1 // SPDX-License-Identifier: GPL-2.0
2 /* TI ADS124S0X chip family driver
3 * Copyright (C) 2018 Texas Instruments Incorporated - https://www.ti.com/
7 #include <linux/delay.h>
8 #include <linux/device.h>
9 #include <linux/kernel.h>
10 #include <linux/module.h>
12 #include <linux/of_gpio.h>
13 #include <linux/slab.h>
14 #include <linux/sysfs.h>
16 #include <linux/gpio/consumer.h>
17 #include <linux/spi/spi.h>
19 #include <linux/iio/iio.h>
20 #include <linux/iio/buffer.h>
21 #include <linux/iio/trigger_consumer.h>
22 #include <linux/iio/triggered_buffer.h>
23 #include <linux/iio/sysfs.h>
25 #include <asm/unaligned.h>
28 #define ADS124S08_CMD_NOP 0x00
29 #define ADS124S08_CMD_WAKEUP 0x02
30 #define ADS124S08_CMD_PWRDWN 0x04
31 #define ADS124S08_CMD_RESET 0x06
32 #define ADS124S08_CMD_START 0x08
33 #define ADS124S08_CMD_STOP 0x0a
34 #define ADS124S08_CMD_SYOCAL 0x16
35 #define ADS124S08_CMD_SYGCAL 0x17
36 #define ADS124S08_CMD_SFOCAL 0x19
37 #define ADS124S08_CMD_RDATA 0x12
38 #define ADS124S08_CMD_RREG 0x20
39 #define ADS124S08_CMD_WREG 0x40
42 #define ADS124S08_ID_REG 0x00
43 #define ADS124S08_STATUS 0x01
44 #define ADS124S08_INPUT_MUX 0x02
45 #define ADS124S08_PGA 0x03
46 #define ADS124S08_DATA_RATE 0x04
47 #define ADS124S08_REF 0x05
48 #define ADS124S08_IDACMAG 0x06
49 #define ADS124S08_IDACMUX 0x07
50 #define ADS124S08_VBIAS 0x08
51 #define ADS124S08_SYS 0x09
52 #define ADS124S08_OFCAL0 0x0a
53 #define ADS124S08_OFCAL1 0x0b
54 #define ADS124S08_OFCAL2 0x0c
55 #define ADS124S08_FSCAL0 0x0d
56 #define ADS124S08_FSCAL1 0x0e
57 #define ADS124S08_FSCAL2 0x0f
58 #define ADS124S08_GPIODAT 0x10
59 #define ADS124S08_GPIOCON 0x11
61 /* ADS124S0x common channels */
62 #define ADS124S08_AIN0 0x00
63 #define ADS124S08_AIN1 0x01
64 #define ADS124S08_AIN2 0x02
65 #define ADS124S08_AIN3 0x03
66 #define ADS124S08_AIN4 0x04
67 #define ADS124S08_AIN5 0x05
68 #define ADS124S08_AINCOM 0x0c
69 /* ADS124S08 only channels */
70 #define ADS124S08_AIN6 0x06
71 #define ADS124S08_AIN7 0x07
72 #define ADS124S08_AIN8 0x08
73 #define ADS124S08_AIN9 0x09
74 #define ADS124S08_AIN10 0x0a
75 #define ADS124S08_AIN11 0x0b
76 #define ADS124S08_MAX_CHANNELS 12
78 #define ADS124S08_POS_MUX_SHIFT 0x04
79 #define ADS124S08_INT_REF 0x09
81 #define ADS124S08_START_REG_MASK 0x1f
82 #define ADS124S08_NUM_BYTES_MASK 0x1f
84 #define ADS124S08_START_CONV 0x01
85 #define ADS124S08_STOP_CONV 0x00
92 struct ads124s_chip_info {
93 const struct iio_chan_spec *channels;
94 unsigned int num_channels;
97 struct ads124s_private {
98 const struct ads124s_chip_info *chip_info;
99 struct gpio_desc *reset_gpio;
100 struct spi_device *spi;
103 * Used to correctly align data.
104 * Ensure timestamp is naturally aligned.
105 * Note that the full buffer length may not be needed if not
106 * all channels are enabled, as long as the alignment of the
107 * timestamp is maintained.
