cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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bcm_iproc_adc.c (17671B)


      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) \
    102do { \
    103	u32 val; \
    104	regmap_read(priv->regmap, reg, &val); \
    105	dev_dbg(dev, "%20s= 0x%08x\n", #reg, val); \
    106} while (0)
    107
    108struct 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
    118static 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
    135static 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
    159static 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
    224static 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
    336adc_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
    352static 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_update_bits(adc_priv->regmap, IPROC_ANALOG_CONTROL,
    361				IPROC_ADC_CHANNEL_SEL_MASK, 0);
    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
    430static 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
    452static 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
    482static 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
    495static 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
    506static 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 -ENODEV;
    545
    546	ret = regmap_update_bits(adc_priv->regmap, IPROC_REGCTL2,
    547				IPROC_ADC_AUXIN_SCAN_ENA, 0);
    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
    589err_clk:
    590	iproc_adc_disable(indio_dev);
    591err_adc_enable:
    592	clk_disable_unprepare(adc_priv->adc_clk);
    593
    594	return ret;
    595}
    596
    597static int 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	return 0;
    607}
    608
    609static const struct of_device_id iproc_adc_of_match[] = {
    610	{.compatible = "brcm,iproc-static-adc", },
    611	{ },
    612};
    613MODULE_DEVICE_TABLE(of, iproc_adc_of_match);
    614
    615static struct platform_driver iproc_adc_driver = {
    616	.probe  = iproc_adc_probe,
    617	.remove	= iproc_adc_remove,
    618	.driver	= {
    619		.name	= "iproc-static-adc",
    620		.of_match_table = iproc_adc_of_match,
    621	},
    622};
    623module_platform_driver(iproc_adc_driver);
    624
    625MODULE_DESCRIPTION("Broadcom iProc ADC controller driver");
    626MODULE_AUTHOR("Raveendra Padasalagi <raveendra.padasalagi@broadcom.com>");
    627MODULE_LICENSE("GPL v2");