mk-rootfs.sh

hc

2023-12-11 072de836f53be56a70cecf70b43ae43b7ce17376

 kernel/drivers/iio/adc/fsl-imx25-gcq.c
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@@ -1,9 +1,6 @@
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+// SPDX-License-Identifier: GPL-2.0-only
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 /*
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  * Copyright (C) 2014-2015 Pengutronix, Markus Pargmann <mpa@pengutronix.de>
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- *
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- * This program is free software; you can redistribute it and/or modify it under
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- * the terms of the GNU General Public License version 2 as published by the
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- * Free Software Foundation.
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  *
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  * This is the driver for the imx25 GCQ (Generic Conversion Queue)
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  * connected to the imx25 ADC.
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@@ -43,6 +40,15 @@
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 	int irq;
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 	struct regulator *vref[4];
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 	u32 channel_vref_mv[MX25_NUM_CFGS];
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+	/*
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+	 * Lock to protect the device state during a potential concurrent
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+	 * read access from userspace. Reading a raw value requires a sequence
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+	 * of register writes, then a wait for a completion callback,
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+	 * and finally a register read, during which userspace could issue
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+	 * another read request. This lock protects a read access from
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+	 * ocurring before another one has finished.
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+	 */
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+	struct mutex lock;
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 };
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 #define MX25_CQG_CHAN(chan, id) {\
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@@ -140,9 +146,9 @@
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 	switch (mask) {
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 	case IIO_CHAN_INFO_RAW:
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-		mutex_lock(&indio_dev->mlock);
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+		mutex_lock(&priv->lock);
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 		ret = mx25_gcq_get_raw_value(&indio_dev->dev, chan, priv, val);
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-		mutex_unlock(&indio_dev->mlock);
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+		mutex_unlock(&priv->lock);
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 		return ret;
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 	case IIO_CHAN_INFO_SCALE:
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@@ -297,7 +303,6 @@
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 	struct mx25_gcq_priv *priv;
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 	struct mx25_tsadc *tsadc = dev_get_drvdata(pdev->dev.parent);
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 	struct device *dev = &pdev->dev;
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-	struct resource *res;
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 	void __iomem *mem;
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 	int ret;
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 	int i;
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@@ -308,8 +313,7 @@
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 	priv = iio_priv(indio_dev);
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-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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-	mem = devm_ioremap_resource(dev, res);
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+	mem = devm_platform_ioremap_resource(pdev, 0);
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 	if (IS_ERR(mem))
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 		return PTR_ERR(mem);
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@@ -318,6 +322,8 @@
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 		dev_err(dev, "Failed to initialize regmap\n");
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 		return PTR_ERR(priv->regs);
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 	}
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+
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+	mutex_init(&priv->lock);
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 	init_completion(&priv->completed);
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@@ -343,7 +349,6 @@
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 	priv->irq = platform_get_irq(pdev, 0);
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 	if (priv->irq <= 0) {
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-		dev_err(dev, "Failed to get IRQ\n");
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 		ret = priv->irq;
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 		if (!ret)
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 			ret = -ENXIO;
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@@ -356,7 +361,6 @@
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 		goto err_clk_unprepare;
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 	}
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-	indio_dev->dev.parent = &pdev->dev;
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 	indio_dev->channels = mx25_gcq_channels;
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 	indio_dev->num_channels = ARRAY_SIZE(mx25_gcq_channels);
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 	indio_dev->info = &mx25_gcq_iio_info;