1 | // SPDX-License-Identifier: GPL-2.0+ |
2 | /* |
3 | * ti-adc161s626.c - Texas Instruments ADC161S626 1-channel differential ADC |
4 | * |
5 | * ADC Devices Supported: |
6 | * adc141s626 - 14-bit ADC |
7 | * adc161s626 - 16-bit ADC |
8 | * |
9 | * Copyright (C) 2016-2018 |
10 | * Author: Matt Ranostay <matt.ranostay@konsulko.com> |
11 | */ |
12 | |
13 | #include <linux/module.h> |
14 | #include <linux/mod_devicetable.h> |
15 | #include <linux/init.h> |
16 | #include <linux/err.h> |
17 | #include <linux/spi/spi.h> |
18 | #include <linux/iio/iio.h> |
19 | #include <linux/iio/trigger.h> |
20 | #include <linux/iio/buffer.h> |
21 | #include <linux/iio/trigger_consumer.h> |
22 | #include <linux/iio/triggered_buffer.h> |
23 | #include <linux/regulator/consumer.h> |
24 | |
25 | #define TI_ADC_DRV_NAME "ti-adc161s626" |
26 | |
27 | enum { |
28 | TI_ADC141S626, |
29 | TI_ADC161S626, |
30 | }; |
31 | |
32 | static const struct iio_chan_spec ti_adc141s626_channels[] = { |
33 | { |
34 | .type = IIO_VOLTAGE, |
35 | .channel = 0, |
36 | .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | |
37 | BIT(IIO_CHAN_INFO_SCALE) | |
38 | BIT(IIO_CHAN_INFO_OFFSET), |
39 | .scan_index = 0, |
40 | .scan_type = { |
41 | .sign = 's', |
42 | .realbits = 14, |
43 | .storagebits = 16, |
44 | }, |
45 | }, |
46 | IIO_CHAN_SOFT_TIMESTAMP(1), |
47 | }; |
48 | |
49 | static const struct iio_chan_spec ti_adc161s626_channels[] = { |
50 | { |
51 | .type = IIO_VOLTAGE, |
52 | .channel = 0, |
53 | .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | |
54 | BIT(IIO_CHAN_INFO_SCALE) | |
55 | BIT(IIO_CHAN_INFO_OFFSET), |
56 | .scan_index = 0, |
57 | .scan_type = { |
58 | .sign = 's', |
59 | .realbits = 16, |
60 | .storagebits = 16, |
61 | }, |
62 | }, |
63 | IIO_CHAN_SOFT_TIMESTAMP(1), |
64 | }; |
65 | |
66 | struct ti_adc_data { |
67 | struct iio_dev *indio_dev; |
68 | struct spi_device *spi; |
69 | struct regulator *ref; |
70 | |
71 | u8 read_size; |
72 | u8 shift; |
73 | |
74 | u8 buffer[16] __aligned(IIO_DMA_MINALIGN); |
75 | }; |
76 | |
77 | static int ti_adc_read_measurement(struct ti_adc_data *data, |
78 | struct iio_chan_spec const *chan, int *val) |
79 | { |
80 | int ret; |
81 | |
82 | switch (data->read_size) { |
83 | case 2: { |
84 | __be16 buf; |
85 | |
86 | ret = spi_read(spi: data->spi, buf: (void *) &buf, len: 2); |
87 | if (ret) |
88 | return ret; |
89 | |
90 | *val = be16_to_cpu(buf); |
91 | break; |
92 | } |
93 | case 3: { |
94 | __be32 buf; |
95 | |
96 | ret = spi_read(spi: data->spi, buf: (void *) &buf, len: 3); |
97 | if (ret) |
98 | return ret; |
99 | |
100 | *val = be32_to_cpu(buf) >> 8; |
101 | break; |
102 | } |
103 | default: |
104 | return -EINVAL; |
105 | } |
106 | |
107 | *val = sign_extend32(value: *val >> data->shift, index: chan->scan_type.realbits - 1); |
108 | |
109 | return 0; |
110 | } |
111 | |
112 | static irqreturn_t ti_adc_trigger_handler(int irq, void *private) |
113 | { |
114 | struct iio_poll_func *pf = private; |
115 | struct iio_dev *indio_dev = pf->indio_dev; |
116 | struct ti_adc_data *data = iio_priv(indio_dev); |
117 | int ret; |
118 | |
119 | ret = ti_adc_read_measurement(data, chan: &indio_dev->channels[0], |
120 | val: (int *) &data->buffer); |
121 | if (!ret) |
122 | iio_push_to_buffers_with_timestamp(indio_dev, |
123 | data: data->buffer, |
124 | timestamp: iio_get_time_ns(indio_dev)); |
125 | |
126 | iio_trigger_notify_done(trig: indio_dev->trig); |
127 | |
128 | return IRQ_HANDLED; |
129 | } |
130 | |
131 | static int ti_adc_read_raw(struct iio_dev *indio_dev, |
132 | struct iio_chan_spec const *chan, |
133 | int *val, int *val2, long mask) |
134 | { |
