1 files changed, 88 insertions, 135 deletions

diff --git a/drivers/iio/adc/imx7d_adc.c b/drivers/iio/adc/imx7d_adc.c
index ad6764fb2a23..039c0387da23 100644
--- a/drivers/iio/adc/imx7d_adc.c
+++ b/drivers/iio/adc/imx7d_adc.c
@@ -1,12 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Freescale i.MX7D ADC driver
  *
  * Copyright (C) 2015 Freescale Semiconductor, Inc.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
  */
 
 #include <linux/clk.h>
@@ -15,7 +11,9 @@
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
+#include <linux/mod_devicetable.h>
 #include <linux/module.h>
+#include <linux/mutex.h>
 #include <linux/platform_device.h>
 #include <linux/regulator/consumer.h>
 
@@ -82,6 +80,7 @@
 #define IMX7D_REG_ADC_INT_STATUS_CHANNEL_CONV_TIME_OUT		0xf0000
 
 #define IMX7D_ADC_TIMEOUT		msecs_to_jiffies(100)
+#define IMX7D_ADC_INPUT_CLK		24000000
 
 enum imx7d_adc_clk_pre_div {
 	IMX7D_ADC_ANALOG_CLK_PRE_DIV_4,
@@ -104,15 +103,14 @@ struct imx7d_adc_feature {
 	enum imx7d_adc_average_num avg_num;
 
 	u32 core_time_unit;	/* impact the sample rate */
-
-	bool average_en;
 };
 
 struct imx7d_adc {
 	struct device *dev;
 	void __iomem *regs;
 	struct clk *clk;
-
+	/* lock to protect against multiple access to the device */
+	struct mutex lock;
 	u32 vref_uv;
 	u32 value;
 	u32 channel;
@@ -183,7 +181,6 @@ static void imx7d_adc_feature_config(struct imx7d_adc *info)
 	info->adc_feature.clk_pre_div = IMX7D_ADC_ANALOG_CLK_PRE_DIV_4;
 	info->adc_feature.avg_num = IMX7D_ADC_AVERAGE_NUM_32;
 	info->adc_feature.core_time_unit = 1;
-	info->adc_feature.average_en = true;
 }
 
 static void imx7d_adc_sample_rate_set(struct imx7d_adc *info)
@@ -244,9 +241,8 @@ static void imx7d_adc_channel_set(struct imx7d_adc *info)
 
 	/* the channel choose single conversion, and enable average mode */
 	cfg1 |= (IMX7D_REG_ADC_CH_CFG1_CHANNEL_EN |
-		 IMX7D_REG_ADC_CH_CFG1_CHANNEL_SINGLE);
-	if (info->adc_feature.average_en)
-		cfg1 |= IMX7D_REG_ADC_CH_CFG1_CHANNEL_AVG_EN;
+		 IMX7D_REG_ADC_CH_CFG1_CHANNEL_SINGLE |
+		 IMX7D_REG_ADC_CH_CFG1_CHANNEL_AVG_EN);
 
 	/*
 	 * physical channel 0 chose logical channel A
@@ -276,13 +272,11 @@ static void imx7d_adc_channel_set(struct imx7d_adc *info)
 
 static u32 imx7d_adc_get_sample_rate(struct imx7d_adc *info)
 {
-	/* input clock is always 24MHz */
-	u32 input_clk = 24000000;
 	u32 analogue_core_clk;
 	u32 core_time_unit = info->adc_feature.core_time_unit;
 	u32 tmp;
 
-	analogue_core_clk = input_clk / info->pre_div_num;
+	analogue_core_clk = IMX7D_ADC_INPUT_CLK / info->pre_div_num;
 	tmp = (core_time_unit + 1) * 6;
 
 	return analogue_core_clk / tmp;
@@ -301,7 +295,7 @@ static int imx7d_adc_read_raw(struct iio_dev *indio_dev,
 
 	switch (mask) {
 	case IIO_CHAN_INFO_RAW:
-		mutex_lock(&indio_dev->mlock);
+		mutex_lock(&info->lock);
 		reinit_completion(&info->completion);
 
 		channel = chan->channel & 0x03;
@@ -311,16 +305,16 @@ static int imx7d_adc_read_raw(struct iio_dev *indio_dev,
 		ret = wait_for_completion_interruptible_timeout
 				(&info->completion, IMX7D_ADC_TIMEOUT);
 		if (ret == 0) {
-			mutex_unlock(&indio_dev->mlock);
+			mutex_unlock(&info->lock);
 			return -ETIMEDOUT;
 		}
 		if (ret < 0) {
-			mutex_unlock(&indio_dev->mlock);
+			mutex_unlock(&info->lock);
 			return ret;
 		}
 
