drivers/iio/adc/imx8qxp-adc.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0+
 /*
  * NXP i.MX8QXP ADC driver
  *
  * Based on the work of Haibo Chen <haibo.chen@nxp.com>
  * The initial developer of the original code is Haibo Chen.
  * Portions created by Haibo Chen are Copyright (C) 2018 NXP.
  * All Rights Reserved.
  *
  * Copyright (C) 2018 NXP
  * Copyright (C) 2021 Cai Huoqing
  */
 #include <linux/bitfield.h>
 #include <linux/bits.h>
 #include <linux/clk.h>
 #include <linux/completion.h>
 #include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
 #include <linux/mod_devicetable.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/regulator/consumer.h>

 #include <linux/iio/iio.h>

 #define ADC_DRIVER_NAME		"imx8qxp-adc"

 /* Register map definition */
 #define IMX8QXP_ADR_ADC_CTRL		0x10
 #define IMX8QXP_ADR_ADC_STAT		0x14
 #define IMX8QXP_ADR_ADC_IE		0x18
 #define IMX8QXP_ADR_ADC_DE		0x1c
 #define IMX8QXP_ADR_ADC_CFG		0x20
 #define IMX8QXP_ADR_ADC_FCTRL		0x30
 #define IMX8QXP_ADR_ADC_SWTRIG		0x34
 #define IMX8QXP_ADR_ADC_TCTRL(tid)	(0xc0 + (tid) * 4)
 #define IMX8QXP_ADR_ADC_CMDH(cid)	(0x100 + (cid) * 8)
 #define IMX8QXP_ADR_ADC_CMDL(cid)	(0x104 + (cid) * 8)
 #define IMX8QXP_ADR_ADC_RESFIFO		0x300
 #define IMX8QXP_ADR_ADC_TST		0xffc

 /* ADC bit shift */
 #define IMX8QXP_ADC_IE_FWMIE_MASK		GENMASK(1, 0)
 #define IMX8QXP_ADC_CTRL_FIFO_RESET_MASK	BIT(8)
 #define IMX8QXP_ADC_CTRL_SOFTWARE_RESET_MASK	BIT(1)
 #define IMX8QXP_ADC_CTRL_ADC_EN_MASK		BIT(0)
 #define IMX8QXP_ADC_TCTRL_TCMD_MASK		GENMASK(31, 24)
 #define IMX8QXP_ADC_TCTRL_TDLY_MASK		GENMASK(23, 16)
 #define IMX8QXP_ADC_TCTRL_TPRI_MASK		GENMASK(15, 8)
 #define IMX8QXP_ADC_TCTRL_HTEN_MASK		GENMASK(7, 0)
 #define IMX8QXP_ADC_CMDL_CSCALE_MASK		GENMASK(13, 8)
 #define IMX8QXP_ADC_CMDL_MODE_MASK		BIT(7)
 #define IMX8QXP_ADC_CMDL_DIFF_MASK		BIT(6)
 #define IMX8QXP_ADC_CMDL_ABSEL_MASK		BIT(5)
 #define IMX8QXP_ADC_CMDL_ADCH_MASK		GENMASK(2, 0)
 #define IMX8QXP_ADC_CMDH_NEXT_MASK		GENMASK(31, 24)
 #define IMX8QXP_ADC_CMDH_LOOP_MASK		GENMASK(23, 16)
 #define IMX8QXP_ADC_CMDH_AVGS_MASK		GENMASK(15, 12)
 #define IMX8QXP_ADC_CMDH_STS_MASK		BIT(8)
 #define IMX8QXP_ADC_CMDH_LWI_MASK		GENMASK(7, 7)
 #define IMX8QXP_ADC_CMDH_CMPEN_MASK		GENMASK(0, 0)
 #define IMX8QXP_ADC_CFG_PWREN_MASK		BIT(28)
 #define IMX8QXP_ADC_CFG_PUDLY_MASK		GENMASK(23, 16)
 #define IMX8QXP_ADC_CFG_REFSEL_MASK		GENMASK(7, 6)
 #define IMX8QXP_ADC_CFG_PWRSEL_MASK		GENMASK(5, 4)
 #define IMX8QXP_ADC_CFG_TPRICTRL_MASK		GENMASK(3, 0)
 #define IMX8QXP_ADC_FCTRL_FWMARK_MASK		GENMASK(20, 16)
 #define IMX8QXP_ADC_FCTRL_FCOUNT_MASK		GENMASK(4, 0)
 #define IMX8QXP_ADC_RESFIFO_VAL_MASK		GENMASK(18, 3)

 /* ADC PARAMETER*/
 #define IMX8QXP_ADC_CMDL_CHANNEL_SCALE_FULL		GENMASK(5, 0)
 #define IMX8QXP_ADC_CMDL_SEL_A_A_B_CHANNEL		0
 #define IMX8QXP_ADC_CMDL_STANDARD_RESOLUTION		0
 #define IMX8QXP_ADC_CMDL_MODE_SINGLE			0
 #define IMX8QXP_ADC_CMDH_LWI_INCREMENT_DIS		0
 #define IMX8QXP_ADC_CMDH_CMPEN_DIS			0
 #define IMX8QXP_ADC_PAUSE_EN				BIT(31)
 #define IMX8QXP_ADC_TCTRL_TPRI_PRIORITY_HIGH		0

 #define IMX8QXP_ADC_TCTRL_HTEN_HW_TIRG_DIS		0

 #define IMX8QXP_ADC_TIMEOUT		msecs_to_jiffies(100)

 struct imx8qxp_adc {
 	struct device *dev;
 	void __iomem *regs;
 	struct clk *clk;
 	struct clk *ipg_clk;
 	struct regulator *vref;
 	/* Serialise ADC channel reads */
 	struct mutex lock;
 	struct completion completion;
 };

