xref: /openbmc/linux/drivers/iio/adc/imx7d_adc.c (revision b1c3d2be)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Freescale i.MX7D ADC driver
4  *
5  * Copyright (C) 2015 Freescale Semiconductor, Inc.
6  */
7 
8 #include <linux/clk.h>
9 #include <linux/completion.h>
10 #include <linux/err.h>
11 #include <linux/interrupt.h>
12 #include <linux/io.h>
13 #include <linux/kernel.h>
14 #include <linux/mod_devicetable.h>
15 #include <linux/module.h>
16 #include <linux/mutex.h>
17 #include <linux/platform_device.h>
18 #include <linux/regulator/consumer.h>
19 
20 #include <linux/iio/iio.h>
21 #include <linux/iio/driver.h>
22 #include <linux/iio/sysfs.h>
23 
24 /* ADC register */
25 #define IMX7D_REG_ADC_CH_A_CFG1			0x00
26 #define IMX7D_REG_ADC_CH_A_CFG2			0x10
27 #define IMX7D_REG_ADC_CH_B_CFG1			0x20
28 #define IMX7D_REG_ADC_CH_B_CFG2			0x30
29 #define IMX7D_REG_ADC_CH_C_CFG1			0x40
30 #define IMX7D_REG_ADC_CH_C_CFG2			0x50
31 #define IMX7D_REG_ADC_CH_D_CFG1			0x60
32 #define IMX7D_REG_ADC_CH_D_CFG2			0x70
33 #define IMX7D_REG_ADC_CH_SW_CFG			0x80
34 #define IMX7D_REG_ADC_TIMER_UNIT		0x90
35 #define IMX7D_REG_ADC_DMA_FIFO			0xa0
36 #define IMX7D_REG_ADC_FIFO_STATUS		0xb0
37 #define IMX7D_REG_ADC_INT_SIG_EN		0xc0
38 #define IMX7D_REG_ADC_INT_EN			0xd0
39 #define IMX7D_REG_ADC_INT_STATUS		0xe0
40 #define IMX7D_REG_ADC_CHA_B_CNV_RSLT		0xf0
41 #define IMX7D_REG_ADC_CHC_D_CNV_RSLT		0x100
42 #define IMX7D_REG_ADC_CH_SW_CNV_RSLT		0x110
43 #define IMX7D_REG_ADC_DMA_FIFO_DAT		0x120
44 #define IMX7D_REG_ADC_ADC_CFG			0x130
45 
46 #define IMX7D_REG_ADC_CHANNEL_CFG2_BASE		0x10
47 #define IMX7D_EACH_CHANNEL_REG_OFFSET		0x20
48 
49 #define IMX7D_REG_ADC_CH_CFG1_CHANNEL_EN			(0x1 << 31)
50 #define IMX7D_REG_ADC_CH_CFG1_CHANNEL_SINGLE			BIT(30)
51 #define IMX7D_REG_ADC_CH_CFG1_CHANNEL_AVG_EN			BIT(29)
52 #define IMX7D_REG_ADC_CH_CFG1_CHANNEL_SEL(x)			((x) << 24)
53 
54 #define IMX7D_REG_ADC_CH_CFG2_AVG_NUM_4				(0x0 << 12)
55 #define IMX7D_REG_ADC_CH_CFG2_AVG_NUM_8				(0x1 << 12)
56 #define IMX7D_REG_ADC_CH_CFG2_AVG_NUM_16			(0x2 << 12)
57 #define IMX7D_REG_ADC_CH_CFG2_AVG_NUM_32			(0x3 << 12)
58 
59 #define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_4			(0x0 << 29)
60 #define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_8			(0x1 << 29)
61 #define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_16			(0x2 << 29)
62 #define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_32			(0x3 << 29)
63 #define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_64			(0x4 << 29)
64 #define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_128			(0x5 << 29)
65 
66 #define IMX7D_REG_ADC_ADC_CFG_ADC_CLK_DOWN			BIT(31)
67 #define IMX7D_REG_ADC_ADC_CFG_ADC_POWER_DOWN			BIT(1)
68 #define IMX7D_REG_ADC_ADC_CFG_ADC_EN				BIT(0)
69 
70 #define IMX7D_REG_ADC_INT_CHA_COV_INT_EN			BIT(8)
