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 | |
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(indio_dev: iio); |
51 | int err; |
52 | |
53 | switch (mask) { |
54 | case IIO_CHAN_INFO_RAW: |
55 | err = i2c_smbus_read_word_swapped(client: 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(regulator: 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 | |
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(client: 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: &data->scan, |
144 | timestamp: iio_get_time_ns(indio_dev)); |
145 | out: |
146 | iio_trigger_notify_done(trig: indio_dev->trig); |
147 | return IRQ_HANDLED; |
148 | } |
149 | |
150 | static void adc081c_reg_disable(void *reg) |
151 | { |
152 | regulator_disable(regulator: reg); |
153 | } |
154 | |
155 | static int adc081c_probe(struct i2c_client *client) |
156 | { |
157 | struct iio_dev *iio; |
158 | struct adc081c *adc; |
159 | const struct adcxx1c_model *model; |
160 | int err; |
161 | |
162 | if (!i2c_check_functionality(adap: client->adapter, I2C_FUNC_SMBUS_WORD_DATA)) |
163 | return -EOPNOTSUPP; |
164 | |
165 | model = i2c_get_match_data(client); |
166 | |
167 | iio = devm_iio_device_alloc(parent: &client->dev, sizeof_priv: sizeof(*adc)); |
168 | if (!iio) |
169 | return -ENOMEM; |
170 | |
171 | adc = iio_priv(indio_dev: iio); |
172 | adc->i2c = client; |
173 | adc->bits = model->bits; |
174 | |
175 | adc->ref = devm_regulator_get(dev: &client->dev, id: "vref" ); |
176 | if (IS_ERR(ptr: adc->ref)) |
177 | return PTR_ERR(ptr: adc->ref); |
178 | |
179 | err = regulator_enable(regulator: adc->ref); |
180 | if (err < 0) |
181 | return err; |
182 | |
183 | err = devm_add_action_or_reset(&client->dev, adc081c_reg_disable, |
184 | adc->ref); |
185 | if (err) |
186 | return err; |
187 | |
188 | iio->name = dev_name(dev: &client->dev); |
189 | iio->modes = INDIO_DIRECT_MODE; |
190 | iio->info = &adc081c_info; |
191 | |
192 | iio->channels = model->channels; |
193 | iio->num_channels = ADC081C_NUM_CHANNELS; |
194 | |
195 | err = devm_iio_triggered_buffer_setup(&client->dev, iio, NULL, |
196 | adc081c_trigger_handler, NULL); |
197 | if (err < 0) { |
198 | dev_err(&client->dev, "iio triggered buffer setup failed\n" ); |
199 | return err; |
200 | } |
201 | |
202 | return devm_iio_device_register(&client->dev, iio); |
203 | } |
204 | |
205 | static const struct i2c_device_id adc081c_id[] = { |
206 | { "adc081c" , (kernel_ulong_t)&adcxx1c_models[ADC081C] }, |
207 | { "adc101c" , (kernel_ulong_t)&adcxx1c_models[ADC101C] }, |
208 | { "adc121c" , (kernel_ulong_t)&adcxx1c_models[ADC121C] }, |
209 | { } |
210 | }; |
211 | MODULE_DEVICE_TABLE(i2c, adc081c_id); |
212 | |
213 | static const struct acpi_device_id adc081c_acpi_match[] = { |
214 | /* Used on some AAEON boards */ |
215 | { "ADC081C" , (kernel_ulong_t)&adcxx1c_models[ADC081C] }, |
216 | { } |
217 | }; |
218 | MODULE_DEVICE_TABLE(acpi, adc081c_acpi_match); |
219 | |
220 | static const struct of_device_id adc081c_of_match[] = { |
221 | { .compatible = "ti,adc081c" , .data = &adcxx1c_models[ADC081C] }, |
222 | { .compatible = "ti,adc101c" , .data = &adcxx1c_models[ADC101C] }, |
223 | { .compatible = "ti,adc121c" , .data = &adcxx1c_models[ADC121C] }, |
224 | { } |
225 | }; |
226 | MODULE_DEVICE_TABLE(of, adc081c_of_match); |
227 | |
228 | static struct i2c_driver adc081c_driver = { |
229 | .driver = { |
230 | .name = "adc081c" , |
231 | .of_match_table = adc081c_of_match, |
232 | .acpi_match_table = adc081c_acpi_match, |
233 | }, |
234 | .probe = adc081c_probe, |
235 | .id_table = adc081c_id, |
236 | }; |
237 | module_i2c_driver(adc081c_driver); |
238 | |
239 | MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>" ); |
240 | MODULE_DESCRIPTION("Texas Instruments ADC081C/ADC101C/ADC121C driver" ); |
241 | MODULE_LICENSE("GPL v2" ); |
242 | |