 #define IMX8QXP_ADC_CHAN(_idx) {				\
 	.type = IIO_VOLTAGE,					\
 	.indexed = 1,						\
 	.channel = (_idx),					\
 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |	\
 				BIT(IIO_CHAN_INFO_SAMP_FREQ),	\
 }

 static const struct iio_chan_spec imx8qxp_adc_iio_channels[] = {
 	IMX8QXP_ADC_CHAN(0),
 	IMX8QXP_ADC_CHAN(1),
 	IMX8QXP_ADC_CHAN(2),
 	IMX8QXP_ADC_CHAN(3),
 	IMX8QXP_ADC_CHAN(4),
 	IMX8QXP_ADC_CHAN(5),
 	IMX8QXP_ADC_CHAN(6),
 	IMX8QXP_ADC_CHAN(7),
 };

 static void imx8qxp_adc_reset(struct imx8qxp_adc *adc)
 {
 	u32 ctrl;

 	/*software reset, need to clear the set bit*/
 	ctrl = readl(adc->regs + IMX8QXP_ADR_ADC_CTRL);
 	ctrl |= FIELD_PREP(IMX8QXP_ADC_CTRL_SOFTWARE_RESET_MASK, 1);
 	writel(ctrl, adc->regs + IMX8QXP_ADR_ADC_CTRL);
 	udelay(10);
 	ctrl &= ~FIELD_PREP(IMX8QXP_ADC_CTRL_SOFTWARE_RESET_MASK, 1);
 	writel(ctrl, adc->regs + IMX8QXP_ADR_ADC_CTRL);

 	/* reset the fifo */
 	ctrl |= FIELD_PREP(IMX8QXP_ADC_CTRL_FIFO_RESET_MASK, 1);
 	writel(ctrl, adc->regs + IMX8QXP_ADR_ADC_CTRL);
 }

 static void imx8qxp_adc_reg_config(struct imx8qxp_adc *adc, int channel)
 {
 	u32 adc_cfg, adc_tctrl, adc_cmdl, adc_cmdh;

 	/* ADC configuration */
 	adc_cfg = FIELD_PREP(IMX8QXP_ADC_CFG_PWREN_MASK, 1) |
 		  FIELD_PREP(IMX8QXP_ADC_CFG_PUDLY_MASK, 0x80)|
 		  FIELD_PREP(IMX8QXP_ADC_CFG_REFSEL_MASK, 0) |
 		  FIELD_PREP(IMX8QXP_ADC_CFG_PWRSEL_MASK, 3) |
 		  FIELD_PREP(IMX8QXP_ADC_CFG_TPRICTRL_MASK, 0);
 	writel(adc_cfg, adc->regs + IMX8QXP_ADR_ADC_CFG);

 	/* config the trigger control */
 	adc_tctrl = FIELD_PREP(IMX8QXP_ADC_TCTRL_TCMD_MASK, 1) |
 		    FIELD_PREP(IMX8QXP_ADC_TCTRL_TDLY_MASK, 0) |
 		    FIELD_PREP(IMX8QXP_ADC_TCTRL_TPRI_MASK, IMX8QXP_ADC_TCTRL_TPRI_PRIORITY_HIGH) |
 		    FIELD_PREP(IMX8QXP_ADC_TCTRL_HTEN_MASK, IMX8QXP_ADC_TCTRL_HTEN_HW_TIRG_DIS);
 	writel(adc_tctrl, adc->regs + IMX8QXP_ADR_ADC_TCTRL(0));

 	/* config the cmd */
 	adc_cmdl = FIELD_PREP(IMX8QXP_ADC_CMDL_CSCALE_MASK, IMX8QXP_ADC_CMDL_CHANNEL_SCALE_FULL) |
 		   FIELD_PREP(IMX8QXP_ADC_CMDL_MODE_MASK, IMX8QXP_ADC_CMDL_STANDARD_RESOLUTION) |
 		   FIELD_PREP(IMX8QXP_ADC_CMDL_DIFF_MASK, IMX8QXP_ADC_CMDL_MODE_SINGLE) |
 		   FIELD_PREP(IMX8QXP_ADC_CMDL_ABSEL_MASK, IMX8QXP_ADC_CMDL_SEL_A_A_B_CHANNEL) |
 		   FIELD_PREP(IMX8QXP_ADC_CMDL_ADCH_MASK, channel);
 	writel(adc_cmdl, adc->regs + IMX8QXP_ADR_ADC_CMDL(0));

 	adc_cmdh = FIELD_PREP(IMX8QXP_ADC_CMDH_NEXT_MASK, 0) |
 		   FIELD_PREP(IMX8QXP_ADC_CMDH_LOOP_MASK, 0) |
 		   FIELD_PREP(IMX8QXP_ADC_CMDH_AVGS_MASK, 7) |
 		   FIELD_PREP(IMX8QXP_ADC_CMDH_STS_MASK, 0) |
 		   FIELD_PREP(IMX8QXP_ADC_CMDH_LWI_MASK, IMX8QXP_ADC_CMDH_LWI_INCREMENT_DIS) |
 		   FIELD_PREP(IMX8QXP_ADC_CMDH_CMPEN_MASK, IMX8QXP_ADC_CMDH_CMPEN_DIS);
 	writel(adc_cmdh, adc->regs + IMX8QXP_ADR_ADC_CMDH(0));
 }

 static void imx8qxp_adc_fifo_config(struct imx8qxp_adc *adc)
 {
 	u32 fifo_ctrl, interrupt_en;

 	fifo_ctrl = readl(adc->regs + IMX8QXP_ADR_ADC_FCTRL);
 	fifo_ctrl &= ~IMX8QXP_ADC_FCTRL_FWMARK_MASK;
 	/* set the watermark level to 1 */
 	fifo_ctrl |= FIELD_PREP(IMX8QXP_ADC_FCTRL_FWMARK_MASK, 0);
 	writel(fifo_ctrl, adc->regs + IMX8QXP_ADR_ADC_FCTRL);

