extcon-adc-jack.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * drivers/extcon/extcon-adc-jack.c
  4 *
  5 * Analog Jack extcon driver with ADC-based detection capability.
  6 *
  7 * Copyright (C) 2016 Samsung Electronics
  8 * Chanwoo Choi <cw00.choi@samsung.com>
  9 *
 10 * Copyright (C) 2012 Samsung Electronics
 11 * MyungJoo Ham <myungjoo.ham@samsung.com>
 12 *
 13 * Modified for calling to IIO to get adc by <anish.singh@samsung.com>
 14 */
 15
 16#include <linux/module.h>
 17#include <linux/slab.h>
 18#include <linux/device.h>
 19#include <linux/platform_device.h>
 20#include <linux/err.h>
 21#include <linux/interrupt.h>
 22#include <linux/workqueue.h>
 23#include <linux/iio/consumer.h>
 24#include <linux/extcon/extcon-adc-jack.h>
 25#include <linux/extcon-provider.h>
 26
 27/**
 28 * struct adc_jack_data - internal data for adc_jack device driver
 29 * @dev:		The device structure associated with the adc_jack.
 30 * @edev:		extcon device.
 31 * @cable_names:	list of supported cables.
 32 * @adc_conditions:	list of adc value conditions.
 33 * @num_conditions:	size of adc_conditions.
 34 * @irq:		irq number of attach/detach event (0 if not exist).
 35 * @handling_delay:	interrupt handler will schedule extcon event
 36 *			handling at handling_delay jiffies.
 37 * @handler:		extcon event handler called by interrupt handler.
 38 * @chan:		iio channel being queried.
 39 * @wakeup_source:	Indicates if the device can wake up the system.
 40 */
 41struct adc_jack_data {
 42	struct device *dev;
 43	struct extcon_dev *edev;
 44
 45	const unsigned int **cable_names;
 46	struct adc_jack_cond *adc_conditions;
 47	int num_conditions;
 48
 49	int irq;
 50	unsigned long handling_delay; /* in jiffies */
 51	struct delayed_work handler;
 52
 53	struct iio_channel *chan;
 54	bool wakeup_source;
 55};
 56
 57static void adc_jack_handler(struct work_struct *work)
 58{
 59	struct adc_jack_data *data = container_of(to_delayed_work(work),
 60			struct adc_jack_data,
 61			handler);
 62	struct adc_jack_cond *def;
 63	int ret, adc_val;
 64	int i;
 65
 66	ret = iio_read_channel_raw(data->chan, &adc_val);
 67	if (ret < 0) {
 68		dev_err(data->dev, "read channel() error: %d\n", ret);
 69		return;
 70	}
 71
 72	/* Get state from adc value with adc_conditions */
 73	for (i = 0; i < data->num_conditions; i++) {
 74		def = &data->adc_conditions[i];
 75		if (def->min_adc <= adc_val && def->max_adc >= adc_val) {
 76			extcon_set_state_sync(data->edev, def->id, true);
 77			return;
 78		}
 79	}
 80
 81	/* Set the detached state if adc value is not included in the range */
 82	for (i = 0; i < data->num_conditions; i++) {
 83		def = &data->adc_conditions[i];
 84		extcon_set_state_sync(data->edev, def->id, false);
 85	}
 86}
 87
 88static irqreturn_t adc_jack_irq_thread(int irq, void *_data)
 89{
 90	struct adc_jack_data *data = _data;
 91
 92	queue_delayed_work(system_power_efficient_wq,
 93			   &data->handler, data->handling_delay);
 94	return IRQ_HANDLED;
 95}
 96
 97static int adc_jack_probe(struct platform_device *pdev)
 98{
 99	struct adc_jack_data *data;
100	struct adc_jack_pdata *pdata = dev_get_platdata(&pdev->dev);
101	int i, err = 0;
102
103	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
104	if (!data)
105		return -ENOMEM;
106
107	if (!pdata->cable_names) {
108		dev_err(&pdev->dev, "error: cable_names not defined.\n");
109		return -EINVAL;
110	}
111
112	data->dev = &pdev->dev;
113	data->edev = devm_extcon_dev_allocate(&pdev->dev, pdata->cable_names);
114	if (IS_ERR(data->edev)) {
115		dev_err(&pdev->dev, "failed to allocate extcon device\n");
116		return -ENOMEM;
117	}
118
119	if (!pdata->adc_conditions) {
120		dev_err(&pdev->dev, "error: adc_conditions not defined.\n");
121		return -EINVAL;
122	}
123	data->adc_conditions = pdata->adc_conditions;
124
125	/* Check the length of array and set num_conditions */
126	for (i = 0; data->adc_conditions[i].id != EXTCON_NONE; i++);
127	data->num_conditions = i;
128
129	data->chan = devm_iio_channel_get(&pdev->dev, pdata->consumer_channel);
130	if (IS_ERR(data->chan))
131		return PTR_ERR(data->chan);
132
133	data->handling_delay = msecs_to_jiffies(pdata->handling_delay_ms);
134	data->wakeup_source = pdata->wakeup_source;
135
136	INIT_DEFERRABLE_WORK(&data->handler, adc_jack_handler);
137
138	platform_set_drvdata(pdev, data);
139
140	err = devm_extcon_dev_register(&pdev->dev, data->edev);
141	if (err)
142		return err;
143
144	data->irq = platform_get_irq(pdev, 0);
145	if (data->irq < 0)
146		return -ENODEV;
147
148	err = request_any_context_irq(data->irq, adc_jack_irq_thread,
149			pdata->irq_flags, pdata->name, data);
150
151	if (err < 0) {
152		dev_err(&pdev->dev, "error: irq %d\n", data->irq);
153		return err;
154	}
155
156	if (data->wakeup_source)
157		device_init_wakeup(&pdev->dev, 1);
158
159	adc_jack_handler(&data->handler.work);
160	return 0;
161}
162
163static void adc_jack_remove(struct platform_device *pdev)
164{
165	struct adc_jack_data *data = platform_get_drvdata(pdev);
166
167	if (data->wakeup_source)
168		device_init_wakeup(&pdev->dev, false);
169	free_irq(data->irq, data);
170	cancel_work_sync(&data->handler.work);
171}
172
173#ifdef CONFIG_PM_SLEEP
174static int adc_jack_suspend(struct device *dev)
175{
176	struct adc_jack_data *data = dev_get_drvdata(dev);
177
178	cancel_delayed_work_sync(&data->handler);
179	if (device_may_wakeup(data->dev))
180		enable_irq_wake(data->irq);
181
182	return 0;
183}
184
185static int adc_jack_resume(struct device *dev)
186{
187	struct adc_jack_data *data = dev_get_drvdata(dev);
188
189	if (device_may_wakeup(data->dev))
190		disable_irq_wake(data->irq);
191
192	return 0;
193}
194#endif /* CONFIG_PM_SLEEP */
195
196static SIMPLE_DEV_PM_OPS(adc_jack_pm_ops,
197		adc_jack_suspend, adc_jack_resume);
198
199static struct platform_driver adc_jack_driver = {
200	.probe          = adc_jack_probe,
201	.remove         = adc_jack_remove,
202	.driver         = {
203		.name   = "adc-jack",
204		.pm = &adc_jack_pm_ops,
205	},
206};
207
208module_platform_driver(adc_jack_driver);
209
210MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
211MODULE_DESCRIPTION("ADC Jack extcon driver");
212MODULE_LICENSE("GPL v2");