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v5.4
  1// SPDX-License-Identifier: GPL-2.0
  2// Copyright (c) 2019 Nuvoton Technology corporation.
  3
  4#include <linux/clk.h>
  5#include <linux/device.h>
  6#include <linux/mfd/syscon.h>
  7#include <linux/io.h>
  8#include <linux/iio/iio.h>
  9#include <linux/interrupt.h>
 10#include <linux/kernel.h>
 11#include <linux/module.h>
 12#include <linux/platform_device.h>
 13#include <linux/regmap.h>
 14#include <linux/regulator/consumer.h>
 15#include <linux/spinlock.h>
 16#include <linux/uaccess.h>
 
 17
 18struct npcm_adc {
 19	bool int_status;
 20	u32 adc_sample_hz;
 21	struct device *dev;
 22	void __iomem *regs;
 23	struct clk *adc_clk;
 24	wait_queue_head_t wq;
 25	struct regulator *vref;
 26	struct regmap *rst_regmap;
 27};
 28
 29/* NPCM7xx reset module */
 30#define NPCM7XX_IPSRST1_OFFSET		0x020
 31#define NPCM7XX_IPSRST1_ADC_RST		BIT(27)
 32
 33/* ADC registers */
 34#define NPCM_ADCCON	 0x00
 35#define NPCM_ADCDATA	 0x04
 36
 37/* ADCCON Register Bits */
 38#define NPCM_ADCCON_ADC_INT_EN		BIT(21)
 39#define NPCM_ADCCON_REFSEL		BIT(19)
 40#define NPCM_ADCCON_ADC_INT_ST		BIT(18)
 41#define NPCM_ADCCON_ADC_EN		BIT(17)
 42#define NPCM_ADCCON_ADC_RST		BIT(16)
 43#define NPCM_ADCCON_ADC_CONV		BIT(13)
 44
 45#define NPCM_ADCCON_CH_MASK		GENMASK(27, 24)
 46#define NPCM_ADCCON_CH(x)		((x) << 24)
 47#define NPCM_ADCCON_DIV_SHIFT		1
 48#define NPCM_ADCCON_DIV_MASK		GENMASK(8, 1)
 49#define NPCM_ADC_DATA_MASK(x)		((x) & GENMASK(9, 0))
 50
 51#define NPCM_ADC_ENABLE		(NPCM_ADCCON_ADC_EN | NPCM_ADCCON_ADC_INT_EN)
 52
 53/* ADC General Definition */
 54#define NPCM_RESOLUTION_BITS		10
 55#define NPCM_INT_VREF_MV		2000
 56
 57#define NPCM_ADC_CHAN(ch) {					\
 58	.type = IIO_VOLTAGE,					\
 59	.indexed = 1,						\
 60	.channel = ch,						\
 61	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
 62	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |	\
 63				BIT(IIO_CHAN_INFO_SAMP_FREQ),	\
 64}
 65
 66static const struct iio_chan_spec npcm_adc_iio_channels[] = {
 67	NPCM_ADC_CHAN(0),
 68	NPCM_ADC_CHAN(1),
 69	NPCM_ADC_CHAN(2),
 70	NPCM_ADC_CHAN(3),
 71	NPCM_ADC_CHAN(4),
 72	NPCM_ADC_CHAN(5),
 73	NPCM_ADC_CHAN(6),
 74	NPCM_ADC_CHAN(7),
 75};
 76
 77static irqreturn_t npcm_adc_isr(int irq, void *data)
 78{
 79	u32 regtemp;
 80	struct iio_dev *indio_dev = data;
 81	struct npcm_adc *info = iio_priv(indio_dev);
 82
 83	regtemp = ioread32(info->regs + NPCM_ADCCON);
 84	if (regtemp & NPCM_ADCCON_ADC_INT_ST) {
 85		iowrite32(regtemp, info->regs + NPCM_ADCCON);
 86		wake_up_interruptible(&info->wq);
 87		info->int_status = true;
 88	}
 89
 90	return IRQ_HANDLED;
 91}
 92
 93static int npcm_adc_read(struct npcm_adc *info, int *val, u8 channel)
 94{
 95	int ret;
 96	u32 regtemp;
 97
 98	/* Select ADC channel */
 99	regtemp = ioread32(info->regs + NPCM_ADCCON);
100	regtemp &= ~NPCM_ADCCON_CH_MASK;
