xref: /linux/drivers/iio/adc/bcm_iproc_adc.c (revision da5b2ad1c2f18834cb1ce429e2e5a5cf5cbdf21b)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright 2016 Broadcom
4  */
5 
6 #include <linux/module.h>
7 #include <linux/mod_devicetable.h>
8 #include <linux/io.h>
9 #include <linux/clk.h>
10 #include <linux/mfd/syscon.h>
11 #include <linux/regmap.h>
12 #include <linux/delay.h>
13 #include <linux/interrupt.h>
14 #include <linux/platform_device.h>
15 
16 #include <linux/iio/iio.h>
17 
18 /* Below Register's are common to IPROC ADC and Touchscreen IP */
19 #define IPROC_REGCTL1			0x00
20 #define IPROC_REGCTL2			0x04
21 #define IPROC_INTERRUPT_THRES		0x08
22 #define IPROC_INTERRUPT_MASK		0x0c
23 #define IPROC_INTERRUPT_STATUS		0x10
24 #define IPROC_ANALOG_CONTROL		0x1c
25 #define IPROC_CONTROLLER_STATUS		0x14
26 #define IPROC_AUX_DATA			0x20
27 #define IPROC_SOFT_BYPASS_CONTROL	0x38
28 #define IPROC_SOFT_BYPASS_DATA		0x3C
29 
30 /* IPROC ADC Channel register offsets */
31 #define IPROC_ADC_CHANNEL_REGCTL1		0x800
32 #define IPROC_ADC_CHANNEL_REGCTL2		0x804
33 #define IPROC_ADC_CHANNEL_STATUS		0x808
34 #define IPROC_ADC_CHANNEL_INTERRUPT_STATUS	0x80c
35 #define IPROC_ADC_CHANNEL_INTERRUPT_MASK	0x810
36 #define IPROC_ADC_CHANNEL_DATA			0x814
37 #define IPROC_ADC_CHANNEL_OFFSET		0x20
38 
39 /* Bit definitions for IPROC_REGCTL2 */
40 #define IPROC_ADC_AUXIN_SCAN_ENA	BIT(0)
41 #define IPROC_ADC_PWR_LDO		BIT(5)
42 #define IPROC_ADC_PWR_ADC		BIT(4)
43 #define IPROC_ADC_PWR_BG		BIT(3)
44 #define IPROC_ADC_CONTROLLER_EN		BIT(17)
45 
46 /* Bit definitions for IPROC_INTERRUPT_MASK and IPROC_INTERRUPT_STATUS */
47 #define IPROC_ADC_AUXDATA_RDY_INTR	BIT(3)
48 #define IPROC_ADC_INTR			9
49 #define IPROC_ADC_INTR_MASK		(0xFF << IPROC_ADC_INTR)
50 
51 /* Bit definitions for IPROC_ANALOG_CONTROL */
52 #define IPROC_ADC_CHANNEL_SEL		11
53 #define IPROC_ADC_CHANNEL_SEL_MASK	(0x7 << IPROC_ADC_CHANNEL_SEL)
54 
55 /* Bit definitions for IPROC_ADC_CHANNEL_REGCTL1 */
56 #define IPROC_ADC_CHANNEL_ROUNDS	0x2
57 #define IPROC_ADC_CHANNEL_ROUNDS_MASK	(0x3F << IPROC_ADC_CHANNEL_ROUNDS)
58 #define IPROC_ADC_CHANNEL_MODE		0x1
59 #define IPROC_ADC_CHANNEL_MODE_MASK	(0x1 << IPROC_ADC_CHANNEL_MODE)
60 #define IPROC_ADC_CHANNEL_MODE_TDM	0x1
61 #define IPROC_ADC_CHANNEL_MODE_SNAPSHOT 0x0
62 #define IPROC_ADC_CHANNEL_ENABLE	0x0
63 #define IPROC_ADC_CHANNEL_ENABLE_MASK	0x1
64 
65 /* Bit definitions for IPROC_ADC_CHANNEL_REGCTL2 */
66 #define IPROC_ADC_CHANNEL_WATERMARK	0x0
67 #define IPROC_ADC_CHANNEL_WATERMARK_MASK \
68 		(0x3F << IPROC_ADC_CHANNEL_WATERMARK)
69 
70 #define IPROC_ADC_WATER_MARK_LEVEL	0x1
71 
72 /* Bit definitions for IPROC_ADC_CHANNEL_STATUS */