71 #define IMX7D_REG_ADC_INT_CHB_COV_INT_EN			BIT(9)
72 #define IMX7D_REG_ADC_INT_CHC_COV_INT_EN			BIT(10)
73 #define IMX7D_REG_ADC_INT_CHD_COV_INT_EN			BIT(11)
74 #define IMX7D_REG_ADC_INT_CHANNEL_INT_EN \
75 	(IMX7D_REG_ADC_INT_CHA_COV_INT_EN | \
76 	 IMX7D_REG_ADC_INT_CHB_COV_INT_EN | \
77 	 IMX7D_REG_ADC_INT_CHC_COV_INT_EN | \
78 	 IMX7D_REG_ADC_INT_CHD_COV_INT_EN)
79 #define IMX7D_REG_ADC_INT_STATUS_CHANNEL_INT_STATUS		0xf00
80 #define IMX7D_REG_ADC_INT_STATUS_CHANNEL_CONV_TIME_OUT		0xf0000
81 
82 #define IMX7D_ADC_TIMEOUT		msecs_to_jiffies(100)
83 #define IMX7D_ADC_INPUT_CLK		24000000
84 
85 enum imx7d_adc_clk_pre_div {
86 	IMX7D_ADC_ANALOG_CLK_PRE_DIV_4,
87 	IMX7D_ADC_ANALOG_CLK_PRE_DIV_8,
88 	IMX7D_ADC_ANALOG_CLK_PRE_DIV_16,
89 	IMX7D_ADC_ANALOG_CLK_PRE_DIV_32,
90 	IMX7D_ADC_ANALOG_CLK_PRE_DIV_64,
91 	IMX7D_ADC_ANALOG_CLK_PRE_DIV_128,
92 };
93 
94 enum imx7d_adc_average_num {
95 	IMX7D_ADC_AVERAGE_NUM_4,
96 	IMX7D_ADC_AVERAGE_NUM_8,
97 	IMX7D_ADC_AVERAGE_NUM_16,
98 	IMX7D_ADC_AVERAGE_NUM_32,
99 };
100 
101 struct imx7d_adc_feature {
102 	enum imx7d_adc_clk_pre_div clk_pre_div;
103 	enum imx7d_adc_average_num avg_num;
104 
105 	u32 core_time_unit;	/* impact the sample rate */
106 };
107 
108 struct imx7d_adc {
109 	struct device *dev;
110 	void __iomem *regs;
111 	struct clk *clk;
112 	/* lock to protect against multiple access to the device */
113 	struct mutex lock;
114 	u32 vref_uv;
115 	u32 value;
116 	u32 channel;
117 	u32 pre_div_num;
118 
119 	struct regulator *vref;
120 	struct imx7d_adc_feature adc_feature;
121 
122 	struct completion completion;
123 };
124 
125 struct imx7d_adc_analogue_core_clk {
126 	u32 pre_div;
127 	u32 reg_config;
128 };
129 
130 #define IMX7D_ADC_ANALOGUE_CLK_CONFIG(_pre_div, _reg_conf) {	\
131 	.pre_div = (_pre_div),					\
132 	.reg_config = (_reg_conf),				\
133 }
134 
135 static const struct imx7d_adc_analogue_core_clk imx7d_adc_analogue_clk[] = {
136 	IMX7D_ADC_ANALOGUE_CLK_CONFIG(4, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_4),
137 	IMX7D_ADC_ANALOGUE_CLK_CONFIG(8, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_8),
138 	IMX7D_ADC_ANALOGUE_CLK_CONFIG(16, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_16),
139 	IMX7D_ADC_ANALOGUE_CLK_CONFIG(32, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_32),
140 	IMX7D_ADC_ANALOGUE_CLK_CONFIG(64, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_64),
141 	IMX7D_ADC_ANALOGUE_CLK_CONFIG(128, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_128),
142 };
143 
144 #define IMX7D_ADC_CHAN(_idx) {					\
145 	.type = IIO_VOLTAGE,					\
146 	.indexed = 1,						\
147 	.channel = (_idx),					\
148 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
149 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |	\
150 				BIT(IIO_CHAN_INFO_SAMP_FREQ),	\
151 }
152 
153 static const struct iio_chan_spec imx7d_adc_iio_channels[] = {
