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 * https://www.ti.com/lit/ds/symlink/adc128s052.pdf
8 * https://www.ti.com/lit/ds/symlink/adc122s021.pdf
9 * https://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/mod_devicetable.h>
17 #include <linux/iio/iio.h>
18 #include <linux/property.h>
19 #include <linux/regulator/consumer.h>
20
21 struct adc128_configuration {
22 const struct iio_chan_spec *channels;
23 u8 num_channels;
24 };
25
26 struct adc128 {
27 struct spi_device *spi;
28
29 struct regulator *reg;
30 struct mutex lock;
31
32 u8 buffer[2] __aligned(IIO_DMA_MINALIGN);
33 };
34
adc128_adc_conversion(struct adc128 * adc,u8 channel)35 static int adc128_adc_conversion(struct adc128 *adc, u8 channel)
36 {
37 int ret;
38
39 mutex_lock(&adc->lock);
40
41 adc->buffer[0] = channel << 3;
42 adc->buffer[1] = 0;
43
44 ret = spi_write(adc->spi, &adc->buffer, 2);
45 if (ret < 0) {
46 mutex_unlock(&adc->lock);
47 return ret;
48 }
49
50 ret = spi_read(adc->spi, &adc->buffer, 2);
51
52 mutex_unlock(&adc->lock);
53
54 if (ret < 0)
55 return ret;
56
57 return ((adc->buffer[0] << 8 | adc->buffer[1]) & 0xFFF);
58 }
59
adc128_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * channel,int * val,int * val2,long mask)60 static int adc128_read_raw(struct iio_dev *indio_dev,
61 struct iio_chan_spec const *channel, int *val,
62 int *val2, long mask)
63 {
64 struct adc128 *adc = iio_priv(indio_dev);
65 int ret;
66
67 switch (mask) {
68 case IIO_CHAN_INFO_RAW:
69
70 ret = adc128_adc_conversion(adc, channel->channel);
71 if (ret < 0)
72 return ret;
73
74 *val = ret;
75 return IIO_VAL_INT;
76
77 case IIO_CHAN_INFO_SCALE:
78
79 ret = regulator_get_voltage(adc->reg);
80 if (ret < 0)
81 return ret;
82
83 *val = ret / 1000;
84 *val2 = 12;
85 return IIO_VAL_FRACTIONAL_LOG2;
86
87 default:
88 return -EINVAL;
89 }
90
91 }
92
93 #define ADC128_VOLTAGE_CHANNEL(num) \
94 { \
95 .type = IIO_VOLTAGE, \
96 .indexed = 1, \
97 .channel = (num), \
98 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
99 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
100 }
101
102 static const struct iio_chan_spec adc128s052_channels[] = {
103 ADC128_VOLTAGE_CHANNEL(0),
104 ADC128_VOLTAGE_CHANNEL(1),
105 ADC128_VOLTAGE_CHANNEL(2),
106 ADC128_VOLTAGE_CHANNEL(3),
107 ADC128_VOLTAGE_CHANNEL(4),
108 ADC128_VOLTAGE_CHANNEL(5),
109 ADC128_VOLTAGE_CHANNEL(6),
110 ADC128_VOLTAGE_CHANNEL(7),
111 };
112
113 static const struct iio_chan_spec adc122s021_channels[] = {
114 ADC128_VOLTAGE_CHANNEL(0),
115 ADC128_VOLTAGE_CHANNEL(1),
116 };
117
118 static const struct iio_chan_spec adc124s021_channels[] = {
119 ADC128_VOLTAGE_CHANNEL(0),
120 ADC128_VOLTAGE_CHANNEL(1),
121 ADC128_VOLTAGE_CHANNEL(2),
122 ADC128_VOLTAGE_CHANNEL(3),
123 };
124
125 static const struct adc128_configuration adc128_config[] = {
126 { adc128s052_channels, ARRAY_SIZE(adc128s052_channels) },
127 { adc122s021_channels, ARRAY_SIZE(adc122s021_channels) },
128 { adc124s021_channels, ARRAY_SIZE(adc124s021_channels) },
129 };
130
131 static const struct iio_info adc128_info = {
132 .read_raw = adc128_read_raw,
133 };
134
adc128_disable_regulator(void * reg)135 static void adc128_disable_regulator(void *reg)
136 {
137 regulator_disable(reg);
138 }
139
adc128_probe(struct spi_device * spi)140 static int adc128_probe(struct spi_device *spi)
141 {
142 struct iio_dev *indio_dev;
143 unsigned int config;
144 struct adc128 *adc;
145 int ret;
146
147 if (dev_fwnode(&spi->dev))
148 config = (unsigned long) device_get_match_data(&spi->dev);
149 else
150 config = spi_get_device_id(spi)->driver_data;
151
152 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc));
153 if (!indio_dev)
154 return -ENOMEM;
155
156 adc = iio_priv(indio_dev);
157 adc->spi = spi;
158
159 indio_dev->name = spi_get_device_id(spi)->name;
160 indio_dev->modes = INDIO_DIRECT_MODE;
161 indio_dev->info = &adc128_info;
162
163 indio_dev->channels = adc128_config[config].channels;
164 indio_dev->num_channels = adc128_config[config].num_channels;
165
166 adc->reg = devm_regulator_get(&spi->dev, "vref");
167 if (IS_ERR(adc->reg))
168 return PTR_ERR(adc->reg);
169
170 ret = regulator_enable(adc->reg);
171 if (ret < 0)
172 return ret;
173 ret = devm_add_action_or_reset(&spi->dev, adc128_disable_regulator,
174 adc->reg);
175 if (ret)
176 return ret;
177
178 mutex_init(&adc->lock);
179
180 return devm_iio_device_register(&spi->dev, indio_dev);
181 }
182
183 static const struct of_device_id adc128_of_match[] = {
184 { .compatible = "ti,adc128s052", },
185 { .compatible = "ti,adc122s021", },
186 { .compatible = "ti,adc122s051", },
187 { .compatible = "ti,adc122s101", },
188 { .compatible = "ti,adc124s021", },
189 { .compatible = "ti,adc124s051", },
190 { .compatible = "ti,adc124s101", },
191 { /* sentinel */ },
192 };
193 MODULE_DEVICE_TABLE(of, adc128_of_match);
194
195 static const struct spi_device_id adc128_id[] = {
196 { "adc128s052", 0 }, /* index into adc128_config */
197 { "adc122s021", 1 },
198 { "adc122s051", 1 },
199 { "adc122s101", 1 },
200 { "adc124s021", 2 },
201 { "adc124s051", 2 },
202 { "adc124s101", 2 },
203 { }
204 };
205 MODULE_DEVICE_TABLE(spi, adc128_id);
206
207 #ifdef CONFIG_ACPI
208 static const struct acpi_device_id adc128_acpi_match[] = {
209 { "AANT1280", 2 }, /* ADC124S021 compatible ACPI ID */
210 { }
211 };
212 MODULE_DEVICE_TABLE(acpi, adc128_acpi_match);
213 #endif
214
215 static struct spi_driver adc128_driver = {
216 .driver = {
217 .name = "adc128s052",
218 .of_match_table = adc128_of_match,
219 .acpi_match_table = ACPI_PTR(adc128_acpi_match),
220 },
221 .probe = adc128_probe,
222 .id_table = adc128_id,
223 };
224 module_spi_driver(adc128_driver);
225
226 MODULE_AUTHOR("Angelo Compagnucci <angelo.compagnucci@gmail.com>");
227 MODULE_DESCRIPTION("Texas Instruments ADC128S052");
228 MODULE_LICENSE("GPL v2");
229
