1/*
  2 * ON pin driver for Dialog DA9052 PMICs
  3 *
  4 * Copyright(c) 2012 Dialog Semiconductor Ltd.
  5 *
  6 * Author: David Dajun Chen <dchen@diasemi.com>
  7 *
  8 * This program is free software; you can redistribute  it and/or modify it
  9 * under  the terms of  the GNU General  Public License as published by the
 10 * Free Software Foundation;  either version 2 of the  License, or (at your
 11 * option) any later version.
 12 */
 13
 14#include <linux/init.h>
 15#include <linux/input.h>
 16#include <linux/module.h>
 17#include <linux/platform_device.h>
 18#include <linux/workqueue.h>
 19
 20#include <linux/mfd/da9052/da9052.h>
 21#include <linux/mfd/da9052/reg.h>
 22
 23struct da9052_onkey {
 24	struct da9052 *da9052;
 25	struct input_dev *input;
 26	struct delayed_work work;
 27	unsigned int irq;
 28};
 29
 30static void da9052_onkey_query(struct da9052_onkey *onkey)
 31{
 32	int key_stat;
 33
 34	key_stat = da9052_reg_read(onkey->da9052, DA9052_EVENT_B_REG);
 35	if (key_stat < 0) {
 36		dev_err(onkey->da9052->dev,
 37			"Failed to read onkey event %d\n", key_stat);
 38	} else {
 39		/*
 40		 * Since interrupt for deassertion of ONKEY pin is not
 41		 * generated, onkey event state determines the onkey
 42		 * button state.
 43		 */
 44		key_stat &= DA9052_EVENTB_ENONKEY;
 45		input_report_key(onkey->input, KEY_POWER, key_stat);
 46		input_sync(onkey->input);
 47	}
 48
 49	/*
 50	 * Interrupt is generated only when the ONKEY pin is asserted.
 51	 * Hence the deassertion of the pin is simulated through work queue.
 52	 */
 53	if (key_stat)
 54		schedule_delayed_work(&onkey->work, msecs_to_jiffies(50));
 55}
 56
 57static void da9052_onkey_work(struct work_struct *work)
 58{
 59	struct da9052_onkey *onkey = container_of(work, struct da9052_onkey,
 60						  work.work);
 61
 62	da9052_onkey_query(onkey);
 63}
 64
 65static irqreturn_t da9052_onkey_irq(int irq, void *data)
 66{
 67	struct da9052_onkey *onkey = data;
 68
 69	da9052_onkey_query(onkey);
 70
 71	return IRQ_HANDLED;
 72}
 73
 74static int __devinit da9052_onkey_probe(struct platform_device *pdev)
 75{
 76	struct da9052 *da9052 = dev_get_drvdata(pdev->dev.parent);
 77	struct da9052_onkey *onkey;
 78	struct input_dev *input_dev;
 79	int irq;
 80	int error;
 81
 82	if (!da9052) {
 83		dev_err(&pdev->dev, "Failed to get the driver's data\n");
 84		return -EINVAL;
 85	}
 86
 87	irq = platform_get_irq_byname(pdev, "ONKEY");
 88	if (irq < 0) {
 89		dev_err(&pdev->dev,
 90			"Failed to get an IRQ for input device, %d\n", irq);
 91		return -EINVAL;
 92	}
 93
 94	onkey = kzalloc(sizeof(*onkey), GFP_KERNEL);
 95	input_dev = input_allocate_device();
 96	if (!onkey || !input_dev) {
 97		dev_err(&pdev->dev, "Failed to allocate memory\n");
 98		error = -ENOMEM;
 99		goto err_free_mem;
100	}
101
102	onkey->input = input_dev;
103	onkey->da9052 = da9052;
104	onkey->irq = irq;
105	INIT_DELAYED_WORK(&onkey->work, da9052_onkey_work);
106
107	input_dev->name = "da9052-onkey";
108	input_dev->phys = "da9052-onkey/input0";
109	input_dev->dev.parent = &pdev->dev;
110
111	input_dev->evbit[0] = BIT_MASK(EV_KEY);
112	__set_bit(KEY_POWER, input_dev->keybit);
113
114	error = request_threaded_irq(onkey->irq, NULL, da9052_onkey_irq,
115				     IRQF_TRIGGER_LOW | IRQF_ONESHOT,
116				     "ONKEY", onkey);
117	if (error < 0) {
118		dev_err(onkey->da9052->dev,
119			"Failed to register ONKEY IRQ %d, error = %d\n",
120			onkey->irq, error);
121		goto err_free_mem;
122	}
123
124	error = input_register_device(onkey->input);
125	if (error) {
126		dev_err(&pdev->dev, "Unable to register input device, %d\n",
127			error);
128		goto err_free_irq;
129	}
130
131	platform_set_drvdata(pdev, onkey);
132	return 0;
133
134err_free_irq:
135	free_irq(onkey->irq, onkey);
136	cancel_delayed_work_sync(&onkey->work);
137err_free_mem:
138	input_free_device(input_dev);
139	kfree(onkey);
140
141	return error;
142}
143
144static int __devexit da9052_onkey_remove(struct platform_device *pdev)
145{
146	struct da9052_onkey *onkey = platform_get_drvdata(pdev);
147
148	free_irq(onkey->irq, onkey);
149	cancel_delayed_work_sync(&onkey->work);
150
151	input_unregister_device(onkey->input);
152	kfree(onkey);
153
154	return 0;
155}
156
157static struct platform_driver da9052_onkey_driver = {
158	.probe	= da9052_onkey_probe,
159	.remove	= __devexit_p(da9052_onkey_remove),
160	.driver = {
161		.name	= "da9052-onkey",
162		.owner	= THIS_MODULE,
163	},
164};
165module_platform_driver(da9052_onkey_driver);
166
167MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
168MODULE_DESCRIPTION("Onkey driver for DA9052");
169MODULE_LICENSE("GPL");
170MODULE_ALIAS("platform:da9052-onkey");