154 	IMX7D_ADC_CHAN(0),
155 	IMX7D_ADC_CHAN(1),
156 	IMX7D_ADC_CHAN(2),
157 	IMX7D_ADC_CHAN(3),
158 	IMX7D_ADC_CHAN(4),
159 	IMX7D_ADC_CHAN(5),
160 	IMX7D_ADC_CHAN(6),
161 	IMX7D_ADC_CHAN(7),
162 	IMX7D_ADC_CHAN(8),
163 	IMX7D_ADC_CHAN(9),
164 	IMX7D_ADC_CHAN(10),
165 	IMX7D_ADC_CHAN(11),
166 	IMX7D_ADC_CHAN(12),
167 	IMX7D_ADC_CHAN(13),
168 	IMX7D_ADC_CHAN(14),
169 	IMX7D_ADC_CHAN(15),
170 };
171 
172 static const u32 imx7d_adc_average_num[] = {
173 	IMX7D_REG_ADC_CH_CFG2_AVG_NUM_4,
174 	IMX7D_REG_ADC_CH_CFG2_AVG_NUM_8,
175 	IMX7D_REG_ADC_CH_CFG2_AVG_NUM_16,
176 	IMX7D_REG_ADC_CH_CFG2_AVG_NUM_32,
177 };
178 
179 static void imx7d_adc_feature_config(struct imx7d_adc *info)
180 {
181 	info->adc_feature.clk_pre_div = IMX7D_ADC_ANALOG_CLK_PRE_DIV_4;
182 	info->adc_feature.avg_num = IMX7D_ADC_AVERAGE_NUM_32;
183 	info->adc_feature.core_time_unit = 1;
184 }
185 
186 static void imx7d_adc_sample_rate_set(struct imx7d_adc *info)
187 {
188 	struct imx7d_adc_feature *adc_feature = &info->adc_feature;
189 	struct imx7d_adc_analogue_core_clk adc_analogure_clk;
190 	u32 i;
191 	u32 tmp_cfg1;
192 	u32 sample_rate = 0;
193 
194 	/*
195 	 * Before sample set, disable channel A,B,C,D. Here we
196 	 * clear the bit 31 of register REG_ADC_CH_A\B\C\D_CFG1.
197 	 */
198 	for (i = 0; i < 4; i++) {
199 		tmp_cfg1 =
200 			readl(info->regs + i * IMX7D_EACH_CHANNEL_REG_OFFSET);
201 		tmp_cfg1 &= ~IMX7D_REG_ADC_CH_CFG1_CHANNEL_EN;
202 		writel(tmp_cfg1,
203 		       info->regs + i * IMX7D_EACH_CHANNEL_REG_OFFSET);
204 	}
205 
206 	adc_analogure_clk = imx7d_adc_analogue_clk[adc_feature->clk_pre_div];
207 	sample_rate |= adc_analogure_clk.reg_config;
208 	info->pre_div_num = adc_analogure_clk.pre_div;
209 
210 	sample_rate |= adc_feature->core_time_unit;
211 	writel(sample_rate, info->regs + IMX7D_REG_ADC_TIMER_UNIT);
212 }
213 
214 static void imx7d_adc_hw_init(struct imx7d_adc *info)
215 {
216 	u32 cfg;
217 
218 	/* power up and enable adc analogue core */
219 	cfg = readl(info->regs + IMX7D_REG_ADC_ADC_CFG);
220 	cfg &= ~(IMX7D_REG_ADC_ADC_CFG_ADC_CLK_DOWN |
221 		 IMX7D_REG_ADC_ADC_CFG_ADC_POWER_DOWN);
222 	cfg |= IMX7D_REG_ADC_ADC_CFG_ADC_EN;
223 	writel(cfg, info->regs + IMX7D_REG_ADC_ADC_CFG);
224 
225 	/* enable channel A,B,C,D interrupt */
226 	writel(IMX7D_REG_ADC_INT_CHANNEL_INT_EN,
227 	       info->regs + IMX7D_REG_ADC_INT_SIG_EN);
228 	writel(IMX7D_REG_ADC_INT_CHANNEL_INT_EN,
229 	       info->regs + IMX7D_REG_ADC_INT_EN);
230 
231 	imx7d_adc_sample_rate_set(info);
232 }
233 
234 static void imx7d_adc_channel_set(struct imx7d_adc *info)
235 {
236 	u32 cfg1 = 0;
237 	u32 cfg2;
238 	u32 channel;
239 
240 	channel = info->channel;
241 
242 	/* the channel choose single conversion, and enable average mode */
243 	cfg1 |= (IMX7D_REG_ADC_CH_CFG1_CHANNEL_EN |