 	/* FIFO Watermark Interrupt Enable */
 	interrupt_en = readl(adc->regs + IMX8QXP_ADR_ADC_IE);
 	interrupt_en |= FIELD_PREP(IMX8QXP_ADC_IE_FWMIE_MASK, 1);
 	writel(interrupt_en, adc->regs + IMX8QXP_ADR_ADC_IE);
 }

 static void imx8qxp_adc_disable(struct imx8qxp_adc *adc)
 {
 	u32 ctrl;

 	ctrl = readl(adc->regs + IMX8QXP_ADR_ADC_CTRL);
 	ctrl &= ~FIELD_PREP(IMX8QXP_ADC_CTRL_ADC_EN_MASK, 1);
 	writel(ctrl, adc->regs + IMX8QXP_ADR_ADC_CTRL);
 }

 static int imx8qxp_adc_read_raw(struct iio_dev *indio_dev,
 				struct iio_chan_spec const *chan,
 				int *val, int *val2, long mask)
 {
 	struct imx8qxp_adc *adc = iio_priv(indio_dev);
 	struct device *dev = adc->dev;

 	u32 ctrl, vref_uv;
 	long ret;

 	switch (mask) {
 	case IIO_CHAN_INFO_RAW:
 		pm_runtime_get_sync(dev);

 		mutex_lock(&adc->lock);
 		reinit_completion(&adc->completion);

 		imx8qxp_adc_reg_config(adc, chan->channel);

 		imx8qxp_adc_fifo_config(adc);

 		/* adc enable */
 		ctrl = readl(adc->regs + IMX8QXP_ADR_ADC_CTRL);
 		ctrl |= FIELD_PREP(IMX8QXP_ADC_CTRL_ADC_EN_MASK, 1);
 		writel(ctrl, adc->regs + IMX8QXP_ADR_ADC_CTRL);
 		/* adc start */
 		writel(1, adc->regs + IMX8QXP_ADR_ADC_SWTRIG);

 		ret = wait_for_completion_interruptible_timeout(&adc->completion,
 								IMX8QXP_ADC_TIMEOUT);

 		pm_runtime_mark_last_busy(dev);
 		pm_runtime_put_sync_autosuspend(dev);

 		if (ret == 0) {
 			mutex_unlock(&adc->lock);
 			return -ETIMEDOUT;
 		}
 		if (ret < 0) {
 			mutex_unlock(&adc->lock);
 			return ret;
 		}

 		*val = FIELD_GET(IMX8QXP_ADC_RESFIFO_VAL_MASK,
 				 readl(adc->regs + IMX8QXP_ADR_ADC_RESFIFO));

 		mutex_unlock(&adc->lock);
 		return IIO_VAL_INT;

 	case IIO_CHAN_INFO_SCALE:
 		vref_uv = regulator_get_voltage(adc->vref);
 		*val = vref_uv / 1000;
 		*val2 = 12;
 		return IIO_VAL_FRACTIONAL_LOG2;

 	case IIO_CHAN_INFO_SAMP_FREQ:
 		*val = clk_get_rate(adc->clk) / 3;
 		return IIO_VAL_INT;

 	default:
 		return -EINVAL;
 	}
 }

 static irqreturn_t imx8qxp_adc_isr(int irq, void *dev_id)
 {
 	struct imx8qxp_adc *adc = dev_id;
 	u32 fifo_count;

 	fifo_count = FIELD_GET(IMX8QXP_ADC_FCTRL_FCOUNT_MASK,
 			       readl(adc->regs + IMX8QXP_ADR_ADC_FCTRL));

 	if (fifo_count)
 		complete(&adc->completion);

 	return IRQ_HANDLED;
 }

 static int imx8qxp_adc_reg_access(struct iio_dev *indio_dev, unsigned int reg,
 				  unsigned int writeval, unsigned int *readval)
 {
 	struct imx8qxp_adc *adc = iio_priv(indio_dev);
 	struct device *dev = adc->dev;

 	if (!readval || reg % 4 || reg > IMX8QXP_ADR_ADC_TST)
 		return -EINVAL;

 	pm_runtime_get_sync(dev);

 	*readval = readl(adc->regs + reg);

 	pm_runtime_mark_last_busy(dev);
 	pm_runtime_put_sync_autosuspend(dev);

 	return 0;
 }

 static const struct iio_info imx8qxp_adc_iio_info = {
 	.read_raw = &imx8qxp_adc_read_raw,
 	.debugfs_reg_access = &imx8qxp_adc_reg_access,
 };

 static int imx8qxp_adc_probe(struct platform_device *pdev)
 {
 	struct imx8qxp_adc *adc;
 	struct iio_dev *indio_dev;
 	struct device *dev = &pdev->dev;
 	int irq;
 	int ret;

 	indio_dev = devm_iio_device_alloc(dev, sizeof(*adc));
 	if (!indio_dev) {
 		dev_err(dev, "Failed allocating iio device\n");
 		return -ENOMEM;
 	}

 	adc = iio_priv(indio_dev);
 	adc->dev = dev;

