xref: /openbmc/linux/drivers/iio/adc/ti-ads7950.c (revision 63705da3)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Texas Instruments ADS7950 SPI ADC driver
4  *
5  * Copyright 2016 David Lechner <david@lechnology.com>
6  *
7  * Based on iio/ad7923.c:
8  * Copyright 2011 Analog Devices Inc
9  * Copyright 2012 CS Systemes d'Information
10  *
11  * And also on hwmon/ads79xx.c
12  * Copyright (C) 2013 Texas Instruments Incorporated - https://www.ti.com/
13  *	Nishanth Menon
14  */
15 
16 #include <linux/acpi.h>
17 #include <linux/bitops.h>
18 #include <linux/device.h>
19 #include <linux/err.h>
20 #include <linux/gpio/driver.h>
21 #include <linux/interrupt.h>
22 #include <linux/kernel.h>
23 #include <linux/module.h>
24 #include <linux/regulator/consumer.h>
25 #include <linux/slab.h>
26 #include <linux/spi/spi.h>
27 
28 #include <linux/iio/buffer.h>
29 #include <linux/iio/iio.h>
30 #include <linux/iio/sysfs.h>
31 #include <linux/iio/trigger_consumer.h>
32 #include <linux/iio/triggered_buffer.h>
33 
34 /*
35  * In case of ACPI, we use the 5000 mV as default for the reference pin.
36  * Device tree users encode that via the vref-supply regulator.
37  */
38 #define TI_ADS7950_VA_MV_ACPI_DEFAULT	5000
39 
40 #define TI_ADS7950_CR_GPIO	BIT(14)
41 #define TI_ADS7950_CR_MANUAL	BIT(12)
42 #define TI_ADS7950_CR_WRITE	BIT(11)
43 #define TI_ADS7950_CR_CHAN(ch)	((ch) << 7)
44 #define TI_ADS7950_CR_RANGE_5V	BIT(6)
45 #define TI_ADS7950_CR_GPIO_DATA	BIT(4)
46 
47 #define TI_ADS7950_MAX_CHAN	16
48 #define TI_ADS7950_NUM_GPIOS	4
49 
50 #define TI_ADS7950_TIMESTAMP_SIZE (sizeof(int64_t) / sizeof(__be16))
51 
52 /* val = value, dec = left shift, bits = number of bits of the mask */
53 #define TI_ADS7950_EXTRACT(val, dec, bits) \
54 	(((val) >> (dec)) & ((1 << (bits)) - 1))
55 
56 #define TI_ADS7950_MAN_CMD(cmd)         (TI_ADS7950_CR_MANUAL | (cmd))
57 #define TI_ADS7950_GPIO_CMD(cmd)        (TI_ADS7950_CR_GPIO | (cmd))
58 
59 /* Manual mode configuration */
60 #define TI_ADS7950_MAN_CMD_SETTINGS(st) \
61 	(TI_ADS7950_MAN_CMD(TI_ADS7950_CR_WRITE | st->cmd_settings_bitmask))
62 /* GPIO mode configuration */
63 #define TI_ADS7950_GPIO_CMD_SETTINGS(st) \
64 	(TI_ADS7950_GPIO_CMD(st->gpio_cmd_settings_bitmask))
65 
66 struct ti_ads7950_state {
67 	struct spi_device	*spi;
68 	struct spi_transfer	ring_xfer;
69 	struct spi_transfer	scan_single_xfer[3];
70 	struct spi_message	ring_msg;
71 	struct spi_message	scan_single_msg;
72 
73 	/* Lock to protect the spi xfer buffers */
74 	struct mutex		slock;
75 	struct gpio_chip	chip;
76 
77 	struct regulator	*reg;
78 	unsigned int		vref_mv;
79 
80 	/*
81 	 * Bitmask of lower 7 bits used for configuration
82 	 * These bits only can be written when TI_ADS7950_CR_WRITE
83 	 * is set, otherwise it retains its original state.
