1 // SPDX-License-Identifier: GPL-2.0-only
4 * Copyright (C) 2014 Philippe Reynes
6 * based on linux/drivers/iio/ad7923.c
7 * Copyright 2011 Analog Devices Inc (from AD7923 Driver)
8 * Copyright 2012 CS Systemes d'Information
12 * Partial support for max1027 and similar chips.
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/mod_devicetable.h>
18 #include <linux/spi/spi.h>
19 #include <linux/delay.h>
21 #include <linux/iio/iio.h>
22 #include <linux/iio/buffer.h>
23 #include <linux/iio/trigger.h>
24 #include <linux/iio/trigger_consumer.h>
25 #include <linux/iio/triggered_buffer.h>
27 #define MAX1027_CONV_REG BIT(7)
28 #define MAX1027_SETUP_REG BIT(6)
29 #define MAX1027_AVG_REG BIT(5)
30 #define MAX1027_RST_REG BIT(4)
32 /* conversion register */
33 #define MAX1027_TEMP BIT(0)
34 #define MAX1027_SCAN_0_N (0x00 << 1)
35 #define MAX1027_SCAN_N_M (0x01 << 1)
36 #define MAX1027_SCAN_N (0x02 << 1)
37 #define MAX1027_NOSCAN (0x03 << 1)
38 #define MAX1027_CHAN(n) ((n) << 3)
41 #define MAX1027_UNIPOLAR 0x02
42 #define MAX1027_BIPOLAR 0x03
43 #define MAX1027_REF_MODE0 (0x00 << 2)
44 #define MAX1027_REF_MODE1 (0x01 << 2)
45 #define MAX1027_REF_MODE2 (0x02 << 2)
46 #define MAX1027_REF_MODE3 (0x03 << 2)
47 #define MAX1027_CKS_MODE0 (0x00 << 4)
48 #define MAX1027_CKS_MODE1 (0x01 << 4)
49 #define MAX1027_CKS_MODE2 (0x02 << 4)
50 #define MAX1027_CKS_MODE3 (0x03 << 4)
52 /* averaging register */
53 #define MAX1027_NSCAN_4 0x00
54 #define MAX1027_NSCAN_8 0x01
55 #define MAX1027_NSCAN_12 0x02
56 #define MAX1027_NSCAN_16 0x03
57 #define MAX1027_NAVG_4 (0x00 << 2)
58 #define MAX1027_NAVG_8 (0x01 << 2)
59 #define MAX1027_NAVG_16 (0x02 << 2)
60 #define MAX1027_NAVG_32 (0x03 << 2)
61 #define MAX1027_AVG_EN BIT(4)
72 static const struct spi_device_id max1027_id[] = {
81 MODULE_DEVICE_TABLE(spi, max1027_id);
83 static const struct of_device_id max1027_adc_dt_ids[] = {
84 { .compatible = "maxim,max1027" },
85 { .compatible = "maxim,max1029" },
86 { .compatible = "maxim,max1031" },
87 { .compatible = "maxim,max1227" },
88 { .compatible = "maxim,max1229" },
89 { .compatible = "maxim,max1231" },
92 MODULE_DEVICE_TABLE(of, max1027_adc_dt_ids);
94 #define MAX1027_V_CHAN(index, depth) \
96 .type = IIO_VOLTAGE, \
99 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
100 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
101 .scan_index = index + 1, \
107 .endianness = IIO_BE, \
111 #define MAX1027_T_CHAN \
115 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
116 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
122 .endianness = IIO_BE, \
126 #define MAX1X27_CHANNELS(depth) \
128 MAX1027_V_CHAN(0, depth), \
129 MAX1027_V_CHAN(1, depth), \
130 MAX1027_V_CHAN(2, depth), \
131 MAX1027_V_CHAN(3, depth), \
132 MAX1027_V_CHAN(4, depth), \
133 MAX1027_V_CHAN(5, depth), \
134 MAX1027_V_CHAN(6, depth), \
135 MAX1027_V_CHAN(7, depth)
137 #define MAX1X29_CHANNELS(depth) \
138 MAX1X27_CHANNELS(depth), \
139 MAX1027_V_CHAN(8, depth), \
140 MAX1027_V_CHAN(9, depth), \
141 MAX1027_V_CHAN(10, depth), \
142 MAX1027_V_CHAN(11, depth)
144 #define MAX1X31_CHANNELS(depth) \
145 MAX1X27_CHANNELS(depth), \
146 MAX1X29_CHANNELS(depth), \
147 MAX1027_V_CHAN(12, depth), \
148 MAX1027_V_CHAN(13, depth), \
149 MAX1027_V_CHAN(14, depth), \
150 MAX1027_V_CHAN(15, depth)
152 static const struct iio_chan_spec max1027_channels[] = {
153 MAX1X27_CHANNELS(10),
156 static const struct iio_chan_spec max1029_channels[] = {
157 MAX1X29_CHANNELS(10),
160 static const struct iio_chan_spec max1031_channels[] = {
161 MAX1X31_CHANNELS(10),
164 static const struct iio_chan_spec max1227_channels[] = {
165 MAX1X27_CHANNELS(12),
168 static const struct iio_chan_spec max1229_channels[] = {
169 MAX1X29_CHANNELS(12),
