xref: /linux/drivers/iio/adc/exynos_adc.c (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
1 /*
2  *  exynos_adc.c - Support for ADC in EXYNOS SoCs
3  *
4  *  8 ~ 10 channel, 10/12-bit ADC
5  *
6  *  Copyright (C) 2013 Naveen Krishna Chatradhi <ch.naveen@samsung.com>
7  *
8  *  This program is free software; you can redistribute it and/or modify
9  *  it under the terms of the GNU General Public License as published by
10  *  the Free Software Foundation; either version 2 of the License, or
11  *  (at your option) any later version.
12  *
13  *  This program is distributed in the hope that it will be useful,
14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  *  GNU General Public License for more details.
17  *
18  *  You should have received a copy of the GNU General Public License
19  *  along with this program; if not, write to the Free Software
20  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21  */
22 
23 #include <linux/module.h>
24 #include <linux/platform_device.h>
25 #include <linux/interrupt.h>
26 #include <linux/delay.h>
27 #include <linux/errno.h>
28 #include <linux/kernel.h>
29 #include <linux/slab.h>
30 #include <linux/io.h>
31 #include <linux/clk.h>
32 #include <linux/completion.h>
33 #include <linux/of.h>
34 #include <linux/of_irq.h>
35 #include <linux/regulator/consumer.h>
36 #include <linux/of_platform.h>
37 #include <linux/err.h>
38 
39 #include <linux/iio/iio.h>
40 #include <linux/iio/machine.h>
41 #include <linux/iio/driver.h>
42 #include <linux/mfd/syscon.h>
43 #include <linux/regmap.h>
44 
45 /* S3C/EXYNOS4412/5250 ADC_V1 registers definitions */
46 #define ADC_V1_CON(x)		((x) + 0x00)
47 #define ADC_V1_DLY(x)		((x) + 0x08)
48 #define ADC_V1_DATX(x)		((x) + 0x0C)
49 #define ADC_V1_INTCLR(x)	((x) + 0x18)
50 #define ADC_V1_MUX(x)		((x) + 0x1c)
51 
52 /* S3C2410 ADC registers definitions */
53 #define ADC_S3C2410_MUX(x)	((x) + 0x18)
54 
55 /* Future ADC_V2 registers definitions */
56 #define ADC_V2_CON1(x)		((x) + 0x00)
57 #define ADC_V2_CON2(x)		((x) + 0x04)
58 #define ADC_V2_STAT(x)		((x) + 0x08)
59 #define ADC_V2_INT_EN(x)	((x) + 0x10)
60 #define ADC_V2_INT_ST(x)	((x) + 0x14)
61 #define ADC_V2_VER(x)		((x) + 0x20)
62 
63 /* Bit definitions for ADC_V1 */
64 #define ADC_V1_CON_RES		(1u << 16)
65 #define ADC_V1_CON_PRSCEN	(1u << 14)
66 #define ADC_V1_CON_PRSCLV(x)	(((x) & 0xFF) << 6)
67 #define ADC_V1_CON_STANDBY	(1u << 2)
68 
69 /* Bit definitions for S3C2410 ADC */
70 #define ADC_S3C2410_CON_SELMUX(x) (((x) & 7) << 3)
71 #define ADC_S3C2410_DATX_MASK	0x3FF
72 #define ADC_S3C2416_CON_RES_SEL	(1u << 3)
73 
74 /* Bit definitions for ADC_V2 */
75 #define ADC_V2_CON1_SOFT_RESET	(1u << 2)
76 
77 #define ADC_V2_CON2_OSEL	(1u << 10)
78 #define ADC_V2_CON2_ESEL	(1u << 9)
79 #define ADC_V2_CON2_HIGHF	(1u << 8)
