1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * TI ADC081C/ADC101C/ADC121C 8/10/12-bit ADC driver
4 *
5 * Copyright (C) 2012 Avionic Design GmbH
6 * Copyright (C) 2016 Intel
7 *
8 * Datasheets:
9 * https://www.ti.com/lit/ds/symlink/adc081c021.pdf
10 * https://www.ti.com/lit/ds/symlink/adc101c021.pdf
11 * https://www.ti.com/lit/ds/symlink/adc121c021.pdf
12 *
13 * The devices have a very similar interface and differ mostly in the number of
14 * bits handled. For the 8-bit and 10-bit models the least-significant 4 or 2
15 * bits of value registers are reserved.
16 */
17
18 #include <linux/err.h>
19 #include <linux/i2c.h>
20 #include <linux/module.h>
21 #include <linux/mod_devicetable.h>
22 #include <linux/property.h>
23
24 #include <linux/iio/iio.h>
25 #include <linux/iio/buffer.h>
26 #include <linux/iio/trigger_consumer.h>
27 #include <linux/iio/triggered_buffer.h>
28 #include <linux/regulator/consumer.h>
29
30 struct adc081c {
31 struct i2c_client *i2c;
32 struct regulator *ref;
33
34 /* 8, 10 or 12 */
35 int bits;
36
37 /* Ensure natural alignment of buffer elements */
38 struct {
39 u16 channel;
40 s64 ts __aligned(8);
41 } scan;
42 };
43
44 #define REG_CONV_RES 0x00
45
adc081c_read_raw(struct iio_dev * iio,struct iio_chan_spec const * channel,int * value,int * shift,long mask)46 static int adc081c_read_raw(struct iio_dev *iio,
47 struct iio_chan_spec const *channel, int *value,
48 int *shift, long mask)
49 {
50 struct adc081c *adc = iio_priv(iio);
51 int err;
52
53 switch (mask) {
54 case IIO_CHAN_INFO_RAW:
55 err = i2c_smbus_read_word_swapped(adc->i2c, REG_CONV_RES);
56 if (err < 0)
57 return err;
58
59 *value = (err & 0xFFF) >> (12 - adc->bits);
60 return IIO_VAL_INT;
61
62 case IIO_CHAN_INFO_SCALE:
63 err = regulator_get_voltage(adc->ref);
64 if (err < 0)
65 return err;
66
67 *value = err / 1000;
68 *shift = adc->bits;
69
70 return IIO_VAL_FRACTIONAL_LOG2;
71
72 default:
73 break;
74 }
75
76 return -EINVAL;
77 }
78
79 #define ADCxx1C_CHAN(_bits) { \
80 .type = IIO_VOLTAGE, \
81 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
82 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
83 .scan_type = { \
84 .sign = 'u', \
85 .realbits = (_bits), \
86 .storagebits = 16, \
87 .shift = 12 - (_bits), \
88 .endianness = IIO_CPU, \
89 }, \
90 }
91
92 #define DEFINE_ADCxx1C_CHANNELS(_name, _bits) \
93 static const struct iio_chan_spec _name ## _channels[] = { \
94 ADCxx1C_CHAN((_bits)), \
95 IIO_CHAN_SOFT_TIMESTAMP(1), \
96 }; \
97
98 #define ADC081C_NUM_CHANNELS 2
99
100 struct adcxx1c_model {
101 const struct iio_chan_spec* channels;
102 int bits;
103 };
104
105 #define ADCxx1C_MODEL(_name, _bits) \
106 { \
107 .channels = _name ## _channels, \
108 .bits = (_bits), \
109 }
110
111 DEFINE_ADCxx1C_CHANNELS(adc081c, 8);
112 DEFINE_ADCxx1C_CHANNELS(adc101c, 10);
113 DEFINE_ADCxx1C_CHANNELS(adc121c, 12);
114
115 /* Model ids are indexes in _models array */
116 enum adcxx1c_model_id {
117 ADC081C = 0,
118 ADC101C = 1,
119 ADC121C = 2,
120 };
121
122 static struct adcxx1c_model adcxx1c_models[] = {
123 ADCxx1C_MODEL(adc081c, 8),
124 ADCxx1C_MODEL(adc101c, 10),
125 ADCxx1C_MODEL(adc121c, 12),
126 };
127
128 static const struct iio_info adc081c_info = {
129 .read_raw = adc081c_read_raw,
130 };
131
adc081c_trigger_handler(int irq,void * p)132 static irqreturn_t adc081c_trigger_handler(int irq, void *p)
133 {
134 struct iio_poll_func *pf = p;
135 struct iio_dev *indio_dev = pf->indio_dev;
136 struct adc081c *data = iio_priv(indio_dev);
