summaryrefslogtreecommitdiff
path: root/drivers/extcon/extcon-adc-jack.c
blob: 549d8207aacf4219f560ca64a1cc5bb2bce27430 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
/*
 * drivers/extcon/extcon-adc-jack.c
 *
 * Analog Jack extcon driver with ADC-based detection capability.
 *
 * Copyright (C) 2012 Samsung Electronics
 * MyungJoo Ham <myungjoo.ham@samsung.com>
 *
 * Modified for calling to IIO to get adc by <anish.singh@samsung.com>
 *
 * 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/module.h>
#include <linux/slab.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/workqueue.h>
#include <linux/iio/consumer.h>
#include <linux/extcon/extcon-adc-jack.h>
#include <linux/extcon.h>

/**
 * struct adc_jack_data - internal data for adc_jack device driver
 * @edev:		extcon device.
 * @cable_names:	list of supported cables.
 * @num_cables:		size of cable_names.
 * @adc_conditions:	list of adc value conditions.
 * @num_conditions:	size of adc_conditions.
 * @irq:		irq number of attach/detach event (0 if not exist).
 * @handling_delay:	interrupt handler will schedule extcon event
 *			handling at handling_delay jiffies.
 * @handler:		extcon event handler called by interrupt handler.
 * @chan:		iio channel being queried.
 */
struct adc_jack_data {
	struct extcon_dev edev;

	const char **cable_names;
	int num_cables;
	struct adc_jack_cond *adc_conditions;
	int num_conditions;

	int irq;
	unsigned long handling_delay; /* in jiffies */
	struct delayed_work handler;

	struct iio_channel *chan;
};

static void adc_jack_handler(struct work_struct *work)
{
	struct adc_jack_data *data = container_of(to_delayed_work(work),
			struct adc_jack_data,
			handler);
	u32 state = 0;
	int ret, adc_val;
	int i;

	ret = iio_read_channel_raw(data->chan, &adc_val);
	if (ret < 0) {
		dev_err(&data->edev.dev, "read channel() error: %d\n", ret);
		return;
	}

	/* Get state from adc value with adc_conditions */
	for (i = 0; i < data->num_conditions; i++) {
		struct adc_jack_cond *def = &data->adc_conditions[i];
		if (!def->state)
			break;
		if (def->min_adc <= adc_val && def->max_adc >= adc_val) {
			state = def->state;
			break;
		}
	}
	/* if no def has met, it means state = 0 (no cables attached) */

	extcon_set_state(&data->edev, state);
}

static irqreturn_t adc_jack_irq_thread(int irq, void *_data)
{
	struct adc_jack_data *data = _data;

	queue_delayed_work(system_power_efficient_wq,
			   &data->handler, data->handling_delay);
	return IRQ_HANDLED;
}

static int adc_jack_probe(struct platform_device *pdev)
{
	struct adc_jack_data *data;
	struct adc_jack_pdata *pdata = dev_get_platdata(&pdev->dev);
	int i, err = 0;

	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	data->edev.name = pdata->name;

	if (!pdata->cable_names) {
		dev_err(&pdev->dev, "error: cable_names not defined.\n");
		return -EINVAL;
	}

	data->edev.dev.parent = &pdev->dev;
	data->edev.supported_cable = pdata->cable_names;

	/* Check the length of array and set num_cables */
	for (i = 0; data->edev.supported_cable[i]; i++)
		;
	if (i == 0 || i > SUPPORTED_CABLE_MAX) {
		dev_err(&pdev->dev, "error: pdata->cable_names size = %d\n",
				i - 1);
		return -EINVAL;
	}
	data->num_cables = i;

	if (!pdata->adc_conditions ||
			!pdata->adc_conditions[0].state) {
		dev_err(&pdev->dev, "error: adc_conditions not defined.\n");
		return -EINVAL;
	}
	data->adc_conditions = pdata->adc_conditions;

	/* Check the length of array and set num_conditions */
	for (i = 0; data->adc_conditions[i].state; i++)
		;
	data->num_conditions = i;

	data->chan = iio_channel_get(&pdev->dev, pdata->consumer_channel);
	if (IS_ERR(data->chan))
		return PTR_ERR(data->chan);

	data->handling_delay = msecs_to_jiffies(pdata->handling_delay_ms);

	INIT_DEFERRABLE_WORK(&data->handler, adc_jack_handler);

	platform_set_drvdata(pdev, data);

	err = devm_extcon_dev_register(&pdev->dev, &data->edev);
	if (err)
		return err;

	data->irq = platform_get_irq(pdev, 0);
	if (!data->irq) {
		dev_err(&pdev->dev, "platform_get_irq failed\n");
		return -ENODEV;
	}

	err = request_any_context_irq(data->irq, adc_jack_irq_thread,
			pdata->irq_flags, pdata->name, data);

	if (err < 0) {
		dev_err(&pdev->dev, "error: irq %d\n", data->irq);
		return err;
	}

	return 0;
}

static int adc_jack_remove(struct platform_device *pdev)
{
	struct adc_jack_data *data = platform_get_drvdata(pdev);

	free_irq(data->irq, data);
	cancel_work_sync(&data->handler.work);

	return 0;
}

static struct platform_driver adc_jack_driver = {
	.probe          = adc_jack_probe,
	.remove         = adc_jack_remove,
	.driver         = {
		.name   = "adc-jack",
		.owner  = THIS_MODULE,
	},
};

module_platform_driver(adc_jack_driver);

MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
MODULE_DESCRIPTION("ADC Jack extcon driver");
MODULE_LICENSE("GPL v2");