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  * @edev:		extcon device.
30  * @cable_names:	list of supported cables.
31  * @adc_conditions:	list of adc value conditions.
32  * @num_conditions:	size of adc_conditions.
33  * @irq:		irq number of attach/detach event (0 if not exist).
34  * @handling_delay:	interrupt handler will schedule extcon event
35  *			handling at handling_delay jiffies.
36  * @handler:		extcon event handler called by interrupt handler.
37  * @chan:		iio channel being queried.
38  */
39 struct adc_jack_data {
40 	struct device *dev;
41 	struct extcon_dev *edev;
42 
43 	const unsigned int **cable_names;
44 	struct adc_jack_cond *adc_conditions;
45 	int num_conditions;
46 
47 	int irq;
48 	unsigned long handling_delay; /* in jiffies */
49 	struct delayed_work handler;
50 
51 	struct iio_channel *chan;
52 	bool wakeup_source;
53 };
54 
adc_jack_handler(struct work_struct * work)55 static void adc_jack_handler(struct work_struct *work)
56 {
57 	struct adc_jack_data *data = container_of(to_delayed_work(work),
58 			struct adc_jack_data,
59 			handler);
60 	struct adc_jack_cond *def;
61 	int ret, adc_val;
62 	int i;
63 
64 	ret = iio_read_channel_raw(data->chan, &adc_val);
65 	if (ret < 0) {
66 		dev_err(data->dev, "read channel() error: %d\n", ret);
67 		return;
68 	}
69 
70 	/* Get state from adc value with adc_conditions */
71 	for (i = 0; i < data->num_conditions; i++) {
72 		def = &data->adc_conditions[i];
73 		if (def->min_adc <= adc_val && def->max_adc >= adc_val) {
74 			extcon_set_state_sync(data->edev, def->id, true);
75 			return;
76 		}
77 	}
78 
79 	/* Set the detached state if adc value is not included in the range */
80 	for (i = 0; i < data->num_conditions; i++) {
81 		def = &data->adc_conditions[i];
82 		extcon_set_state_sync(data->edev, def->id, false);
83 	}
84 }
85 
adc_jack_irq_thread(int irq,void * _data)86 static 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 
adc_jack_probe(struct platform_device * pdev)95 static 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->dev = &pdev->dev;
111 	data->edev = devm_extcon_dev_allocate(&pdev->dev, pdata->cable_names);
112 	if (IS_ERR(data->edev)) {
113 		dev_err(&pdev->dev, "failed to allocate extcon device\n");
114 		return -ENOMEM;
115 	}
116 
117 	if (!pdata->adc_conditions) {
118 		dev_err(&pdev->dev, "error: adc_conditions not defined.\n");
119 		return -EINVAL;
120 	}
121 	data->adc_conditions = pdata->adc_conditions;
122 
123 	/* Check the length of array and set num_conditions */
124 	for (i = 0; data->adc_conditions[i].id != EXTCON_NONE; i++);
125 	data->num_conditions = i;
126 
127 	data->chan = devm_iio_channel_get(&pdev->dev, pdata->consumer_channel);
128 	if (IS_ERR(data->chan))
129 		return PTR_ERR(data->chan);
130 
131 	data->handling_delay = msecs_to_jiffies(pdata->handling_delay_ms);
132 	data->wakeup_source = pdata->wakeup_source;
133 
134 	INIT_DEFERRABLE_WORK(&data->handler, adc_jack_handler);
135 
136 	platform_set_drvdata(pdev, data);
137 
138 	err = devm_extcon_dev_register(&pdev->dev, data->edev);
139 	if (err)
140 		return err;
141 
142 	data->irq = platform_get_irq(pdev, 0);
143 	if (data->irq < 0)
144 		return -ENODEV;
145 
146 	err = request_any_context_irq(data->irq, adc_jack_irq_thread,
147 			pdata->irq_flags, pdata->name, data);
148 
149 	if (err < 0) {
150 		dev_err(&pdev->dev, "error: irq %d\n", data->irq);
151 		return err;
152 	}
153 
154 	if (data->wakeup_source)
155 		device_init_wakeup(&pdev->dev, 1);
156 
157 	adc_jack_handler(&data->handler.work);
158 	return 0;
159 }
160 
adc_jack_remove(struct platform_device * pdev)161 static int adc_jack_remove(struct platform_device *pdev)
162 {
163 	struct adc_jack_data *data = platform_get_drvdata(pdev);
164 
165 	free_irq(data->irq, data);
166 	cancel_work_sync(&data->handler.work);
167 
168 	return 0;
169 }
170 
171 #ifdef CONFIG_PM_SLEEP
adc_jack_suspend(struct device * dev)172 static int adc_jack_suspend(struct device *dev)
173 {
174 	struct adc_jack_data *data = dev_get_drvdata(dev);
175 
176 	cancel_delayed_work_sync(&data->handler);
177 	if (device_may_wakeup(data->dev))
178 		enable_irq_wake(data->irq);
179 
180 	return 0;
181 }
182 
adc_jack_resume(struct device * dev)183 static int adc_jack_resume(struct device *dev)
184 {
185 	struct adc_jack_data *data = dev_get_drvdata(dev);
186 
187 	if (device_may_wakeup(data->dev))
188 		disable_irq_wake(data->irq);
189 
190 	return 0;
191 }
192 #endif /* CONFIG_PM_SLEEP */
193 
194 static SIMPLE_DEV_PM_OPS(adc_jack_pm_ops,
195 		adc_jack_suspend, adc_jack_resume);
196 
197 static struct platform_driver adc_jack_driver = {
198 	.probe          = adc_jack_probe,
199 	.remove         = adc_jack_remove,
200 	.driver         = {
201 		.name   = "adc-jack",
202 		.pm = &adc_jack_pm_ops,
203 	},
204 };
205 
206 module_platform_driver(adc_jack_driver);
207 
208 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
209 MODULE_DESCRIPTION("ADC Jack extcon driver");
210 MODULE_LICENSE("GPL v2");
211