xref: /openbmc/linux/drivers/iio/adc/imx7d_adc.c (revision b8466760)
1 /*
2  * Freescale i.MX7D ADC driver
3  *
4  * Copyright (C) 2015 Freescale Semiconductor, Inc.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  */
11 
12 #include <linux/clk.h>
13 #include <linux/completion.h>
14 #include <linux/err.h>
15 #include <linux/interrupt.h>
16 #include <linux/io.h>
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/platform_device.h>
20 #include <linux/regulator/consumer.h>
21 
22 #include <linux/iio/iio.h>
23 #include <linux/iio/driver.h>
24 #include <linux/iio/sysfs.h>
25 
26 /* ADC register */
27 #define IMX7D_REG_ADC_CH_A_CFG1			0x00
28 #define IMX7D_REG_ADC_CH_A_CFG2			0x10
29 #define IMX7D_REG_ADC_CH_B_CFG1			0x20
30 #define IMX7D_REG_ADC_CH_B_CFG2			0x30
31 #define IMX7D_REG_ADC_CH_C_CFG1			0x40
32 #define IMX7D_REG_ADC_CH_C_CFG2			0x50
33 #define IMX7D_REG_ADC_CH_D_CFG1			0x60
34 #define IMX7D_REG_ADC_CH_D_CFG2			0x70
35 #define IMX7D_REG_ADC_CH_SW_CFG			0x80
36 #define IMX7D_REG_ADC_TIMER_UNIT		0x90
37 #define IMX7D_REG_ADC_DMA_FIFO			0xa0
38 #define IMX7D_REG_ADC_FIFO_STATUS		0xb0
39 #define IMX7D_REG_ADC_INT_SIG_EN		0xc0
40 #define IMX7D_REG_ADC_INT_EN			0xd0
41 #define IMX7D_REG_ADC_INT_STATUS		0xe0
42 #define IMX7D_REG_ADC_CHA_B_CNV_RSLT		0xf0
43 #define IMX7D_REG_ADC_CHC_D_CNV_RSLT		0x100
44 #define IMX7D_REG_ADC_CH_SW_CNV_RSLT		0x110
45 #define IMX7D_REG_ADC_DMA_FIFO_DAT		0x120
46 #define IMX7D_REG_ADC_ADC_CFG			0x130
47 
48 #define IMX7D_REG_ADC_CHANNEL_CFG2_BASE		0x10
49 #define IMX7D_EACH_CHANNEL_REG_OFFSET		0x20
50 
51 #define IMX7D_REG_ADC_CH_CFG1_CHANNEL_EN			(0x1 << 31)
52 #define IMX7D_REG_ADC_CH_CFG1_CHANNEL_SINGLE			BIT(30)
53 #define IMX7D_REG_ADC_CH_CFG1_CHANNEL_AVG_EN			BIT(29)
54 #define IMX7D_REG_ADC_CH_CFG1_CHANNEL_SEL(x)			((x) << 24)
55 
56 #define IMX7D_REG_ADC_CH_CFG2_AVG_NUM_4				(0x0 << 12)
57 #define IMX7D_REG_ADC_CH_CFG2_AVG_NUM_8				(0x1 << 12)
58 #define IMX7D_REG_ADC_CH_CFG2_AVG_NUM_16			(0x2 << 12)
59 #define IMX7D_REG_ADC_CH_CFG2_AVG_NUM_32			(0x3 << 12)
60 
61 #define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_4			(0x0 << 29)
62 #define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_8			(0x1 << 29)
63 #define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_16			(0x2 << 29)
64 #define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_32			(0x3 << 29)
65 #define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_64			(0x4 << 29)
66 #define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_128			(0x5 << 29)
67 
68 #define IMX7D_REG_ADC_ADC_CFG_ADC_CLK_DOWN			BIT(31)
69 #define IMX7D_REG_ADC_ADC_CFG_ADC_POWER_DOWN			BIT(1)
70 #define IMX7D_REG_ADC_ADC_CFG_ADC_EN				BIT(0)
71 
72 #define IMX7D_REG_ADC_INT_CHA_COV_INT_EN			BIT(8)
73 #define IMX7D_REG_ADC_INT_CHB_COV_INT_EN			BIT(9)
74 #define IMX7D_REG_ADC_INT_CHC_COV_INT_EN			BIT(10)