84 	 * [0-3] GPIO signal
85 	 * [4]   Set following frame to return GPIO signal values
86 	 * [5]   Powers down device
87 	 * [6]   Sets Vref range1(2.5v) or range2(5v)
88 	 *
89 	 * Bits present on Manual/Auto1/Auto2 commands
90 	 */
91 	unsigned int		cmd_settings_bitmask;
92 
93 	/*
94 	 * Bitmask of GPIO command
95 	 * [0-3] GPIO direction
96 	 * [4-6] Different GPIO alarm mode configurations
97 	 * [7]   GPIO 2 as device range input
98 	 * [8]   GPIO 3 as device power down input
99 	 * [9]   Reset all registers
100 	 * [10-11] N/A
101 	 */
102 	unsigned int		gpio_cmd_settings_bitmask;
103 
104 	/*
105 	 * DMA (thus cache coherency maintenance) requires the
106 	 * transfer buffers to live in their own cache lines.
107 	 */
108 	u16 rx_buf[TI_ADS7950_MAX_CHAN + 2 + TI_ADS7950_TIMESTAMP_SIZE]
109 							____cacheline_aligned;
110 	u16 tx_buf[TI_ADS7950_MAX_CHAN + 2];
111 	u16 single_tx;
112 	u16 single_rx;
113 
114 };
115 
116 struct ti_ads7950_chip_info {
117 	const struct iio_chan_spec *channels;
118 	unsigned int num_channels;
119 };
120 
121 enum ti_ads7950_id {
122 	TI_ADS7950,
123 	TI_ADS7951,
124 	TI_ADS7952,
125 	TI_ADS7953,
126 	TI_ADS7954,
127 	TI_ADS7955,
128 	TI_ADS7956,
129 	TI_ADS7957,
130 	TI_ADS7958,
131 	TI_ADS7959,
132 	TI_ADS7960,
133 	TI_ADS7961,
134 };
135 
136 #define TI_ADS7950_V_CHAN(index, bits)				\
137 {								\
138 	.type = IIO_VOLTAGE,					\
139 	.indexed = 1,						\
140 	.channel = index,					\
141 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
142 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
143 	.address = index,					\
144 	.datasheet_name = "CH##index",				\
145 	.scan_index = index,					\
146 	.scan_type = {						\
147 		.sign = 'u',					\
148 		.realbits = bits,				\
149 		.storagebits = 16,				\
150 		.shift = 12 - (bits),				\
151 		.endianness = IIO_CPU,				\
152 	},							\
153 }
154 
155 #define DECLARE_TI_ADS7950_4_CHANNELS(name, bits) \
156 const struct iio_chan_spec name ## _channels[] = { \
157 	TI_ADS7950_V_CHAN(0, bits), \
158 	TI_ADS7950_V_CHAN(1, bits), \
159 	TI_ADS7950_V_CHAN(2, bits), \
160 	TI_ADS7950_V_CHAN(3, bits), \
161 	IIO_CHAN_SOFT_TIMESTAMP(4), \
162 }
163 
164 #define DECLARE_TI_ADS7950_8_CHANNELS(name, bits) \
165 const struct iio_chan_spec name ## _channels[] = { \
166 	TI_ADS7950_V_CHAN(0, bits), \
167 	TI_ADS7950_V_CHAN(1, bits), \
168 	TI_ADS7950_V_CHAN(2, bits), \
169 	TI_ADS7950_V_CHAN(3, bits), \
170 	TI_ADS7950_V_CHAN(4, bits), \
171 	TI_ADS7950_V_CHAN(5, bits), \
172 	TI_ADS7950_V_CHAN(6, bits), \
173 	TI_ADS7950_V_CHAN(7, bits), \
174 	IIO_CHAN_SOFT_TIMESTAMP(8), \
175 }
176 
177 #define DECLARE_TI_ADS7950_12_CHANNELS(name, bits) \
178 const struct iio_chan_spec name ## _channels[] = { \
179 	TI_ADS7950_V_CHAN(0, bits), \
180 	TI_ADS7950_V_CHAN(1, bits), \
181 	TI_ADS7950_V_CHAN(2, bits), \
182 	TI_ADS7950_V_CHAN(3, bits), \
183 	TI_ADS7950_V_CHAN(4, bits), \