80 #define ADC_V2_CON2_C_TIME(x)	(((x) & 7) << 4)
81 #define ADC_V2_CON2_ACH_SEL(x)	(((x) & 0xF) << 0)
82 #define ADC_V2_CON2_ACH_MASK	0xF
83 
84 #define MAX_ADC_V2_CHANNELS		10
85 #define MAX_ADC_V1_CHANNELS		8
86 #define MAX_EXYNOS3250_ADC_CHANNELS	2
87 
88 /* Bit definitions common for ADC_V1 and ADC_V2 */
89 #define ADC_CON_EN_START	(1u << 0)
90 #define ADC_CON_EN_START_MASK	(0x3 << 0)
91 #define ADC_DATX_MASK		0xFFF
92 
93 #define EXYNOS_ADC_TIMEOUT	(msecs_to_jiffies(100))
94 
95 #define EXYNOS_ADCV1_PHY_OFFSET	0x0718
96 #define EXYNOS_ADCV2_PHY_OFFSET	0x0720
97 
98 struct exynos_adc {
99 	struct exynos_adc_data	*data;
100 	struct device		*dev;
101 	void __iomem		*regs;
102 	struct regmap		*pmu_map;
103 	struct clk		*clk;
104 	struct clk		*sclk;
105 	unsigned int		irq;
106 	struct regulator	*vdd;
107 
108 	struct completion	completion;
109 
110 	u32			value;
111 	unsigned int            version;
112 };
113 
114 struct exynos_adc_data {
115 	int num_channels;
116 	bool needs_sclk;
117 	bool needs_adc_phy;
118 	int phy_offset;
119 	u32 mask;
120 
121 	void (*init_hw)(struct exynos_adc *info);
122 	void (*exit_hw)(struct exynos_adc *info);
123 	void (*clear_irq)(struct exynos_adc *info);
124 	void (*start_conv)(struct exynos_adc *info, unsigned long addr);
125 };
126 
127 static void exynos_adc_unprepare_clk(struct exynos_adc *info)
128 {
129 	if (info->data->needs_sclk)
130 		clk_unprepare(info->sclk);
131 	clk_unprepare(info->clk);
132 }
133 
134 static int exynos_adc_prepare_clk(struct exynos_adc *info)
135 {
136 	int ret;
137 
138 	ret = clk_prepare(info->clk);
139 	if (ret) {
140 		dev_err(info->dev, "failed preparing adc clock: %d\n", ret);
141 		return ret;
142 	}
143 
144 	if (info->data->needs_sclk) {
145 		ret = clk_prepare(info->sclk);
146 		if (ret) {
147 			clk_unprepare(info->clk);
148 			dev_err(info->dev,
149 				"failed preparing sclk_adc clock: %d\n", ret);
150 			return ret;
151 		}
152 	}
153 
154 	return 0;
155 }
156 
157 static void exynos_adc_disable_clk(struct exynos_adc *info)
158 {
159 	if (info->data->needs_sclk)
160 		clk_disable(info->sclk);
161 	clk_disable(info->clk);
162 }
163 
164 static int exynos_adc_enable_clk(struct exynos_adc *info)
165 {
166 	int ret;
167 
168 	ret = clk_enable(info->clk);
169 	if (ret) {
170 		dev_err(info->dev, "failed enabling adc clock: %d\n", ret);
171 		return ret;
172 	}
173 
174 	if (info->data->needs_sclk) {
175 		ret = clk_enable(info->sclk);
176 		if (ret) {
177 			clk_disable(info->clk);
178 			dev_err(info->dev,
179 				"failed enabling sclk_adc clock: %d\n", ret);
180 			return ret;
181 		}
182 	}
183 
184 	return 0;
185 }
186 
187 static void exynos_adc_v1_init_hw(struct exynos_adc *info)
188 {
189 	u32 con1;
190 
191 	if (info->data->needs_adc_phy)
192 		regmap_write(info->pmu_map, info->data->phy_offset, 1);
