372 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			372 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Marvell Berlin2 ADC driver
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|  *
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|  * Copyright (C) 2015 Marvell Technology Group Ltd.
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|  *
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|  * Antoine Tenart <antoine.tenart@free-electrons.com>
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|  *
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|  * This file is licensed under the terms of the GNU General Public
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|  * License version 2. This program is licensed "as is" without any
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|  * warranty of any kind, whether express or implied.
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|  */
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| 
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| #include <linux/iio/iio.h>
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| #include <linux/iio/driver.h>
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| #include <linux/iio/machine.h>
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| #include <linux/interrupt.h>
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| #include <linux/kernel.h>
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| #include <linux/mod_devicetable.h>
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| #include <linux/module.h>
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| #include <linux/of.h>
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| #include <linux/platform_device.h>
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| #include <linux/slab.h>
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| #include <linux/mfd/syscon.h>
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| #include <linux/regmap.h>
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| #include <linux/sched.h>
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| #include <linux/wait.h>
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| 
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| #define BERLIN2_SM_CTRL				0x14
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| #define  BERLIN2_SM_CTRL_SM_SOC_INT		BIT(1)
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| #define  BERLIN2_SM_CTRL_SOC_SM_INT		BIT(2)
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| #define  BERLIN2_SM_CTRL_ADC_SEL(x)		((x) << 5)	/* 0-15 */
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| #define  BERLIN2_SM_CTRL_ADC_SEL_MASK		GENMASK(8, 5)
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| #define  BERLIN2_SM_CTRL_ADC_POWER		BIT(9)
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| #define  BERLIN2_SM_CTRL_ADC_CLKSEL_DIV2	(0x0 << 10)
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| #define  BERLIN2_SM_CTRL_ADC_CLKSEL_DIV3	(0x1 << 10)
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| #define  BERLIN2_SM_CTRL_ADC_CLKSEL_DIV4	(0x2 << 10)
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| #define  BERLIN2_SM_CTRL_ADC_CLKSEL_DIV8	(0x3 << 10)
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| #define  BERLIN2_SM_CTRL_ADC_CLKSEL_MASK	GENMASK(11, 10)
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| #define  BERLIN2_SM_CTRL_ADC_START		BIT(12)
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| #define  BERLIN2_SM_CTRL_ADC_RESET		BIT(13)
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| #define  BERLIN2_SM_CTRL_ADC_BANDGAP_RDY	BIT(14)
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| #define  BERLIN2_SM_CTRL_ADC_CONT_SINGLE	(0x0 << 15)
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| #define  BERLIN2_SM_CTRL_ADC_CONT_CONTINUOUS	(0x1 << 15)
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| #define  BERLIN2_SM_CTRL_ADC_BUFFER_EN		BIT(16)
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| #define  BERLIN2_SM_CTRL_ADC_VREF_EXT		(0x0 << 17)
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| #define  BERLIN2_SM_CTRL_ADC_VREF_INT		(0x1 << 17)
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| #define  BERLIN2_SM_CTRL_ADC_ROTATE		BIT(19)
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| #define  BERLIN2_SM_CTRL_TSEN_EN		BIT(20)
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| #define  BERLIN2_SM_CTRL_TSEN_CLK_SEL_125	(0x0 << 21)	/* 1.25 MHz */
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| #define  BERLIN2_SM_CTRL_TSEN_CLK_SEL_250	(0x1 << 21)	/* 2.5 MHz */
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| #define  BERLIN2_SM_CTRL_TSEN_MODE_0_125	(0x0 << 22)	/* 0-125 C */
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| #define  BERLIN2_SM_CTRL_TSEN_MODE_10_50	(0x1 << 22)	/* 10-50 C */
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| #define  BERLIN2_SM_CTRL_TSEN_RESET		BIT(29)
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| #define BERLIN2_SM_ADC_DATA			0x20
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| #define  BERLIN2_SM_ADC_MASK			GENMASK(9, 0)
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| #define BERLIN2_SM_ADC_STATUS			0x1c
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| #define  BERLIN2_SM_ADC_STATUS_DATA_RDY(x)	BIT(x)		/* 0-15 */
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| #define  BERLIN2_SM_ADC_STATUS_DATA_RDY_MASK	GENMASK(15, 0)
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| #define  BERLIN2_SM_ADC_STATUS_INT_EN(x)	(BIT(x) << 16)	/* 0-15 */
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| #define  BERLIN2_SM_ADC_STATUS_INT_EN_MASK	GENMASK(31, 16)
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| #define BERLIN2_SM_TSEN_STATUS			0x24
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| #define  BERLIN2_SM_TSEN_STATUS_DATA_RDY	BIT(0)
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| #define  BERLIN2_SM_TSEN_STATUS_INT_EN		BIT(1)
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| #define BERLIN2_SM_TSEN_DATA			0x28
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| #define  BERLIN2_SM_TSEN_MASK			GENMASK(9, 0)
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| #define BERLIN2_SM_TSEN_CTRL			0x74
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| #define  BERLIN2_SM_TSEN_CTRL_START		BIT(8)
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| #define  BERLIN2_SM_TSEN_CTRL_SETTLING_4	(0x0 << 21)	/* 4 us */
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| #define  BERLIN2_SM_TSEN_CTRL_SETTLING_12	(0x1 << 21)	/* 12 us */
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| #define  BERLIN2_SM_TSEN_CTRL_SETTLING_MASK	BIT(21)
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| #define  BERLIN2_SM_TSEN_CTRL_TRIM(x)		((x) << 22)
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| #define  BERLIN2_SM_TSEN_CTRL_TRIM_MASK		GENMASK(25, 22)
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| 
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| struct berlin2_adc_priv {
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| 	struct regmap		*regmap;
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| 	struct mutex		lock;
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| 	wait_queue_head_t	wq;
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| 	bool			data_available;
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| 	int			data;
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| };
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| 
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| #define BERLIN2_ADC_CHANNEL(n, t)					\