101	info->int_status = false;
102	iowrite32(regtemp | NPCM_ADCCON_CH(channel) |
103		  NPCM_ADCCON_ADC_CONV, info->regs + NPCM_ADCCON);
104
105	ret = wait_event_interruptible_timeout(info->wq, info->int_status,
106					       msecs_to_jiffies(10));
107	if (ret == 0) {
108		regtemp = ioread32(info->regs + NPCM_ADCCON);
109		if ((regtemp & NPCM_ADCCON_ADC_CONV) && info->rst_regmap) {
110			/* if conversion failed - reset ADC module */
111			regmap_write(info->rst_regmap, NPCM7XX_IPSRST1_OFFSET,
112				     NPCM7XX_IPSRST1_ADC_RST);
113			msleep(100);
114			regmap_write(info->rst_regmap, NPCM7XX_IPSRST1_OFFSET,
115				     0x0);
116			msleep(100);
117
118			/* Enable ADC and start conversion module */
119			iowrite32(NPCM_ADC_ENABLE | NPCM_ADCCON_ADC_CONV,
120				  info->regs + NPCM_ADCCON);
121			dev_err(info->dev, "RESET ADC Complete\n");
122		}
123		return -ETIMEDOUT;
124	}
125	if (ret < 0)
126		return ret;
127
128	*val = NPCM_ADC_DATA_MASK(ioread32(info->regs + NPCM_ADCDATA));
129
130	return 0;
131}
132
133static int npcm_adc_read_raw(struct iio_dev *indio_dev,
134			     struct iio_chan_spec const *chan, int *val,
135			     int *val2, long mask)
136{
137	int ret;
138	int vref_uv;
139	struct npcm_adc *info = iio_priv(indio_dev);
140
141	switch (mask) {
142	case IIO_CHAN_INFO_RAW:
143		mutex_lock(&indio_dev->mlock);
144		ret = npcm_adc_read(info, val, chan->channel);
145		mutex_unlock(&indio_dev->mlock);
146		if (ret) {
147			dev_err(info->dev, "NPCM ADC read failed\n");
148			return ret;
149		}
150		return IIO_VAL_INT;
151	case IIO_CHAN_INFO_SCALE:
152		if (!IS_ERR(info->vref)) {
153			vref_uv = regulator_get_voltage(info->vref);
154			*val = vref_uv / 1000;
155		} else {
156			*val = NPCM_INT_VREF_MV;
157		}
158		*val2 = NPCM_RESOLUTION_BITS;
159		return IIO_VAL_FRACTIONAL_LOG2;
160	case IIO_CHAN_INFO_SAMP_FREQ:
161		*val = info->adc_sample_hz;
162		return IIO_VAL_INT;
163	default:
164		return -EINVAL;
165	}
166
167	return 0;
168}
169
170static const struct iio_info npcm_adc_iio_info = {
171	.read_raw = &npcm_adc_read_raw,
172};
173
174static const struct of_device_id npcm_adc_match[] = {
175	{ .compatible = "nuvoton,npcm750-adc", },
176	{ /* sentinel */ }
177};
178MODULE_DEVICE_TABLE(of, npcm_adc_match);
179
180static int npcm_adc_probe(struct platform_device *pdev)
181{
182	int ret;
183	int irq;
184	u32 div;
185	u32 reg_con;
186	struct resource *res;
187	struct npcm_adc *info;
188	struct iio_dev *indio_dev;
189	struct device *dev = &pdev->dev;
190	struct device_node *np = pdev->dev.of_node;
191
192	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*info));
193	if (!indio_dev)
194		return -ENOMEM;
195	info = iio_priv(indio_dev);
196
197	info->dev = &pdev->dev;
198
199	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
200	info->regs = devm_ioremap_resource(&pdev->dev, res);
201	if (IS_ERR(info->regs))
202		return PTR_ERR(info->regs);
203
 
 
 