193 
194 	/* set default prescaler values and Enable prescaler */
195 	con1 =  ADC_V1_CON_PRSCLV(49) | ADC_V1_CON_PRSCEN;
196 
197 	/* Enable 12-bit ADC resolution */
198 	con1 |= ADC_V1_CON_RES;
199 	writel(con1, ADC_V1_CON(info->regs));
200 }
201 
202 static void exynos_adc_v1_exit_hw(struct exynos_adc *info)
203 {
204 	u32 con;
205 
206 	if (info->data->needs_adc_phy)
207 		regmap_write(info->pmu_map, info->data->phy_offset, 0);
208 
209 	con = readl(ADC_V1_CON(info->regs));
210 	con |= ADC_V1_CON_STANDBY;
211 	writel(con, ADC_V1_CON(info->regs));
212 }
213 
214 static void exynos_adc_v1_clear_irq(struct exynos_adc *info)
215 {
216 	writel(1, ADC_V1_INTCLR(info->regs));
217 }
218 
219 static void exynos_adc_v1_start_conv(struct exynos_adc *info,
220 				     unsigned long addr)
221 {
222 	u32 con1;
223 
224 	writel(addr, ADC_V1_MUX(info->regs));
225 
226 	con1 = readl(ADC_V1_CON(info->regs));
227 	writel(con1 | ADC_CON_EN_START, ADC_V1_CON(info->regs));
228 }
229 
230 static const struct exynos_adc_data exynos_adc_v1_data = {
231 	.num_channels	= MAX_ADC_V1_CHANNELS,
232 	.mask		= ADC_DATX_MASK,	/* 12 bit ADC resolution */
233 	.needs_adc_phy	= true,
234 	.phy_offset	= EXYNOS_ADCV1_PHY_OFFSET,
235 
236 	.init_hw	= exynos_adc_v1_init_hw,
237 	.exit_hw	= exynos_adc_v1_exit_hw,
238 	.clear_irq	= exynos_adc_v1_clear_irq,
239 	.start_conv	= exynos_adc_v1_start_conv,
240 };
241 
242 static void exynos_adc_s3c2416_start_conv(struct exynos_adc *info,
243 					  unsigned long addr)
244 {
245 	u32 con1;
246 
247 	/* Enable 12 bit ADC resolution */
248 	con1 = readl(ADC_V1_CON(info->regs));
249 	con1 |= ADC_S3C2416_CON_RES_SEL;
250 	writel(con1, ADC_V1_CON(info->regs));
251 
252 	/* Select channel for S3C2416 */
253 	writel(addr, ADC_S3C2410_MUX(info->regs));
254 
255 	con1 = readl(ADC_V1_CON(info->regs));
256 	writel(con1 | ADC_CON_EN_START, ADC_V1_CON(info->regs));
257 }
258 
259 static struct exynos_adc_data const exynos_adc_s3c2416_data = {
260 	.num_channels	= MAX_ADC_V1_CHANNELS,
261 	.mask		= ADC_DATX_MASK,	/* 12 bit ADC resolution */
262 
263 	.init_hw	= exynos_adc_v1_init_hw,
264 	.exit_hw	= exynos_adc_v1_exit_hw,
265 	.start_conv	= exynos_adc_s3c2416_start_conv,
266 };
267 
268 static void exynos_adc_s3c2443_start_conv(struct exynos_adc *info,
269 					  unsigned long addr)
270 {
271 	u32 con1;
272 
273 	/* Select channel for S3C2433 */
274 	writel(addr, ADC_S3C2410_MUX(info->regs));
275 
276 	con1 = readl(ADC_V1_CON(info->regs));
277 	writel(con1 | ADC_CON_EN_START, ADC_V1_CON(info->regs));
278 }
279 
280 static struct exynos_adc_data const exynos_adc_s3c2443_data = {
281 	.num_channels	= MAX_ADC_V1_CHANNELS,
282 	.mask		= ADC_S3C2410_DATX_MASK, /* 10 bit ADC resolution */
283 
284 	.init_hw	= exynos_adc_v1_init_hw,
285 	.exit_hw	= exynos_adc_v1_exit_hw,