73 #define IPROC_ADC_CHANNEL_DATA_LOST		0x0
74 #define IPROC_ADC_CHANNEL_DATA_LOST_MASK	\
75 		(0x0 << IPROC_ADC_CHANNEL_DATA_LOST)
76 #define IPROC_ADC_CHANNEL_VALID_ENTERIES	0x1
77 #define IPROC_ADC_CHANNEL_VALID_ENTERIES_MASK	\
78 		(0xFF << IPROC_ADC_CHANNEL_VALID_ENTERIES)
79 #define IPROC_ADC_CHANNEL_TOTAL_ENTERIES	0x9
80 #define IPROC_ADC_CHANNEL_TOTAL_ENTERIES_MASK	\
81 		(0xFF << IPROC_ADC_CHANNEL_TOTAL_ENTERIES)
82 
83 /* Bit definitions for IPROC_ADC_CHANNEL_INTERRUPT_MASK */
84 #define IPROC_ADC_CHANNEL_WTRMRK_INTR			0x0
85 #define IPROC_ADC_CHANNEL_WTRMRK_INTR_MASK		\
86 		(0x1 << IPROC_ADC_CHANNEL_WTRMRK_INTR)
87 #define IPROC_ADC_CHANNEL_FULL_INTR			0x1
88 #define IPROC_ADC_CHANNEL_FULL_INTR_MASK		\
89 		(0x1 << IPROC_ADC_IPROC_ADC_CHANNEL_FULL_INTR)
90 #define IPROC_ADC_CHANNEL_EMPTY_INTR			0x2
91 #define IPROC_ADC_CHANNEL_EMPTY_INTR_MASK		\
92 		(0x1 << IPROC_ADC_CHANNEL_EMPTY_INTR)
93 
94 #define IPROC_ADC_WATER_MARK_INTR_ENABLE		0x1
95 
96 /* Number of time to retry a set of the interrupt mask reg */
97 #define IPROC_ADC_INTMASK_RETRY_ATTEMPTS		10
98 
99 #define IPROC_ADC_READ_TIMEOUT        (HZ*2)
100 
101 #define iproc_adc_dbg_reg(dev, priv, reg) \
102 do { \
103 	u32 val; \
104 	regmap_read(priv->regmap, reg, &val); \
105 	dev_dbg(dev, "%20s= 0x%08x\n", #reg, val); \
106 } while (0)
107 
108 struct iproc_adc_priv {
109 	struct regmap *regmap;
110 	struct clk *adc_clk;
111 	struct mutex mutex;
112 	int  irqno;
113 	int chan_val;
114 	int chan_id;
115 	struct completion completion;
116 };
117 
118 static void iproc_adc_reg_dump(struct iio_dev *indio_dev)
119 {
120 	struct device *dev = &indio_dev->dev;
121 	struct iproc_adc_priv *adc_priv = iio_priv(indio_dev);
122 
123 	iproc_adc_dbg_reg(dev, adc_priv, IPROC_REGCTL1);
124 	iproc_adc_dbg_reg(dev, adc_priv, IPROC_REGCTL2);
125 	iproc_adc_dbg_reg(dev, adc_priv, IPROC_INTERRUPT_THRES);
126 	iproc_adc_dbg_reg(dev, adc_priv, IPROC_INTERRUPT_MASK);
127 	iproc_adc_dbg_reg(dev, adc_priv, IPROC_INTERRUPT_STATUS);
128 	iproc_adc_dbg_reg(dev, adc_priv, IPROC_CONTROLLER_STATUS);
129 	iproc_adc_dbg_reg(dev, adc_priv, IPROC_ANALOG_CONTROL);
130 	iproc_adc_dbg_reg(dev, adc_priv, IPROC_AUX_DATA);
131 	iproc_adc_dbg_reg(dev, adc_priv, IPROC_SOFT_BYPASS_CONTROL);
132 	iproc_adc_dbg_reg(dev, adc_priv, IPROC_SOFT_BYPASS_DATA);
133 }
134 
135 static irqreturn_t iproc_adc_interrupt_thread(int irq, void *data)
136 {
137 	u32 channel_intr_status;
138 	u32 intr_status;
139 	u32 intr_mask;
140 	struct iio_dev *indio_dev = data;
141 	struct iproc_adc_priv *adc_priv = iio_priv(indio_dev);
142 
143 	/*
144 	 * This interrupt is shared with the touchscreen driver.