 		*val = info->value;
-		mutex_unlock(&indio_dev->mlock);
+		mutex_unlock(&info->lock);
 		return IIO_VAL_INT;
 
 	case IIO_CHAN_INFO_SCALE:
@@ -388,8 +382,9 @@ static irqreturn_t imx7d_adc_isr(int irq, void *dev_id)
 	 * timeout flags.
 	 */
 	if (status & IMX7D_REG_ADC_INT_STATUS_CHANNEL_CONV_TIME_OUT) {
-		pr_err("%s: ADC got conversion time out interrupt: 0x%08x\n",
-			dev_name(info->dev), status);
+		dev_err(info->dev,
+			"ADC got conversion time out interrupt: 0x%08x\n",
+			status);
 		status &= ~IMX7D_REG_ADC_INT_STATUS_CHANNEL_CONV_TIME_OUT;
 		writel(status, info->regs + IMX7D_REG_ADC_INT_STATUS);
 	}
@@ -418,7 +413,7 @@ static const struct iio_info imx7d_adc_iio_info = {
 
 static const struct of_device_id imx7d_adc_match[] = {
 	{ .compatible = "fsl,imx7d-adc", },
-	{ /* sentinel */ }
+	{ }
 };
 MODULE_DEVICE_TABLE(of, imx7d_adc_match);
 
@@ -433,114 +428,38 @@ static void imx7d_adc_power_down(struct imx7d_adc *info)
 	writel(adc_cfg, info->regs + IMX7D_REG_ADC_ADC_CFG);
 }
 
-static int imx7d_adc_probe(struct platform_device *pdev)
+static int imx7d_adc_enable(struct device *dev)
 {
-	struct imx7d_adc *info;
-	struct iio_dev *indio_dev;
-	struct resource *mem;
-	int irq;
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct imx7d_adc *info = iio_priv(indio_dev);
 	int ret;
 
-	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*info));
-	if (!indio_dev) {
-		dev_err(&pdev->dev, "Failed allocating iio device\n");
-		return -ENOMEM;
-	}
-
-	info = iio_priv(indio_dev);
-	info->dev = &pdev->dev;
-
-	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	info->regs = devm_ioremap_resource(&pdev->dev, mem);
-	if (IS_ERR(info->regs)) {
-		ret = PTR_ERR(info->regs);
-		dev_err(&pdev->dev,
-			"Failed to remap adc memory, err = %d\n", ret);
-		return ret;
-	}
-
-	irq = platform_get_irq(pdev, 0);
-	if (irq < 0) {
-		dev_err(&pdev->dev, "No irq resource?\n");
-		return irq;
-	}
-
-	info->clk = devm_clk_get(&pdev->dev, "adc");
-	if (IS_ERR(info->clk)) {
-		ret = PTR_ERR(info->clk);
-		dev_err(&pdev->dev, "Failed getting clock, err = %d\n", ret);
-		return ret;
-	}
-
-	info->vref = devm_regulator_get(&pdev->dev, "vref");
-	if (IS_ERR(info->vref)) {
-		ret = PTR_ERR(info->vref);
-		dev_err(&pdev->dev,
-			"Failed getting reference voltage, err = %d\n", ret);
-		return ret;
-	}
-
 	ret = regulator_enable(info->vref);
 	if (ret) {
-		dev_err(&pdev->dev,
+		dev_err(info->dev,
 			"Can't enable adc reference top voltage, err = %d\n",
 			ret);
 		return ret;
 	}
 
-	platform_set_drvdata(pdev, indio_dev);
-
-	init_completion(&info->completion);
-
-	indio_dev->name = dev_name(&pdev->dev);
-	indio_dev->dev.parent = &pdev->dev;
-	indio_dev->info = &imx7d_adc_iio_info;
-	indio_dev->modes = INDIO_DIRECT_MODE;
-	indio_dev->channels = imx7d_adc_iio_channels;
-	indio_dev->num_channels = ARRAY_SIZE(imx7d_adc_iio_channels);
-
 	ret = clk_prepare_enable(info->clk);
 	if (ret) {
-		dev_err(&pdev->dev,
-			"Could not prepare or enable the clock.\n");
-		goto error_adc_clk_enable;
-	}
-
-	ret = devm_request_irq(info->dev, irq,
-				imx7d_adc_isr, 0,
-				dev_name(&pdev->dev), info);
-	if (ret < 0) {
-		dev_err(&pdev->dev, "Failed requesting irq, irq = %d\n", irq);
-		goto error_iio_device_register;
+		dev_err(info->dev,
+			"Could not prepare or enable clock.\n");
+		regulator_disable(info->vref);
+		return ret;
 	}
 
-	imx7d_adc_feature_config(info);
 	imx7d_adc_hw_init(info);
 
