1 /*
2  * drivers/extcon/extcon-adc-jack.c
3  *
4  * Analog Jack extcon driver with ADC-based detection capability.
5  *
6  * Copyright (C) 2016 Samsung Electronics
7  * Chanwoo Choi <cw00.choi@samsung.com>
8  *
9  * Copyright (C) 2012 Samsung Electronics
10  * MyungJoo Ham <myungjoo.ham@samsung.com>
11  *
12  * Modified for calling to IIO to get adc by <anish.singh@samsung.com>
13  *
14  * This program is free software; you can redistribute it and/or modify
15  * it under the terms of the GNU General Public License version 2 as
16  * published by the Free Software Foundation.
17  *
18  */
19 
20 #include <linux/module.h>
21 #include <linux/slab.h>
22 #include <linux/device.h>
23 #include <linux/platform_device.h>
24 #include <linux/err.h>
25 #include <linux/interrupt.h>
26 #include <linux/workqueue.h>
27 #include <linux/iio/consumer.h>
28 #include <linux/extcon/extcon-adc-jack.h>
29 #include <linux/extcon.h>
30 
31 /**
32  * struct adc_jack_data - internal data for adc_jack device driver
33  * @edev:		extcon device.
34  * @cable_names:	list of supported cables.
35  * @adc_conditions:	list of adc value conditions.
36  * @num_conditions:	size of adc_conditions.
37  * @irq:		irq number of attach/detach event (0 if not exist).
38  * @handling_delay:	interrupt handler will schedule extcon event
39  *			handling at handling_delay jiffies.
40  * @handler:		extcon event handler called by interrupt handler.
41  * @chan:		iio channel being queried.
42  */
43 struct adc_jack_data {
44 	struct device *dev;
45 	struct extcon_dev *edev;
46 
47 	const unsigned int **cable_names;
48 	struct adc_jack_cond *adc_conditions;
49 	int num_conditions;
50 
51 	int irq;
52 	unsigned long handling_delay; /* in jiffies */
53 	struct delayed_work handler;
54 
55 	struct iio_channel *chan;
56 	bool wakeup_source;
57 };
58 
59 static void adc_jack_handler(struct work_struct *work)
60 {
61 	struct adc_jack_data *data = container_of(to_delayed_work(work),
62 			struct adc_jack_data,
63 			handler);
64 	struct adc_jack_cond *def;
65 	int ret, adc_val;
66 	int i;
67 
68 	ret = iio_read_channel_raw(data->chan, &adc_val);
69 	if (ret < 0) {
70 		dev_err(data->dev, "read channel() error: %d\n", ret);
71 		return;
72 	}
73 
74 	/* Get state from adc value with adc_conditions */
75 	for (i = 0; i < data->num_conditions; i++) {
76 		def = &data->adc_conditions[i];
77 		if (def->min_adc <= adc_val && def->max_adc >= adc_val) {
78 			extcon_set_state_sync(data->edev, def->id, true);
79 			return;
80 		}
81 	}
82 
83 	/* Set the detached state if adc value is not included in the range */
84 	for (i = 0; i < data->num_conditions; i++) {
85 		def = &data->adc_conditions[i];
86 		extcon_set_state_sync(data->edev, def->id, false);
87 	}
88 }
89 
90 static irqreturn_t adc_jack_irq_thread(int irq, void *_data)
91 {
92 	struct adc_jack_data *data = _data;
93 
94 	queue_delayed_work(system_power_efficient_wq,
95 			   &data->handler, data->handling_delay);
96 	return IRQ_HANDLED;
97 }
98 
99 static int adc_jack_probe(struct platform_device *pdev)
100 {
101 	struct adc_jack_data *data;
102 	struct adc_jack_pdata *pdata = dev_get_platdata(&pdev->dev);
103 	int i, err = 0;