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| 	{								\
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| 		.channel		= n,				\
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| 		.datasheet_name		= "channel"#n,			\
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| 		.type			= t,				\
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| 		.indexed		= 1,				\
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| 		.info_mask_separate	= BIT(IIO_CHAN_INFO_RAW),	\
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| 	}
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| 
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| static const struct iio_chan_spec berlin2_adc_channels[] = {
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| 	BERLIN2_ADC_CHANNEL(0, IIO_VOLTAGE),	/* external input */
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| 	BERLIN2_ADC_CHANNEL(1, IIO_VOLTAGE),	/* external input */
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| 	BERLIN2_ADC_CHANNEL(2, IIO_VOLTAGE),	/* external input */
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| 	BERLIN2_ADC_CHANNEL(3, IIO_VOLTAGE),	/* external input */
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| 	BERLIN2_ADC_CHANNEL(4, IIO_VOLTAGE),	/* reserved */
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| 	BERLIN2_ADC_CHANNEL(5, IIO_VOLTAGE),	/* reserved */
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| 	{					/* temperature sensor */
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| 		.channel		= 6,
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| 		.datasheet_name		= "channel6",
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| 		.type			= IIO_TEMP,
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| 		.indexed		= 0,
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| 		.info_mask_separate	= BIT(IIO_CHAN_INFO_PROCESSED),
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| 	},
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| 	BERLIN2_ADC_CHANNEL(7, IIO_VOLTAGE),	/* reserved */
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| 	IIO_CHAN_SOFT_TIMESTAMP(8),		/* timestamp */
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| };
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| 
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| static int berlin2_adc_read(struct iio_dev *indio_dev, int channel)
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| {
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| 	struct berlin2_adc_priv *priv = iio_priv(indio_dev);
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| 	int data, ret;
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| 
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| 	mutex_lock(&priv->lock);
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| 
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| 	/* Enable the interrupts */
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| 	regmap_write(priv->regmap, BERLIN2_SM_ADC_STATUS,
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| 		     BERLIN2_SM_ADC_STATUS_INT_EN(channel));
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| 
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| 	/* Configure the ADC */
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| 	regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
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| 			   BERLIN2_SM_CTRL_ADC_RESET |
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| 			   BERLIN2_SM_CTRL_ADC_SEL_MASK |
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| 			   BERLIN2_SM_CTRL_ADC_START,
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| 			   BERLIN2_SM_CTRL_ADC_SEL(channel) |
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| 			   BERLIN2_SM_CTRL_ADC_START);
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| 
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| 	ret = wait_event_interruptible_timeout(priv->wq, priv->data_available,
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| 					       msecs_to_jiffies(1000));
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| 
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| 	/* Disable the interrupts */
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| 	regmap_update_bits(priv->regmap, BERLIN2_SM_ADC_STATUS,
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| 			   BERLIN2_SM_ADC_STATUS_INT_EN(channel), 0);
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| 
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| 	if (ret == 0)
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| 		ret = -ETIMEDOUT;
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| 	if (ret < 0) {
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| 		mutex_unlock(&priv->lock);
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| 		return ret;
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| 	}
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| 
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| 	regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
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| 			   BERLIN2_SM_CTRL_ADC_START, 0);
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| 
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| 	data = priv->data;
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| 	priv->data_available = false;
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| 
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| 	mutex_unlock(&priv->lock);
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| 
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| 	return data;
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| }
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| 
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| static int berlin2_adc_tsen_read(struct iio_dev *indio_dev)
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| {
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| 	struct berlin2_adc_priv *priv = iio_priv(indio_dev);
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| 	int data, ret;
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| 
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| 	mutex_lock(&priv->lock);
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| 
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| 	/* Enable interrupts */
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| 	regmap_write(priv->regmap, BERLIN2_SM_TSEN_STATUS,
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| 		     BERLIN2_SM_TSEN_STATUS_INT_EN);
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| 
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| 	/* Configure the ADC */
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| 	regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
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| 			   BERLIN2_SM_CTRL_TSEN_RESET |
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| 			   BERLIN2_SM_CTRL_ADC_ROTATE,
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| 			   BERLIN2_SM_CTRL_ADC_ROTATE);
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| 
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| 	/* Configure the temperature sensor */
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| 	regmap_update_bits(priv->regmap, BERLIN2_SM_TSEN_CTRL,
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| 			   BERLIN2_SM_TSEN_CTRL_TRIM_MASK |
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| 			   BERLIN2_SM_TSEN_CTRL_SETTLING_MASK |
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| 			   BERLIN2_SM_TSEN_CTRL_START,
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| 			   BERLIN2_SM_TSEN_CTRL_TRIM(3) |
