1 // SPDX-License-Identifier: GPL-2.0+
3 * ti-adc161s626.c - Texas Instruments ADC161S626 1-channel differential ADC
5 * ADC Devices Supported:
6 * adc141s626 - 14-bit ADC
7 * adc161s626 - 16-bit ADC
9 * Copyright (C) 2016-2018
10 * Author: Matt Ranostay <matt.ranostay@konsulko.com>
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>
25 #define TI_ADC_DRV_NAME "ti-adc161s626"
32 static const struct iio_chan_spec ti_adc141s626_channels[] = {
36 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
37 BIT(IIO_CHAN_INFO_SCALE) |
38 BIT(IIO_CHAN_INFO_OFFSET),
46 IIO_CHAN_SOFT_TIMESTAMP(1),
49 static const struct iio_chan_spec ti_adc161s626_channels[] = {
53 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
54 BIT(IIO_CHAN_INFO_SCALE) |
55 BIT(IIO_CHAN_INFO_OFFSET),
63 IIO_CHAN_SOFT_TIMESTAMP(1),
67 struct iio_dev *indio_dev;
68 struct spi_device *spi;
69 struct regulator *ref;
74 u8 buffer[16] ____cacheline_aligned;
77 static int ti_adc_read_measurement(struct ti_adc_data *data,
78 struct iio_chan_spec const *chan, int *val)
82 switch (data->read_size) {
86 ret = spi_read(data->spi, (void *) &buf, 2);
90 *val = be16_to_cpu(buf);
96 ret = spi_read(data->spi, (void *) &buf, 3);
100 *val = be32_to_cpu(buf) >> 8;
107 *val = sign_extend32(*val >> data->shift, chan->scan_type.realbits - 1);
112 static irqreturn_t ti_adc_trigger_handler(int irq, void *private)
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);
119 ret = ti_adc_read_measurement(data, &indio_dev->channels[0],
120 (int *) &data->buffer);
122 iio_push_to_buffers_with_timestamp(indio_dev,
124 iio_get_time_ns(indio_dev));
126 iio_trigger_notify_done(indio_dev->trig);
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)
135 struct ti_adc_data *data = iio_priv(indio_dev);
139 case IIO_CHAN_INFO_RAW:
140 ret = iio_device_claim_direct_mode(indio_dev);
144 ret = ti_adc_read_measurement(data, chan, val);
145 iio_device_release_direct_mode(indio_dev);
151 case IIO_CHAN_INFO_SCALE:
152 ret = regulator_get_voltage(data->ref);
157 *val2 = chan->scan_type.realbits;
159 return IIO_VAL_FRACTIONAL_LOG2;
160 case IIO_CHAN_INFO_OFFSET:
161 *val = 1 << (chan->scan_type.realbits - 1);
168 static const struct iio_info ti_adc_info = {
169 .read_raw = ti_adc_read_raw,
172 static int ti_adc_probe(struct spi_device *spi)
174 struct iio_dev *indio_dev;
175 struct ti_adc_data *data;
178 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*data));
182 indio_dev->info = &ti_adc_info;
183 indio_dev->name = TI_ADC_DRV_NAME;
184 indio_dev->modes = INDIO_DIRECT_MODE;
185 spi_set_drvdata(spi, indio_dev);
187 data = iio_priv(indio_dev);
190 switch (spi_get_device_id(spi)->driver_data) {
192 indio_dev->channels = ti_adc141s626_channels;
193 indio_dev->num_channels = ARRAY_SIZE(ti_adc141s626_channels);
198 indio_dev->channels = ti_adc161s626_channels;
199 indio_dev->num_channels = ARRAY_SIZE(ti_adc161s626_channels);
205 data->ref = devm_regulator_get(&spi->dev, "vdda");
206 if (!IS_ERR(data->ref)) {
207 ret = regulator_enable(data->ref);
212 ret = iio_triggered_buffer_setup(indio_dev, NULL,
213 ti_adc_trigger_handler, NULL);
215 goto error_regulator_disable;
217 ret = iio_device_register(indio_dev);
219 goto error_unreg_buffer;
224 iio_triggered_buffer_cleanup(indio_dev);
226 error_regulator_disable:
227 regulator_disable(data->ref);
232 static int ti_adc_remove(struct spi_device *spi)
234 struct iio_dev *indio_dev = spi_get_drvdata(spi);
235 struct ti_adc_data *data = iio_priv(indio_dev);
237 iio_device_unregister(indio_dev);
238 iio_triggered_buffer_cleanup(indio_dev);
239 regulator_disable(data->ref);
244 static const struct of_device_id ti_adc_dt_ids[] = {
245 { .compatible = "ti,adc141s626", },
246 { .compatible = "ti,adc161s626", },
249 MODULE_DEVICE_TABLE(of, ti_adc_dt_ids);
251 static const struct spi_device_id ti_adc_id[] = {
252 {"adc141s626", TI_ADC141S626},
253 {"adc161s626", TI_ADC161S626},
256 MODULE_DEVICE_TABLE(spi, ti_adc_id);
258 static struct spi_driver ti_adc_driver = {
260 .name = TI_ADC_DRV_NAME,
261 .of_match_table = ti_adc_dt_ids,
263 .probe = ti_adc_probe,
264 .remove = ti_adc_remove,
265 .id_table = ti_adc_id,
267 module_spi_driver(ti_adc_driver);
269 MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
270 MODULE_DESCRIPTION("Texas Instruments ADC1x1S 1-channel differential ADC");
271 MODULE_LICENSE("GPL");