104 
105 	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
106 	if (!data)
107 		return -ENOMEM;
108 
109 	if (!pdata->cable_names) {
110 		dev_err(&pdev->dev, "error: cable_names not defined.\n");
111 		return -EINVAL;
112 	}
113 
114 	data->dev = &pdev->dev;
115 	data->edev = devm_extcon_dev_allocate(&pdev->dev, pdata->cable_names);
116 	if (IS_ERR(data->edev)) {
117 		dev_err(&pdev->dev, "failed to allocate extcon device\n");
118 		return -ENOMEM;
119 	}
120 
121 	if (!pdata->adc_conditions) {
122 		dev_err(&pdev->dev, "error: adc_conditions not defined.\n");
123 		return -EINVAL;
124 	}
125 	data->adc_conditions = pdata->adc_conditions;
126 
127 	/* Check the length of array and set num_conditions */
128 	for (i = 0; data->adc_conditions[i].id != EXTCON_NONE; i++);
129 	data->num_conditions = i;
130 
131 	data->chan = iio_channel_get(&pdev->dev, pdata->consumer_channel);
132 	if (IS_ERR(data->chan))
133 		return PTR_ERR(data->chan);
134 
135 	data->handling_delay = msecs_to_jiffies(pdata->handling_delay_ms);
136 	data->wakeup_source = pdata->wakeup_source;
137 
138 	INIT_DEFERRABLE_WORK(&data->handler, adc_jack_handler);
139 
140 	platform_set_drvdata(pdev, data);
141 
142 	err = devm_extcon_dev_register(&pdev->dev, data->edev);
143 	if (err)
144 		return err;
145 
146 	data->irq = platform_get_irq(pdev, 0);
147 	if (!data->irq) {
148 		dev_err(&pdev->dev, "platform_get_irq failed\n");
149 		return -ENODEV;
150 	}
151 
152 	err = request_any_context_irq(data->irq, adc_jack_irq_thread,
153 			pdata->irq_flags, pdata->name, data);
154 
155 	if (err < 0) {
156 		dev_err(&pdev->dev, "error: irq %d\n", data->irq);
157 		return err;
158 	}
159 
160 	if (data->wakeup_source)
161 		device_init_wakeup(&pdev->dev, 1);
162 
163 	adc_jack_handler(&data->handler.work);
164 	return 0;
165 }
166 
167 static int adc_jack_remove(struct platform_device *pdev)
168 {
169 	struct adc_jack_data *data = platform_get_drvdata(pdev);
170 
171 	free_irq(data->irq, data);
172 	cancel_work_sync(&data->handler.work);
173 	iio_channel_release(data->chan);
174 
175 	return 0;
176 }
177 
178 #ifdef CONFIG_PM_SLEEP
179 static int adc_jack_suspend(struct device *dev)
180 {
181 	struct adc_jack_data *data = dev_get_drvdata(dev);
182 
183 	cancel_delayed_work_sync(&data->handler);
184 	if (device_may_wakeup(data->dev))
185 		enable_irq_wake(data->irq);
186 
187 	return 0;
188 }
189 
190 static int adc_jack_resume(struct device *dev)
191 {
192 	struct adc_jack_data *data = dev_get_drvdata(dev);
193 
194 	if (device_may_wakeup(data->dev))
195 		disable_irq_wake(data->irq);
196 
197 	return 0;
198 }
199 #endif /* CONFIG_PM_SLEEP */
200 
201 static SIMPLE_DEV_PM_OPS(adc_jack_pm_ops,
202 		adc_jack_suspend, adc_jack_resume);
203 
204 static struct platform_driver adc_jack_driver = {
205 	.probe          = adc_jack_probe,
206 	.remove         = adc_jack_remove,
207 	.driver         = {
208 		.name   = "adc-jack",
209 		.pm = &adc_jack_pm_ops,
210 	},
211 };
212 
213 module_platform_driver(adc_jack_driver);
214 
215 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
216 MODULE_DESCRIPTION("ADC Jack extcon driver");
217 MODULE_LICENSE("GPL v2");
218