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| 			   BERLIN2_SM_TSEN_CTRL_SETTLING_12 |
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| 			   BERLIN2_SM_TSEN_CTRL_START);
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| 
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| 	ret = wait_event_interruptible_timeout(priv->wq, priv->data_available,
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| 					       msecs_to_jiffies(1000));
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| 
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| 	/* Disable interrupts */
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| 	regmap_update_bits(priv->regmap, BERLIN2_SM_TSEN_STATUS,
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| 			   BERLIN2_SM_TSEN_STATUS_INT_EN, 0);
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| 
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| 	if (ret == 0)
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| 		ret = -ETIMEDOUT;
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| 	if (ret < 0) {
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| 		mutex_unlock(&priv->lock);
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| 		return ret;
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| 	}
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| 
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| 	regmap_update_bits(priv->regmap, BERLIN2_SM_TSEN_CTRL,
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| 			   BERLIN2_SM_TSEN_CTRL_START, 0);
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| 
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| 	data = priv->data;
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| 	priv->data_available = false;
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| 
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| 	mutex_unlock(&priv->lock);
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| 
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| 	return data;
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| }
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| 
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| static int berlin2_adc_read_raw(struct iio_dev *indio_dev,
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| 				struct iio_chan_spec const *chan, int *val,
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| 				int *val2, long mask)
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| {
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| 	int temp;
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| 
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| 	switch (mask) {
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| 	case IIO_CHAN_INFO_RAW:
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| 		if (chan->type != IIO_VOLTAGE)
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| 			return -EINVAL;
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| 
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| 		*val = berlin2_adc_read(indio_dev, chan->channel);
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| 		if (*val < 0)
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| 			return *val;
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| 
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| 		return IIO_VAL_INT;
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| 	case IIO_CHAN_INFO_PROCESSED:
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| 		if (chan->type != IIO_TEMP)
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| 			return -EINVAL;
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| 
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| 		temp = berlin2_adc_tsen_read(indio_dev);
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| 		if (temp < 0)
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| 			return temp;
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| 
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| 		if (temp > 2047)
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| 			temp -= 4096;
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| 
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| 		/* Convert to milli Celsius */
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| 		*val = ((temp * 100000) / 264 - 270000);
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| 		return IIO_VAL_INT;
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| 	default:
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| 		break;
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| 	}
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| 
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| 	return -EINVAL;
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| }
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| 
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| static irqreturn_t berlin2_adc_irq(int irq, void *private)
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| {
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| 	struct berlin2_adc_priv *priv = iio_priv(private);
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| 	unsigned val;
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| 
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| 	regmap_read(priv->regmap, BERLIN2_SM_ADC_STATUS, &val);
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| 	if (val & BERLIN2_SM_ADC_STATUS_DATA_RDY_MASK) {
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| 		regmap_read(priv->regmap, BERLIN2_SM_ADC_DATA, &priv->data);
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| 		priv->data &= BERLIN2_SM_ADC_MASK;
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| 
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| 		val &= ~BERLIN2_SM_ADC_STATUS_DATA_RDY_MASK;
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| 		regmap_write(priv->regmap, BERLIN2_SM_ADC_STATUS, val);
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| 
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| 		priv->data_available = true;
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| 		wake_up_interruptible(&priv->wq);
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| 	}
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| 
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| 	return IRQ_HANDLED;
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| }
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| 
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| static irqreturn_t berlin2_adc_tsen_irq(int irq, void *private)
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| {
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| 	struct berlin2_adc_priv *priv = iio_priv(private);
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| 	unsigned val;
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| 
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| 	regmap_read(priv->regmap, BERLIN2_SM_TSEN_STATUS, &val);
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| 	if (val & BERLIN2_SM_TSEN_STATUS_DATA_RDY) {
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| 		regmap_read(priv->regmap, BERLIN2_SM_TSEN_DATA, &priv->data);
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| 		priv->data &= BERLIN2_SM_TSEN_MASK;
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| 
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| 		val &= ~BERLIN2_SM_TSEN_STATUS_DATA_RDY;
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| 		regmap_write(priv->regmap, BERLIN2_SM_TSEN_STATUS, val);
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| 
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| 		priv->data_available = true;