244 		 IMX7D_REG_ADC_CH_CFG1_CHANNEL_SINGLE |
245 		 IMX7D_REG_ADC_CH_CFG1_CHANNEL_AVG_EN);
246 
247 	/*
248 	 * physical channel 0 chose logical channel A
249 	 * physical channel 1 chose logical channel B
250 	 * physical channel 2 chose logical channel C
251 	 * physical channel 3 chose logical channel D
252 	 */
253 	cfg1 |= IMX7D_REG_ADC_CH_CFG1_CHANNEL_SEL(channel);
254 
255 	/*
256 	 * read register REG_ADC_CH_A\B\C\D_CFG2, according to the
257 	 * channel chosen
258 	 */
259 	cfg2 = readl(info->regs + IMX7D_EACH_CHANNEL_REG_OFFSET * channel +
260 		     IMX7D_REG_ADC_CHANNEL_CFG2_BASE);
261 
262 	cfg2 |= imx7d_adc_average_num[info->adc_feature.avg_num];
263 
264 	/*
265 	 * write the register REG_ADC_CH_A\B\C\D_CFG2, according to
266 	 * the channel chosen
267 	 */
268 	writel(cfg2, info->regs + IMX7D_EACH_CHANNEL_REG_OFFSET * channel +
269 	       IMX7D_REG_ADC_CHANNEL_CFG2_BASE);
270 	writel(cfg1, info->regs + IMX7D_EACH_CHANNEL_REG_OFFSET * channel);
271 }
272 
273 static u32 imx7d_adc_get_sample_rate(struct imx7d_adc *info)
274 {
275 	u32 analogue_core_clk;
276 	u32 core_time_unit = info->adc_feature.core_time_unit;
277 	u32 tmp;
278 
279 	analogue_core_clk = IMX7D_ADC_INPUT_CLK / info->pre_div_num;
280 	tmp = (core_time_unit + 1) * 6;
281 
282 	return analogue_core_clk / tmp;
283 }
284 
285 static int imx7d_adc_read_raw(struct iio_dev *indio_dev,
286 			struct iio_chan_spec const *chan,
287 			int *val,
288 			int *val2,
289 			long mask)
290 {
291 	struct imx7d_adc *info = iio_priv(indio_dev);
292 
293 	u32 channel;
294 	long ret;
295 
296 	switch (mask) {
297 	case IIO_CHAN_INFO_RAW:
298 		mutex_lock(&info->lock);
299 		reinit_completion(&info->completion);
300 
301 		channel = chan->channel & 0x03;
302 		info->channel = channel;
303 		imx7d_adc_channel_set(info);
304 
305 		ret = wait_for_completion_interruptible_timeout
306 				(&info->completion, IMX7D_ADC_TIMEOUT);
307 		if (ret == 0) {
308 			mutex_unlock(&info->lock);
309 			return -ETIMEDOUT;
310 		}
311 		if (ret < 0) {
312 			mutex_unlock(&info->lock);
313 			return ret;
314 		}
315 
316 		*val = info->value;
317 		mutex_unlock(&info->lock);
318 		return IIO_VAL_INT;
319 
320 	case IIO_CHAN_INFO_SCALE:
321 		info->vref_uv = regulator_get_voltage(info->vref);
322 		*val = info->vref_uv / 1000;
323 		*val2 = 12;
324 		return IIO_VAL_FRACTIONAL_LOG2;
325 
326 	case IIO_CHAN_INFO_SAMP_FREQ:
327 		*val = imx7d_adc_get_sample_rate(info);
328 		return IIO_VAL_INT;
329 
330 	default:
331 		return -EINVAL;
332 	}
333 }
334 
335 static int imx7d_adc_read_data(struct imx7d_adc *info)
336 {
337 	u32 channel;
338 	u32 value;
339 
340 	channel = info->channel & 0x03;
341 
342 	/*
343 	 * channel A and B conversion result share one register,
344 	 * bit[27~16] is the channel B conversion result,
345 	 * bit[11~0] is the channel A conversion result.
