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/err.h> |
13 | #include <linux/iio/iio.h> |
14 | #include <linux/mod_devicetable.h> |
15 | #include <linux/module.h> |
16 | #include <linux/property.h> |
17 | #include <linux/regulator/consumer.h> |
18 | #include <linux/spi/spi.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] __aligned(IIO_DMA_MINALIGN); |
32 | }; |
33 | |
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(spi: adc->spi, buf: &adc->buffer, len: 2); |
44 | if (ret < 0) { |
45 | mutex_unlock(lock: &adc->lock); |
46 | return ret; |
47 | } |
48 | |
49 | ret = spi_read(spi: adc->spi, buf: &adc->buffer, len: 2); |
50 | |
51 | mutex_unlock(lock: &adc->lock); |
52 | |
53 | if (ret < 0) |
54 | return ret; |
55 | |
56 | return ((adc->buffer[0] << 8 | adc->buffer[1]) & 0xFFF); |
57 | } |
58 | |
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->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(regulator: 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 | |
134 | static void adc128_disable_regulator(void *reg) |
135 | { |
136 | regulator_disable(regulator: reg); |
137 | } |
138 | |
139 | static int adc128_probe(struct spi_device *spi) |
140 | { |
141 | const struct adc128_configuration *config; |
142 | struct iio_dev *indio_dev; |
143 | struct adc128 *adc; |
144 | int ret; |
145 | |
146 | indio_dev = devm_iio_device_alloc(parent: &spi->dev, sizeof_priv: sizeof(*adc)); |
147 | if (!indio_dev) |
148 | return -ENOMEM; |
149 | |
150 | adc = iio_priv(indio_dev); |
151 | adc->spi = spi; |
152 | |
153 | indio_dev->name = spi_get_device_id(sdev: spi)->name; |
154 | indio_dev->modes = INDIO_DIRECT_MODE; |
155 | indio_dev->info = &adc128_info; |
156 | |
157 | config = spi_get_device_match_data(sdev: spi); |
158 | |
159 | indio_dev->channels = config->channels; |
160 | indio_dev->num_channels = config->num_channels; |
161 | |
162 | adc->reg = devm_regulator_get(dev: &spi->dev, id: "vref" ); |
163 | if (IS_ERR(ptr: adc->reg)) |
164 | return PTR_ERR(ptr: adc->reg); |
165 | |
166 | ret = regulator_enable(regulator: adc->reg); |
167 | if (ret < 0) |
168 | return ret; |
169 | ret = devm_add_action_or_reset(&spi->dev, adc128_disable_regulator, |
170 | adc->reg); |
171 | if (ret) |
172 | return ret; |
173 | |
174 | mutex_init(&adc->lock); |
175 | |
176 | return devm_iio_device_register(&spi->dev, indio_dev); |
177 | } |
178 | |
179 | static const struct of_device_id adc128_of_match[] = { |
180 | { .compatible = "ti,adc128s052" , .data = &adc128_config[0] }, |
181 | { .compatible = "ti,adc122s021" , .data = &adc128_config[1] }, |
182 | { .compatible = "ti,adc122s051" , .data = &adc128_config[1] }, |
183 | { .compatible = "ti,adc122s101" , .data = &adc128_config[1] }, |
184 | { .compatible = "ti,adc124s021" , .data = &adc128_config[2] }, |
185 | { .compatible = "ti,adc124s051" , .data = &adc128_config[2] }, |
186 | { .compatible = "ti,adc124s101" , .data = &adc128_config[2] }, |
187 | { /* sentinel */ }, |
188 | }; |
189 | MODULE_DEVICE_TABLE(of, adc128_of_match); |
190 | |
191 | static const struct spi_device_id adc128_id[] = { |
192 | { "adc128s052" , (kernel_ulong_t)&adc128_config[0] }, |
193 | { "adc122s021" , (kernel_ulong_t)&adc128_config[1] }, |
194 | { "adc122s051" , (kernel_ulong_t)&adc128_config[1] }, |
195 | { "adc122s101" , (kernel_ulong_t)&adc128_config[1] }, |
196 | { "adc124s021" , (kernel_ulong_t)&adc128_config[2] }, |
197 | { "adc124s051" , (kernel_ulong_t)&adc128_config[2] }, |
198 | { "adc124s101" , (kernel_ulong_t)&adc128_config[2] }, |
199 | { } |
200 | }; |
201 | MODULE_DEVICE_TABLE(spi, adc128_id); |
202 | |
203 | static const struct acpi_device_id adc128_acpi_match[] = { |
204 | { "AANT1280" , (kernel_ulong_t)&adc128_config[2] }, |
205 | { } |
206 | }; |
207 | MODULE_DEVICE_TABLE(acpi, adc128_acpi_match); |
208 | |
209 | static struct spi_driver adc128_driver = { |
210 | .driver = { |
211 | .name = "adc128s052" , |
212 | .of_match_table = adc128_of_match, |
213 | .acpi_match_table = adc128_acpi_match, |
214 | }, |
215 | .probe = adc128_probe, |
216 | .id_table = adc128_id, |
217 | }; |
218 | module_spi_driver(adc128_driver); |
219 | |
220 | MODULE_AUTHOR("Angelo Compagnucci <angelo.compagnucci@gmail.com>" ); |
221 | MODULE_DESCRIPTION("Texas Instruments ADC128S052" ); |
222 | MODULE_LICENSE("GPL v2" ); |
223 | |