145 	 * Make sure this interrupt is intended for us.
146 	 * Handle only ADC channel specific interrupts.
147 	 */
148 	regmap_read(adc_priv->regmap, IPROC_INTERRUPT_STATUS, &intr_status);
149 	regmap_read(adc_priv->regmap, IPROC_INTERRUPT_MASK, &intr_mask);
150 	intr_status = intr_status & intr_mask;
151 	channel_intr_status = (intr_status & IPROC_ADC_INTR_MASK) >>
152 				IPROC_ADC_INTR;
153 	if (channel_intr_status)
154 		return IRQ_WAKE_THREAD;
155 
156 	return IRQ_NONE;
157 }
158 
159 static irqreturn_t iproc_adc_interrupt_handler(int irq, void *data)
160 {
161 	irqreturn_t retval = IRQ_NONE;
162 	struct iproc_adc_priv *adc_priv;
163 	struct iio_dev *indio_dev = data;
164 	unsigned int valid_entries;
165 	u32 intr_status;
166 	u32 intr_channels;
167 	u32 channel_status;
168 	u32 ch_intr_status;
169 
170 	adc_priv = iio_priv(indio_dev);
171 
172 	regmap_read(adc_priv->regmap, IPROC_INTERRUPT_STATUS, &intr_status);
173 	dev_dbg(&indio_dev->dev, "iproc_adc_interrupt_handler(),INTRPT_STS:%x\n",
174 			intr_status);
175 
176 	intr_channels = (intr_status & IPROC_ADC_INTR_MASK) >> IPROC_ADC_INTR;
177 	if (intr_channels) {
178 		regmap_read(adc_priv->regmap,
179 			    IPROC_ADC_CHANNEL_INTERRUPT_STATUS +
180 			    IPROC_ADC_CHANNEL_OFFSET * adc_priv->chan_id,
181 			    &ch_intr_status);
182 
183 		if (ch_intr_status & IPROC_ADC_CHANNEL_WTRMRK_INTR_MASK) {
184 			regmap_read(adc_priv->regmap,
185 					IPROC_ADC_CHANNEL_STATUS +
186 					IPROC_ADC_CHANNEL_OFFSET *
187 					adc_priv->chan_id,
188 					&channel_status);
189 
190 			valid_entries = ((channel_status &
191 				IPROC_ADC_CHANNEL_VALID_ENTERIES_MASK) >>
192 				IPROC_ADC_CHANNEL_VALID_ENTERIES);
193 			if (valid_entries >= 1) {
194 				regmap_read(adc_priv->regmap,
195 					IPROC_ADC_CHANNEL_DATA +
196 					IPROC_ADC_CHANNEL_OFFSET *
197 					adc_priv->chan_id,
198 					&adc_priv->chan_val);
199 				complete(&adc_priv->completion);
200 			} else {
201 				dev_err(&indio_dev->dev,
202 					"No data rcvd on channel %d\n",
203 					adc_priv->chan_id);
204 			}
205 			regmap_write(adc_priv->regmap,
206 					IPROC_ADC_CHANNEL_INTERRUPT_MASK +
207 					IPROC_ADC_CHANNEL_OFFSET *
208 					adc_priv->chan_id,
209 					(ch_intr_status &
210 					~(IPROC_ADC_CHANNEL_WTRMRK_INTR_MASK)));
211 		}
212 		regmap_write(adc_priv->regmap,
213 				IPROC_ADC_CHANNEL_INTERRUPT_STATUS +
214 				IPROC_ADC_CHANNEL_OFFSET * adc_priv->chan_id,
215 				ch_intr_status);
216 		regmap_write(adc_priv->regmap, IPROC_INTERRUPT_STATUS,
217 				intr_channels);
218 		retval = IRQ_HANDLED;
219 	}
220 
221 	return retval;
222 }
223 
224 static int iproc_adc_do_read(struct iio_dev *indio_dev,
225 			   int channel,
226 			   u16 *p_adc_data)
227 {
228 	int read_len = 0;
229 	u32 val;
230 	u32 mask;
231 	u32 val_check;
232 	int failed_cnt = 0;
233 	struct iproc_adc_priv *adc_priv = iio_priv(indio_dev);
234 
235 	mutex_lock(&adc_priv->mutex);
236 
237 	/*
238 	 * After a read is complete the ADC interrupts will be disabled so
239 	 * we can assume this section of code is safe from interrupts.