286 	.start_conv	= exynos_adc_s3c2443_start_conv,
287 };
288 
289 static void exynos_adc_s3c64xx_start_conv(struct exynos_adc *info,
290 					  unsigned long addr)
291 {
292 	u32 con1;
293 
294 	con1 = readl(ADC_V1_CON(info->regs));
295 	con1 &= ~ADC_S3C2410_CON_SELMUX(0x7);
296 	con1 |= ADC_S3C2410_CON_SELMUX(addr);
297 	writel(con1 | ADC_CON_EN_START, ADC_V1_CON(info->regs));
298 }
299 
300 static struct exynos_adc_data const exynos_adc_s3c24xx_data = {
301 	.num_channels	= MAX_ADC_V1_CHANNELS,
302 	.mask		= ADC_S3C2410_DATX_MASK, /* 10 bit ADC resolution */
303 
304 	.init_hw	= exynos_adc_v1_init_hw,
305 	.exit_hw	= exynos_adc_v1_exit_hw,
306 	.start_conv	= exynos_adc_s3c64xx_start_conv,
307 };
308 
309 static struct exynos_adc_data const exynos_adc_s3c64xx_data = {
310 	.num_channels	= MAX_ADC_V1_CHANNELS,
311 	.mask		= ADC_DATX_MASK,	/* 12 bit ADC resolution */
312 
313 	.init_hw	= exynos_adc_v1_init_hw,
314 	.exit_hw	= exynos_adc_v1_exit_hw,
315 	.clear_irq	= exynos_adc_v1_clear_irq,
316 	.start_conv	= exynos_adc_s3c64xx_start_conv,
317 };
318 
319 static void exynos_adc_v2_init_hw(struct exynos_adc *info)
320 {
321 	u32 con1, con2;
322 
323 	if (info->data->needs_adc_phy)
324 		regmap_write(info->pmu_map, info->data->phy_offset, 1);
325 
326 	con1 = ADC_V2_CON1_SOFT_RESET;
327 	writel(con1, ADC_V2_CON1(info->regs));
328 
329 	con2 = ADC_V2_CON2_OSEL | ADC_V2_CON2_ESEL |
330 		ADC_V2_CON2_HIGHF | ADC_V2_CON2_C_TIME(0);
331 	writel(con2, ADC_V2_CON2(info->regs));
332 
333 	/* Enable interrupts */
334 	writel(1, ADC_V2_INT_EN(info->regs));
335 }
336 
337 static void exynos_adc_v2_exit_hw(struct exynos_adc *info)
338 {
339 	u32 con;
340 
341 	if (info->data->needs_adc_phy)
342 		regmap_write(info->pmu_map, info->data->phy_offset, 0);
343 
344 	con = readl(ADC_V2_CON1(info->regs));
345 	con &= ~ADC_CON_EN_START;
346 	writel(con, ADC_V2_CON1(info->regs));
347 }
348 
349 static void exynos_adc_v2_clear_irq(struct exynos_adc *info)
350 {
351 	writel(1, ADC_V2_INT_ST(info->regs));
352 }
353 
354 static void exynos_adc_v2_start_conv(struct exynos_adc *info,
355 				     unsigned long addr)
356 {
357 	u32 con1, con2;
358 
359 	con2 = readl(ADC_V2_CON2(info->regs));
360 	con2 &= ~ADC_V2_CON2_ACH_MASK;
361 	con2 |= ADC_V2_CON2_ACH_SEL(addr);
362 	writel(con2, ADC_V2_CON2(info->regs));
363 
364 	con1 = readl(ADC_V2_CON1(info->regs));
365 	writel(con1 | ADC_CON_EN_START, ADC_V2_CON1(info->regs));
366 }
367 
368 static const struct exynos_adc_data exynos_adc_v2_data = {
369 	.num_channels	= MAX_ADC_V2_CHANNELS,
370 	.mask		= ADC_DATX_MASK, /* 12 bit ADC resolution */
371 	.needs_adc_phy	= true,
372 	.phy_offset	= EXYNOS_ADCV2_PHY_OFFSET,
373 
374 	.init_hw	= exynos_adc_v2_init_hw,
375 	.exit_hw	= exynos_adc_v2_exit_hw,
376 	.clear_irq	= exynos_adc_v2_clear_irq,