184 	TI_ADS7950_V_CHAN(5, bits), \
185 	TI_ADS7950_V_CHAN(6, bits), \
186 	TI_ADS7950_V_CHAN(7, bits), \
187 	TI_ADS7950_V_CHAN(8, bits), \
188 	TI_ADS7950_V_CHAN(9, bits), \
189 	TI_ADS7950_V_CHAN(10, bits), \
190 	TI_ADS7950_V_CHAN(11, bits), \
191 	IIO_CHAN_SOFT_TIMESTAMP(12), \
192 }
193 
194 #define DECLARE_TI_ADS7950_16_CHANNELS(name, bits) \
195 const struct iio_chan_spec name ## _channels[] = { \
196 	TI_ADS7950_V_CHAN(0, bits), \
197 	TI_ADS7950_V_CHAN(1, bits), \
198 	TI_ADS7950_V_CHAN(2, bits), \
199 	TI_ADS7950_V_CHAN(3, bits), \
200 	TI_ADS7950_V_CHAN(4, bits), \
201 	TI_ADS7950_V_CHAN(5, bits), \
202 	TI_ADS7950_V_CHAN(6, bits), \
203 	TI_ADS7950_V_CHAN(7, bits), \
204 	TI_ADS7950_V_CHAN(8, bits), \
205 	TI_ADS7950_V_CHAN(9, bits), \
206 	TI_ADS7950_V_CHAN(10, bits), \
207 	TI_ADS7950_V_CHAN(11, bits), \
208 	TI_ADS7950_V_CHAN(12, bits), \
209 	TI_ADS7950_V_CHAN(13, bits), \
210 	TI_ADS7950_V_CHAN(14, bits), \
211 	TI_ADS7950_V_CHAN(15, bits), \
212 	IIO_CHAN_SOFT_TIMESTAMP(16), \
213 }
214 
215 static DECLARE_TI_ADS7950_4_CHANNELS(ti_ads7950, 12);
216 static DECLARE_TI_ADS7950_8_CHANNELS(ti_ads7951, 12);
217 static DECLARE_TI_ADS7950_12_CHANNELS(ti_ads7952, 12);
218 static DECLARE_TI_ADS7950_16_CHANNELS(ti_ads7953, 12);
219 static DECLARE_TI_ADS7950_4_CHANNELS(ti_ads7954, 10);
220 static DECLARE_TI_ADS7950_8_CHANNELS(ti_ads7955, 10);
221 static DECLARE_TI_ADS7950_12_CHANNELS(ti_ads7956, 10);
222 static DECLARE_TI_ADS7950_16_CHANNELS(ti_ads7957, 10);
223 static DECLARE_TI_ADS7950_4_CHANNELS(ti_ads7958, 8);
224 static DECLARE_TI_ADS7950_8_CHANNELS(ti_ads7959, 8);
225 static DECLARE_TI_ADS7950_12_CHANNELS(ti_ads7960, 8);
226 static DECLARE_TI_ADS7950_16_CHANNELS(ti_ads7961, 8);
227 
228 static const struct ti_ads7950_chip_info ti_ads7950_chip_info[] = {
229 	[TI_ADS7950] = {
230 		.channels	= ti_ads7950_channels,
231 		.num_channels	= ARRAY_SIZE(ti_ads7950_channels),
232 	},
233 	[TI_ADS7951] = {
234 		.channels	= ti_ads7951_channels,
235 		.num_channels	= ARRAY_SIZE(ti_ads7951_channels),
236 	},
237 	[TI_ADS7952] = {
238 		.channels	= ti_ads7952_channels,
239 		.num_channels	= ARRAY_SIZE(ti_ads7952_channels),
240 	},
241 	[TI_ADS7953] = {
242 		.channels	= ti_ads7953_channels,
243 		.num_channels	= ARRAY_SIZE(ti_ads7953_channels),
244 	},
245 	[TI_ADS7954] = {
246 		.channels	= ti_ads7954_channels,
247 		.num_channels	= ARRAY_SIZE(ti_ads7954_channels),
248 	},
249 	[TI_ADS7955] = {
250 		.channels	= ti_ads7955_channels,
251 		.num_channels	= ARRAY_SIZE(ti_ads7955_channels),
252 	},
253 	[TI_ADS7956] = {
254 		.channels	= ti_ads7956_channels,
255 		.num_channels	= ARRAY_SIZE(ti_ads7956_channels),
256 	},
257 	[TI_ADS7957] = {
258 		.channels	= ti_ads7957_channels,
259 		.num_channels	= ARRAY_SIZE(ti_ads7957_channels),
260 	},
261 	[TI_ADS7958] = {
262 		.channels	= ti_ads7958_channels,
263 		.num_channels	= ARRAY_SIZE(ti_ads7958_channels),
264 	},
265 	[TI_ADS7959] = {