240 	 */
241 	adc_priv->chan_val = -1;
242 	adc_priv->chan_id = channel;
243 
244 	reinit_completion(&adc_priv->completion);
245 	/* Clear any pending interrupt */
246 	regmap_update_bits(adc_priv->regmap, IPROC_INTERRUPT_STATUS,
247 			IPROC_ADC_INTR_MASK | IPROC_ADC_AUXDATA_RDY_INTR,
248 			((0x0 << channel) << IPROC_ADC_INTR) |
249 			IPROC_ADC_AUXDATA_RDY_INTR);
250 
251 	/* Configure channel for snapshot mode and enable  */
252 	val = (BIT(IPROC_ADC_CHANNEL_ROUNDS) |
253 		(IPROC_ADC_CHANNEL_MODE_SNAPSHOT << IPROC_ADC_CHANNEL_MODE) |
254 		(0x1 << IPROC_ADC_CHANNEL_ENABLE));
255 
256 	mask = IPROC_ADC_CHANNEL_ROUNDS_MASK | IPROC_ADC_CHANNEL_MODE_MASK |
257 		IPROC_ADC_CHANNEL_ENABLE_MASK;
258 	regmap_update_bits(adc_priv->regmap, (IPROC_ADC_CHANNEL_REGCTL1 +
259 				IPROC_ADC_CHANNEL_OFFSET * channel),
260 				mask, val);
261 
262 	/* Set the Watermark for a channel */
263 	regmap_update_bits(adc_priv->regmap, (IPROC_ADC_CHANNEL_REGCTL2 +
264 					IPROC_ADC_CHANNEL_OFFSET * channel),
265 					IPROC_ADC_CHANNEL_WATERMARK_MASK,
266 					0x1);
267 
268 	/* Enable water mark interrupt */
269 	regmap_update_bits(adc_priv->regmap, (IPROC_ADC_CHANNEL_INTERRUPT_MASK +
270 					IPROC_ADC_CHANNEL_OFFSET *
271 					channel),
272 					IPROC_ADC_CHANNEL_WTRMRK_INTR_MASK,
273 					IPROC_ADC_WATER_MARK_INTR_ENABLE);
274 	regmap_read(adc_priv->regmap, IPROC_INTERRUPT_MASK, &val);
275 
276 	/* Enable ADC interrupt for a channel */
277 	val |= (BIT(channel) << IPROC_ADC_INTR);
278 	regmap_write(adc_priv->regmap, IPROC_INTERRUPT_MASK, val);
279 
280 	/*
281 	 * There seems to be a very rare issue where writing to this register
282 	 * does not take effect.  To work around the issue we will try multiple
283 	 * writes.  In total we will spend about 10*10 = 100 us attempting this.
284 	 * Testing has shown that this may loop a few time, but we have never
285 	 * hit the full count.
286 	 */
287 	regmap_read(adc_priv->regmap, IPROC_INTERRUPT_MASK, &val_check);
288 	while (val_check != val) {
289 		failed_cnt++;
290 
291 		if (failed_cnt > IPROC_ADC_INTMASK_RETRY_ATTEMPTS)
292 			break;
293 
294 		udelay(10);
295 		regmap_update_bits(adc_priv->regmap, IPROC_INTERRUPT_MASK,
296 				IPROC_ADC_INTR_MASK,
297 				((0x1 << channel) <<
298 				IPROC_ADC_INTR));
299 
300 		regmap_read(adc_priv->regmap, IPROC_INTERRUPT_MASK, &val_check);
301 	}
302 
303 	if (failed_cnt) {
304 		dev_dbg(&indio_dev->dev,
305 			"IntMask failed (%d times)", failed_cnt);
306 		if (failed_cnt > IPROC_ADC_INTMASK_RETRY_ATTEMPTS) {
307 			dev_err(&indio_dev->dev,
308 				"IntMask set failed. Read will likely fail.");
309 			read_len = -EIO;
310 			goto adc_err;
311 		}
312 	}
313 	regmap_read(adc_priv->regmap, IPROC_INTERRUPT_MASK, &val_check);
314 
315 	if (wait_for_completion_timeout(&adc_priv->completion,
316 		IPROC_ADC_READ_TIMEOUT) > 0) {
317 
318 		/* Only the lower 16 bits are relevant */
319 		*p_adc_data = adc_priv->chan_val & 0xFFFF;
320 		read_len = sizeof(*p_adc_data);
321 
322 	} else {
323 		/*
324 		 * We never got the interrupt, something went wrong.