346 	 * channel C and D is the same.
347 	 */
348 	if (channel < 2)
349 		value = readl(info->regs + IMX7D_REG_ADC_CHA_B_CNV_RSLT);
350 	else
351 		value = readl(info->regs + IMX7D_REG_ADC_CHC_D_CNV_RSLT);
352 	if (channel & 0x1)	/* channel B or D */
353 		value = (value >> 16) & 0xFFF;
354 	else			/* channel A or C */
355 		value &= 0xFFF;
356 
357 	return value;
358 }
359 
360 static irqreturn_t imx7d_adc_isr(int irq, void *dev_id)
361 {
362 	struct imx7d_adc *info = dev_id;
363 	int status;
364 
365 	status = readl(info->regs + IMX7D_REG_ADC_INT_STATUS);
366 	if (status & IMX7D_REG_ADC_INT_STATUS_CHANNEL_INT_STATUS) {
367 		info->value = imx7d_adc_read_data(info);
368 		complete(&info->completion);
369 
370 		/*
371 		 * The register IMX7D_REG_ADC_INT_STATUS can't clear
372 		 * itself after read operation, need software to write
373 		 * 0 to the related bit. Here we clear the channel A/B/C/D
374 		 * conversion finished flag.
375 		 */
376 		status &= ~IMX7D_REG_ADC_INT_STATUS_CHANNEL_INT_STATUS;
377 		writel(status, info->regs + IMX7D_REG_ADC_INT_STATUS);
378 	}
379 
380 	/*
381 	 * If the channel A/B/C/D conversion timeout, report it and clear these
382 	 * timeout flags.
383 	 */
384 	if (status & IMX7D_REG_ADC_INT_STATUS_CHANNEL_CONV_TIME_OUT) {
385 		dev_err(info->dev,
386 			"ADC got conversion time out interrupt: 0x%08x\n",
387 			status);
388 		status &= ~IMX7D_REG_ADC_INT_STATUS_CHANNEL_CONV_TIME_OUT;
389 		writel(status, info->regs + IMX7D_REG_ADC_INT_STATUS);
390 	}
391 
392 	return IRQ_HANDLED;
393 }
394 
395 static int imx7d_adc_reg_access(struct iio_dev *indio_dev,
396 			unsigned reg, unsigned writeval,
397 			unsigned *readval)
398 {
399 	struct imx7d_adc *info = iio_priv(indio_dev);
400 
401 	if (!readval || reg % 4 || reg > IMX7D_REG_ADC_ADC_CFG)
402 		return -EINVAL;
403 
404 	*readval = readl(info->regs + reg);
405 
406 	return 0;
407 }
408 
409 static const struct iio_info imx7d_adc_iio_info = {
410 	.read_raw = &imx7d_adc_read_raw,
411 	.debugfs_reg_access = &imx7d_adc_reg_access,
412 };
413 
414 static const struct of_device_id imx7d_adc_match[] = {
415 	{ .compatible = "fsl,imx7d-adc", },
416 	{ /* sentinel */ }
417 };
418 MODULE_DEVICE_TABLE(of, imx7d_adc_match);
419 
420 static void imx7d_adc_power_down(struct imx7d_adc *info)
421 {
422 	u32 adc_cfg;
423 
424 	adc_cfg = readl(info->regs + IMX7D_REG_ADC_ADC_CFG);
425 	adc_cfg |= IMX7D_REG_ADC_ADC_CFG_ADC_CLK_DOWN |
426 		   IMX7D_REG_ADC_ADC_CFG_ADC_POWER_DOWN;
427 	adc_cfg &= ~IMX7D_REG_ADC_ADC_CFG_ADC_EN;
428 	writel(adc_cfg, info->regs + IMX7D_REG_ADC_ADC_CFG);
429 }
430 
431 static int imx7d_adc_enable(struct device *dev)
432 {
433 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
434 	struct imx7d_adc *info = iio_priv(indio_dev);
435 	int ret;
436 
437 	ret = regulator_enable(info->vref);
438 	if (ret) {
439 		dev_err(info->dev,
440 			"Can't enable adc reference top voltage, err = %d\n",
441 			ret);
442 		return ret;
443 	}
444 
445 	ret = clk_prepare_enable(info->clk);
446 	if (ret) {
447 		dev_err(info->dev,
448 			"Could not prepare or enable clock.\n");