 	mutex_init(&adc->lock);
 	adc->regs = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(adc->regs))
 		return PTR_ERR(adc->regs);

 	irq = platform_get_irq(pdev, 0);
 	if (irq < 0)
 		return irq;

 	adc->clk = devm_clk_get(dev, "per");
 	if (IS_ERR(adc->clk))
 		return dev_err_probe(dev, PTR_ERR(adc->clk), "Failed getting clock\n");

 	adc->ipg_clk = devm_clk_get(dev, "ipg");
 	if (IS_ERR(adc->ipg_clk))
 		return dev_err_probe(dev, PTR_ERR(adc->ipg_clk), "Failed getting clock\n");

 	adc->vref = devm_regulator_get(dev, "vref");
 	if (IS_ERR(adc->vref))
 		return dev_err_probe(dev, PTR_ERR(adc->vref), "Failed getting reference voltage\n");

 	ret = regulator_enable(adc->vref);
 	if (ret) {
 		dev_err(dev, "Can't enable adc reference top voltage\n");
 		return ret;
 	}

 	platform_set_drvdata(pdev, indio_dev);

 	init_completion(&adc->completion);

 	indio_dev->name = ADC_DRIVER_NAME;
 	indio_dev->info = &imx8qxp_adc_iio_info;
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->channels = imx8qxp_adc_iio_channels;
 	indio_dev->num_channels = ARRAY_SIZE(imx8qxp_adc_iio_channels);

 	ret = clk_prepare_enable(adc->clk);
 	if (ret) {
 		dev_err(&pdev->dev, "Could not prepare or enable the clock.\n");
 		goto error_regulator_disable;
 	}

 	ret = clk_prepare_enable(adc->ipg_clk);
 	if (ret) {
 		dev_err(&pdev->dev, "Could not prepare or enable the clock.\n");
 		goto error_adc_clk_disable;
 	}

 	ret = devm_request_irq(dev, irq, imx8qxp_adc_isr, 0, ADC_DRIVER_NAME, adc);
 	if (ret < 0) {
 		dev_err(dev, "Failed requesting irq, irq = %d\n", irq);
 		goto error_ipg_clk_disable;
 	}

 	imx8qxp_adc_reset(adc);

 	ret = iio_device_register(indio_dev);
 	if (ret) {
 		imx8qxp_adc_disable(adc);
 		dev_err(dev, "Couldn't register the device.\n");
 		goto error_ipg_clk_disable;
 	}

 	pm_runtime_set_active(dev);
 	pm_runtime_set_autosuspend_delay(dev, 50);
 	pm_runtime_use_autosuspend(dev);
 	pm_runtime_enable(dev);

 	return 0;

 error_ipg_clk_disable:
 	clk_disable_unprepare(adc->ipg_clk);
 error_adc_clk_disable:
 	clk_disable_unprepare(adc->clk);
 error_regulator_disable:
 	regulator_disable(adc->vref);

 	return ret;
 }

 static int imx8qxp_adc_remove(struct platform_device *pdev)
 {
 	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
 	struct imx8qxp_adc *adc = iio_priv(indio_dev);
 	struct device *dev = adc->dev;

 	pm_runtime_get_sync(dev);

 	iio_device_unregister(indio_dev);

 	imx8qxp_adc_disable(adc);

 	clk_disable_unprepare(adc->clk);
 	clk_disable_unprepare(adc->ipg_clk);
 	regulator_disable(adc->vref);

 	pm_runtime_disable(dev);
 	pm_runtime_put_noidle(dev);

 	return 0;
 }

 static int imx8qxp_adc_runtime_suspend(struct device *dev)
 {
 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
 	struct imx8qxp_adc *adc = iio_priv(indio_dev);

 	imx8qxp_adc_disable(adc);

 	clk_disable_unprepare(adc->clk);
 	clk_disable_unprepare(adc->ipg_clk);
 	regulator_disable(adc->vref);

 	return 0;
 }

 static int imx8qxp_adc_runtime_resume(struct device *dev)
 {
 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
 	struct imx8qxp_adc *adc = iio_priv(indio_dev);
 	int ret;

 	ret = regulator_enable(adc->vref);
 	if (ret) {
 		dev_err(dev, "Can't enable adc reference top voltage, err = %d\n", ret);
 		return ret;
 	}

 	ret = clk_prepare_enable(adc->clk);
 	if (ret) {
 		dev_err(dev, "Could not prepare or enable clock.\n");
 		goto err_disable_reg;
 	}

 	ret = clk_prepare_enable(adc->ipg_clk);
 	if (ret) {
 		dev_err(dev, "Could not prepare or enable clock.\n");
 		goto err_unprepare_clk;
 	}

 	imx8qxp_adc_reset(adc);

 	return 0;

 err_unprepare_clk:
 	clk_disable_unprepare(adc->clk);

 err_disable_reg:
 	regulator_disable(adc->vref);

 	return ret;
 }

 static DEFINE_RUNTIME_DEV_PM_OPS(imx8qxp_adc_pm_ops,
 				 imx8qxp_adc_runtime_suspend,
 				 imx8qxp_adc_runtime_resume, NULL);

 static const struct of_device_id imx8qxp_adc_match[] = {
 	{ .compatible = "nxp,imx8qxp-adc", },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, imx8qxp_adc_match);

 static struct platform_driver imx8qxp_adc_driver = {
 	.probe		= imx8qxp_adc_probe,
 	.remove		= imx8qxp_adc_remove,
 	.driver		= {
 		.name	= ADC_DRIVER_NAME,
 		.of_match_table = imx8qxp_adc_match,
 		.pm	= pm_ptr(&imx8qxp_adc_pm_ops),
 	},
 };

 module_platform_driver(imx8qxp_adc_driver);

