1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2014 Angelo Compagnucci <angelo.compagnucci@gmail.com>
4 *
5 * Driver for Texas Instruments' ADC128S052, ADC122S021 and ADC124S021 ADC chip.
6 * Datasheets can be found here:
7 * http://www.ti.com/lit/ds/symlink/adc128s052.pdf
8 * http://www.ti.com/lit/ds/symlink/adc122s021.pdf
9 * http://www.ti.com/lit/ds/symlink/adc124s021.pdf
10 */
11
12 #include <linux/acpi.h>
13 #include <linux/err.h>
14 #include <linux/spi/spi.h>
15 #include <linux/module.h>
16 #include <linux/iio/iio.h>
17 #include <linux/property.h>
18 #include <linux/regulator/consumer.h>
19
20 struct adc128_configuration {
21 const struct iio_chan_spec *channels;
22 u8 num_channels;
23 };
24
25 struct adc128 {
26 struct spi_device *spi;
27
28 struct regulator *reg;
29 struct mutex lock;
30
31 u8 buffer[2] ____cacheline_aligned;
32 };
33
adc128_adc_conversion(struct adc128 * adc,u8 channel)34 static int adc128_adc_conversion(struct adc128 *adc, u8 channel)
35 {
36 int ret;
37
38 mutex_lock(&adc->lock);
39
40 adc->buffer[0] = channel << 3;
41 adc->buffer[1] = 0;
42
43 ret = spi_write(adc->spi, &adc->buffer, 2);
44 if (ret < 0) {
45 mutex_unlock(&adc->lock);
46 return ret;
47 }
48
49 ret = spi_read(adc->spi, &adc->buffer, 2);
50
51 mutex_unlock(&adc->lock);
52
53 if (ret < 0)
54 return ret;
55
56 return ((adc->buffer[0] << 8 | adc->buffer[1]) & 0xFFF);
57 }
58
adc128_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * channel,int * val,int * val2,long mask)59 static int adc128_read_raw(struct iio_dev *indio_dev,
60 struct iio_chan_spec const *channel, int *val,
61 int *val2, long mask)
62 {
63 struct adc128 *adc = iio_priv(indio_dev);
64 int ret;
65
66 switch (mask) {
67 case IIO_CHAN_INFO_RAW:
68
69 ret = adc128_adc_conversion(adc, channel->channel);
70 if (ret < 0)
71 return ret;
72
73 *val = ret;
74 return IIO_VAL_INT;
75
76 case IIO_CHAN_INFO_SCALE:
77
78 ret = regulator_get_voltage(adc->reg);
79 if (ret < 0)
80 return ret;
81
82 *val = ret / 1000;
83 *val2 = 12;
84 return IIO_VAL_FRACTIONAL_LOG2;
85
86 default:
87 return -EINVAL;
88 }
89
90 }
91
92 #define ADC128_VOLTAGE_CHANNEL(num) \
93 { \
94 .type = IIO_VOLTAGE, \
95 .indexed = 1, \
96 .channel = (num), \
97 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
98 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
99 }
100
101 static const struct iio_chan_spec adc128s052_channels[] = {
102 ADC128_VOLTAGE_CHANNEL(0),
103 ADC128_VOLTAGE_CHANNEL(1),
104 ADC128_VOLTAGE_CHANNEL(2),
105 ADC128_VOLTAGE_CHANNEL(3),
106 ADC128_VOLTAGE_CHANNEL(4),
107 ADC128_VOLTAGE_CHANNEL(5),
108 ADC128_VOLTAGE_CHANNEL(6),
109 ADC128_VOLTAGE_CHANNEL(7),
110 };
111
112 static const struct iio_chan_spec adc122s021_channels[] = {
113 ADC128_VOLTAGE_CHANNEL(0),
114 ADC128_VOLTAGE_CHANNEL(1),
115 };
116
117 static const struct iio_chan_spec adc124s021_channels[] = {
118 ADC128_VOLTAGE_CHANNEL(0),
119 ADC128_VOLTAGE_CHANNEL(1),
120 ADC128_VOLTAGE_CHANNEL(2),
121 ADC128_VOLTAGE_CHANNEL(3),
122 };
123
124 static const struct adc128_configuration adc128_config[] = {
125 { adc128s052_channels, ARRAY_SIZE(adc128s052_channels) },
126 { adc122s021_channels, ARRAY_SIZE(adc122s021_channels) },
127 { adc124s021_channels, ARRAY_SIZE(adc124s021_channels) },
128 };
129