75 #define IMX7D_REG_ADC_INT_CHD_COV_INT_EN			BIT(11)
76 #define IMX7D_REG_ADC_INT_CHANNEL_INT_EN \
77 	(IMX7D_REG_ADC_INT_CHA_COV_INT_EN | \
78 	 IMX7D_REG_ADC_INT_CHB_COV_INT_EN | \
79 	 IMX7D_REG_ADC_INT_CHC_COV_INT_EN | \
80 	 IMX7D_REG_ADC_INT_CHD_COV_INT_EN)
81 #define IMX7D_REG_ADC_INT_STATUS_CHANNEL_INT_STATUS		0xf00
82 #define IMX7D_REG_ADC_INT_STATUS_CHANNEL_CONV_TIME_OUT		0xf0000
83 
84 #define IMX7D_ADC_TIMEOUT		msecs_to_jiffies(100)
85 
86 enum imx7d_adc_clk_pre_div {
87 	IMX7D_ADC_ANALOG_CLK_PRE_DIV_4,
88 	IMX7D_ADC_ANALOG_CLK_PRE_DIV_8,
89 	IMX7D_ADC_ANALOG_CLK_PRE_DIV_16,
90 	IMX7D_ADC_ANALOG_CLK_PRE_DIV_32,
91 	IMX7D_ADC_ANALOG_CLK_PRE_DIV_64,
92 	IMX7D_ADC_ANALOG_CLK_PRE_DIV_128,
93 };
94 
95 enum imx7d_adc_average_num {
96 	IMX7D_ADC_AVERAGE_NUM_4,
97 	IMX7D_ADC_AVERAGE_NUM_8,
98 	IMX7D_ADC_AVERAGE_NUM_16,
99 	IMX7D_ADC_AVERAGE_NUM_32,
100 };
101 
102 struct imx7d_adc_feature {
103 	enum imx7d_adc_clk_pre_div clk_pre_div;
104 	enum imx7d_adc_average_num avg_num;
105 
106 	u32 core_time_unit;	/* impact the sample rate */
107 
108 	bool average_en;
109 };
110 
111 struct imx7d_adc {
112 	struct device *dev;
113 	void __iomem *regs;
114 	struct clk *clk;
115 
116 	u32 vref_uv;
117 	u32 value;
118 	u32 channel;
119 	u32 pre_div_num;
120 
121 	struct regulator *vref;
122 	struct imx7d_adc_feature adc_feature;
123 
124 	struct completion completion;
125 };
126 
127 struct imx7d_adc_analogue_core_clk {
128 	u32 pre_div;
129 	u32 reg_config;
130 };
131 
132 #define IMX7D_ADC_ANALOGUE_CLK_CONFIG(_pre_div, _reg_conf) {	\
133 	.pre_div = (_pre_div),					\
134 	.reg_config = (_reg_conf),				\
135 }
136 
137 static const struct imx7d_adc_analogue_core_clk imx7d_adc_analogue_clk[] = {
138 	IMX7D_ADC_ANALOGUE_CLK_CONFIG(4, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_4),
139 	IMX7D_ADC_ANALOGUE_CLK_CONFIG(8, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_8),
140 	IMX7D_ADC_ANALOGUE_CLK_CONFIG(16, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_16),
141 	IMX7D_ADC_ANALOGUE_CLK_CONFIG(32, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_32),
142 	IMX7D_ADC_ANALOGUE_CLK_CONFIG(64, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_64),
143 	IMX7D_ADC_ANALOGUE_CLK_CONFIG(128, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_128),
144 };
145 
146 #define IMX7D_ADC_CHAN(_idx) {					\
147 	.type = IIO_VOLTAGE,					\
148 	.indexed = 1,						\
149 	.channel = (_idx),					\
150 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
151 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |	\
152 				BIT(IIO_CHAN_INFO_SAMP_FREQ),	\
153 }
154 
155 static const struct iio_chan_spec imx7d_adc_iio_channels[] = {
156 	IMX7D_ADC_CHAN(0),
157 	IMX7D_ADC_CHAN(1),
158 	IMX7D_ADC_CHAN(2),
159 	IMX7D_ADC_CHAN(3),
160 	IMX7D_ADC_CHAN(4),
161 	IMX7D_ADC_CHAN(5),
162 	IMX7D_ADC_CHAN(6),