172 static const struct iio_chan_spec max1231_channels[] = {
173 MAX1X31_CHANNELS(12),
176 static const unsigned long max1027_available_scan_masks[] = {
181 static const unsigned long max1029_available_scan_masks[] = {
186 static const unsigned long max1031_available_scan_masks[] = {
191 struct max1027_chip_info {
192 const struct iio_chan_spec *channels;
193 unsigned int num_channels;
194 const unsigned long *available_scan_masks;
197 static const struct max1027_chip_info max1027_chip_info_tbl[] = {
199 .channels = max1027_channels,
200 .num_channels = ARRAY_SIZE(max1027_channels),
201 .available_scan_masks = max1027_available_scan_masks,
204 .channels = max1029_channels,
205 .num_channels = ARRAY_SIZE(max1029_channels),
206 .available_scan_masks = max1029_available_scan_masks,
209 .channels = max1031_channels,
210 .num_channels = ARRAY_SIZE(max1031_channels),
211 .available_scan_masks = max1031_available_scan_masks,
214 .channels = max1227_channels,
215 .num_channels = ARRAY_SIZE(max1227_channels),
216 .available_scan_masks = max1027_available_scan_masks,
219 .channels = max1229_channels,
220 .num_channels = ARRAY_SIZE(max1229_channels),
221 .available_scan_masks = max1029_available_scan_masks,
224 .channels = max1231_channels,
225 .num_channels = ARRAY_SIZE(max1231_channels),
226 .available_scan_masks = max1031_available_scan_masks,
230 struct max1027_state {
231 const struct max1027_chip_info *info;
232 struct spi_device *spi;
233 struct iio_trigger *trig;
237 u8 reg ____cacheline_aligned;
240 static int max1027_read_single_value(struct iio_dev *indio_dev,
241 struct iio_chan_spec const *chan,
245 struct max1027_state *st = iio_priv(indio_dev);
247 if (iio_buffer_enabled(indio_dev)) {
248 dev_warn(&indio_dev->dev, "trigger mode already enabled");
252 /* Start acquisition on conversion register write */
253 st->reg = MAX1027_SETUP_REG | MAX1027_REF_MODE2 | MAX1027_CKS_MODE2;
254 ret = spi_write(st->spi, &st->reg, 1);
256 dev_err(&indio_dev->dev,
257 "Failed to configure setup register\n");
261 /* Configure conversion register with the requested chan */
262 st->reg = MAX1027_CONV_REG | MAX1027_CHAN(chan->channel) |
264 if (chan->type == IIO_TEMP)
265 st->reg |= MAX1027_TEMP;
266 ret = spi_write(st->spi, &st->reg, 1);
268 dev_err(&indio_dev->dev,
269 "Failed to configure conversion register\n");
274 * For an unknown reason, when we use the mode "10" (write
275 * conversion register), the interrupt doesn't occur every time.
276 * So we just wait 1 ms.
281 ret = spi_read(st->spi, st->buffer, (chan->type == IIO_TEMP) ? 4 : 2);
285 *val = be16_to_cpu(st->buffer[0]);
290 static int max1027_read_raw(struct iio_dev *indio_dev,
291 struct iio_chan_spec const *chan,
292 int *val, int *val2, long mask)
295 struct max1027_state *st = iio_priv(indio_dev);
297 mutex_lock(&st->lock);
300 case IIO_CHAN_INFO_RAW:
301 ret = max1027_read_single_value(indio_dev, chan, val);
303 case IIO_CHAN_INFO_SCALE:
304 switch (chan->type) {
308 ret = IIO_VAL_FRACTIONAL;
312 *val2 = chan->scan_type.realbits;
313 ret = IIO_VAL_FRACTIONAL_LOG2;
325 mutex_unlock(&st->lock);
330 static int max1027_debugfs_reg_access(struct iio_dev *indio_dev,
331 unsigned reg, unsigned writeval,
334 struct max1027_state *st = iio_priv(indio_dev);
335 u8 *val = (u8 *)st->buffer;
338 int ret = spi_read(st->spi, val, 2);
339 *readval = be16_to_cpu(st->buffer[0]);
344 return spi_write(st->spi, val, 1);
347 static int max1027_validate_trigger(struct iio_dev *indio_dev,
348 struct iio_trigger *trig)
350 struct max1027_state *st = iio_priv(indio_dev);
352 if (st->trig != trig)
358 static int max1027_set_trigger_state(struct iio_trigger *trig, bool state)
360 struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
361 struct max1027_state *st = iio_priv(indio_dev);