 
204	info->adc_clk = devm_clk_get(&pdev->dev, NULL);
205	if (IS_ERR(info->adc_clk)) {
206		dev_warn(&pdev->dev, "ADC clock failed: can't read clk\n");
207		return PTR_ERR(info->adc_clk);
208	}
209
210	/* calculate ADC clock sample rate */
211	reg_con = ioread32(info->regs + NPCM_ADCCON);
212	div = reg_con & NPCM_ADCCON_DIV_MASK;
213	div = div >> NPCM_ADCCON_DIV_SHIFT;
214	info->adc_sample_hz = clk_get_rate(info->adc_clk) / ((div + 1) * 2);
215
216	if (of_device_is_compatible(np, "nuvoton,npcm750-adc")) {
217		info->rst_regmap = syscon_regmap_lookup_by_compatible
218			("nuvoton,npcm750-rst");
219		if (IS_ERR(info->rst_regmap)) {
220			dev_err(&pdev->dev, "Failed to find nuvoton,npcm750-rst\n");
221			ret = PTR_ERR(info->rst_regmap);
222			goto err_disable_clk;
223		}
224	}
225
226	irq = platform_get_irq(pdev, 0);
227	if (irq <= 0) {
228		ret = -EINVAL;
229		goto err_disable_clk;
230	}
231
232	ret = devm_request_irq(&pdev->dev, irq, npcm_adc_isr, 0,
233			       "NPCM_ADC", indio_dev);
234	if (ret < 0) {
235		dev_err(dev, "failed requesting interrupt\n");
236		goto err_disable_clk;
237	}
238
239	reg_con = ioread32(info->regs + NPCM_ADCCON);
240	info->vref = devm_regulator_get_optional(&pdev->dev, "vref");
241	if (!IS_ERR(info->vref)) {
242		ret = regulator_enable(info->vref);
243		if (ret) {
244			dev_err(&pdev->dev, "Can't enable ADC reference voltage\n");
245			goto err_disable_clk;
246		}
247
248		iowrite32(reg_con & ~NPCM_ADCCON_REFSEL,
249			  info->regs + NPCM_ADCCON);
250	} else {
251		/*
252		 * Any error which is not ENODEV indicates the regulator
253		 * has been specified and so is a failure case.
254		 */
255		if (PTR_ERR(info->vref) != -ENODEV) {
256			ret = PTR_ERR(info->vref);
257			goto err_disable_clk;
258		}
259
260		/* Use internal reference */
261		iowrite32(reg_con | NPCM_ADCCON_REFSEL,
262			  info->regs + NPCM_ADCCON);
263	}
264
265	init_waitqueue_head(&info->wq);
266
267	reg_con = ioread32(info->regs + NPCM_ADCCON);
268	reg_con |= NPCM_ADC_ENABLE;
269
270	/* Enable the ADC Module */
271	iowrite32(reg_con, info->regs + NPCM_ADCCON);
272
273	/* Start ADC conversion */
274	iowrite32(reg_con | NPCM_ADCCON_ADC_CONV, info->regs + NPCM_ADCCON);
275
276	platform_set_drvdata(pdev, indio_dev);
277	indio_dev->name = dev_name(&pdev->dev);
278	indio_dev->dev.parent = &pdev->dev;
279	indio_dev->info = &npcm_adc_iio_info;
280	indio_dev->modes = INDIO_DIRECT_MODE;
281	indio_dev->channels = npcm_adc_iio_channels;
282	indio_dev->num_channels = ARRAY_SIZE(npcm_adc_iio_channels);
283
284	ret = iio_device_register(indio_dev);
285	if (ret) {
286		dev_err(&pdev->dev, "Couldn't register the device.\n");
287		goto err_iio_register;
288	}
289
290	pr_info("NPCM ADC driver probed\n");
291
292	return 0;
293
294err_iio_register:
295	iowrite32(reg_con & ~NPCM_ADCCON_ADC_EN, info->regs + NPCM_ADCCON);
296	if (!IS_ERR(info->vref))
297		regulator_disable(info->vref);
298err_disable_clk:
299	clk_disable_unprepare(info->adc_clk);
300
301	return ret;
302}
303
304static int npcm_adc_remove(struct platform_device *pdev)
305{
306	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
307	struct npcm_adc *info = iio_priv(indio_dev);
308	u32 regtemp;
309
310	iio_device_unregister(indio_dev);
311
312	regtemp = ioread32(info->regs + NPCM_ADCCON);
313	iowrite32(regtemp & ~NPCM_ADCCON_ADC_EN, info->regs + NPCM_ADCCON);
314	if (!IS_ERR(info->vref))
315		regulator_disable(info->vref);
316	clk_disable_unprepare(info->adc_clk);
317
318	return 0;
319}
320
321static struct platform_driver npcm_adc_driver = {
322	.probe		= npcm_adc_probe,
323	.remove		= npcm_adc_remove,
324	.driver		= {
325		.name	= "npcm_adc",
326		.of_match_table = npcm_adc_match,
327	},
328};
329
330module_platform_driver(npcm_adc_driver);
331
332MODULE_DESCRIPTION("Nuvoton NPCM ADC Driver");
333MODULE_AUTHOR("Tomer Maimon <tomer.maimon@nuvoton.com>");
334MODULE_LICENSE("GPL v2");
v5.9
  1// SPDX-License-Identifier: GPL-2.0
  2// Copyright (c) 2019 Nuvoton Technology corporation.
  3
  4#include <linux/clk.h>
  5#include <linux/device.h>
  6#include <linux/mfd/syscon.h>
  7#include <linux/io.h>
  8#include <linux/iio/iio.h>
  9#include <linux/interrupt.h>
 10#include <linux/kernel.h>
 11#include <linux/module.h>
 12#include <linux/platform_device.h>
 13#include <linux/regmap.h>
 14#include <linux/regulator/consumer.h>
 15#include <linux/spinlock.h>
 16#include <linux/uaccess.h>
 17#include <linux/reset.h>
 18
 19struct npcm_adc {
 20	bool int_status;
 21	u32 adc_sample_hz;
 22	struct device *dev;
 23	void __iomem *regs;
 24	struct clk *adc_clk;
 25	wait_queue_head_t wq;
 26	struct regulator *vref;
 27	struct reset_control *reset;
 28};
 29
 