163 	IMX7D_ADC_CHAN(7),
164 	IMX7D_ADC_CHAN(8),
165 	IMX7D_ADC_CHAN(9),
166 	IMX7D_ADC_CHAN(10),
167 	IMX7D_ADC_CHAN(11),
168 	IMX7D_ADC_CHAN(12),
169 	IMX7D_ADC_CHAN(13),
170 	IMX7D_ADC_CHAN(14),
171 	IMX7D_ADC_CHAN(15),
172 };
173 
174 static const u32 imx7d_adc_average_num[] = {
175 	IMX7D_REG_ADC_CH_CFG2_AVG_NUM_4,
176 	IMX7D_REG_ADC_CH_CFG2_AVG_NUM_8,
177 	IMX7D_REG_ADC_CH_CFG2_AVG_NUM_16,
178 	IMX7D_REG_ADC_CH_CFG2_AVG_NUM_32,
179 };
180 
181 static void imx7d_adc_feature_config(struct imx7d_adc *info)
182 {
183 	info->adc_feature.clk_pre_div = IMX7D_ADC_ANALOG_CLK_PRE_DIV_4;
184 	info->adc_feature.avg_num = IMX7D_ADC_AVERAGE_NUM_32;
185 	info->adc_feature.core_time_unit = 1;
186 	info->adc_feature.average_en = true;
187 }
188 
189 static void imx7d_adc_sample_rate_set(struct imx7d_adc *info)
190 {
191 	struct imx7d_adc_feature *adc_feature = &info->adc_feature;
192 	struct imx7d_adc_analogue_core_clk adc_analogure_clk;
193 	u32 i;
194 	u32 tmp_cfg1;
195 	u32 sample_rate = 0;
196 
197 	/*
198 	 * Before sample set, disable channel A,B,C,D. Here we
199 	 * clear the bit 31 of register REG_ADC_CH_A\B\C\D_CFG1.
200 	 */
201 	for (i = 0; i < 4; i++) {
202 		tmp_cfg1 =
203 			readl(info->regs + i * IMX7D_EACH_CHANNEL_REG_OFFSET);
204 		tmp_cfg1 &= ~IMX7D_REG_ADC_CH_CFG1_CHANNEL_EN;
205 		writel(tmp_cfg1,
206 		       info->regs + i * IMX7D_EACH_CHANNEL_REG_OFFSET);
207 	}
208 
209 	adc_analogure_clk = imx7d_adc_analogue_clk[adc_feature->clk_pre_div];
210 	sample_rate |= adc_analogure_clk.reg_config;
211 	info->pre_div_num = adc_analogure_clk.pre_div;
212 
213 	sample_rate |= adc_feature->core_time_unit;
214 	writel(sample_rate, info->regs + IMX7D_REG_ADC_TIMER_UNIT);
215 }
216 
217 static void imx7d_adc_hw_init(struct imx7d_adc *info)
218 {
219 	u32 cfg;
220 
221 	/* power up and enable adc analogue core */
222 	cfg = readl(info->regs + IMX7D_REG_ADC_ADC_CFG);
223 	cfg &= ~(IMX7D_REG_ADC_ADC_CFG_ADC_CLK_DOWN |
224 		 IMX7D_REG_ADC_ADC_CFG_ADC_POWER_DOWN);
225 	cfg |= IMX7D_REG_ADC_ADC_CFG_ADC_EN;
226 	writel(cfg, info->regs + IMX7D_REG_ADC_ADC_CFG);
227 
228 	/* enable channel A,B,C,D interrupt */
229 	writel(IMX7D_REG_ADC_INT_CHANNEL_INT_EN,
230 	       info->regs + IMX7D_REG_ADC_INT_SIG_EN);
231 	writel(IMX7D_REG_ADC_INT_CHANNEL_INT_EN,
232 	       info->regs + IMX7D_REG_ADC_INT_EN);
233 
234 	imx7d_adc_sample_rate_set(info);
235 }
236 
237 static void imx7d_adc_channel_set(struct imx7d_adc *info)
238 {
239 	u32 cfg1 = 0;
240 	u32 cfg2;
241 	u32 channel;
242 
243 	channel = info->channel;
244 
245 	/* the channel choose single conversion, and enable average mode */
246 	cfg1 |= (IMX7D_REG_ADC_CH_CFG1_CHANNEL_EN |
247 		 IMX7D_REG_ADC_CH_CFG1_CHANNEL_SINGLE);
248 	if (info->adc_feature.average_en)
249 		cfg1 |= IMX7D_REG_ADC_CH_CFG1_CHANNEL_AVG_EN;
250 
251 	/*
252 	 * physical channel 0 chose logical channel A