266 		.channels	= ti_ads7959_channels,
267 		.num_channels	= ARRAY_SIZE(ti_ads7959_channels),
268 	},
269 	[TI_ADS7960] = {
270 		.channels	= ti_ads7960_channels,
271 		.num_channels	= ARRAY_SIZE(ti_ads7960_channels),
272 	},
273 	[TI_ADS7961] = {
274 		.channels	= ti_ads7961_channels,
275 		.num_channels	= ARRAY_SIZE(ti_ads7961_channels),
276 	},
277 };
278 
279 /*
280  * ti_ads7950_update_scan_mode() setup the spi transfer buffer for the new
281  * scan mask
282  */
283 static int ti_ads7950_update_scan_mode(struct iio_dev *indio_dev,
284 				       const unsigned long *active_scan_mask)
285 {
286 	struct ti_ads7950_state *st = iio_priv(indio_dev);
287 	int i, cmd, len;
288 
289 	len = 0;
290 	for_each_set_bit(i, active_scan_mask, indio_dev->num_channels) {
291 		cmd = TI_ADS7950_MAN_CMD(TI_ADS7950_CR_CHAN(i));
292 		st->tx_buf[len++] = cmd;
293 	}
294 
295 	/* Data for the 1st channel is not returned until the 3rd transfer */
296 	st->tx_buf[len++] = 0;
297 	st->tx_buf[len++] = 0;
298 
299 	st->ring_xfer.len = len * 2;
300 
301 	return 0;
302 }
303 
304 static irqreturn_t ti_ads7950_trigger_handler(int irq, void *p)
305 {
306 	struct iio_poll_func *pf = p;
307 	struct iio_dev *indio_dev = pf->indio_dev;
308 	struct ti_ads7950_state *st = iio_priv(indio_dev);
309 	int ret;
310 
311 	mutex_lock(&st->slock);
312 	ret = spi_sync(st->spi, &st->ring_msg);
313 	if (ret < 0)
314 		goto out;
315 
316 	iio_push_to_buffers_with_timestamp(indio_dev, &st->rx_buf[2],
317 					   iio_get_time_ns(indio_dev));
318 
319 out:
320 	mutex_unlock(&st->slock);
321 	iio_trigger_notify_done(indio_dev->trig);
322 
323 	return IRQ_HANDLED;
324 }
325 
326 static int ti_ads7950_scan_direct(struct iio_dev *indio_dev, unsigned int ch)
327 {
328 	struct ti_ads7950_state *st = iio_priv(indio_dev);
329 	int ret, cmd;
330 
331 	mutex_lock(&st->slock);
332 	cmd = TI_ADS7950_MAN_CMD(TI_ADS7950_CR_CHAN(ch));
333 	st->single_tx = cmd;
334 
335 	ret = spi_sync(st->spi, &st->scan_single_msg);
336 	if (ret)
337 		goto out;
338 
339 	ret = st->single_rx;
340 
341 out:
342 	mutex_unlock(&st->slock);
343 
344 	return ret;
345 }
346 
347 static int ti_ads7950_get_range(struct ti_ads7950_state *st)
348 {
349 	int vref;
350 
351 	if (st->vref_mv) {
352 		vref = st->vref_mv;
353 	} else {
354 		vref = regulator_get_voltage(st->reg);
355 		if (vref < 0)
356 			return vref;
357 
358 		vref /= 1000;
359 	}
360 
361 	if (st->cmd_settings_bitmask & TI_ADS7950_CR_RANGE_5V)
362 		vref *= 2;
363 
364 	return vref;
365 }
366 
367 static int ti_ads7950_read_raw(struct iio_dev *indio_dev,
368 			       struct iio_chan_spec const *chan,
369 			       int *val, int *val2, long m)
370 {
371 	struct ti_ads7950_state *st = iio_priv(indio_dev);
372 	int ret;
373 
374 	switch (m) {
375 	case IIO_CHAN_INFO_RAW:
376 		ret = ti_ads7950_scan_direct(indio_dev, chan->address);
377 		if (ret < 0)
378 			return ret;
379 