 
 
 
 30/* ADC registers */
 31#define NPCM_ADCCON	 0x00
 32#define NPCM_ADCDATA	 0x04
 33
 34/* ADCCON Register Bits */
 35#define NPCM_ADCCON_ADC_INT_EN		BIT(21)
 36#define NPCM_ADCCON_REFSEL		BIT(19)
 37#define NPCM_ADCCON_ADC_INT_ST		BIT(18)
 38#define NPCM_ADCCON_ADC_EN		BIT(17)
 39#define NPCM_ADCCON_ADC_RST		BIT(16)
 40#define NPCM_ADCCON_ADC_CONV		BIT(13)
 41
 42#define NPCM_ADCCON_CH_MASK		GENMASK(27, 24)
 43#define NPCM_ADCCON_CH(x)		((x) << 24)
 44#define NPCM_ADCCON_DIV_SHIFT		1
 45#define NPCM_ADCCON_DIV_MASK		GENMASK(8, 1)
 46#define NPCM_ADC_DATA_MASK(x)		((x) & GENMASK(9, 0))
 47
 48#define NPCM_ADC_ENABLE		(NPCM_ADCCON_ADC_EN | NPCM_ADCCON_ADC_INT_EN)
 49
 50/* ADC General Definition */
 51#define NPCM_RESOLUTION_BITS		10
 52#define NPCM_INT_VREF_MV		2000
 53
 54#define NPCM_ADC_CHAN(ch) {					\
 55	.type = IIO_VOLTAGE,					\
 56	.indexed = 1,						\
 57	.channel = ch,						\
 58	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
 59	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |	\
 60				BIT(IIO_CHAN_INFO_SAMP_FREQ),	\
 61}
 62
 63static const struct iio_chan_spec npcm_adc_iio_channels[] = {
 64	NPCM_ADC_CHAN(0),
 65	NPCM_ADC_CHAN(1),
 66	NPCM_ADC_CHAN(2),
 67	NPCM_ADC_CHAN(3),
 68	NPCM_ADC_CHAN(4),
 69	NPCM_ADC_CHAN(5),
 70	NPCM_ADC_CHAN(6),
 71	NPCM_ADC_CHAN(7),
 72};
 73
 74static irqreturn_t npcm_adc_isr(int irq, void *data)
 75{
 76	u32 regtemp;
 77	struct iio_dev *indio_dev = data;
 78	struct npcm_adc *info = iio_priv(indio_dev);
 79
 80	regtemp = ioread32(info->regs + NPCM_ADCCON);
 81	if (regtemp & NPCM_ADCCON_ADC_INT_ST) {
 82		iowrite32(regtemp, info->regs + NPCM_ADCCON);
 83		wake_up_interruptible(&info->wq);
 84		info->int_status = true;
 85	}
 86
 87	return IRQ_HANDLED;
 88}
 89
 90static int npcm_adc_read(struct npcm_adc *info, int *val, u8 channel)
 91{
 92	int ret;
 93	u32 regtemp;
 94
 95	/* Select ADC channel */
 96	regtemp = ioread32(info->regs + NPCM_ADCCON);
 97	regtemp &= ~NPCM_ADCCON_CH_MASK;
 98	info->int_status = false;
 99	iowrite32(regtemp | NPCM_ADCCON_CH(channel) |
100		  NPCM_ADCCON_ADC_CONV, info->regs + NPCM_ADCCON);
101
102	ret = wait_event_interruptible_timeout(info->wq, info->int_status,
103					       msecs_to_jiffies(10));
104	if (ret == 0) {
105		regtemp = ioread32(info->regs + NPCM_ADCCON);
106		if (regtemp & NPCM_ADCCON_ADC_CONV) {
107			/* if conversion failed - reset ADC module */
108			reset_control_assert(info->reset);
 