253 	 * physical channel 1 chose logical channel B
254 	 * physical channel 2 chose logical channel C
255 	 * physical channel 3 chose logical channel D
256 	 */
257 	cfg1 |= IMX7D_REG_ADC_CH_CFG1_CHANNEL_SEL(channel);
258 
259 	/*
260 	 * read register REG_ADC_CH_A\B\C\D_CFG2, according to the
261 	 * channel chosen
262 	 */
263 	cfg2 = readl(info->regs + IMX7D_EACH_CHANNEL_REG_OFFSET * channel +
264 		     IMX7D_REG_ADC_CHANNEL_CFG2_BASE);
265 
266 	cfg2 |= imx7d_adc_average_num[info->adc_feature.avg_num];
267 
268 	/*
269 	 * write the register REG_ADC_CH_A\B\C\D_CFG2, according to
270 	 * the channel chosen
271 	 */
272 	writel(cfg2, info->regs + IMX7D_EACH_CHANNEL_REG_OFFSET * channel +
273 	       IMX7D_REG_ADC_CHANNEL_CFG2_BASE);
274 	writel(cfg1, info->regs + IMX7D_EACH_CHANNEL_REG_OFFSET * channel);
275 }
276 
277 static u32 imx7d_adc_get_sample_rate(struct imx7d_adc *info)
278 {
279 	/* input clock is always 24MHz */
280 	u32 input_clk = 24000000;
281 	u32 analogue_core_clk;
282 	u32 core_time_unit = info->adc_feature.core_time_unit;
283 	u32 tmp;
284 
285 	analogue_core_clk = input_clk / info->pre_div_num;
286 	tmp = (core_time_unit + 1) * 6;
287 
288 	return analogue_core_clk / tmp;
289 }
290 
291 static int imx7d_adc_read_raw(struct iio_dev *indio_dev,
292 			struct iio_chan_spec const *chan,
293 			int *val,
294 			int *val2,
295 			long mask)
296 {
297 	struct imx7d_adc *info = iio_priv(indio_dev);
298 
299 	u32 channel;
300 	long ret;
301 
302 	switch (mask) {
303 	case IIO_CHAN_INFO_RAW:
304 		mutex_lock(&indio_dev->mlock);
305 		reinit_completion(&info->completion);
306 
307 		channel = chan->channel & 0x03;
308 		info->channel = channel;
309 		imx7d_adc_channel_set(info);
310 
311 		ret = wait_for_completion_interruptible_timeout
312 				(&info->completion, IMX7D_ADC_TIMEOUT);
313 		if (ret == 0) {
314 			mutex_unlock(&indio_dev->mlock);
315 			return -ETIMEDOUT;
316 		}
317 		if (ret < 0) {
318 			mutex_unlock(&indio_dev->mlock);
319 			return ret;
320 		}
321 
322 		*val = info->value;
323 		mutex_unlock(&indio_dev->mlock);
324 		return IIO_VAL_INT;
325 
326 	case IIO_CHAN_INFO_SCALE:
327 		info->vref_uv = regulator_get_voltage(info->vref);
328 		*val = info->vref_uv / 1000;
329 		*val2 = 12;
330 		return IIO_VAL_FRACTIONAL_LOG2;
331 
332 	case IIO_CHAN_INFO_SAMP_FREQ:
333 		*val = imx7d_adc_get_sample_rate(info);
334 		return IIO_VAL_INT;
335 
336 	default:
337 		return -EINVAL;
338 	}
339 }
340 
341 static int imx7d_adc_read_data(struct imx7d_adc *info)
342 {
343 	u32 channel;
344 	u32 value;
345 
346 	channel = info->channel & 0x03;
347 
348 	/*
349 	 * channel A and B conversion result share one register,
350 	 * bit[27~16] is the channel B conversion result,
351 	 * bit[11~0] is the channel A conversion result.
352 	 * channel C and D is the same.
