2 * ti-adc161s626.c - Texas Instruments ADC161S626 1-channel differential ADC
4 * ADC Devices Supported:
5 * adc141s626 - 14-bit ADC
6 * adc161s626 - 16-bit ADC
8 * Copyright (C) 2016 Matt Ranostay <mranostay@gmail.com>
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
21 #include <linux/module.h>
22 #include <linux/init.h>
23 #include <linux/err.h>
24 #include <linux/spi/spi.h>
25 #include <linux/iio/iio.h>
26 #include <linux/iio/trigger.h>
27 #include <linux/iio/buffer.h>
28 #include <linux/iio/trigger_consumer.h>
29 #include <linux/iio/triggered_buffer.h>
30 #include <linux/regulator/consumer.h>
32 #define TI_ADC_DRV_NAME "ti-adc161s626"
39 static const struct iio_chan_spec ti_adc141s626_channels[] = {
43 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
44 BIT(IIO_CHAN_INFO_SCALE) |
45 BIT(IIO_CHAN_INFO_OFFSET),
53 IIO_CHAN_SOFT_TIMESTAMP(1),
56 static const struct iio_chan_spec ti_adc161s626_channels[] = {
60 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
61 BIT(IIO_CHAN_INFO_SCALE) |
62 BIT(IIO_CHAN_INFO_OFFSET),
70 IIO_CHAN_SOFT_TIMESTAMP(1),
74 struct iio_dev *indio_dev;
75 struct spi_device *spi;
76 struct regulator *ref;
81 u8 buffer[16] ____cacheline_aligned;
84 static int ti_adc_read_measurement(struct ti_adc_data *data,
85 struct iio_chan_spec const *chan, int *val)
89 switch (data->read_size) {
93 ret = spi_read(data->spi, (void *) &buf, 2);
97 *val = be16_to_cpu(buf);
103 ret = spi_read(data->spi, (void *) &buf, 3);
107 *val = be32_to_cpu(buf) >> 8;
114 *val = sign_extend32(*val >> data->shift, chan->scan_type.realbits - 1);
119 static irqreturn_t ti_adc_trigger_handler(int irq, void *private)
121 struct iio_poll_func *pf = private;
122 struct iio_dev *indio_dev = pf->indio_dev;
123 struct ti_adc_data *data = iio_priv(indio_dev);
126 ret = ti_adc_read_measurement(data, &indio_dev->channels[0],
127 (int *) &data->buffer);
129 iio_push_to_buffers_with_timestamp(indio_dev,
131 iio_get_time_ns(indio_dev));
133 iio_trigger_notify_done(indio_dev->trig);
138 static int ti_adc_read_raw(struct iio_dev *indio_dev,
139 struct iio_chan_spec const *chan,
140 int *val, int *val2, long mask)
142 struct ti_adc_data *data = iio_priv(indio_dev);
146 case IIO_CHAN_INFO_RAW:
147 ret = iio_device_claim_direct_mode(indio_dev);
151 ret = ti_adc_read_measurement(data, chan, val);
152 iio_device_release_direct_mode(indio_dev);
158 case IIO_CHAN_INFO_SCALE:
159 ret = regulator_get_voltage(data->ref);
164 *val2 = chan->scan_type.realbits;
166 return IIO_VAL_FRACTIONAL_LOG2;
167 case IIO_CHAN_INFO_OFFSET:
168 *val = 1 << (chan->scan_type.realbits - 1);
175 static const struct iio_info ti_adc_info = {
176 .driver_module = THIS_MODULE,
177 .read_raw = ti_adc_read_raw,
180 static int ti_adc_probe(struct spi_device *spi)
182 struct iio_dev *indio_dev;
183 struct ti_adc_data *data;
186 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*data));
190 indio_dev->info = &ti_adc_info;
191 indio_dev->dev.parent = &spi->dev;
192 indio_dev->dev.of_node = spi->dev.of_node;
193 indio_dev->name = TI_ADC_DRV_NAME;
194 indio_dev->modes = INDIO_DIRECT_MODE;
195 spi_set_drvdata(spi, indio_dev);
197 data = iio_priv(indio_dev);
200 switch (spi_get_device_id(spi)->driver_data) {
202 indio_dev->channels = ti_adc141s626_channels;
203 indio_dev->num_channels = ARRAY_SIZE(ti_adc141s626_channels);
208 indio_dev->channels = ti_adc161s626_channels;
209 indio_dev->num_channels = ARRAY_SIZE(ti_adc161s626_channels);
215 data->ref = devm_regulator_get(&spi->dev, "vdda");
216 if (!IS_ERR(data->ref)) {
217 ret = regulator_enable(data->ref);
222 ret = iio_triggered_buffer_setup(indio_dev, NULL,
223 ti_adc_trigger_handler, NULL);
225 goto error_regulator_disable;
227 ret = iio_device_register(indio_dev);
229 goto error_unreg_buffer;
234 iio_triggered_buffer_cleanup(indio_dev);
236 error_regulator_disable:
237 regulator_disable(data->ref);
242 static int ti_adc_remove(struct spi_device *spi)
244 struct iio_dev *indio_dev = spi_get_drvdata(spi);
245 struct ti_adc_data *data = iio_priv(indio_dev);
247 iio_device_unregister(indio_dev);
248 iio_triggered_buffer_cleanup(indio_dev);
249 regulator_disable(data->ref);
254 static const struct of_device_id ti_adc_dt_ids[] = {
255 { .compatible = "ti,adc141s626", },
256 { .compatible = "ti,adc161s626", },
259 MODULE_DEVICE_TABLE(of, ti_adc_dt_ids);
261 static const struct spi_device_id ti_adc_id[] = {
262 {"adc141s626", TI_ADC141S626},
263 {"adc161s626", TI_ADC161S626},
266 MODULE_DEVICE_TABLE(spi, ti_adc_id);
268 static struct spi_driver ti_adc_driver = {
270 .name = TI_ADC_DRV_NAME,
271 .of_match_table = of_match_ptr(ti_adc_dt_ids),
273 .probe = ti_adc_probe,
274 .remove = ti_adc_remove,
275 .id_table = ti_adc_id,
277 module_spi_driver(ti_adc_driver);
279 MODULE_AUTHOR("Matt Ranostay <mranostay@gmail.com>");
280 MODULE_DESCRIPTION("Texas Instruments ADC1x1S 1-channel differential ADC");
281 MODULE_LICENSE("GPL");