130 static const struct iio_info adc128_info = {
131 .read_raw = adc128_read_raw,
132 };
133
adc128_probe(struct spi_device * spi)134 static int adc128_probe(struct spi_device *spi)
135 {
136 struct iio_dev *indio_dev;
137 unsigned int config;
138 struct adc128 *adc;
139 int ret;
140
141 if (dev_fwnode(&spi->dev))
142 config = (unsigned long) device_get_match_data(&spi->dev);
143 else
144 config = spi_get_device_id(spi)->driver_data;
145
146 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc));
147 if (!indio_dev)
148 return -ENOMEM;
149
150 adc = iio_priv(indio_dev);
151 adc->spi = spi;
152
153 spi_set_drvdata(spi, indio_dev);
154
155 indio_dev->dev.parent = &spi->dev;
156 indio_dev->dev.of_node = spi->dev.of_node;
157 indio_dev->name = spi_get_device_id(spi)->name;
158 indio_dev->modes = INDIO_DIRECT_MODE;
159 indio_dev->info = &adc128_info;
160
161 indio_dev->channels = adc128_config[config].channels;
162 indio_dev->num_channels = adc128_config[config].num_channels;
163
164 adc->reg = devm_regulator_get(&spi->dev, "vref");
165 if (IS_ERR(adc->reg))
166 return PTR_ERR(adc->reg);
167
168 ret = regulator_enable(adc->reg);
169 if (ret < 0)
170 return ret;
171
172 mutex_init(&adc->lock);
173
174 ret = iio_device_register(indio_dev);
175 if (ret)
176 goto err_disable_regulator;
177
178 return 0;
179
180 err_disable_regulator:
181 regulator_disable(adc->reg);
182 return ret;
183 }
184
adc128_remove(struct spi_device * spi)185 static int adc128_remove(struct spi_device *spi)
186 {
187 struct iio_dev *indio_dev = spi_get_drvdata(spi);
188 struct adc128 *adc = iio_priv(indio_dev);
189
190 iio_device_unregister(indio_dev);
191 regulator_disable(adc->reg);
192
193 return 0;
194 }
195
196 static const struct of_device_id adc128_of_match[] = {
197 { .compatible = "ti,adc128s052", .data = (void*)0L, },
198 { .compatible = "ti,adc122s021", .data = (void*)1L, },
199 { .compatible = "ti,adc122s051", .data = (void*)1L, },
200 { .compatible = "ti,adc122s101", .data = (void*)1L, },
201 { .compatible = "ti,adc124s021", .data = (void*)2L, },
202 { .compatible = "ti,adc124s051", .data = (void*)2L, },
203 { .compatible = "ti,adc124s101", .data = (void*)2L, },
204 { /* sentinel */ },
205 };
206 MODULE_DEVICE_TABLE(of, adc128_of_match);
207
208 static const struct spi_device_id adc128_id[] = {
209 { "adc128s052", 0 }, /* index into adc128_config */
210 { "adc122s021", 1 },
211 { "adc122s051", 1 },
212 { "adc122s101", 1 },
213 { "adc124s021", 2 },
214 { "adc124s051", 2 },
215 { "adc124s101", 2 },
216 { }
217 };
218 MODULE_DEVICE_TABLE(spi, adc128_id);
219
220 #ifdef CONFIG_ACPI
221 static const struct acpi_device_id adc128_acpi_match[] = {
222 { "AANT1280", 2 }, /* ADC124S021 compatible ACPI ID */
223 { }
224 };
225 MODULE_DEVICE_TABLE(acpi, adc128_acpi_match);
226 #endif
227
228 static struct spi_driver adc128_driver = {
229 .driver = {
230 .name = "adc128s052",
231 .of_match_table = of_match_ptr(adc128_of_match),
232 .acpi_match_table = ACPI_PTR(adc128_acpi_match),
233 },
234 .probe = adc128_probe,
235 .remove = adc128_remove,
236 .id_table = adc128_id,
237 };
238 module_spi_driver(adc128_driver);
239
240 MODULE_AUTHOR("Angelo Compagnucci <angelo.compagnucci@gmail.com>");
241 MODULE_DESCRIPTION("Texas Instruments ADC128S052");
242 MODULE_LICENSE("GPL v2");
243