353 	 */
354 	if (channel < 2)
355 		value = readl(info->regs + IMX7D_REG_ADC_CHA_B_CNV_RSLT);
356 	else
357 		value = readl(info->regs + IMX7D_REG_ADC_CHC_D_CNV_RSLT);
358 	if (channel & 0x1)	/* channel B or D */
359 		value = (value >> 16) & 0xFFF;
360 	else			/* channel A or C */
361 		value &= 0xFFF;
362 
363 	return value;
364 }
365 
366 static irqreturn_t imx7d_adc_isr(int irq, void *dev_id)
367 {
368 	struct imx7d_adc *info = dev_id;
369 	int status;
370 
371 	status = readl(info->regs + IMX7D_REG_ADC_INT_STATUS);
372 	if (status & IMX7D_REG_ADC_INT_STATUS_CHANNEL_INT_STATUS) {
373 		info->value = imx7d_adc_read_data(info);
374 		complete(&info->completion);
375 
376 		/*
377 		 * The register IMX7D_REG_ADC_INT_STATUS can't clear
378 		 * itself after read operation, need software to write
379 		 * 0 to the related bit. Here we clear the channel A/B/C/D
380 		 * conversion finished flag.
381 		 */
382 		status &= ~IMX7D_REG_ADC_INT_STATUS_CHANNEL_INT_STATUS;
383 		writel(status, info->regs + IMX7D_REG_ADC_INT_STATUS);
384 	}
385 
386 	/*
387 	 * If the channel A/B/C/D conversion timeout, report it and clear these
388 	 * timeout flags.
389 	 */
390 	if (status & IMX7D_REG_ADC_INT_STATUS_CHANNEL_CONV_TIME_OUT) {
391 		dev_err(info->dev,
392 			"ADC got conversion time out interrupt: 0x%08x\n",
393 			status);
394 		status &= ~IMX7D_REG_ADC_INT_STATUS_CHANNEL_CONV_TIME_OUT;
395 		writel(status, info->regs + IMX7D_REG_ADC_INT_STATUS);
396 	}
397 
398 	return IRQ_HANDLED;
399 }
400 
401 static int imx7d_adc_reg_access(struct iio_dev *indio_dev,
402 			unsigned reg, unsigned writeval,
403 			unsigned *readval)
404 {
405 	struct imx7d_adc *info = iio_priv(indio_dev);
406 
407 	if (!readval || reg % 4 || reg > IMX7D_REG_ADC_ADC_CFG)
408 		return -EINVAL;
409 
410 	*readval = readl(info->regs + reg);
411 
412 	return 0;
413 }
414 
415 static const struct iio_info imx7d_adc_iio_info = {
416 	.read_raw = &imx7d_adc_read_raw,
417 	.debugfs_reg_access = &imx7d_adc_reg_access,
418 };
419 
420 static const struct of_device_id imx7d_adc_match[] = {
421 	{ .compatible = "fsl,imx7d-adc", },
422 	{ /* sentinel */ }
423 };
424 MODULE_DEVICE_TABLE(of, imx7d_adc_match);
425 
426 static void imx7d_adc_power_down(struct imx7d_adc *info)
427 {
428 	u32 adc_cfg;
429 
430 	adc_cfg = readl(info->regs + IMX7D_REG_ADC_ADC_CFG);
431 	adc_cfg |= IMX7D_REG_ADC_ADC_CFG_ADC_CLK_DOWN |
432 		   IMX7D_REG_ADC_ADC_CFG_ADC_POWER_DOWN;
433 	adc_cfg &= ~IMX7D_REG_ADC_ADC_CFG_ADC_EN;
434 	writel(adc_cfg, info->regs + IMX7D_REG_ADC_ADC_CFG);
435 }
436 
437 static int imx7d_adc_enable(struct device *dev)
438 {
439 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
440 	struct imx7d_adc *info = iio_priv(indio_dev);
441 	int ret;
442 
443 	ret = regulator_enable(info->vref);
444 	if (ret) {
445 		dev_err(info->dev,
446 			"Can't enable adc reference top voltage, err = %d\n",
447 			ret);
448 		return ret;
449 	}
450 
451 	ret = clk_prepare_enable(info->clk);
452 	if (ret) {
453 		dev_err(info->dev,
454 			"Could not prepare or enable clock.\n");
455 		regulator_disable(info->vref);
456 		return ret;
457 	}
458 
459 	imx7d_adc_hw_init(info);
460 
461 	return 0;
462 }
463 
464 static int imx7d_adc_disable(struct device *dev)
465 {
466 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