137 int ret;
138
139 ret = i2c_smbus_read_word_swapped(data->i2c, REG_CONV_RES);
140 if (ret < 0)
141 goto out;
142 data->scan.channel = ret;
143 iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
144 iio_get_time_ns(indio_dev));
145 out:
146 iio_trigger_notify_done(indio_dev->trig);
147 return IRQ_HANDLED;
148 }
149
adc081c_probe(struct i2c_client * client,const struct i2c_device_id * id)150 static int adc081c_probe(struct i2c_client *client,
151 const struct i2c_device_id *id)
152 {
153 struct iio_dev *iio;
154 struct adc081c *adc;
155 const struct adcxx1c_model *model;
156 int err;
157
158 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
159 return -EOPNOTSUPP;
160
161 if (dev_fwnode(&client->dev))
162 model = device_get_match_data(&client->dev);
163 else
164 model = &adcxx1c_models[id->driver_data];
165
166 iio = devm_iio_device_alloc(&client->dev, sizeof(*adc));
167 if (!iio)
168 return -ENOMEM;
169
170 adc = iio_priv(iio);
171 adc->i2c = client;
172 adc->bits = model->bits;
173
174 adc->ref = devm_regulator_get(&client->dev, "vref");
175 if (IS_ERR(adc->ref))
176 return PTR_ERR(adc->ref);
177
178 err = regulator_enable(adc->ref);
179 if (err < 0)
180 return err;
181
182 iio->name = dev_name(&client->dev);
183 iio->modes = INDIO_DIRECT_MODE;
184 iio->info = &adc081c_info;
185
186 iio->channels = model->channels;
187 iio->num_channels = ADC081C_NUM_CHANNELS;
188
189 err = iio_triggered_buffer_setup(iio, NULL, adc081c_trigger_handler, NULL);
190 if (err < 0) {
191 dev_err(&client->dev, "iio triggered buffer setup failed\n");
192 goto err_regulator_disable;
193 }
194
195 err = iio_device_register(iio);
196 if (err < 0)
197 goto err_buffer_cleanup;
198
199 i2c_set_clientdata(client, iio);
200
201 return 0;
202
203 err_buffer_cleanup:
204 iio_triggered_buffer_cleanup(iio);
205 err_regulator_disable:
206 regulator_disable(adc->ref);
207
208 return err;
209 }
210
adc081c_remove(struct i2c_client * client)211 static int adc081c_remove(struct i2c_client *client)
212 {
213 struct iio_dev *iio = i2c_get_clientdata(client);
214 struct adc081c *adc = iio_priv(iio);
215
216 iio_device_unregister(iio);
217 iio_triggered_buffer_cleanup(iio);
218 regulator_disable(adc->ref);
219
220 return 0;
221 }
222
223 static const struct i2c_device_id adc081c_id[] = {
224 { "adc081c", ADC081C },
225 { "adc101c", ADC101C },
226 { "adc121c", ADC121C },
227 { }
228 };
229 MODULE_DEVICE_TABLE(i2c, adc081c_id);
230
231 static const struct acpi_device_id adc081c_acpi_match[] = {
232 /* Used on some AAEON boards */
233 { "ADC081C", (kernel_ulong_t)&adcxx1c_models[ADC081C] },
234 { }
235 };
236 MODULE_DEVICE_TABLE(acpi, adc081c_acpi_match);
237
238 static const struct of_device_id adc081c_of_match[] = {
239 { .compatible = "ti,adc081c", .data = &adcxx1c_models[ADC081C] },
240 { .compatible = "ti,adc101c", .data = &adcxx1c_models[ADC101C] },
241 { .compatible = "ti,adc121c", .data = &adcxx1c_models[ADC121C] },
242 { }
243 };
244 MODULE_DEVICE_TABLE(of, adc081c_of_match);
245
246 static struct i2c_driver adc081c_driver = {
247 .driver = {
248 .name = "adc081c",
249 .of_match_table = adc081c_of_match,
250 .acpi_match_table = adc081c_acpi_match,
251 },
252 .probe = adc081c_probe,
253 .remove = adc081c_remove,
254 .id_table = adc081c_id,
255 };
256 module_i2c_driver(adc081c_driver);
257
258 MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>");
259 MODULE_DESCRIPTION("Texas Instruments ADC081C/ADC101C/ADC121C driver");
260 MODULE_LICENSE("GPL v2");
261