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| 		wake_up_interruptible(&priv->wq);
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| 	}
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| 
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| 	return IRQ_HANDLED;
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| }
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| 
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| static const struct iio_info berlin2_adc_info = {
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| 	.read_raw	= berlin2_adc_read_raw,
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| };
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| 
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| static void berlin2_adc_powerdown(void *regmap)
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| {
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| 	regmap_update_bits(regmap, BERLIN2_SM_CTRL,
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| 			   BERLIN2_SM_CTRL_ADC_POWER, 0);
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| 
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| }
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| 
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| static int berlin2_adc_probe(struct platform_device *pdev)
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| {
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| 	struct iio_dev *indio_dev;
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| 	struct berlin2_adc_priv *priv;
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| 	struct device_node *parent_np = of_get_parent(pdev->dev.of_node);
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| 	int irq, tsen_irq;
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| 	int ret;
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| 
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| 	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*priv));
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| 	if (!indio_dev) {
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| 		of_node_put(parent_np);
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| 		return -ENOMEM;
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| 	}
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| 
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| 	priv = iio_priv(indio_dev);
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| 
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| 	priv->regmap = syscon_node_to_regmap(parent_np);
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| 	of_node_put(parent_np);
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| 	if (IS_ERR(priv->regmap))
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| 		return PTR_ERR(priv->regmap);
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| 
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| 	irq = platform_get_irq_byname(pdev, "adc");
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| 	if (irq < 0)
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| 		return irq;
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| 
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| 	tsen_irq = platform_get_irq_byname(pdev, "tsen");
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| 	if (tsen_irq < 0)
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| 		return tsen_irq;
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| 
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| 	ret = devm_request_irq(&pdev->dev, irq, berlin2_adc_irq, 0,
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| 			       pdev->dev.driver->name, indio_dev);
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| 	if (ret)
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| 		return ret;
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| 
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| 	ret = devm_request_irq(&pdev->dev, tsen_irq, berlin2_adc_tsen_irq,
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| 			       0, pdev->dev.driver->name, indio_dev);
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| 	if (ret)
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| 		return ret;
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| 
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| 	init_waitqueue_head(&priv->wq);
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| 	mutex_init(&priv->lock);
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| 
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| 	indio_dev->name = dev_name(&pdev->dev);
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| 	indio_dev->modes = INDIO_DIRECT_MODE;
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| 	indio_dev->info = &berlin2_adc_info;
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| 
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| 	indio_dev->channels = berlin2_adc_channels;
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| 	indio_dev->num_channels = ARRAY_SIZE(berlin2_adc_channels);
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| 
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| 	/* Power up the ADC */
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| 	regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
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| 			   BERLIN2_SM_CTRL_ADC_POWER,
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| 			   BERLIN2_SM_CTRL_ADC_POWER);
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| 
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| 	ret = devm_add_action_or_reset(&pdev->dev, berlin2_adc_powerdown,
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| 				       priv->regmap);
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| 	if (ret)
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| 		return ret;
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| 
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| 	return devm_iio_device_register(&pdev->dev, indio_dev);
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| }
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| 
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| static const struct of_device_id berlin2_adc_match[] = {
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| 	{ .compatible = "marvell,berlin2-adc", },
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| 	{ },
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| };
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| MODULE_DEVICE_TABLE(of, berlin2_adc_match);
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| 
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| static struct platform_driver berlin2_adc_driver = {
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| 	.driver	= {
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| 		.name		= "berlin2-adc",
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| 		.of_match_table	= berlin2_adc_match,
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| 	},
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| 	.probe	= berlin2_adc_probe,
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| };
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| module_platform_driver(berlin2_adc_driver);
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| 
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| MODULE_AUTHOR("Antoine Tenart <antoine.tenart@free-electrons.com>");
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| MODULE_DESCRIPTION("Marvell Berlin2 ADC driver");
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| MODULE_LICENSE("GPL v2");
 |