449 		regulator_disable(info->vref);
450 		return ret;
451 	}
452 
453 	imx7d_adc_hw_init(info);
454 
455 	return 0;
456 }
457 
458 static int imx7d_adc_disable(struct device *dev)
459 {
460 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
461 	struct imx7d_adc *info = iio_priv(indio_dev);
462 
463 	imx7d_adc_power_down(info);
464 
465 	clk_disable_unprepare(info->clk);
466 	regulator_disable(info->vref);
467 
468 	return 0;
469 }
470 
471 static void __imx7d_adc_disable(void *data)
472 {
473 	imx7d_adc_disable(data);
474 }
475 
476 static int imx7d_adc_probe(struct platform_device *pdev)
477 {
478 	struct imx7d_adc *info;
479 	struct iio_dev *indio_dev;
480 	struct device *dev = &pdev->dev;
481 	int irq;
482 	int ret;
483 
484 	indio_dev = devm_iio_device_alloc(dev, sizeof(*info));
485 	if (!indio_dev) {
486 		dev_err(&pdev->dev, "Failed allocating iio device\n");
487 		return -ENOMEM;
488 	}
489 
490 	info = iio_priv(indio_dev);
491 	info->dev = dev;
492 
493 	info->regs = devm_platform_ioremap_resource(pdev, 0);
494 	if (IS_ERR(info->regs))
495 		return PTR_ERR(info->regs);
496 
497 	irq = platform_get_irq(pdev, 0);
498 	if (irq < 0)
499 		return dev_err_probe(dev, irq, "Failed getting irq\n");
500 
501 	info->clk = devm_clk_get(dev, "adc");
502 	if (IS_ERR(info->clk))
503 		return dev_err_probe(dev, PTR_ERR(info->clk), "Failed getting clock\n");
504 
505 	info->vref = devm_regulator_get(dev, "vref");
506 	if (IS_ERR(info->vref))
507 		return dev_err_probe(dev, PTR_ERR(info->vref),
508 				     "Failed getting reference voltage\n");
509 
510 	platform_set_drvdata(pdev, indio_dev);
511 
512 	init_completion(&info->completion);
513 
514 	indio_dev->name = dev_name(dev);
515 	indio_dev->info = &imx7d_adc_iio_info;
516 	indio_dev->modes = INDIO_DIRECT_MODE;
517 	indio_dev->channels = imx7d_adc_iio_channels;
518 	indio_dev->num_channels = ARRAY_SIZE(imx7d_adc_iio_channels);
519 
520 	ret = devm_request_irq(dev, irq, imx7d_adc_isr, 0, dev_name(dev), info);
521 	if (ret < 0) {
522 		dev_err(dev, "Failed requesting irq, irq = %d\n", irq);
523 		return ret;
524 	}
525 
526 	imx7d_adc_feature_config(info);
527 
528 	ret = imx7d_adc_enable(dev);
529 	if (ret)
530 		return ret;
531 
532 	ret = devm_add_action_or_reset(dev, __imx7d_adc_disable, dev);
533 	if (ret)
534 		return ret;
535 
536 	mutex_init(&info->lock);
537 
538 	ret = devm_iio_device_register(dev, indio_dev);
539 	if (ret) {
540 		dev_err(&pdev->dev, "Couldn't register the device.\n");
541 		return ret;
542 	}
543 
544 	return 0;
545 }
546 
547 static DEFINE_SIMPLE_DEV_PM_OPS(imx7d_adc_pm_ops, imx7d_adc_disable,
548 				imx7d_adc_enable);
549 
550 static struct platform_driver imx7d_adc_driver = {
551 	.probe		= imx7d_adc_probe,
552 	.driver		= {
553 		.name	= "imx7d_adc",
554 		.of_match_table = imx7d_adc_match,
555 		.pm	= pm_sleep_ptr(&imx7d_adc_pm_ops),
556 	},
557 };
558 
559 module_platform_driver(imx7d_adc_driver);
560 
561 MODULE_AUTHOR("Haibo Chen <haibo.chen@freescale.com>");
562 MODULE_DESCRIPTION("Freescale IMX7D ADC driver");
563 MODULE_LICENSE("GPL v2");
564