380 		if (chan->address != TI_ADS7950_EXTRACT(ret, 12, 4))
381 			return -EIO;
382 
383 		*val = TI_ADS7950_EXTRACT(ret, chan->scan_type.shift,
384 					  chan->scan_type.realbits);
385 
386 		return IIO_VAL_INT;
387 	case IIO_CHAN_INFO_SCALE:
388 		ret = ti_ads7950_get_range(st);
389 		if (ret < 0)
390 			return ret;
391 
392 		*val = ret;
393 		*val2 = (1 << chan->scan_type.realbits) - 1;
394 
395 		return IIO_VAL_FRACTIONAL;
396 	}
397 
398 	return -EINVAL;
399 }
400 
401 static const struct iio_info ti_ads7950_info = {
402 	.read_raw		= &ti_ads7950_read_raw,
403 	.update_scan_mode	= ti_ads7950_update_scan_mode,
404 };
405 
406 static void ti_ads7950_set(struct gpio_chip *chip, unsigned int offset,
407 			   int value)
408 {
409 	struct ti_ads7950_state *st = gpiochip_get_data(chip);
410 
411 	mutex_lock(&st->slock);
412 
413 	if (value)
414 		st->cmd_settings_bitmask |= BIT(offset);
415 	else
416 		st->cmd_settings_bitmask &= ~BIT(offset);
417 
418 	st->single_tx = TI_ADS7950_MAN_CMD_SETTINGS(st);
419 	spi_sync(st->spi, &st->scan_single_msg);
420 
421 	mutex_unlock(&st->slock);
422 }
423 
424 static int ti_ads7950_get(struct gpio_chip *chip, unsigned int offset)
425 {
426 	struct ti_ads7950_state *st = gpiochip_get_data(chip);
427 	int ret;
428 
429 	mutex_lock(&st->slock);
430 
431 	/* If set as output, return the output */
432 	if (st->gpio_cmd_settings_bitmask & BIT(offset)) {
433 		ret = st->cmd_settings_bitmask & BIT(offset);
434 		goto out;
435 	}
436 
437 	/* GPIO data bit sets SDO bits 12-15 to GPIO input */
438 	st->cmd_settings_bitmask |= TI_ADS7950_CR_GPIO_DATA;
439 	st->single_tx = TI_ADS7950_MAN_CMD_SETTINGS(st);
440 	ret = spi_sync(st->spi, &st->scan_single_msg);
441 	if (ret)
442 		goto out;
443 
444 	ret = ((st->single_rx >> 12) & BIT(offset)) ? 1 : 0;
445 
446 	/* Revert back to original settings */
447 	st->cmd_settings_bitmask &= ~TI_ADS7950_CR_GPIO_DATA;
448 	st->single_tx = TI_ADS7950_MAN_CMD_SETTINGS(st);
449 	ret = spi_sync(st->spi, &st->scan_single_msg);
450 	if (ret)
451 		goto out;
452 
453 out:
454 	mutex_unlock(&st->slock);
455 
456 	return ret;
457 }
458 
459 static int ti_ads7950_get_direction(struct gpio_chip *chip,
460 				    unsigned int offset)
461 {
462 	struct ti_ads7950_state *st = gpiochip_get_data(chip);
463 
464 	/* Bitmask is inverted from GPIO framework 0=input/1=output */
465 	return !(st->gpio_cmd_settings_bitmask & BIT(offset));
466 }
467 
468 static int _ti_ads7950_set_direction(struct gpio_chip *chip, int offset,
469 				     int input)
470 {
471 	struct ti_ads7950_state *st = gpiochip_get_data(chip);
472 	int ret = 0;
473 
474 	mutex_lock(&st->slock);
475 
476 	/* Only change direction if needed */
477 	if (input && (st->gpio_cmd_settings_bitmask & BIT(offset)))
478 		st->gpio_cmd_settings_bitmask &= ~BIT(offset);
479 	else if (!input && !(st->gpio_cmd_settings_bitmask & BIT(offset)))
480 		st->gpio_cmd_settings_bitmask |= BIT(offset);