 MODULE_DESCRIPTION("i.MX8QuadXPlus ADC driver");
 MODULE_LICENSE("GPL v2");
	// SPDX-License-Identifier: GPL-2.0+
	/*
	* NXP i.MX8QXP ADC driver
	*
	* Based on the work of Haibo Chen <haibo.chen@nxp.com>
	* The initial developer of the original code is Haibo Chen.
	* Portions created by Haibo Chen are Copyright (C) 2018 NXP.
	* All Rights Reserved.
	*
	* Copyright (C) 2018 NXP
	* Copyright (C) 2021 Cai Huoqing
	*/
	#include <linux/bitfield.h>
	#include <linux/bits.h>
	#include <linux/clk.h>
	#include <linux/completion.h>
	#include <linux/delay.h>
	#include <linux/err.h>
	#include <linux/interrupt.h>
	#include <linux/io.h>
	#include <linux/kernel.h>
	#include <linux/mod_devicetable.h>
	#include <linux/module.h>
	#include <linux/platform_device.h>
	#include <linux/pm_runtime.h>
	#include <linux/regulator/consumer.h>

	#include <linux/iio/iio.h>

	#define ADC_DRIVER_NAME "imx8qxp-adc"

	/* Register map definition */
	#define IMX8QXP_ADR_ADC_CTRL 0x10
	#define IMX8QXP_ADR_ADC_STAT 0x14
	#define IMX8QXP_ADR_ADC_IE 0x18
	#define IMX8QXP_ADR_ADC_DE 0x1c
	#define IMX8QXP_ADR_ADC_CFG 0x20
	#define IMX8QXP_ADR_ADC_FCTRL 0x30
	#define IMX8QXP_ADR_ADC_SWTRIG 0x34
	#define IMX8QXP_ADR_ADC_TCTRL(tid) (0xc0 + (tid) * 4)
	#define IMX8QXP_ADR_ADC_CMDH(cid) (0x100 + (cid) * 8)
	#define IMX8QXP_ADR_ADC_CMDL(cid) (0x104 + (cid) * 8)
	#define IMX8QXP_ADR_ADC_RESFIFO 0x300
	#define IMX8QXP_ADR_ADC_TST 0xffc

	/* ADC bit shift */
	#define IMX8QXP_ADC_IE_FWMIE_MASK GENMASK(1, 0)
	#define IMX8QXP_ADC_CTRL_FIFO_RESET_MASK BIT(8)
	#define IMX8QXP_ADC_CTRL_SOFTWARE_RESET_MASK BIT(1)
	#define IMX8QXP_ADC_CTRL_ADC_EN_MASK BIT(0)
	#define IMX8QXP_ADC_TCTRL_TCMD_MASK GENMASK(31, 24)
	#define IMX8QXP_ADC_TCTRL_TDLY_MASK GENMASK(23, 16)
	#define IMX8QXP_ADC_TCTRL_TPRI_MASK GENMASK(15, 8)
	#define IMX8QXP_ADC_TCTRL_HTEN_MASK GENMASK(7, 0)
	#define IMX8QXP_ADC_CMDL_CSCALE_MASK GENMASK(13, 8)
	#define IMX8QXP_ADC_CMDL_MODE_MASK BIT(7)
	#define IMX8QXP_ADC_CMDL_DIFF_MASK BIT(6)
	#define IMX8QXP_ADC_CMDL_ABSEL_MASK BIT(5)
	#define IMX8QXP_ADC_CMDL_ADCH_MASK GENMASK(2, 0)
	#define IMX8QXP_ADC_CMDH_NEXT_MASK GENMASK(31, 24)
	#define IMX8QXP_ADC_CMDH_LOOP_MASK GENMASK(23, 16)
	#define IMX8QXP_ADC_CMDH_AVGS_MASK GENMASK(15, 12)
	#define IMX8QXP_ADC_CMDH_STS_MASK BIT(8)
	#define IMX8QXP_ADC_CMDH_LWI_MASK GENMASK(7, 7)
	#define IMX8QXP_ADC_CMDH_CMPEN_MASK GENMASK(0, 0)
	#define IMX8QXP_ADC_CFG_PWREN_MASK BIT(28)
	#define IMX8QXP_ADC_CFG_PUDLY_MASK GENMASK(23, 16)
	#define IMX8QXP_ADC_CFG_REFSEL_MASK GENMASK(7, 6)
	#define IMX8QXP_ADC_CFG_PWRSEL_MASK GENMASK(5, 4)
	#define IMX8QXP_ADC_CFG_TPRICTRL_MASK GENMASK(3, 0)
	#define IMX8QXP_ADC_FCTRL_FWMARK_MASK GENMASK(20, 16)
	#define IMX8QXP_ADC_FCTRL_FCOUNT_MASK GENMASK(4, 0)
	#define IMX8QXP_ADC_RESFIFO_VAL_MASK GENMASK(18, 3)

	/* ADC PARAMETER*/
	#define IMX8QXP_ADC_CMDL_CHANNEL_SCALE_FULL GENMASK(5, 0)
	#define IMX8QXP_ADC_CMDL_SEL_A_A_B_CHANNEL 0
	#define IMX8QXP_ADC_CMDL_STANDARD_RESOLUTION 0
	#define IMX8QXP_ADC_CMDL_MODE_SINGLE 0
	#define IMX8QXP_ADC_CMDH_LWI_INCREMENT_DIS 0
	#define IMX8QXP_ADC_CMDH_CMPEN_DIS 0
	#define IMX8QXP_ADC_PAUSE_EN BIT(31)
	#define IMX8QXP_ADC_TCTRL_TPRI_PRIORITY_HIGH 0