109			msleep(100);
110			reset_control_deassert(info->reset);
 
111			msleep(100);
112
113			/* Enable ADC and start conversion module */
114			iowrite32(NPCM_ADC_ENABLE | NPCM_ADCCON_ADC_CONV,
115				  info->regs + NPCM_ADCCON);
116			dev_err(info->dev, "RESET ADC Complete\n");
117		}
118		return -ETIMEDOUT;
119	}
120	if (ret < 0)
121		return ret;
122
123	*val = NPCM_ADC_DATA_MASK(ioread32(info->regs + NPCM_ADCDATA));
124
125	return 0;
126}
127
128static int npcm_adc_read_raw(struct iio_dev *indio_dev,
129			     struct iio_chan_spec const *chan, int *val,
130			     int *val2, long mask)
131{
132	int ret;
133	int vref_uv;
134	struct npcm_adc *info = iio_priv(indio_dev);
135
136	switch (mask) {
137	case IIO_CHAN_INFO_RAW:
138		mutex_lock(&indio_dev->mlock);
139		ret = npcm_adc_read(info, val, chan->channel);
140		mutex_unlock(&indio_dev->mlock);
141		if (ret) {
142			dev_err(info->dev, "NPCM ADC read failed\n");
143			return ret;
144		}
145		return IIO_VAL_INT;
146	case IIO_CHAN_INFO_SCALE:
147		if (!IS_ERR(info->vref)) {
148			vref_uv = regulator_get_voltage(info->vref);
149			*val = vref_uv / 1000;
150		} else {
151			*val = NPCM_INT_VREF_MV;
152		}
153		*val2 = NPCM_RESOLUTION_BITS;
154		return IIO_VAL_FRACTIONAL_LOG2;
155	case IIO_CHAN_INFO_SAMP_FREQ:
156		*val = info->adc_sample_hz;
157		return IIO_VAL_INT;
158	default:
159		return -EINVAL;
160	}
161
162	return 0;
163}
164
165static const struct iio_info npcm_adc_iio_info = {
166	.read_raw = &npcm_adc_read_raw,
167};
168
169static const struct of_device_id npcm_adc_match[] = {
170	{ .compatible = "nuvoton,npcm750-adc", },
171	{ /* sentinel */ }
172};
173MODULE_DEVICE_TABLE(of, npcm_adc_match);
174
175static int npcm_adc_probe(struct platform_device *pdev)
176{
177	int ret;
178	int irq;
179	u32 div;
180	u32 reg_con;
 
181	struct npcm_adc *info;
182	struct iio_dev *indio_dev;
183	struct device *dev = &pdev->dev;
 
184
185	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*info));
186	if (!indio_dev)
187		return -ENOMEM;
188	info = iio_priv(indio_dev);
189
190	info->dev = &pdev->dev;
191
192	info->regs = devm_platform_ioremap_resource(pdev, 0);
 
193	if (IS_ERR(info->regs))
194		return PTR_ERR(info->regs);
195
196	info->reset = devm_reset_control_get(&pdev->dev, NULL);
197	if (IS_ERR(info->reset))
198		return PTR_ERR(info->reset);
199
200	info->adc_clk = devm_clk_get(&pdev->dev, NULL);
201	if (IS_ERR(info->adc_clk)) {
202		dev_warn(&pdev->dev, "ADC clock failed: can't read clk\n");
203		return PTR_ERR(info->adc_clk);
204	}
205
206	/* calculate ADC clock sample rate */
207	reg_con = ioread32(info->regs + NPCM_ADCCON);
208	div = reg_con & NPCM_ADCCON_DIV_MASK;
209	div = div >> NPCM_ADCCON_DIV_SHIFT;
210	info->adc_sample_hz = clk_get_rate(info->adc_clk) / ((div + 1) * 2);
211
 
