gpio_a, GPIOF_IN, dev_name(dev));
73969ff0	305	if (err) {
429a34d7	306	dev_err(dev, "unable to request GPIO %d\n", pdata->gpio_a);
80c99bcd	307	goto exit_free_mem;
73969ff0 DM	308	}
73969ff0 DM	309
429a34d7	310	err = gpio_request_one(pdata->gpio_b, GPIOF_IN, dev_name(dev));
5deeac99	311	if (err) {
429a34d7	312	dev_err(dev, "unable to request GPIO %d\n", pdata->gpio_b);
5deeac99 AC	313	goto exit_free_gpio_a;
	314	}
	315
a78769b8 DM	316	encoder->irq_a = gpio_to_irq(pdata->gpio_a);
	317	encoder->irq_b = gpio_to_irq(pdata->gpio_b);
	318
3a341a4c EG	319	switch (pdata->steps_per_period) {
	320	case 4:
	321	handler = &rotary_encoder_quarter_period_irq;
	322	encoder->last_stable = rotary_encoder_get_state(pdata);
	323	break;
	324	case 2:
e70bdd41 JH	325	handler = &rotary_encoder_half_period_irq;
e70bdd41 JH	326	encoder->last_stable = rotary_encoder_get_state(pdata);
3a341a4c EG	327	break;
3a341a4c EG	328	case 1:
e70bdd41	329	handler = &rotary_encoder_irq;
3a341a4c EG	330	break;
	331	default:
	332	dev_err(dev, "'%d' is not a valid steps-per-period value\n",
	333	pdata->steps_per_period);
	334	err = -EINVAL;
	335	goto exit_free_gpio_b;
e70bdd41 JH	336	}
	337
	338	err = request_irq(encoder->irq_a, handler,
e0d5f4c3	339	IRQF_TRIGGER_RISING \| IRQF_TRIGGER_FALLING,
73969ff0 DM	340	DRV_NAME, encoder);
73969ff0 DM	341	if (err) {
429a34d7	342	dev_err(dev, "unable to request IRQ %d\n", encoder->irq_a);
73969ff0 DM	343	goto exit_free_gpio_b;
	344	}
	345
e70bdd41	346	err = request_irq(encoder->irq_b, handler,
e0d5f4c3	347	IRQF_TRIGGER_RISING \| IRQF_TRIGGER_FALLING,
73969ff0 DM	348	DRV_NAME, encoder);
73969ff0 DM	349	if (err) {
429a34d7	350	dev_err(dev, "unable to request IRQ %d\n", encoder->irq_b);
73969ff0 DM	351	goto exit_free_irq_a;
	352	}
	353
80c99bcd DM	354	err = input_register_device(input);
	355	if (err) {
	356	dev_err(dev, "failed to register input device\n");
	357	goto exit_free_irq_b;
	358	}
	359
47ec6e5a SR	360	device_init_wakeup(&pdev->dev, pdata->wakeup_source);
47ec6e5a SR	361
73969ff0 DM	362	platform_set_drvdata(pdev, encoder);
	363
	364	return 0;
	365
80c99bcd DM	366	exit_free_irq_b:
80c99bcd DM	367	free_irq(encoder->irq_b, encoder);
73969ff0 DM	368	exit_free_irq_a:
	369	free_irq(encoder->irq_a, encoder);
	370	exit_free_gpio_b:
	371	gpio_free(pdata->gpio_b);
	372	exit_free_gpio_a:
	373	gpio_free(pdata->gpio_a);
73969ff0 DM	374	exit_free_mem:
	375	input_free_device(input);
	376	kfree(encoder);
80c99bcd DM	377	if (!dev_get_platdata(&pdev->dev))
	378	kfree(pdata);
	379
73969ff0 DM	380	return err;
	381	}
	382
e2619cf7	383	static int rotary_encoder_remove(struct platform_device *pdev)
73969ff0 DM	384	{
73969ff0 DM	385	struct rotary_encoder *encoder = platform_get_drvdata(pdev);
ce919537	386	const struct rotary_encoder_platform_data *pdata = encoder->pdata;
73969ff0	387
47ec6e5a SR	388	device_init_wakeup(&pdev->dev, false);
47ec6e5a SR	389
73969ff0 DM	390	free_irq(encoder->irq_a, encoder);
	391	free_irq(encoder->irq_b, encoder);
	392	gpio_free(pdata->gpio_a);
	393	gpio_free(pdata->gpio_b);
80c99bcd	394
73969ff0	395	input_unregister_device(encoder->input);
73969ff0 DM	396	kfree(encoder);
73969ff0 DM	397
80c99bcd DM	398	if (!dev_get_platdata(&pdev->dev))
	399	kfree(pdata);
	400
73969ff0 DM	401	return 0;
	402	}
	403
47ec6e5a SR	404	#ifdef CONFIG_PM_SLEEP
	405	static int rotary_encoder_suspend(struct device *dev)
	406	{
	407	struct rotary_encoder *encoder = dev_get_drvdata(dev);
	408
	409	if (device_may_wakeup(dev)) {
	410	enable_irq_wake(encoder->irq_a);
	411	enable_irq_wake(encoder->irq_b);
	412	}
	413
	414	return 0;
	415	}
	416
	417	static int rotary_encoder_resume(struct device *dev)
	418	{
	419	struct rotary_encoder *encoder = dev_get_drvdata(dev);
	420
	421	if (device_may_wakeup(dev)) {
	422	disable_irq_wake(encoder->irq_a);
	423	disable_irq_wake(encoder->irq_b);
	424	}
	425
	426	return 0;
	427	}
	428	#endif
	429
	430	static SIMPLE_DEV_PM_OPS(rotary_encoder_pm_ops,
	431	rotary_encoder_suspend, rotary_encoder_resume);
	432
73969ff0 DM	433	static struct platform_driver rotary_encoder_driver = {
73969ff0 DM	434	.probe = rotary_encoder_probe,
1cb0aa88	435	.remove = rotary_encoder_remove,
73969ff0 DM	436	.driver = {
73969ff0 DM	437	.name = DRV_NAME,
47ec6e5a	438	.pm = &rotary_encoder_pm_ops,
80c99bcd	439	.of_match_table = of_match_ptr(rotary_encoder_of_match),
73969ff0 DM	440	}
73969ff0 DM	441	};
840a746b	442	module_platform_driver(rotary_encoder_driver);
73969ff0 DM	443
	444	MODULE_ALIAS("platform:" DRV_NAME);
	445	MODULE_DESCRIPTION("GPIO rotary encoder driver");
e70bdd41	446	MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>, Johan Hovold");
73969ff0	447	MODULE_LICENSE("GPL v2");