	#define IMX8QXP_ADC_TCTRL_HTEN_HW_TIRG_DIS 0

	#define IMX8QXP_ADC_TIMEOUT msecs_to_jiffies(100)

	struct imx8qxp_adc {
	struct device *dev;
	void __iomem *regs;
	struct clk *clk;
	struct clk *ipg_clk;
	struct regulator *vref;
	/* Serialise ADC channel reads */
	struct mutex lock;
	struct completion completion;
	};

	#define IMX8QXP_ADC_CHAN(_idx) { \
	.type = IIO_VOLTAGE, \
	.indexed = 1, \
	.channel = (_idx), \
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \| \
	BIT(IIO_CHAN_INFO_SAMP_FREQ), \
	}

	static const struct iio_chan_spec imx8qxp_adc_iio_channels[] = {
	IMX8QXP_ADC_CHAN(0),
	IMX8QXP_ADC_CHAN(1),
	IMX8QXP_ADC_CHAN(2),
	IMX8QXP_ADC_CHAN(3),
	IMX8QXP_ADC_CHAN(4),
	IMX8QXP_ADC_CHAN(5),
	IMX8QXP_ADC_CHAN(6),
	IMX8QXP_ADC_CHAN(7),
	};

	static void imx8qxp_adc_reset(struct imx8qxp_adc *adc)
	{
	u32 ctrl;

	/software reset, need to clear the set bit/
	ctrl = readl(adc->regs + IMX8QXP_ADR_ADC_CTRL);
	ctrl \|= FIELD_PREP(IMX8QXP_ADC_CTRL_SOFTWARE_RESET_MASK, 1);
	writel(ctrl, adc->regs + IMX8QXP_ADR_ADC_CTRL);
	udelay(10);
	ctrl &= ~FIELD_PREP(IMX8QXP_ADC_CTRL_SOFTWARE_RESET_MASK, 1);
	writel(ctrl, adc->regs + IMX8QXP_ADR_ADC_CTRL);

	/* reset the fifo */
	ctrl \|= FIELD_PREP(IMX8QXP_ADC_CTRL_FIFO_RESET_MASK, 1);
	writel(ctrl, adc->regs + IMX8QXP_ADR_ADC_CTRL);
	}

	static void imx8qxp_adc_reg_config(struct imx8qxp_adc *adc, int channel)
	{
	u32 adc_cfg, adc_tctrl, adc_cmdl, adc_cmdh;

	/* ADC configuration */
	adc_cfg = FIELD_PREP(IMX8QXP_ADC_CFG_PWREN_MASK, 1) \|
	FIELD_PREP(IMX8QXP_ADC_CFG_PUDLY_MASK, 0x80)\|
	FIELD_PREP(IMX8QXP_ADC_CFG_REFSEL_MASK, 0) \|
	FIELD_PREP(IMX8QXP_ADC_CFG_PWRSEL_MASK, 3) \|
	FIELD_PREP(IMX8QXP_ADC_CFG_TPRICTRL_MASK, 0);
	writel(adc_cfg, adc->regs + IMX8QXP_ADR_ADC_CFG);

	/* config the trigger control */
	adc_tctrl = FIELD_PREP(IMX8QXP_ADC_TCTRL_TCMD_MASK, 1) \|
	FIELD_PREP(IMX8QXP_ADC_TCTRL_TDLY_MASK, 0) \|
	FIELD_PREP(IMX8QXP_ADC_TCTRL_TPRI_MASK, IMX8QXP_ADC_TCTRL_TPRI_PRIORITY_HIGH) \|
	FIELD_PREP(IMX8QXP_ADC_TCTRL_HTEN_MASK, IMX8QXP_ADC_TCTRL_HTEN_HW_TIRG_DIS);
	writel(adc_tctrl, adc->regs + IMX8QXP_ADR_ADC_TCTRL(0));

	/* config the cmd */
	adc_cmdl = FIELD_PREP(IMX8QXP_ADC_CMDL_CSCALE_MASK, IMX8QXP_ADC_CMDL_CHANNEL_SCALE_FULL) \|
	FIELD_PREP(IMX8QXP_ADC_CMDL_MODE_MASK, IMX8QXP_ADC_CMDL_STANDARD_RESOLUTION) \|
	FIELD_PREP(IMX8QXP_ADC_CMDL_DIFF_MASK, IMX8QXP_ADC_CMDL_MODE_SINGLE) \|
	FIELD_PREP(IMX8QXP_ADC_CMDL_ABSEL_MASK, IMX8QXP_ADC_CMDL_SEL_A_A_B_CHANNEL) \|
	FIELD_PREP(IMX8QXP_ADC_CMDL_ADCH_MASK, channel);
	writel(adc_cmdl, adc->regs + IMX8QXP_ADR_ADC_CMDL(0));

	adc_cmdh = FIELD_PREP(IMX8QXP_ADC_CMDH_NEXT_MASK, 0) \|
	FIELD_PREP(IMX8QXP_ADC_CMDH_LOOP_MASK, 0) \|
	FIELD_PREP(IMX8QXP_ADC_CMDH_AVGS_MASK, 7) \|
	FIELD_PREP(IMX8QXP_ADC_CMDH_STS_MASK, 0) \|
	FIELD_PREP(IMX8QXP_ADC_CMDH_LWI_MASK, IMX8QXP_ADC_CMDH_LWI_INCREMENT_DIS) \|
	FIELD_PREP(IMX8QXP_ADC_CMDH_CMPEN_MASK, IMX8QXP_ADC_CMDH_CMPEN_DIS);
	writel(adc_cmdh, adc->regs + IMX8QXP_ADR_ADC_CMDH(0));
	}

	static void imx8qxp_adc_fifo_config(struct imx8qxp_adc *adc)
	{
	u32 fifo_ctrl, interrupt_en;

	fifo_ctrl = readl(adc->regs + IMX8QXP_ADR_ADC_FCTRL);
	fifo_ctrl &= ~IMX8QXP_ADC_FCTRL_FWMARK_MASK;
	/* set the watermark level to 1 */
	fifo_ctrl \|= FIELD_PREP(IMX8QXP_ADC_FCTRL_FWMARK_MASK, 0);
	writel(fifo_ctrl, adc->regs + IMX8QXP_ADR_ADC_FCTRL);