365 /* Start acquisition on cnvst */
366 st->reg = MAX1027_SETUP_REG | MAX1027_CKS_MODE0 |
368 ret = spi_write(st->spi, &st->reg, 1);
372 /* Scan from 0 to max */
373 st->reg = MAX1027_CONV_REG | MAX1027_CHAN(0) |
374 MAX1027_SCAN_N_M | MAX1027_TEMP;
375 ret = spi_write(st->spi, &st->reg, 1);
379 /* Start acquisition on conversion register write */
380 st->reg = MAX1027_SETUP_REG | MAX1027_CKS_MODE2 |
382 ret = spi_write(st->spi, &st->reg, 1);
390 static irqreturn_t max1027_trigger_handler(int irq, void *private)
392 struct iio_poll_func *pf = private;
393 struct iio_dev *indio_dev = pf->indio_dev;
394 struct max1027_state *st = iio_priv(indio_dev);
396 pr_debug("%s(irq=%d, private=0x%p)\n", __func__, irq, private);
398 /* fill buffer with all channel */
399 spi_read(st->spi, st->buffer, indio_dev->masklength * 2);
401 iio_push_to_buffers(indio_dev, st->buffer);
403 iio_trigger_notify_done(indio_dev->trig);
408 static const struct iio_trigger_ops max1027_trigger_ops = {
409 .validate_device = &iio_trigger_validate_own_device,
410 .set_trigger_state = &max1027_set_trigger_state,
413 static const struct iio_info max1027_info = {
414 .read_raw = &max1027_read_raw,
415 .validate_trigger = &max1027_validate_trigger,
416 .debugfs_reg_access = &max1027_debugfs_reg_access,
419 static int max1027_probe(struct spi_device *spi)
422 struct iio_dev *indio_dev;
423 struct max1027_state *st;
425 pr_debug("%s: probe(spi = 0x%p)\n", __func__, spi);
427 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
428 if (indio_dev == NULL) {
429 pr_err("Can't allocate iio device\n");
433 spi_set_drvdata(spi, indio_dev);
435 st = iio_priv(indio_dev);
437 st->info = &max1027_chip_info_tbl[spi_get_device_id(spi)->driver_data];
439 mutex_init(&st->lock);
441 indio_dev->name = spi_get_device_id(spi)->name;
442 indio_dev->info = &max1027_info;
443 indio_dev->modes = INDIO_DIRECT_MODE;
444 indio_dev->channels = st->info->channels;
445 indio_dev->num_channels = st->info->num_channels;
446 indio_dev->available_scan_masks = st->info->available_scan_masks;
448 st->buffer = devm_kmalloc_array(&indio_dev->dev,
449 indio_dev->num_channels, 2,
451 if (st->buffer == NULL) {
452 dev_err(&indio_dev->dev, "Can't allocate buffer\n");
457 ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,
458 &iio_pollfunc_store_time,
459 &max1027_trigger_handler,
462 dev_err(&indio_dev->dev, "Failed to setup buffer\n");
466 st->trig = devm_iio_trigger_alloc(&spi->dev, "%s-trigger",
468 if (st->trig == NULL) {
470 dev_err(&indio_dev->dev,
471 "Failed to allocate iio trigger\n");
475 st->trig->ops = &max1027_trigger_ops;
476 st->trig->dev.parent = &spi->dev;
477 iio_trigger_set_drvdata(st->trig, indio_dev);
478 ret = devm_iio_trigger_register(&indio_dev->dev,
481 dev_err(&indio_dev->dev,
482 "Failed to register iio trigger\n");
486 ret = devm_request_threaded_irq(&spi->dev, spi->irq,
487 iio_trigger_generic_data_rdy_poll,
489 IRQF_TRIGGER_FALLING,
490 spi->dev.driver->name,
493 dev_err(&indio_dev->dev, "Failed to allocate IRQ.\n");
499 st->reg = MAX1027_RST_REG;
500 ret = spi_write(st->spi, &st->reg, 1);
502 dev_err(&indio_dev->dev, "Failed to reset the ADC\n");
506 /* Disable averaging */
507 st->reg = MAX1027_AVG_REG;
508 ret = spi_write(st->spi, &st->reg, 1);
510 dev_err(&indio_dev->dev, "Failed to configure averaging register\n");
514 return devm_iio_device_register(&spi->dev, indio_dev);
517 static struct spi_driver max1027_driver = {
520 .of_match_table = max1027_adc_dt_ids,
522 .probe = max1027_probe,
523 .id_table = max1027_id,
525 module_spi_driver(max1027_driver);
527 MODULE_AUTHOR("Philippe Reynes <tremyfr@yahoo.fr>");
528 MODULE_DESCRIPTION("MAX1X27/MAX1X29/MAX1X31 ADC");
529 MODULE_LICENSE("GPL v2");