467 	struct imx7d_adc *info = iio_priv(indio_dev);
468 
469 	imx7d_adc_power_down(info);
470 
471 	clk_disable_unprepare(info->clk);
472 	regulator_disable(info->vref);
473 
474 	return 0;
475 }
476 
477 static void __imx7d_adc_disable(void *data)
478 {
479 	imx7d_adc_disable(data);
480 }
481 
482 static int imx7d_adc_probe(struct platform_device *pdev)
483 {
484 	struct imx7d_adc *info;
485 	struct iio_dev *indio_dev;
486 	struct device *dev = &pdev->dev;
487 	int irq;
488 	int ret;
489 
490 	indio_dev = devm_iio_device_alloc(dev, sizeof(*info));
491 	if (!indio_dev) {
492 		dev_err(&pdev->dev, "Failed allocating iio device\n");
493 		return -ENOMEM;
494 	}
495 
496 	info = iio_priv(indio_dev);
497 	info->dev = dev;
498 
499 	info->regs = devm_platform_ioremap_resource(pdev, 0);
500 	if (IS_ERR(info->regs)) {
501 		ret = PTR_ERR(info->regs);
502 		dev_err(dev, "Failed to remap adc memory, err = %d\n", ret);
503 		return ret;
504 	}
505 
506 	irq = platform_get_irq(pdev, 0);
507 	if (irq < 0) {
508 		dev_err(dev, "No irq resource?\n");
509 		return irq;
510 	}
511 
512 	info->clk = devm_clk_get(dev, "adc");
513 	if (IS_ERR(info->clk)) {
514 		ret = PTR_ERR(info->clk);
515 		dev_err(dev, "Failed getting clock, err = %d\n", ret);
516 		return ret;
517 	}
518 
519 	info->vref = devm_regulator_get(dev, "vref");
520 	if (IS_ERR(info->vref)) {
521 		ret = PTR_ERR(info->vref);
522 		dev_err(dev,
523 			"Failed getting reference voltage, err = %d\n", ret);
524 		return ret;
525 	}
526 
527 	platform_set_drvdata(pdev, indio_dev);
528 
529 	init_completion(&info->completion);
530 
531 	indio_dev->name = dev_name(dev);
532 	indio_dev->dev.parent = dev;
533 	indio_dev->info = &imx7d_adc_iio_info;
534 	indio_dev->modes = INDIO_DIRECT_MODE;
535 	indio_dev->channels = imx7d_adc_iio_channels;
536 	indio_dev->num_channels = ARRAY_SIZE(imx7d_adc_iio_channels);
537 
538 	ret = devm_request_irq(dev, irq,
539 			       imx7d_adc_isr, 0,
540 			       dev_name(dev), info);
541 	if (ret < 0) {
542 		dev_err(dev, "Failed requesting irq, irq = %d\n", irq);
543 		return ret;
544 	}
545 
546 	imx7d_adc_feature_config(info);
547 
548 	ret = imx7d_adc_enable(&indio_dev->dev);
549 	if (ret)
550 		return ret;
551 
552 	ret = devm_add_action_or_reset(dev, __imx7d_adc_disable,
553 				       &indio_dev->dev);
554 	if (ret)
555 		return ret;
556 
557 	ret = iio_device_register(indio_dev);
558 	if (ret) {
559 		dev_err(&pdev->dev, "Couldn't register the device.\n");
560 		return ret;
561 	}
562 
563 	return 0;
564 }
565 
566 static int imx7d_adc_remove(struct platform_device *pdev)
567 {
568 	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
569 
570 	iio_device_unregister(indio_dev);
571 
572 	return 0;
573 }
574 
575 
576 static SIMPLE_DEV_PM_OPS(imx7d_adc_pm_ops, imx7d_adc_disable, imx7d_adc_enable);
577 
578 static struct platform_driver imx7d_adc_driver = {
579 	.probe		= imx7d_adc_probe,
580 	.remove		= imx7d_adc_remove,
581 	.driver		= {
582 		.name	= "imx7d_adc",
583 		.of_match_table = imx7d_adc_match,
584 		.pm	= &imx7d_adc_pm_ops,
585 	},
586 };
587 
588 module_platform_driver(imx7d_adc_driver);
589 
590 MODULE_AUTHOR("Haibo Chen <haibo.chen@freescale.com>");
591 MODULE_DESCRIPTION("Freescale IMX7D ADC driver");
592 MODULE_LICENSE("GPL v2");
593