	/* FIFO Watermark Interrupt Enable */
	interrupt_en = readl(adc->regs + IMX8QXP_ADR_ADC_IE);
	interrupt_en \|= FIELD_PREP(IMX8QXP_ADC_IE_FWMIE_MASK, 1);
	writel(interrupt_en, adc->regs + IMX8QXP_ADR_ADC_IE);
	}

	static void imx8qxp_adc_disable(struct imx8qxp_adc *adc)
	{
	u32 ctrl;

	ctrl = readl(adc->regs + IMX8QXP_ADR_ADC_CTRL);
	ctrl &= ~FIELD_PREP(IMX8QXP_ADC_CTRL_ADC_EN_MASK, 1);
	writel(ctrl, adc->regs + IMX8QXP_ADR_ADC_CTRL);
	}

	static int imx8qxp_adc_read_raw(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan,
	int val, int val2, long mask)
	{
	struct imx8qxp_adc *adc = iio_priv(indio_dev);
	struct device *dev = adc->dev;

	u32 ctrl, vref_uv;
	long ret;

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
	pm_runtime_get_sync(dev);

	mutex_lock(&adc->lock);
	reinit_completion(&adc->completion);

	imx8qxp_adc_reg_config(adc, chan->channel);

	imx8qxp_adc_fifo_config(adc);

	/* adc enable */
	ctrl = readl(adc->regs + IMX8QXP_ADR_ADC_CTRL);
	ctrl \|= FIELD_PREP(IMX8QXP_ADC_CTRL_ADC_EN_MASK, 1);
	writel(ctrl, adc->regs + IMX8QXP_ADR_ADC_CTRL);
	/* adc start */
	writel(1, adc->regs + IMX8QXP_ADR_ADC_SWTRIG);

	ret = wait_for_completion_interruptible_timeout(&adc->completion,
	IMX8QXP_ADC_TIMEOUT);

	pm_runtime_mark_last_busy(dev);
	pm_runtime_put_sync_autosuspend(dev);

	if (ret == 0) {
	mutex_unlock(&adc->lock);
	return -ETIMEDOUT;
	}
	if (ret < 0) {
	mutex_unlock(&adc->lock);
	return ret;
	}

	*val = FIELD_GET(IMX8QXP_ADC_RESFIFO_VAL_MASK,
	readl(adc->regs + IMX8QXP_ADR_ADC_RESFIFO));

	mutex_unlock(&adc->lock);
	return IIO_VAL_INT;

	case IIO_CHAN_INFO_SCALE:
	vref_uv = regulator_get_voltage(adc->vref);
	*val = vref_uv / 1000;
	*val2 = 12;
	return IIO_VAL_FRACTIONAL_LOG2;

	case IIO_CHAN_INFO_SAMP_FREQ:
	*val = clk_get_rate(adc->clk) / 3;
	return IIO_VAL_INT;

	default:
	return -EINVAL;
	}
	}

	static irqreturn_t imx8qxp_adc_isr(int irq, void *dev_id)
	{
	struct imx8qxp_adc *adc = dev_id;
	u32 fifo_count;

	fifo_count = FIELD_GET(IMX8QXP_ADC_FCTRL_FCOUNT_MASK,
	readl(adc->regs + IMX8QXP_ADR_ADC_FCTRL));

	if (fifo_count)
	complete(&adc->completion);

	return IRQ_HANDLED;
	}

	static int imx8qxp_adc_reg_access(struct iio_dev *indio_dev, unsigned int reg,
	unsigned int writeval, unsigned int *readval)
	{
	struct imx8qxp_adc *adc = iio_priv(indio_dev);
	struct device *dev = adc->dev;

	if (!readval \|\| reg % 4 \|\| reg > IMX8QXP_ADR_ADC_TST)
	return -EINVAL;

	pm_runtime_get_sync(dev);

	*readval = readl(adc->regs + reg);

	pm_runtime_mark_last_busy(dev);
	pm_runtime_put_sync_autosuspend(dev);

	return 0;
	}

	static const struct iio_info imx8qxp_adc_iio_info = {
	.read_raw = &imx8qxp_adc_read_raw,
	.debugfs_reg_access = &imx8qxp_adc_reg_access,
	};

	static int imx8qxp_adc_probe(struct platform_device *pdev)
	{
	struct imx8qxp_adc *adc;
	struct iio_dev *indio_dev;
	struct device *dev = &pdev->dev;
	int irq;
	int ret;

	indio_dev = devm_iio_device_alloc(dev, sizeof(*adc));
	if (!indio_dev) {
	dev_err(dev, "Failed allocating iio device\n");
	return -ENOMEM;
	}

	adc = iio_priv(indio_dev);
	adc->dev = dev;

	mutex_init(&adc->lock);
	adc->regs = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(adc->regs))
	return PTR_ERR(adc->regs);

	irq = platform_get_irq(pdev, 0);
	if (irq < 0)
	return irq;