377 	.start_conv	= exynos_adc_v2_start_conv,
378 };
379 
380 static const struct exynos_adc_data exynos3250_adc_data = {
381 	.num_channels	= MAX_EXYNOS3250_ADC_CHANNELS,
382 	.mask		= ADC_DATX_MASK, /* 12 bit ADC resolution */
383 	.needs_sclk	= true,
384 	.needs_adc_phy	= true,
385 	.phy_offset	= EXYNOS_ADCV1_PHY_OFFSET,
386 
387 	.init_hw	= exynos_adc_v2_init_hw,
388 	.exit_hw	= exynos_adc_v2_exit_hw,
389 	.clear_irq	= exynos_adc_v2_clear_irq,
390 	.start_conv	= exynos_adc_v2_start_conv,
391 };
392 
393 static void exynos_adc_exynos7_init_hw(struct exynos_adc *info)
394 {
395 	u32 con1, con2;
396 
397 	if (info->data->needs_adc_phy)
398 		regmap_write(info->pmu_map, info->data->phy_offset, 1);
399 
400 	con1 = ADC_V2_CON1_SOFT_RESET;
401 	writel(con1, ADC_V2_CON1(info->regs));
402 
403 	con2 = readl(ADC_V2_CON2(info->regs));
404 	con2 &= ~ADC_V2_CON2_C_TIME(7);
405 	con2 |= ADC_V2_CON2_C_TIME(0);
406 	writel(con2, ADC_V2_CON2(info->regs));
407 
408 	/* Enable interrupts */
409 	writel(1, ADC_V2_INT_EN(info->regs));
410 }
411 
412 static const struct exynos_adc_data exynos7_adc_data = {
413 	.num_channels	= MAX_ADC_V1_CHANNELS,
414 	.mask		= ADC_DATX_MASK, /* 12 bit ADC resolution */
415 
416 	.init_hw	= exynos_adc_exynos7_init_hw,
417 	.exit_hw	= exynos_adc_v2_exit_hw,
418 	.clear_irq	= exynos_adc_v2_clear_irq,
419 	.start_conv	= exynos_adc_v2_start_conv,
420 };
421 
422 static const struct of_device_id exynos_adc_match[] = {
423 	{
424 		.compatible = "samsung,s3c2410-adc",
425 		.data = &exynos_adc_s3c24xx_data,
426 	}, {
427 		.compatible = "samsung,s3c2416-adc",
428 		.data = &exynos_adc_s3c2416_data,
429 	}, {
430 		.compatible = "samsung,s3c2440-adc",
431 		.data = &exynos_adc_s3c24xx_data,
432 	}, {
433 		.compatible = "samsung,s3c2443-adc",
434 		.data = &exynos_adc_s3c2443_data,
435 	}, {
436 		.compatible = "samsung,s3c6410-adc",
437 		.data = &exynos_adc_s3c64xx_data,
438 	}, {
439 		.compatible = "samsung,exynos-adc-v1",
440 		.data = &exynos_adc_v1_data,
441 	}, {
442 		.compatible = "samsung,exynos-adc-v2",
443 		.data = &exynos_adc_v2_data,
444 	}, {
445 		.compatible = "samsung,exynos3250-adc",
446 		.data = &exynos3250_adc_data,
447 	}, {
448 		.compatible = "samsung,exynos7-adc",
449 		.data = &exynos7_adc_data,
450 	},
451 	{},
452 };
453 MODULE_DEVICE_TABLE(of, exynos_adc_match);
454 
455 static struct exynos_adc_data *exynos_adc_get_data(struct platform_device *pdev)
456 {
457 	const struct of_device_id *match;
458 
459 	match = of_match_node(exynos_adc_match, pdev->dev.of_node);
460 	return (struct exynos_adc_data *)match->data;
461 }
462 
463 static int exynos_read_raw(struct iio_dev *indio_dev,
464 				struct iio_chan_spec const *chan,
465 				int *val,
466 				int *val2,
467 				long mask)
468 {