481 	else
482 		goto out;
483 
484 	st->single_tx = TI_ADS7950_GPIO_CMD_SETTINGS(st);
485 	ret = spi_sync(st->spi, &st->scan_single_msg);
486 
487 out:
488 	mutex_unlock(&st->slock);
489 
490 	return ret;
491 }
492 
493 static int ti_ads7950_direction_input(struct gpio_chip *chip,
494 				      unsigned int offset)
495 {
496 	return _ti_ads7950_set_direction(chip, offset, 1);
497 }
498 
499 static int ti_ads7950_direction_output(struct gpio_chip *chip,
500 				       unsigned int offset, int value)
501 {
502 	ti_ads7950_set(chip, offset, value);
503 
504 	return _ti_ads7950_set_direction(chip, offset, 0);
505 }
506 
507 static int ti_ads7950_init_hw(struct ti_ads7950_state *st)
508 {
509 	int ret = 0;
510 
511 	mutex_lock(&st->slock);
512 
513 	/* Settings for Manual/Auto1/Auto2 commands */
514 	/* Default to 5v ref */
515 	st->cmd_settings_bitmask = TI_ADS7950_CR_RANGE_5V;
516 	st->single_tx = TI_ADS7950_MAN_CMD_SETTINGS(st);
517 	ret = spi_sync(st->spi, &st->scan_single_msg);
518 	if (ret)
519 		goto out;
520 
521 	/* Settings for GPIO command */
522 	st->gpio_cmd_settings_bitmask = 0x0;
523 	st->single_tx = TI_ADS7950_GPIO_CMD_SETTINGS(st);
524 	ret = spi_sync(st->spi, &st->scan_single_msg);
525 
526 out:
527 	mutex_unlock(&st->slock);
528 
529 	return ret;
530 }
531 
532 static int ti_ads7950_probe(struct spi_device *spi)
533 {
534 	struct ti_ads7950_state *st;
535 	struct iio_dev *indio_dev;
536 	const struct ti_ads7950_chip_info *info;
537 	int ret;
538 
539 	spi->bits_per_word = 16;
540 	spi->mode |= SPI_CS_WORD;
541 	ret = spi_setup(spi);
542 	if (ret < 0) {
543 		dev_err(&spi->dev, "Error in spi setup\n");
544 		return ret;
545 	}
546 
547 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
548 	if (!indio_dev)
549 		return -ENOMEM;
550 
551 	st = iio_priv(indio_dev);
552 
553 	spi_set_drvdata(spi, indio_dev);
554 
555 	st->spi = spi;
556 
557 	info = &ti_ads7950_chip_info[spi_get_device_id(spi)->driver_data];
558 
559 	indio_dev->name = spi_get_device_id(spi)->name;
560 	indio_dev->modes = INDIO_DIRECT_MODE;
561 	indio_dev->channels = info->channels;
562 	indio_dev->num_channels = info->num_channels;
563 	indio_dev->info = &ti_ads7950_info;
564 
565 	/* build spi ring message */
566 	spi_message_init(&st->ring_msg);
567 
568 	st->ring_xfer.tx_buf = &st->tx_buf[0];
569 	st->ring_xfer.rx_buf = &st->rx_buf[0];
570 	/* len will be set later */
571 
572 	spi_message_add_tail(&st->ring_xfer, &st->ring_msg);
573 
574 	/*
575 	 * Setup default message. The sample is read at the end of the first
576 	 * transfer, then it takes one full cycle to convert the sample and one
577 	 * more cycle to send the value. The conversion process is driven by
578 	 * the SPI clock, which is why we have 3 transfers. The middle one is
579 	 * just dummy data sent while the chip is converting the sample that
580 	 * was read at the end of the first transfer.
