Merge branch 'for-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
[linux-3.10.git] / drivers / extcon / extcon-adc-jack.c
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/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.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  * @num_cables  - size of cable_names.
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  */
40 struct adc_jack_data {
41         struct extcon_dev edev;
42
43         const char **cable_names;
44         int num_cables;
45         struct adc_jack_cond *adc_conditions;
46         int num_conditions;
47
48         int irq;
49         unsigned long handling_delay; /* in jiffies */
50         struct delayed_work handler;
51
52         struct iio_channel *chan;
53 };
54
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         u32 state = 0;
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->edev.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                 struct adc_jack_cond *def = &data->adc_conditions[i];
73                 if (!def->state)
74                         break;
75                 if (def->min_adc <= adc_val && def->max_adc >= adc_val) {
76                         state = def->state;
77                         break;
78                 }
79         }
80         /* if no def has met, it means state = 0 (no cables attached) */
81
82         extcon_set_state(&data->edev, state);
83 }
84
85 static irqreturn_t adc_jack_irq_thread(int irq, void *_data)
86 {
87         struct adc_jack_data *data = _data;
88
89         schedule_delayed_work(&data->handler, data->handling_delay);
90         return IRQ_HANDLED;
91 }
92
93 static int __devinit adc_jack_probe(struct platform_device *pdev)
94 {
95         struct adc_jack_data *data;
96         struct adc_jack_pdata *pdata = pdev->dev.platform_data;
97         int i, err = 0;
98
99         data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
100         if (!data)
101                 return -ENOMEM;
102
103         data->edev.name = pdata->name;
104
105         if (!pdata->cable_names) {
106                 err = -EINVAL;
107                 dev_err(&pdev->dev, "error: cable_names not defined.\n");
108                 goto out;
109         }
110
111         data->edev.supported_cable = pdata->cable_names;
112
113         /* Check the length of array and set num_cables */
114         for (i = 0; data->edev.supported_cable[i]; i++)
115                 ;
116         if (i == 0 || i > SUPPORTED_CABLE_MAX) {
117                 err = -EINVAL;
118                 dev_err(&pdev->dev, "error: pdata->cable_names size = %d\n",
119                                 i - 1);
120                 goto out;
121         }
122         data->num_cables = i;
123
124         if (!pdata->adc_conditions ||
125                         !pdata->adc_conditions[0].state) {
126                 err = -EINVAL;
127                 dev_err(&pdev->dev, "error: adc_conditions not defined.\n");
128                 goto out;
129         }
130         data->adc_conditions = pdata->adc_conditions;
131
132         /* Check the length of array and set num_conditions */
133         for (i = 0; data->adc_conditions[i].state; i++)
134                 ;
135         data->num_conditions = i;
136
137         data->chan = iio_channel_get(dev_name(&pdev->dev),
138                         pdata->consumer_channel);
139         if (IS_ERR(data->chan)) {
140                 err = PTR_ERR(data->chan);
141                 goto out;
142         }
143
144         data->handling_delay = msecs_to_jiffies(pdata->handling_delay_ms);
145
146         INIT_DEFERRABLE_WORK(&data->handler, adc_jack_handler);
147
148         platform_set_drvdata(pdev, data);
149
150         err = extcon_dev_register(&data->edev, &pdev->dev);
151         if (err)
152                 goto out;
153
154         data->irq = platform_get_irq(pdev, 0);
155         if (!data->irq) {
156                 dev_err(&pdev->dev, "platform_get_irq failed\n");
157                 err = -ENODEV;
158                 goto err_irq;
159         }
160
161         err = request_any_context_irq(data->irq, adc_jack_irq_thread,
162                         pdata->irq_flags, pdata->name, data);
163
164         if (err) {
165                 dev_err(&pdev->dev, "error: irq %d\n", data->irq);
166                 err = -EINVAL;
167                 goto err_irq;
168         }
169
170         goto out;
171
172 err_irq:
173         extcon_dev_unregister(&data->edev);
174 out:
175         return err;
176 }
177
178 static int __devexit adc_jack_remove(struct platform_device *pdev)
179 {
180         struct adc_jack_data *data = platform_get_drvdata(pdev);
181
182         free_irq(data->irq, data);
183         cancel_work_sync(&data->handler.work);
184         extcon_dev_unregister(&data->edev);
185
186         return 0;
187 }
188
189 static struct platform_driver adc_jack_driver = {
190         .probe          = adc_jack_probe,
191         .remove         = __devexit_p(adc_jack_remove),
192         .driver         = {
193                 .name   = "adc-jack",
194                 .owner  = THIS_MODULE,
195         },
196 };
197
198 module_platform_driver(adc_jack_driver);