469 	struct exynos_adc *info = iio_priv(indio_dev);
470 	unsigned long timeout;
471 	int ret;
472 
473 	if (mask != IIO_CHAN_INFO_RAW)
474 		return -EINVAL;
475 
476 	mutex_lock(&indio_dev->mlock);
477 	reinit_completion(&info->completion);
478 
479 	/* Select the channel to be used and Trigger conversion */
480 	if (info->data->start_conv)
481 		info->data->start_conv(info, chan->address);
482 
483 	timeout = wait_for_completion_timeout
484 			(&info->completion, EXYNOS_ADC_TIMEOUT);
485 	if (timeout == 0) {
486 		dev_warn(&indio_dev->dev, "Conversion timed out! Resetting\n");
487 		if (info->data->init_hw)
488 			info->data->init_hw(info);
489 		ret = -ETIMEDOUT;
490 	} else {
491 		*val = info->value;
492 		*val2 = 0;
493 		ret = IIO_VAL_INT;
494 	}
495 
496 	mutex_unlock(&indio_dev->mlock);
497 
498 	return ret;
499 }
500 
501 static irqreturn_t exynos_adc_isr(int irq, void *dev_id)
502 {
503 	struct exynos_adc *info = (struct exynos_adc *)dev_id;
504 	u32 mask = info->data->mask;
505 
506 	/* Read value */
507 	info->value = readl(ADC_V1_DATX(info->regs)) & mask;
508 
509 	/* clear irq */
510 	if (info->data->clear_irq)
511 		info->data->clear_irq(info);
512 
513 	complete(&info->completion);
514 
515 	return IRQ_HANDLED;
516 }
517 
518 static int exynos_adc_reg_access(struct iio_dev *indio_dev,
519 			      unsigned reg, unsigned writeval,
520 			      unsigned *readval)
521 {
522 	struct exynos_adc *info = iio_priv(indio_dev);
523 
524 	if (readval == NULL)
525 		return -EINVAL;
526 
527 	*readval = readl(info->regs + reg);
528 
529 	return 0;
530 }
531 
532 static const struct iio_info exynos_adc_iio_info = {
533 	.read_raw = &exynos_read_raw,
534 	.debugfs_reg_access = &exynos_adc_reg_access,
535 	.driver_module = THIS_MODULE,
536 };
537 
538 #define ADC_CHANNEL(_index, _id) {			\
539 	.type = IIO_VOLTAGE,				\
540 	.indexed = 1,					\
541 	.channel = _index,				\
542 	.address = _index,				\
543 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),	\
544 	.datasheet_name = _id,				\
545 }
546 
547 static const struct iio_chan_spec exynos_adc_iio_channels[] = {
548 	ADC_CHANNEL(0, "adc0"),
549 	ADC_CHANNEL(1, "adc1"),
550 	ADC_CHANNEL(2, "adc2"),
551 	ADC_CHANNEL(3, "adc3"),
552 	ADC_CHANNEL(4, "adc4"),
553 	ADC_CHANNEL(5, "adc5"),
554 	ADC_CHANNEL(6, "adc6"),
555 	ADC_CHANNEL(7, "adc7"),
556 	ADC_CHANNEL(8, "adc8"),
557 	ADC_CHANNEL(9, "adc9"),
558 };
559 
560 static int exynos_adc_remove_devices(struct device *dev, void *c)
561 {
562 	struct platform_device *pdev = to_platform_device(dev);
563 
564 	platform_device_unregister(pdev);
565 
566 	return 0;
567 }
568 
569 static int exynos_adc_probe(struct platform_device *pdev)
570 {
571 	struct exynos_adc *info = NULL;
572 	struct device_node *np = pdev->dev.of_node;
573 	struct iio_dev *indio_dev = NULL;
