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/init.h>
15 #include <linux/err.h>
16 #include <linux/spi/spi.h>
17 #include <linux/iio/iio.h>
18 #include <linux/iio/trigger.h>
19 #include <linux/iio/buffer.h>
20 #include <linux/iio/trigger_consumer.h>
21 #include <linux/iio/triggered_buffer.h>
22 #include <linux/regulator/consumer.h>
24 #define TI_ADC_DRV_NAME "ti-adc161s626"
31 static const struct iio_chan_spec ti_adc141s626_channels[] = {
35 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
36 BIT(IIO_CHAN_INFO_SCALE) |
37 BIT(IIO_CHAN_INFO_OFFSET),
45 IIO_CHAN_SOFT_TIMESTAMP(1),
48 static const struct iio_chan_spec ti_adc161s626_channels[] = {
52 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
53 BIT(IIO_CHAN_INFO_SCALE) |
54 BIT(IIO_CHAN_INFO_OFFSET),
62 IIO_CHAN_SOFT_TIMESTAMP(1),
66 struct iio_dev *indio_dev;
67 struct spi_device *spi;
68 struct regulator *ref;
73 u8 buffer[16] ____cacheline_aligned;
76 static int ti_adc_read_measurement(struct ti_adc_data *data,
77 struct iio_chan_spec const *chan, int *val)
81 switch (data->read_size) {
85 ret = spi_read(data->spi, (void *) &buf, 2);
89 *val = be16_to_cpu(buf);
95 ret = spi_read(data->spi, (void *) &buf, 3);
99 *val = be32_to_cpu(buf) >> 8;
106 *val = sign_extend32(*val >> data->shift, chan->scan_type.realbits - 1);
111 static irqreturn_t ti_adc_trigger_handler(int irq, void *private)
113 struct iio_poll_func *pf = private;
114 struct iio_dev *indio_dev = pf->indio_dev;
115 struct ti_adc_data *data = iio_priv(indio_dev);
118 ret = ti_adc_read_measurement(data, &indio_dev->channels[0],
119 (int *) &data->buffer);
121 iio_push_to_buffers_with_timestamp(indio_dev,
123 iio_get_time_ns(indio_dev));
125 iio_trigger_notify_done(indio_dev->trig);
130 static int ti_adc_read_raw(struct iio_dev *indio_dev,
131 struct iio_chan_spec const *chan,
132 int *val, int *val2, long mask)
134 struct ti_adc_data *data = iio_priv(indio_dev);
138 case IIO_CHAN_INFO_RAW:
139 ret = iio_device_claim_direct_mode(indio_dev);
143 ret = ti_adc_read_measurement(data, chan, val);
144 iio_device_release_direct_mode(indio_dev);
150 case IIO_CHAN_INFO_SCALE:
151 ret = regulator_get_voltage(data->ref);
156 *val2 = chan->scan_type.realbits;
158 return IIO_VAL_FRACTIONAL_LOG2;
159 case IIO_CHAN_INFO_OFFSET:
160 *val = 1 << (chan->scan_type.realbits - 1);
167 static const struct iio_info ti_adc_info = {
168 .read_raw = ti_adc_read_raw,
171 static int ti_adc_probe(struct spi_device *spi)
173 struct iio_dev *indio_dev;
174 struct ti_adc_data *data;
177 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*data));
181 indio_dev->info = &ti_adc_info;
182 indio_dev->name = TI_ADC_DRV_NAME;
183 indio_dev->modes = INDIO_DIRECT_MODE;
184 spi_set_drvdata(spi, indio_dev);
186 data = iio_priv(indio_dev);
189 switch (spi_get_device_id(spi)->driver_data) {
191 indio_dev->channels = ti_adc141s626_channels;
192 indio_dev->num_channels = ARRAY_SIZE(ti_adc141s626_channels);
197 indio_dev->channels = ti_adc161s626_channels;
198 indio_dev->num_channels = ARRAY_SIZE(ti_adc161s626_channels);
204 data->ref = devm_regulator_get(&spi->dev, "vdda");
205 if (!IS_ERR(data->ref)) {
206 ret = regulator_enable(data->ref);
211 ret = iio_triggered_buffer_setup(indio_dev, NULL,
212 ti_adc_trigger_handler, NULL);
214 goto error_regulator_disable;
216 ret = iio_device_register(indio_dev);
218 goto error_unreg_buffer;
223 iio_triggered_buffer_cleanup(indio_dev);
225 error_regulator_disable:
226 regulator_disable(data->ref);
231 static int ti_adc_remove(struct spi_device *spi)
233 struct iio_dev *indio_dev = spi_get_drvdata(spi);
234 struct ti_adc_data *data = iio_priv(indio_dev);
236 iio_device_unregister(indio_dev);
237 iio_triggered_buffer_cleanup(indio_dev);
238 regulator_disable(data->ref);
243 static const struct of_device_id ti_adc_dt_ids[] = {
244 { .compatible = "ti,adc141s626", },
245 { .compatible = "ti,adc161s626", },
248 MODULE_DEVICE_TABLE(of, ti_adc_dt_ids);
250 static const struct spi_device_id ti_adc_id[] = {
251 {"adc141s626", TI_ADC141S626},
252 {"adc161s626", TI_ADC161S626},
255 MODULE_DEVICE_TABLE(spi, ti_adc_id);
257 static struct spi_driver ti_adc_driver = {
259 .name = TI_ADC_DRV_NAME,
260 .of_match_table = of_match_ptr(ti_adc_dt_ids),
262 .probe = ti_adc_probe,
263 .remove = ti_adc_remove,
264 .id_table = ti_adc_id,
266 module_spi_driver(ti_adc_driver);
268 MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
269 MODULE_DESCRIPTION("Texas Instruments ADC1x1S 1-channel differential ADC");
270 MODULE_LICENSE("GPL");