Merge remote-tracking branch 'lsk/v3.10/topic/gic-workaround' into linux-linaro-lsk
[firefly-linux-kernel-4.4.55.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/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  */
41 struct 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
56 static 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
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
95 static int adc_jack_probe(struct platform_device *pdev)
96 {
97         struct adc_jack_data *data;
98         struct adc_jack_pdata *pdata = pdev->dev.platform_data;
99         int i, err = 0;
100
101         data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
102         if (!data)
103                 return -ENOMEM;
104
105         data->edev.name = pdata->name;
106
107         if (!pdata->cable_names) {
108                 err = -EINVAL;
109                 dev_err(&pdev->dev, "error: cable_names not defined.\n");
110                 goto out;
111         }
112
113         data->edev.supported_cable = pdata->cable_names;
114
115         /* Check the length of array and set num_cables */
116         for (i = 0; data->edev.supported_cable[i]; i++)
117                 ;
118         if (i == 0 || i > SUPPORTED_CABLE_MAX) {
119                 err = -EINVAL;
120                 dev_err(&pdev->dev, "error: pdata->cable_names size = %d\n",
121                                 i - 1);
122                 goto out;
123         }
124         data->num_cables = i;
125
126         if (!pdata->adc_conditions ||
127                         !pdata->adc_conditions[0].state) {
128                 err = -EINVAL;
129                 dev_err(&pdev->dev, "error: adc_conditions not defined.\n");
130                 goto out;
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                 err = PTR_ERR(data->chan);
142                 goto out;
143         }
144
145         data->handling_delay = msecs_to_jiffies(pdata->handling_delay_ms);
146
147         INIT_DEFERRABLE_WORK(&data->handler, adc_jack_handler);
148
149         platform_set_drvdata(pdev, data);
150
151         err = extcon_dev_register(&data->edev, &pdev->dev);
152         if (err)
153                 goto out;
154
155         data->irq = platform_get_irq(pdev, 0);
156         if (!data->irq) {
157                 dev_err(&pdev->dev, "platform_get_irq failed\n");
158                 err = -ENODEV;
159                 goto err_irq;
160         }
161
162         err = request_any_context_irq(data->irq, adc_jack_irq_thread,
163                         pdata->irq_flags, pdata->name, data);
164
165         if (err < 0) {
166                 dev_err(&pdev->dev, "error: irq %d\n", data->irq);
167                 goto err_irq;
168         }
169
170         return 0;
171
172 err_irq:
173         extcon_dev_unregister(&data->edev);
174 out:
175         return err;
176 }
177
178 static int 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         = adc_jack_remove,
192         .driver         = {
193                 .name   = "adc-jack",
194                 .owner  = THIS_MODULE,
195         },
196 };
197
198 module_platform_driver(adc_jack_driver);
199
200 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
201 MODULE_DESCRIPTION("ADC Jack extcon driver");
202 MODULE_LICENSE("GPL v2");