 
 
 
 
 
 
 
 
 
212	irq = platform_get_irq(pdev, 0);
213	if (irq <= 0) {
214		ret = -EINVAL;
215		goto err_disable_clk;
216	}
217
218	ret = devm_request_irq(&pdev->dev, irq, npcm_adc_isr, 0,
219			       "NPCM_ADC", indio_dev);
220	if (ret < 0) {
221		dev_err(dev, "failed requesting interrupt\n");
222		goto err_disable_clk;
223	}
224
225	reg_con = ioread32(info->regs + NPCM_ADCCON);
226	info->vref = devm_regulator_get_optional(&pdev->dev, "vref");
227	if (!IS_ERR(info->vref)) {
228		ret = regulator_enable(info->vref);
229		if (ret) {
230			dev_err(&pdev->dev, "Can't enable ADC reference voltage\n");
231			goto err_disable_clk;
232		}
233
234		iowrite32(reg_con & ~NPCM_ADCCON_REFSEL,
235			  info->regs + NPCM_ADCCON);
236	} else {
237		/*
238		 * Any error which is not ENODEV indicates the regulator
239		 * has been specified and so is a failure case.
240		 */
241		if (PTR_ERR(info->vref) != -ENODEV) {
242			ret = PTR_ERR(info->vref);
243			goto err_disable_clk;
244		}
245
246		/* Use internal reference */
247		iowrite32(reg_con | NPCM_ADCCON_REFSEL,
248			  info->regs + NPCM_ADCCON);
249	}
250
251	init_waitqueue_head(&info->wq);
252
253	reg_con = ioread32(info->regs + NPCM_ADCCON);
254	reg_con |= NPCM_ADC_ENABLE;
255
256	/* Enable the ADC Module */
257	iowrite32(reg_con, info->regs + NPCM_ADCCON);
258
259	/* Start ADC conversion */
260	iowrite32(reg_con | NPCM_ADCCON_ADC_CONV, info->regs + NPCM_ADCCON);
261
262	platform_set_drvdata(pdev, indio_dev);
263	indio_dev->name = dev_name(&pdev->dev);
 
264	indio_dev->info = &npcm_adc_iio_info;
265	indio_dev->modes = INDIO_DIRECT_MODE;
266	indio_dev->channels = npcm_adc_iio_channels;
267	indio_dev->num_channels = ARRAY_SIZE(npcm_adc_iio_channels);
268
269	ret = iio_device_register(indio_dev);
270	if (ret) {
271		dev_err(&pdev->dev, "Couldn't register the device.\n");
272		goto err_iio_register;
273	}
274
275	pr_info("NPCM ADC driver probed\n");
276
277	return 0;
278
279err_iio_register:
280	iowrite32(reg_con & ~NPCM_ADCCON_ADC_EN, info->regs + NPCM_ADCCON);
281	if (!IS_ERR(info->vref))
282		regulator_disable(info->vref);
283err_disable_clk:
284	clk_disable_unprepare(info->adc_clk);
285
286	return ret;
287}
288
289static int npcm_adc_remove(struct platform_device *pdev)
290{
291	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
292	struct npcm_adc *info = iio_priv(indio_dev);
293	u32 regtemp;
294
295	iio_device_unregister(indio_dev);
296
297	regtemp = ioread32(info->regs + NPCM_ADCCON);
298	iowrite32(regtemp & ~NPCM_ADCCON_ADC_EN, info->regs + NPCM_ADCCON);
299	if (!IS_ERR(info->vref))
300		regulator_disable(info->vref);
301	clk_disable_unprepare(info->adc_clk);
302
303	return 0;
304}
305
306static struct platform_driver npcm_adc_driver = {
307	.probe		= npcm_adc_probe,
308	.remove		= npcm_adc_remove,
309	.driver		= {
310		.name	= "npcm_adc",
311		.of_match_table = npcm_adc_match,
312	},
313};
314
315module_platform_driver(npcm_adc_driver);
316
317MODULE_DESCRIPTION("Nuvoton NPCM ADC Driver");
318MODULE_AUTHOR("Tomer Maimon <tomer.maimon@nuvoton.com>");
319MODULE_LICENSE("GPL v2");