1/*
2 * drivers/extcon/extcon-adc-jack.c
3 *
4 * Analog Jack extcon driver with ADC-based detection capability.
5 *
6 * Copyright (C) 2012 Samsung Electronics
7 * MyungJoo Ham <myungjoo.ham@samsung.com>
8 *
9 * Modified for calling to IIO to get adc by <anish.singh@samsung.com>
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2 as
13 * published by the Free Software Foundation.
14 *
15 */
16
17#include <linux/module.h>
18#include <linux/slab.h>
19#include <linux/device.h>
20#include <linux/platform_device.h>
21#include <linux/err.h>
22#include <linux/interrupt.h>
23#include <linux/workqueue.h>
24#include <linux/iio/consumer.h>
25#include <linux/extcon/extcon-adc-jack.h>
26#include <linux/extcon.h>
27
28/**
29 * struct adc_jack_data - internal data for adc_jack device driver
30 * @edev:		extcon device.
31 * @cable_names:	list of supported cables.
32 * @num_cables:		size of cable_names.
33 * @adc_conditions:	list of adc value conditions.
34 * @num_conditions:	size of adc_conditions.
35 * @irq:		irq number of attach/detach event (0 if not exist).
36 * @handling_delay:	interrupt handler will schedule extcon event
37 *			handling at handling_delay jiffies.
38 * @handler:		extcon event handler called by interrupt handler.
39 * @chan:		iio channel being queried.
40 */
41struct adc_jack_data {
42	struct extcon_dev *edev;
43
44	const char **cable_names;
45	int num_cables;
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};
55
56static void adc_jack_handler(struct work_struct *work)
57{
58	struct adc_jack_data *data = container_of(to_delayed_work(work),
59			struct adc_jack_data,
60			handler);
61	u32 state = 0;
62	int ret, adc_val;
63	int i;
64
65	ret = iio_read_channel_raw(data->chan, &adc_val);
66	if (ret < 0) {
67		dev_err(&data->edev->dev, "read channel() error: %d\n", ret);
68		return;
69	}
70
71	/* Get state from adc value with adc_conditions */
72	for (i = 0; i < data->num_conditions; i++) {
73		struct adc_jack_cond *def = &data->adc_conditions[i];
74		if (!def->state)
75			break;
76		if (def->min_adc <= adc_val && def->max_adc >= adc_val) {
77			state = def->state;
78			break;
79		}
80	}
81	/* if no def has met, it means state = 0 (no cables attached) */
82
83	extcon_set_state(data->edev, state);
84}
85
86static irqreturn_t adc_jack_irq_thread(int irq, void *_data)
87{
88	struct adc_jack_data *data = _data;
89
90	queue_delayed_work(system_power_efficient_wq,
91			   &data->handler, data->handling_delay);
92	return IRQ_HANDLED;
93}
94
95static int adc_jack_probe(struct platform_device *pdev)
96{
97	struct adc_jack_data *data;
98	struct adc_jack_pdata *pdata = dev_get_platdata(&pdev->dev);
99	int i, err = 0;
100
101	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
102	if (!data)
103		return -ENOMEM;
104
105	if (!pdata->cable_names) {
106		dev_err(&pdev->dev, "error: cable_names not defined.\n");
107		return -EINVAL;
108	}
109
110	data->edev = devm_extcon_dev_allocate(&pdev->dev, pdata->cable_names);
111	if (IS_ERR(data->edev)) {
112		dev_err(&pdev->dev, "failed to allocate extcon device\n");
113		return -ENOMEM;
114	}
115	data->edev->name = pdata->name;
116
117	/* Check the length of array and set num_cables */
118	for (i = 0; data->edev->supported_cable[i]; i++)
119		;
120	if (i == 0 || i > SUPPORTED_CABLE_MAX) {
121		dev_err(&pdev->dev, "error: pdata->cable_names size = %d\n",
122				i - 1);
123		return -EINVAL;
124	}
125	data->num_cables = i;
126
127	if (!pdata->adc_conditions ||
128			!pdata->adc_conditions[0].state) {
129		dev_err(&pdev->dev, "error: adc_conditions not defined.\n");
130		return -EINVAL;
131	}
132	data->adc_conditions = pdata->adc_conditions;
133
134	/* Check the length of array and set num_conditions */
135	for (i = 0; data->adc_conditions[i].state; i++)
136		;
137	data->num_conditions = i;
138
139	data->chan = iio_channel_get(&pdev->dev, pdata->consumer_channel);
140	if (IS_ERR(data->chan))
141		return PTR_ERR(data->chan);
142
143	data->handling_delay = msecs_to_jiffies(pdata->handling_delay_ms);
144
145	INIT_DEFERRABLE_WORK(&data->handler, adc_jack_handler);
146
147	platform_set_drvdata(pdev, data);
148
149	err = devm_extcon_dev_register(&pdev->dev, data->edev);
150	if (err)
151		return err;
152
153	data->irq = platform_get_irq(pdev, 0);
154	if (!data->irq) {
155		dev_err(&pdev->dev, "platform_get_irq failed\n");
156		return -ENODEV;
157	}
158
159	err = request_any_context_irq(data->irq, adc_jack_irq_thread,
160			pdata->irq_flags, pdata->name, data);
161
162	if (err < 0) {
163		dev_err(&pdev->dev, "error: irq %d\n", data->irq);
164		return err;
165	}
166
167	return 0;
168}
169
170static int adc_jack_remove(struct platform_device *pdev)
171{
172	struct adc_jack_data *data = platform_get_drvdata(pdev);
173
174	free_irq(data->irq, data);
175	cancel_work_sync(&data->handler.work);
176	iio_channel_release(data->chan);
177
178	return 0;
179}
180
181static struct platform_driver adc_jack_driver = {
182	.probe          = adc_jack_probe,
183	.remove         = adc_jack_remove,
184	.driver         = {
185		.name   = "adc-jack",
186	},
187};
188
189module_platform_driver(adc_jack_driver);
190
191MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
192MODULE_DESCRIPTION("ADC Jack extcon driver");
193MODULE_LICENSE("GPL v2");
194