325 		 * Perhaps the interrupt may still be coming, we do not want
326 		 * that now.  Lets disable the ADC interrupt, and clear the
327 		 * status to put it back in to normal state.
328 		 */
329 		read_len = -ETIMEDOUT;
330 		goto adc_err;
331 	}
332 	mutex_unlock(&adc_priv->mutex);
333 
334 	return read_len;
335 
336 adc_err:
337 	regmap_update_bits(adc_priv->regmap, IPROC_INTERRUPT_MASK,
338 			   IPROC_ADC_INTR_MASK,
339 			   ((0x0 << channel) << IPROC_ADC_INTR));
340 
341 	regmap_update_bits(adc_priv->regmap, IPROC_INTERRUPT_STATUS,
342 			   IPROC_ADC_INTR_MASK,
343 			   ((0x0 << channel) << IPROC_ADC_INTR));
344 
345 	dev_err(&indio_dev->dev, "Timed out waiting for ADC data!\n");
346 	iproc_adc_reg_dump(indio_dev);
347 	mutex_unlock(&adc_priv->mutex);
348 
349 	return read_len;
350 }
351 
352 static int iproc_adc_enable(struct iio_dev *indio_dev)
353 {
354 	u32 val;
355 	u32 channel_id;
356 	struct iproc_adc_priv *adc_priv = iio_priv(indio_dev);
357 	int ret;
358 
359 	/* Set i_amux = 3b'000, select channel 0 */
360 	ret = regmap_clear_bits(adc_priv->regmap, IPROC_ANALOG_CONTROL,
361 				IPROC_ADC_CHANNEL_SEL_MASK);
362 	if (ret) {
363 		dev_err(&indio_dev->dev,
364 			"failed to write IPROC_ANALOG_CONTROL %d\n", ret);
365 		return ret;
366 	}
367 	adc_priv->chan_val = -1;
368 
369 	/*
370 	 * PWR up LDO, ADC, and Band Gap (0 to enable)
371 	 * Also enable ADC controller (set high)
372 	 */
373 	ret = regmap_read(adc_priv->regmap, IPROC_REGCTL2, &val);
374 	if (ret) {
375 		dev_err(&indio_dev->dev,
376 			"failed to read IPROC_REGCTL2 %d\n", ret);
377 		return ret;
378 	}
379 
380 	val &= ~(IPROC_ADC_PWR_LDO | IPROC_ADC_PWR_ADC | IPROC_ADC_PWR_BG);
381 
382 	ret = regmap_write(adc_priv->regmap, IPROC_REGCTL2, val);
383 	if (ret) {
384 		dev_err(&indio_dev->dev,
385 			"failed to write IPROC_REGCTL2 %d\n", ret);
386 		return ret;
387 	}
388 
389 	ret = regmap_read(adc_priv->regmap, IPROC_REGCTL2, &val);
390 	if (ret) {
391 		dev_err(&indio_dev->dev,
392 			"failed to read IPROC_REGCTL2 %d\n", ret);
393 		return ret;
394 	}
395 
396 	val |= IPROC_ADC_CONTROLLER_EN;
397 	ret = regmap_write(adc_priv->regmap, IPROC_REGCTL2, val);
398 	if (ret) {
399 		dev_err(&indio_dev->dev,
400 			"failed to write IPROC_REGCTL2 %d\n", ret);
401 		return ret;
402 	}
403 
404 	for (channel_id = 0; channel_id < indio_dev->num_channels;
405 		channel_id++) {
406 		ret = regmap_write(adc_priv->regmap,
407 				IPROC_ADC_CHANNEL_INTERRUPT_MASK +
408 				IPROC_ADC_CHANNEL_OFFSET * channel_id, 0);
409 		if (ret) {
410 			dev_err(&indio_dev->dev,
411 			    "failed to write ADC_CHANNEL_INTERRUPT_MASK %d\n",
412 			    ret);
413 			return ret;
414 		}
415 
416 		ret = regmap_write(adc_priv->regmap,
417 				IPROC_ADC_CHANNEL_INTERRUPT_STATUS +
418 				IPROC_ADC_CHANNEL_OFFSET * channel_id, 0);
419 		if (ret) {
420 			dev_err(&indio_dev->dev,