581 	 */
582 
583 	st->scan_single_xfer[0].tx_buf = &st->single_tx;
584 	st->scan_single_xfer[0].len = 2;
585 	st->scan_single_xfer[0].cs_change = 1;
586 	st->scan_single_xfer[1].tx_buf = &st->single_tx;
587 	st->scan_single_xfer[1].len = 2;
588 	st->scan_single_xfer[1].cs_change = 1;
589 	st->scan_single_xfer[2].rx_buf = &st->single_rx;
590 	st->scan_single_xfer[2].len = 2;
591 
592 	spi_message_init_with_transfers(&st->scan_single_msg,
593 					st->scan_single_xfer, 3);
594 
595 	/* Use hard coded value for reference voltage in ACPI case */
596 	if (ACPI_COMPANION(&spi->dev))
597 		st->vref_mv = TI_ADS7950_VA_MV_ACPI_DEFAULT;
598 
599 	mutex_init(&st->slock);
600 
601 	st->reg = devm_regulator_get(&spi->dev, "vref");
602 	if (IS_ERR(st->reg)) {
603 		ret = dev_err_probe(&spi->dev, PTR_ERR(st->reg),
604 				     "Failed to get regulator \"vref\"\n");
605 		goto error_destroy_mutex;
606 	}
607 
608 	ret = regulator_enable(st->reg);
609 	if (ret) {
610 		dev_err(&spi->dev, "Failed to enable regulator \"vref\"\n");
611 		goto error_destroy_mutex;
612 	}
613 
614 	ret = iio_triggered_buffer_setup(indio_dev, NULL,
615 					 &ti_ads7950_trigger_handler, NULL);
616 	if (ret) {
617 		dev_err(&spi->dev, "Failed to setup triggered buffer\n");
618 		goto error_disable_reg;
619 	}
620 
621 	ret = ti_ads7950_init_hw(st);
622 	if (ret) {
623 		dev_err(&spi->dev, "Failed to init adc chip\n");
624 		goto error_cleanup_ring;
625 	}
626 
627 	ret = iio_device_register(indio_dev);
628 	if (ret) {
629 		dev_err(&spi->dev, "Failed to register iio device\n");
630 		goto error_cleanup_ring;
631 	}
632 
633 	/* Add GPIO chip */
634 	st->chip.label = dev_name(&st->spi->dev);
635 	st->chip.parent = &st->spi->dev;
636 	st->chip.owner = THIS_MODULE;
637 	st->chip.base = -1;
638 	st->chip.ngpio = TI_ADS7950_NUM_GPIOS;
639 	st->chip.get_direction = ti_ads7950_get_direction;
640 	st->chip.direction_input = ti_ads7950_direction_input;
641 	st->chip.direction_output = ti_ads7950_direction_output;
642 	st->chip.get = ti_ads7950_get;
643 	st->chip.set = ti_ads7950_set;
644 
645 	ret = gpiochip_add_data(&st->chip, st);
646 	if (ret) {
647 		dev_err(&spi->dev, "Failed to init GPIOs\n");
648 		goto error_iio_device;
649 	}
650 
651 	return 0;
652 
653 error_iio_device:
654 	iio_device_unregister(indio_dev);
655 error_cleanup_ring:
656 	iio_triggered_buffer_cleanup(indio_dev);
657 error_disable_reg:
658 	regulator_disable(st->reg);
659 error_destroy_mutex:
660 	mutex_destroy(&st->slock);
661 
662 	return ret;
663 }
664 
665 static int ti_ads7950_remove(struct spi_device *spi)
666 {
667 	struct iio_dev *indio_dev = spi_get_drvdata(spi);
668 	struct ti_ads7950_state *st = iio_priv(indio_dev);
669 
670 	gpiochip_remove(&st->chip);
671 	iio_device_unregister(indio_dev);
672 	iio_triggered_buffer_cleanup(indio_dev);
673 	regulator_disable(st->reg);
674 	mutex_destroy(&st->slock);
675 
676 	return 0;
677 }
678 
679 static const struct spi_device_id ti_ads7950_id[] = {
680 	{ "ads7950", TI_ADS7950 },
681 	{ "ads7951", TI_ADS7951 },
682 	{ "ads7952", TI_ADS7952 },
683 	{ "ads7953", TI_ADS7953 },
684 	{ "ads7954", TI_ADS7954 },
685 	{ "ads7955", TI_ADS7955 },
686 	{ "ads7956", TI_ADS7956 },
687 	{ "ads7957", TI_ADS7957 },
688 	{ "ads7958", TI_ADS7958 },
689 	{ "ads7959", TI_ADS7959 },
690 	{ "ads7960", TI_ADS7960 },
691 	{ "ads7961", TI_ADS7961 },
692 	{ }
693 };
694 MODULE_DEVICE_TABLE(spi, ti_ads7950_id);
695 
696 static const struct of_device_id ads7950_of_table[] = {
697 	{ .compatible = "ti,ads7950", .data = &ti_ads7950_chip_info[TI_ADS7950] },
698 	{ .compatible = "ti,ads7951", .data = &ti_ads7950_chip_info[TI_ADS7951] },
699 	{ .compatible = "ti,ads7952", .data = &ti_ads7950_chip_info[TI_ADS7952] },
700 	{ .compatible = "ti,ads7953", .data = &ti_ads7950_chip_info[TI_ADS7953] },
701 	{ .compatible = "ti,ads7954", .data = &ti_ads7950_chip_info[TI_ADS7954] },
702 	{ .compatible = "ti,ads7955", .data = &ti_ads7950_chip_info[TI_ADS7955] },
703 	{ .compatible = "ti,ads7956", .data = &ti_ads7950_chip_info[TI_ADS7956] },
704 	{ .compatible = "ti,ads7957", .data = &ti_ads7950_chip_info[TI_ADS7957] },
705 	{ .compatible = "ti,ads7958", .data = &ti_ads7950_chip_info[TI_ADS7958] },
706 	{ .compatible = "ti,ads7959", .data = &ti_ads7950_chip_info[TI_ADS7959] },
707 	{ .compatible = "ti,ads7960", .data = &ti_ads7950_chip_info[TI_ADS7960] },
708 	{ .compatible = "ti,ads7961", .data = &ti_ads7950_chip_info[TI_ADS7961] },
709 	{ },
710 };
711 MODULE_DEVICE_TABLE(of, ads7950_of_table);
712 
713 static struct spi_driver ti_ads7950_driver = {
714 	.driver = {
715 		.name	= "ads7950",
716 		.of_match_table = ads7950_of_table,
717 	},
718 	.probe		= ti_ads7950_probe,
719 	.remove		= ti_ads7950_remove,
720 	.id_table	= ti_ads7950_id,
721 };
722 module_spi_driver(ti_ads7950_driver);
723 
724 MODULE_AUTHOR("David Lechner <david@lechnology.com>");
725 MODULE_DESCRIPTION("TI TI_ADS7950 ADC");
726 MODULE_LICENSE("GPL v2");
727