574 	struct resource	*mem;
575 	int ret = -ENODEV;
576 	int irq;
577 
578 	if (!np)
579 		return ret;
580 
581 	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(struct exynos_adc));
582 	if (!indio_dev) {
583 		dev_err(&pdev->dev, "failed allocating iio device\n");
584 		return -ENOMEM;
585 	}
586 
587 	info = iio_priv(indio_dev);
588 
589 	info->data = exynos_adc_get_data(pdev);
590 	if (!info->data) {
591 		dev_err(&pdev->dev, "failed getting exynos_adc_data\n");
592 		return -EINVAL;
593 	}
594 
595 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
596 	info->regs = devm_ioremap_resource(&pdev->dev, mem);
597 	if (IS_ERR(info->regs))
598 		return PTR_ERR(info->regs);
599 
600 
601 	if (info->data->needs_adc_phy) {
602 		info->pmu_map = syscon_regmap_lookup_by_phandle(
603 					pdev->dev.of_node,
604 					"samsung,syscon-phandle");
605 		if (IS_ERR(info->pmu_map)) {
606 			dev_err(&pdev->dev, "syscon regmap lookup failed.\n");
607 			return PTR_ERR(info->pmu_map);
608 		}
609 	}
610 
611 	irq = platform_get_irq(pdev, 0);
612 	if (irq < 0) {
613 		dev_err(&pdev->dev, "no irq resource?\n");
614 		return irq;
615 	}
616 
617 	info->irq = irq;
618 	info->dev = &pdev->dev;
619 
620 	init_completion(&info->completion);
621 
622 	info->clk = devm_clk_get(&pdev->dev, "adc");
623 	if (IS_ERR(info->clk)) {
624 		dev_err(&pdev->dev, "failed getting clock, err = %ld\n",
625 							PTR_ERR(info->clk));
626 		return PTR_ERR(info->clk);
627 	}
628 
629 	if (info->data->needs_sclk) {
630 		info->sclk = devm_clk_get(&pdev->dev, "sclk");
631 		if (IS_ERR(info->sclk)) {
632 			dev_err(&pdev->dev,
633 				"failed getting sclk clock, err = %ld\n",
634 				PTR_ERR(info->sclk));
635 			return PTR_ERR(info->sclk);
636 		}
637 	}
638 
639 	info->vdd = devm_regulator_get(&pdev->dev, "vdd");
640 	if (IS_ERR(info->vdd)) {
641 		dev_err(&pdev->dev, "failed getting regulator, err = %ld\n",
642 							PTR_ERR(info->vdd));
643 		return PTR_ERR(info->vdd);
644 	}
645 
646 	ret = regulator_enable(info->vdd);
647 	if (ret)
648 		return ret;
649 
650 	ret = exynos_adc_prepare_clk(info);
651 	if (ret)
652 		goto err_disable_reg;
653 
654 	ret = exynos_adc_enable_clk(info);
655 	if (ret)
656 		goto err_unprepare_clk;
657 
658 	platform_set_drvdata(pdev, indio_dev);
659 
660 	indio_dev->name = dev_name(&pdev->dev);
661 	indio_dev->dev.parent = &pdev->dev;
662 	indio_dev->dev.of_node = pdev->dev.of_node;
663 	indio_dev->info = &exynos_adc_iio_info;
664 	indio_dev->modes = INDIO_DIRECT_MODE;
665 	indio_dev->channels = exynos_adc_iio_channels;
666 	indio_dev->num_channels = info->data->num_channels;
667 
668 	ret = request_irq(info->irq, exynos_adc_isr,
669 					0, dev_name(&pdev->dev), info);
670 	if (ret < 0) {
671 		dev_err(&pdev->dev, "failed requesting irq, irq = %d\n",
672 							info->irq);