421 			    "failed to write ADC_CHANNEL_INTERRUPT_STATUS %d\n",
422 			    ret);
423 			return ret;
424 		}
425 	}
426 
427 	return 0;
428 }
429 
430 static void iproc_adc_disable(struct iio_dev *indio_dev)
431 {
432 	u32 val;
433 	int ret;
434 	struct iproc_adc_priv *adc_priv = iio_priv(indio_dev);
435 
436 	ret = regmap_read(adc_priv->regmap, IPROC_REGCTL2, &val);
437 	if (ret) {
438 		dev_err(&indio_dev->dev,
439 			"failed to read IPROC_REGCTL2 %d\n", ret);
440 		return;
441 	}
442 
443 	val &= ~IPROC_ADC_CONTROLLER_EN;
444 	ret = regmap_write(adc_priv->regmap, IPROC_REGCTL2, val);
445 	if (ret) {
446 		dev_err(&indio_dev->dev,
447 			"failed to write IPROC_REGCTL2 %d\n", ret);
448 		return;
449 	}
450 }
451 
452 static int iproc_adc_read_raw(struct iio_dev *indio_dev,
453 			  struct iio_chan_spec const *chan,
454 			  int *val,
455 			  int *val2,
456 			  long mask)
457 {
458 	u16 adc_data;
459 	int err;
460 
461 	switch (mask) {
462 	case IIO_CHAN_INFO_RAW:
463 		err =  iproc_adc_do_read(indio_dev, chan->channel, &adc_data);
464 		if (err < 0)
465 			return err;
466 		*val = adc_data;
467 		return IIO_VAL_INT;
468 	case IIO_CHAN_INFO_SCALE:
469 		switch (chan->type) {
470 		case IIO_VOLTAGE:
471 			*val = 1800;
472 			*val2 = 10;
473 			return IIO_VAL_FRACTIONAL_LOG2;
474 		default:
475 			return -EINVAL;
476 		}
477 	default:
478 		return -EINVAL;
479 	}
480 }
481 
482 static const struct iio_info iproc_adc_iio_info = {
483 	.read_raw = &iproc_adc_read_raw,
484 };
485 
486 #define IPROC_ADC_CHANNEL(_index, _id) {                \
487 	.type = IIO_VOLTAGE,                            \
488 	.indexed = 1,                                   \
489 	.channel = _index,                              \
490 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),   \
491 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
492 	.datasheet_name = _id,                          \
493 }
494 
495 static const struct iio_chan_spec iproc_adc_iio_channels[] = {
496 	IPROC_ADC_CHANNEL(0, "adc0"),
497 	IPROC_ADC_CHANNEL(1, "adc1"),
498 	IPROC_ADC_CHANNEL(2, "adc2"),
499 	IPROC_ADC_CHANNEL(3, "adc3"),
500 	IPROC_ADC_CHANNEL(4, "adc4"),
501 	IPROC_ADC_CHANNEL(5, "adc5"),
502 	IPROC_ADC_CHANNEL(6, "adc6"),
503 	IPROC_ADC_CHANNEL(7, "adc7"),
504 };
505 
506 static int iproc_adc_probe(struct platform_device *pdev)
507 {
508 	struct iproc_adc_priv *adc_priv;
509 	struct iio_dev *indio_dev = NULL;
510 	int ret;
511 
512 	indio_dev = devm_iio_device_alloc(&pdev->dev,
513 					sizeof(*adc_priv));
514 	if (!indio_dev) {
515 		dev_err(&pdev->dev, "failed to allocate iio device\n");
516 		return -ENOMEM;
517 	}
518 
519 	adc_priv = iio_priv(indio_dev);
520 	platform_set_drvdata(pdev, indio_dev);
521 
522 	mutex_init(&adc_priv->mutex);
523 
524 	init_completion(&adc_priv->completion);
525 
526 	adc_priv->regmap = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
527 			   "adc-syscon");
