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9#include <linux/err.h>
10#include <linux/i2c.h>
11#include <linux/module.h>
12#include <linux/of.h>
13
14#include <linux/iio/iio.h>
15#include <linux/regulator/consumer.h>
16
17struct adc081c {
18 struct i2c_client *i2c;
19 struct regulator *ref;
20};
21
22#define REG_CONV_RES 0x00
23
24static int adc081c_read_raw(struct iio_dev *iio,
25 struct iio_chan_spec const *channel, int *value,
26 int *shift, long mask)
27{
28 struct adc081c *adc = iio_priv(iio);
29 int err;
30
31 switch (mask) {
32 case IIO_CHAN_INFO_RAW:
33 err = i2c_smbus_read_word_swapped(adc->i2c, REG_CONV_RES);
34 if (err < 0)
35 return err;
36
37 *value = (err >> 4) & 0xff;
38 return IIO_VAL_INT;
39
40 case IIO_CHAN_INFO_SCALE:
41 err = regulator_get_voltage(adc->ref);
42 if (err < 0)
43 return err;
44
45 *value = err / 1000;
46 *shift = 8;
47
48 return IIO_VAL_FRACTIONAL_LOG2;
49
50 default:
51 break;
52 }
53
54 return -EINVAL;
55}
56
57static const struct iio_chan_spec adc081c_channel = {
58 .type = IIO_VOLTAGE,
59 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
60 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
61};
62
63static const struct iio_info adc081c_info = {
64 .read_raw = adc081c_read_raw,
65 .driver_module = THIS_MODULE,
66};
67
68static int adc081c_probe(struct i2c_client *client,
69 const struct i2c_device_id *id)
70{
71 struct iio_dev *iio;
72 struct adc081c *adc;
73 int err;
74
75 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
76 return -EOPNOTSUPP;
77
78 iio = devm_iio_device_alloc(&client->dev, sizeof(*adc));
79 if (!iio)
80 return -ENOMEM;
81
82 adc = iio_priv(iio);
83 adc->i2c = client;
84
85 adc->ref = devm_regulator_get(&client->dev, "vref");
86 if (IS_ERR(adc->ref))
87 return PTR_ERR(adc->ref);
88
89 err = regulator_enable(adc->ref);
90 if (err < 0)
91 return err;
92
93 iio->dev.parent = &client->dev;
94 iio->name = dev_name(&client->dev);
95 iio->modes = INDIO_DIRECT_MODE;
96 iio->info = &adc081c_info;
97
98 iio->channels = &adc081c_channel;
99 iio->num_channels = 1;
100
101 err = iio_device_register(iio);
102 if (err < 0)
103 goto regulator_disable;
104
105 i2c_set_clientdata(client, iio);
106
107 return 0;
108
109regulator_disable:
110 regulator_disable(adc->ref);
111
112 return err;
113}
114
115static int adc081c_remove(struct i2c_client *client)
116{
117 struct iio_dev *iio = i2c_get_clientdata(client);
118 struct adc081c *adc = iio_priv(iio);
119
120 iio_device_unregister(iio);
121 regulator_disable(adc->ref);
122
123 return 0;
124}
125
126static const struct i2c_device_id adc081c_id[] = {
127 { "adc081c", 0 },
128 { }
129};
130MODULE_DEVICE_TABLE(i2c, adc081c_id);
131
132#ifdef CONFIG_OF
133static const struct of_device_id adc081c_of_match[] = {
134 { .compatible = "ti,adc081c" },
135 { }
136};
137MODULE_DEVICE_TABLE(of, adc081c_of_match);
138#endif
139
140static struct i2c_driver adc081c_driver = {
141 .driver = {
142 .name = "adc081c",
143 .of_match_table = of_match_ptr(adc081c_of_match),
144 },
145 .probe = adc081c_probe,
146 .remove = adc081c_remove,
147 .id_table = adc081c_id,
148};
149module_i2c_driver(adc081c_driver);
150
151MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>");
152MODULE_DESCRIPTION("Texas Instruments ADC081C021/027 driver");
153MODULE_LICENSE("GPL v2");
154