109 u32 buffer[ADS124S08_MAX_CHANNELS + sizeof(s64)/sizeof(u32)] __aligned(8);
110 u8 data[5] ____cacheline_aligned;
113 #define ADS124S08_CHAN(index) \
115 .type = IIO_VOLTAGE, \
118 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
119 .scan_index = index, \
127 static const struct iio_chan_spec ads124s06_channels[] = {
136 static const struct iio_chan_spec ads124s08_channels[] = {
151 static const struct ads124s_chip_info ads124s_chip_info_tbl[] = {
153 .channels = ads124s08_channels,
154 .num_channels = ARRAY_SIZE(ads124s08_channels),
157 .channels = ads124s06_channels,
158 .num_channels = ARRAY_SIZE(ads124s06_channels),
162 static int ads124s_write_cmd(struct iio_dev *indio_dev, u8 command)
164 struct ads124s_private *priv = iio_priv(indio_dev);
166 priv->data[0] = command;
168 return spi_write(priv->spi, &priv->data[0], 1);
171 static int ads124s_write_reg(struct iio_dev *indio_dev, u8 reg, u8 data)
173 struct ads124s_private *priv = iio_priv(indio_dev);
175 priv->data[0] = ADS124S08_CMD_WREG | reg;
177 priv->data[2] = data;
179 return spi_write(priv->spi, &priv->data[0], 3);
182 static int ads124s_reset(struct iio_dev *indio_dev)
184 struct ads124s_private *priv = iio_priv(indio_dev);
186 if (priv->reset_gpio) {
187 gpiod_set_value(priv->reset_gpio, 0);
189 gpiod_set_value(priv->reset_gpio, 1);
191 return ads124s_write_cmd(indio_dev, ADS124S08_CMD_RESET);
197 static int ads124s_read(struct iio_dev *indio_dev, unsigned int chan)
199 struct ads124s_private *priv = iio_priv(indio_dev);
201 struct spi_transfer t[] = {
203 .tx_buf = &priv->data[0],
207 .tx_buf = &priv->data[1],
208 .rx_buf = &priv->data[1],
213 priv->data[0] = ADS124S08_CMD_RDATA;
214 memset(&priv->data[1], ADS124S08_CMD_NOP, sizeof(priv->data) - 1);
216 ret = spi_sync_transfer(priv->spi, t, ARRAY_SIZE(t));
220 return get_unaligned_be24(&priv->data[2]);
223 static int ads124s_read_raw(struct iio_dev *indio_dev,
224 struct iio_chan_spec const *chan,
225 int *val, int *val2, long m)
227 struct ads124s_private *priv = iio_priv(indio_dev);
230 mutex_lock(&priv->lock);
232 case IIO_CHAN_INFO_RAW:
233 ret = ads124s_write_reg(indio_dev, ADS124S08_INPUT_MUX,
236 dev_err(&priv->spi->dev, "Set ADC CH failed\n");
240 ret = ads124s_write_cmd(indio_dev, ADS124S08_START_CONV);
242 dev_err(&priv->spi->dev, "Start conversions failed\n");
246 ret = ads124s_read(indio_dev, chan->channel);
248 dev_err(&priv->spi->dev, "Read ADC failed\n");
254 ret = ads124s_write_cmd(indio_dev, ADS124S08_STOP_CONV);
256 dev_err(&priv->spi->dev, "Stop conversions failed\n");
267 mutex_unlock(&priv->lock);
271 static const struct iio_info ads124s_info = {
272 .read_raw = &ads124s_read_raw,
275 static irqreturn_t ads124s_trigger_handler(int irq, void *p)
277 struct iio_poll_func *pf = p;
278 struct iio_dev *indio_dev = pf->indio_dev;
279 struct ads124s_private *priv = iio_priv(indio_dev);
280 int scan_index, j = 0;
283 for_each_set_bit(scan_index, indio_dev->active_scan_mask,
284 indio_dev->masklength) {
285 ret = ads124s_write_reg(indio_dev, ADS124S08_INPUT_MUX,
288 dev_err(&priv->spi->dev, "Set ADC CH failed\n");
290 ret = ads124s_write_cmd(indio_dev, ADS124S08_START_CONV);
292 dev_err(&priv->spi->dev, "Start ADC conversions failed\n");
294 priv->buffer[j] = ads124s_read(indio_dev, scan_index);
295 ret = ads124s_write_cmd(indio_dev, ADS124S08_STOP_CONV);
297 dev_err(&priv->spi->dev, "Stop ADC conversions failed\n");
302 iio_push_to_buffers_with_timestamp(indio_dev, priv->buffer,
305 iio_trigger_notify_done(indio_dev->trig);
310 static int ads124s_probe(struct spi_device *spi)
312 struct ads124s_private *ads124s_priv;
313 struct iio_dev *indio_dev;
314 const struct spi_device_id *spi_id = spi_get_device_id(spi);
317 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*ads124s_priv));
318 if (indio_dev == NULL)
321 ads124s_priv = iio_priv(indio_dev);
323 ads124s_priv->reset_gpio = devm_gpiod_get_optional(&spi->dev,
324 "reset", GPIOD_OUT_LOW);
325 if (IS_ERR(ads124s_priv->reset_gpio))
326 dev_info(&spi->dev, "Reset GPIO not defined\n");
328 ads124s_priv->chip_info = &ads124s_chip_info_tbl[spi_id->driver_data];
330 spi_set_drvdata(spi, indio_dev);
332 ads124s_priv->spi = spi;
334 indio_dev->name = spi_id->name;
335 indio_dev->modes = INDIO_DIRECT_MODE;
336 indio_dev->channels = ads124s_priv->chip_info->channels;
337 indio_dev->num_channels = ads124s_priv->chip_info->num_channels;
338 indio_dev->info = &ads124s_info;
340 mutex_init(&ads124s_priv->lock);
342 ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev, NULL,
343 ads124s_trigger_handler, NULL);
345 dev_err(&spi->dev, "iio triggered buffer setup failed\n");
349 ads124s_reset(indio_dev);
351 return devm_iio_device_register(&spi->dev, indio_dev);
354 static const struct spi_device_id ads124s_id[] = {
355 { "ads124s06", ADS124S06_ID },
356 { "ads124s08", ADS124S08_ID },
359 MODULE_DEVICE_TABLE(spi, ads124s_id);
361 static const struct of_device_id ads124s_of_table[] = {
362 { .compatible = "ti,ads124s06" },
363 { .compatible = "ti,ads124s08" },
366 MODULE_DEVICE_TABLE(of, ads124s_of_table);
368 static struct spi_driver ads124s_driver = {
371 .of_match_table = ads124s_of_table,
373 .probe = ads124s_probe,
374 .id_table = ads124s_id,
376 module_spi_driver(ads124s_driver);
378 MODULE_AUTHOR("Dan Murphy <dmuprhy@ti.com>");
379 MODULE_DESCRIPTION("TI TI_ADS12S0X ADC");
380 MODULE_LICENSE("GPL v2");