135 | struct ti_adc_data *data = iio_priv(indio_dev); |
136 | int ret; |
137 | |
138 | switch (mask) { |
139 | case IIO_CHAN_INFO_RAW: |
140 | ret = iio_device_claim_direct_mode(indio_dev); |
141 | if (ret) |
142 | return ret; |
143 | |
144 | ret = ti_adc_read_measurement(data, chan, val); |
145 | iio_device_release_direct_mode(indio_dev); |
146 | |
147 | if (ret) |
148 | return ret; |
149 | |
150 | return IIO_VAL_INT; |
151 | case IIO_CHAN_INFO_SCALE: |
152 | ret = regulator_get_voltage(regulator: data->ref); |
153 | if (ret < 0) |
154 | return ret; |
155 | |
156 | *val = ret / 1000; |
157 | *val2 = chan->scan_type.realbits; |
158 | |
159 | return IIO_VAL_FRACTIONAL_LOG2; |
160 | case IIO_CHAN_INFO_OFFSET: |
161 | *val = 1 << (chan->scan_type.realbits - 1); |
162 | return IIO_VAL_INT; |
163 | } |
164 | |
165 | return 0; |
166 | } |
167 | |
168 | static const struct iio_info ti_adc_info = { |
169 | .read_raw = ti_adc_read_raw, |
170 | }; |
171 | |
172 | static void ti_adc_reg_disable(void *reg) |
173 | { |
174 | regulator_disable(regulator: reg); |
175 | } |
176 | |
177 | static int ti_adc_probe(struct spi_device *spi) |
178 | { |
179 | struct iio_dev *indio_dev; |
180 | struct ti_adc_data *data; |
181 | int ret; |
182 | |
183 | indio_dev = devm_iio_device_alloc(parent: &spi->dev, sizeof_priv: sizeof(*data)); |
184 | if (!indio_dev) |
185 | return -ENOMEM; |
186 | |
187 | indio_dev->info = &ti_adc_info; |
188 | indio_dev->name = TI_ADC_DRV_NAME; |
189 | indio_dev->modes = INDIO_DIRECT_MODE; |
190 | |
191 | data = iio_priv(indio_dev); |
192 | data->spi = spi; |
193 | |
194 | switch (spi_get_device_id(sdev: spi)->driver_data) { |
195 | case TI_ADC141S626: |
196 | indio_dev->channels = ti_adc141s626_channels; |
197 | indio_dev->num_channels = ARRAY_SIZE(ti_adc141s626_channels); |
198 | data->shift = 0; |
199 | data->read_size = 2; |
200 | break; |
201 | case TI_ADC161S626: |
202 | indio_dev->channels = ti_adc161s626_channels; |
203 | indio_dev->num_channels = ARRAY_SIZE(ti_adc161s626_channels); |
204 | data->shift = 6; |
205 | data->read_size = 3; |
206 | break; |
207 | } |
208 | |
209 | data->ref = devm_regulator_get(dev: &spi->dev, id: "vdda" ); |
210 | if (IS_ERR(ptr: data->ref)) |
211 | return PTR_ERR(ptr: data->ref); |
212 | |
213 | ret = regulator_enable(regulator: data->ref); |
214 | if (ret < 0) |
215 | return ret; |
216 | |
217 | ret = devm_add_action_or_reset(&spi->dev, ti_adc_reg_disable, |
218 | data->ref); |
219 | if (ret) |
220 | return ret; |
221 | |
222 | ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev, NULL, |
223 | ti_adc_trigger_handler, NULL); |
224 | if (ret) |
225 | return ret; |
226 | |
227 | return devm_iio_device_register(&spi->dev, indio_dev); |
228 | } |
229 | |
230 | static const struct of_device_id ti_adc_dt_ids[] = { |
231 | { .compatible = "ti,adc141s626" , }, |
232 | { .compatible = "ti,adc161s626" , }, |
233 | {} |
234 | }; |
235 | MODULE_DEVICE_TABLE(of, ti_adc_dt_ids); |
236 | |
237 | static const struct spi_device_id ti_adc_id[] = { |
238 | {"adc141s626" , TI_ADC141S626}, |
239 | {"adc161s626" , TI_ADC161S626}, |
240 | {}, |
241 | }; |
242 | MODULE_DEVICE_TABLE(spi, ti_adc_id); |
243 | |
244 | static struct spi_driver ti_adc_driver = { |
245 | .driver = { |
246 | .name = TI_ADC_DRV_NAME, |
247 | .of_match_table = ti_adc_dt_ids, |
248 | }, |
249 | .probe = ti_adc_probe, |
250 | .id_table = ti_adc_id, |
251 | }; |
252 | module_spi_driver(ti_adc_driver); |
253 | |
254 | MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>" ); |
255 | MODULE_DESCRIPTION("Texas Instruments ADC1x1S 1-channel differential ADC" ); |
256 | MODULE_LICENSE("GPL" ); |
257 | |