	adc->clk = devm_clk_get(dev, "per");
	if (IS_ERR(adc->clk))
	return dev_err_probe(dev, PTR_ERR(adc->clk), "Failed getting clock\n");

	adc->ipg_clk = devm_clk_get(dev, "ipg");
	if (IS_ERR(adc->ipg_clk))
	return dev_err_probe(dev, PTR_ERR(adc->ipg_clk), "Failed getting clock\n");

	adc->vref = devm_regulator_get(dev, "vref");
	if (IS_ERR(adc->vref))
	return dev_err_probe(dev, PTR_ERR(adc->vref), "Failed getting reference voltage\n");

	ret = regulator_enable(adc->vref);
	if (ret) {
	dev_err(dev, "Can't enable adc reference top voltage\n");
	return ret;
	}

	platform_set_drvdata(pdev, indio_dev);

	init_completion(&adc->completion);

	indio_dev->name = ADC_DRIVER_NAME;
	indio_dev->info = &imx8qxp_adc_iio_info;
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->channels = imx8qxp_adc_iio_channels;
	indio_dev->num_channels = ARRAY_SIZE(imx8qxp_adc_iio_channels);

	ret = clk_prepare_enable(adc->clk);
	if (ret) {
	dev_err(&pdev->dev, "Could not prepare or enable the clock.\n");
	goto error_regulator_disable;
	}

	ret = clk_prepare_enable(adc->ipg_clk);
	if (ret) {
	dev_err(&pdev->dev, "Could not prepare or enable the clock.\n");
	goto error_adc_clk_disable;
	}

	ret = devm_request_irq(dev, irq, imx8qxp_adc_isr, 0, ADC_DRIVER_NAME, adc);
	if (ret < 0) {
	dev_err(dev, "Failed requesting irq, irq = %d\n", irq);
	goto error_ipg_clk_disable;
	}

	imx8qxp_adc_reset(adc);

	ret = iio_device_register(indio_dev);
	if (ret) {
	imx8qxp_adc_disable(adc);
	dev_err(dev, "Couldn't register the device.\n");
	goto error_ipg_clk_disable;
	}

	pm_runtime_set_active(dev);
	pm_runtime_set_autosuspend_delay(dev, 50);
	pm_runtime_use_autosuspend(dev);
	pm_runtime_enable(dev);

	return 0;

	error_ipg_clk_disable:
	clk_disable_unprepare(adc->ipg_clk);
	error_adc_clk_disable:
	clk_disable_unprepare(adc->clk);
	error_regulator_disable:
	regulator_disable(adc->vref);

	return ret;
	}

	static int imx8qxp_adc_remove(struct platform_device *pdev)
	{
	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
	struct imx8qxp_adc *adc = iio_priv(indio_dev);
	struct device *dev = adc->dev;

	pm_runtime_get_sync(dev);

	iio_device_unregister(indio_dev);

	imx8qxp_adc_disable(adc);

	clk_disable_unprepare(adc->clk);
	clk_disable_unprepare(adc->ipg_clk);
	regulator_disable(adc->vref);

	pm_runtime_disable(dev);
	pm_runtime_put_noidle(dev);

	return 0;
	}

	static int imx8qxp_adc_runtime_suspend(struct device *dev)
	{
	struct iio_dev *indio_dev = dev_get_drvdata(dev);
	struct imx8qxp_adc *adc = iio_priv(indio_dev);

	imx8qxp_adc_disable(adc);

	clk_disable_unprepare(adc->clk);
	clk_disable_unprepare(adc->ipg_clk);
	regulator_disable(adc->vref);

	return 0;
	}

	static int imx8qxp_adc_runtime_resume(struct device *dev)
	{
	struct iio_dev *indio_dev = dev_get_drvdata(dev);
	struct imx8qxp_adc *adc = iio_priv(indio_dev);
	int ret;

	ret = regulator_enable(adc->vref);
	if (ret) {
	dev_err(dev, "Can't enable adc reference top voltage, err = %d\n", ret);
	return ret;
	}

	ret = clk_prepare_enable(adc->clk);
	if (ret) {
	dev_err(dev, "Could not prepare or enable clock.\n");
	goto err_disable_reg;
	}

	ret = clk_prepare_enable(adc->ipg_clk);
	if (ret) {
	dev_err(dev, "Could not prepare or enable clock.\n");
	goto err_unprepare_clk;
	}

	imx8qxp_adc_reset(adc);

	return 0;

	err_unprepare_clk:
	clk_disable_unprepare(adc->clk);

	err_disable_reg:
	regulator_disable(adc->vref);

	return ret;
	}

	static DEFINE_RUNTIME_DEV_PM_OPS(imx8qxp_adc_pm_ops,
	imx8qxp_adc_runtime_suspend,
	imx8qxp_adc_runtime_resume, NULL);

	static const struct of_device_id imx8qxp_adc_match[] = {
	{ .compatible = "nxp,imx8qxp-adc", },
	{ /* sentinel */ }
	};
	MODULE_DEVICE_TABLE(of, imx8qxp_adc_match);

	static struct platform_driver imx8qxp_adc_driver = {
	.probe = imx8qxp_adc_probe,
	.remove = imx8qxp_adc_remove,
	.driver = {
	.name = ADC_DRIVER_NAME,
	.of_match_table = imx8qxp_adc_match,
	.pm = pm_ptr(&imx8qxp_adc_pm_ops),
	},
	};

	module_platform_driver(imx8qxp_adc_driver);

	MODULE_DESCRIPTION("i.MX8QuadXPlus ADC driver");
	MODULE_LICENSE("GPL v2");