-	ret = iio_device_register(indio_dev);
-	if (ret) {
-		imx7d_adc_power_down(info);
-		dev_err(&pdev->dev, "Couldn't register the device.\n");
-		goto error_iio_device_register;
-	}
-
 	return 0;
-
-error_iio_device_register:
-	clk_disable_unprepare(info->clk);
-error_adc_clk_enable:
-	regulator_disable(info->vref);
-
-	return ret;
 }
 
-static int imx7d_adc_remove(struct platform_device *pdev)
+static int imx7d_adc_disable(struct device *dev)
 {
-	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
 	struct imx7d_adc *info = iio_priv(indio_dev);
 
-	iio_device_unregister(indio_dev);
-
 	imx7d_adc_power_down(info);
 
 	clk_disable_unprepare(info->clk);
@@ -549,55 +468,89 @@ static int imx7d_adc_remove(struct platform_device *pdev)
 	return 0;
 }
 
-static int __maybe_unused imx7d_adc_suspend(struct device *dev)
+static void __imx7d_adc_disable(void *data)
 {
-	struct iio_dev *indio_dev = dev_get_drvdata(dev);
-	struct imx7d_adc *info = iio_priv(indio_dev);
-
-	imx7d_adc_power_down(info);
-
-	clk_disable_unprepare(info->clk);
-	regulator_disable(info->vref);
-
-	return 0;
+	imx7d_adc_disable(data);
 }
 
-static int __maybe_unused imx7d_adc_resume(struct device *dev)
+static int imx7d_adc_probe(struct platform_device *pdev)
 {
-	struct iio_dev *indio_dev = dev_get_drvdata(dev);
-	struct imx7d_adc *info = iio_priv(indio_dev);
+	struct imx7d_adc *info;
+	struct iio_dev *indio_dev;
+	struct device *dev = &pdev->dev;
+	int irq;
 	int ret;
 
-	ret = regulator_enable(info->vref);
-	if (ret) {
-		dev_err(info->dev,
-			"Can't enable adc reference top voltage, err = %d\n",
-			ret);
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*info));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	info = iio_priv(indio_dev);
+	info->dev = dev;
+
+	info->regs = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(info->regs))
+		return PTR_ERR(info->regs);
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	info->clk = devm_clk_get(dev, "adc");
+	if (IS_ERR(info->clk))
+		return dev_err_probe(dev, PTR_ERR(info->clk), "Failed getting clock\n");
+
+	info->vref = devm_regulator_get(dev, "vref");
+	if (IS_ERR(info->vref))
+		return dev_err_probe(dev, PTR_ERR(info->vref),
+				     "Failed getting reference voltage\n");
+
+	platform_set_drvdata(pdev, indio_dev);
+
+	init_completion(&info->completion);
+
+	indio_dev->name = dev_name(dev);
+	indio_dev->info = &imx7d_adc_iio_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = imx7d_adc_iio_channels;
+	indio_dev->num_channels = ARRAY_SIZE(imx7d_adc_iio_channels);
+
+	ret = devm_request_irq(dev, irq, imx7d_adc_isr, 0, dev_name(dev), info);
+	if (ret < 0) {
+		dev_err(dev, "Failed requesting irq, irq = %d\n", irq);
 		return ret;
 	}
 
-	ret = clk_prepare_enable(info->clk);
+	imx7d_adc_feature_config(info);
+
+	ret = imx7d_adc_enable(dev);
+	if (ret)
+		return ret;
+
+	ret = devm_add_action_or_reset(dev, __imx7d_adc_disable, dev);
+	if (ret)
+		return ret;
+
+	mutex_init(&info->lock);
+
+	ret = devm_iio_device_register(dev, indio_dev);
 	if (ret) {
-		dev_err(info->dev,
-			"Could not prepare or enable clock.\n");
-		regulator_disable(info->vref);
+		dev_err(&pdev->dev, "Couldn't register the device.\n");
 		return ret;
 	}
 
-	imx7d_adc_hw_init(info);
-
 	return 0;
 }
 
-static SIMPLE_DEV_PM_OPS(imx7d_adc_pm_ops, imx7d_adc_suspend, imx7d_adc_resume);
+static DEFINE_SIMPLE_DEV_PM_OPS(imx7d_adc_pm_ops, imx7d_adc_disable,
+				imx7d_adc_enable);
 
 static struct platform_driver imx7d_adc_driver = {
 	.probe		= imx7d_adc_probe,
-	.remove		= imx7d_adc_remove,
 	.driver		= {
 		.name	= "imx7d_adc",
 		.of_match_table = imx7d_adc_match,
-		.pm	= &imx7d_adc_pm_ops,
+		.pm	= pm_sleep_ptr(&imx7d_adc_pm_ops),
 	},
 };