528 	if (IS_ERR(adc_priv->regmap)) {
529 		dev_err(&pdev->dev, "failed to get handle for tsc syscon\n");
530 		ret = PTR_ERR(adc_priv->regmap);
531 		return ret;
532 	}
533 
534 	adc_priv->adc_clk = devm_clk_get(&pdev->dev, "tsc_clk");
535 	if (IS_ERR(adc_priv->adc_clk)) {
536 		dev_err(&pdev->dev,
537 			"failed getting clock tsc_clk\n");
538 		ret = PTR_ERR(adc_priv->adc_clk);
539 		return ret;
540 	}
541 
542 	adc_priv->irqno = platform_get_irq(pdev, 0);
543 	if (adc_priv->irqno < 0)
544 		return adc_priv->irqno;
545 
546 	ret = regmap_clear_bits(adc_priv->regmap, IPROC_REGCTL2,
547 				IPROC_ADC_AUXIN_SCAN_ENA);
548 	if (ret) {
549 		dev_err(&pdev->dev, "failed to write IPROC_REGCTL2 %d\n", ret);
550 		return ret;
551 	}
552 
553 	ret = devm_request_threaded_irq(&pdev->dev, adc_priv->irqno,
554 				iproc_adc_interrupt_handler,
555 				iproc_adc_interrupt_thread,
556 				IRQF_SHARED, "iproc-adc", indio_dev);
557 	if (ret) {
558 		dev_err(&pdev->dev, "request_irq error %d\n", ret);
559 		return ret;
560 	}
561 
562 	ret = clk_prepare_enable(adc_priv->adc_clk);
563 	if (ret) {
564 		dev_err(&pdev->dev,
565 			"clk_prepare_enable failed %d\n", ret);
566 		return ret;
567 	}
568 
569 	ret = iproc_adc_enable(indio_dev);
570 	if (ret) {
571 		dev_err(&pdev->dev, "failed to enable adc %d\n", ret);
572 		goto err_adc_enable;
573 	}
574 
575 	indio_dev->name = "iproc-static-adc";
576 	indio_dev->info = &iproc_adc_iio_info;
577 	indio_dev->modes = INDIO_DIRECT_MODE;
578 	indio_dev->channels = iproc_adc_iio_channels;
579 	indio_dev->num_channels = ARRAY_SIZE(iproc_adc_iio_channels);
580 
581 	ret = iio_device_register(indio_dev);
582 	if (ret) {
583 		dev_err(&pdev->dev, "iio_device_register failed:err %d\n", ret);
584 		goto err_clk;
585 	}
586 
587 	return 0;
588 
589 err_clk:
590 	iproc_adc_disable(indio_dev);
591 err_adc_enable:
592 	clk_disable_unprepare(adc_priv->adc_clk);
593 
594 	return ret;
595 }
596 
597 static void iproc_adc_remove(struct platform_device *pdev)
598 {
599 	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
600 	struct iproc_adc_priv *adc_priv = iio_priv(indio_dev);
601 
602 	iio_device_unregister(indio_dev);
603 	iproc_adc_disable(indio_dev);
604 	clk_disable_unprepare(adc_priv->adc_clk);
605 }
606 
607 static const struct of_device_id iproc_adc_of_match[] = {
608 	{.compatible = "brcm,iproc-static-adc", },
609 	{ },
610 };
611 MODULE_DEVICE_TABLE(of, iproc_adc_of_match);
612 
613 static struct platform_driver iproc_adc_driver = {
614 	.probe  = iproc_adc_probe,
615 	.remove_new = iproc_adc_remove,
616 	.driver	= {
617 		.name	= "iproc-static-adc",
618 		.of_match_table = iproc_adc_of_match,
619 	},
620 };
621 module_platform_driver(iproc_adc_driver);
622 
623 MODULE_DESCRIPTION("Broadcom iProc ADC controller driver");
624 MODULE_AUTHOR("Raveendra Padasalagi <raveendra.padasalagi@broadcom.com>");
625 MODULE_LICENSE("GPL v2");
626