673 		goto err_disable_clk;
674 	}
675 
676 	ret = iio_device_register(indio_dev);
677 	if (ret)
678 		goto err_irq;
679 
680 	if (info->data->init_hw)
681 		info->data->init_hw(info);
682 
683 	ret = of_platform_populate(np, exynos_adc_match, NULL, &indio_dev->dev);
684 	if (ret < 0) {
685 		dev_err(&pdev->dev, "failed adding child nodes\n");
686 		goto err_of_populate;
687 	}
688 
689 	return 0;
690 
691 err_of_populate:
692 	device_for_each_child(&indio_dev->dev, NULL,
693 				exynos_adc_remove_devices);
694 	iio_device_unregister(indio_dev);
695 err_irq:
696 	free_irq(info->irq, info);
697 err_disable_clk:
698 	if (info->data->exit_hw)
699 		info->data->exit_hw(info);
700 	exynos_adc_disable_clk(info);
701 err_unprepare_clk:
702 	exynos_adc_unprepare_clk(info);
703 err_disable_reg:
704 	regulator_disable(info->vdd);
705 	return ret;
706 }
707 
708 static int exynos_adc_remove(struct platform_device *pdev)
709 {
710 	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
711 	struct exynos_adc *info = iio_priv(indio_dev);
712 
713 	device_for_each_child(&indio_dev->dev, NULL,
714 				exynos_adc_remove_devices);
715 	iio_device_unregister(indio_dev);
716 	free_irq(info->irq, info);
717 	if (info->data->exit_hw)
718 		info->data->exit_hw(info);
719 	exynos_adc_disable_clk(info);
720 	exynos_adc_unprepare_clk(info);
721 	regulator_disable(info->vdd);
722 
723 	return 0;
724 }
725 
726 #ifdef CONFIG_PM_SLEEP
727 static int exynos_adc_suspend(struct device *dev)
728 {
729 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
730 	struct exynos_adc *info = iio_priv(indio_dev);
731 
732 	if (info->data->exit_hw)
733 		info->data->exit_hw(info);
734 	exynos_adc_disable_clk(info);
735 	regulator_disable(info->vdd);
736 
737 	return 0;
738 }
739 
740 static int exynos_adc_resume(struct device *dev)
741 {
742 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
743 	struct exynos_adc *info = iio_priv(indio_dev);
744 	int ret;
745 
746 	ret = regulator_enable(info->vdd);
747 	if (ret)
748 		return ret;
749 
750 	ret = exynos_adc_enable_clk(info);
751 	if (ret)
752 		return ret;
753 
754 	if (info->data->init_hw)
755 		info->data->init_hw(info);
756 
757 	return 0;
758 }
759 #endif
760 
761 static SIMPLE_DEV_PM_OPS(exynos_adc_pm_ops,
762 			exynos_adc_suspend,
763 			exynos_adc_resume);
764 
765 static struct platform_driver exynos_adc_driver = {
766 	.probe		= exynos_adc_probe,
767 	.remove		= exynos_adc_remove,
768 	.driver		= {
769 		.name	= "exynos-adc",
770 		.of_match_table = exynos_adc_match,
771 		.pm	= &exynos_adc_pm_ops,
772 	},
773 };
774 
775 module_platform_driver(exynos_adc_driver);
776 
777 MODULE_AUTHOR("Naveen Krishna Chatradhi <ch.naveen@samsung.com>");
778 MODULE_DESCRIPTION("Samsung EXYNOS5 ADC driver");
779 MODULE_LICENSE("GPL v2");
780