Adding upstream version 5.10.209.upstream/5.10.209

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 428 insertions, 0 deletions

diff --git a/drivers/iio/adc/fsl-imx25-gcq.c b/drivers/iio/adc/fsl-imx25-gcq.c
new file mode 100644
index 000000000..ab5139e91
--- /dev/null
+++ b/drivers/iio/adc/fsl-imx25-gcq.c
@@ -0,0 +1,428 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2014-2015 Pengutronix, Markus Pargmann <mpa@pengutronix.de>
+ *
+ * This is the driver for the imx25 GCQ (Generic Conversion Queue)
+ * connected to the imx25 ADC.
+ */
+
+#include <dt-bindings/iio/adc/fsl-imx25-gcq.h>
+#include <linux/clk.h>
+#include <linux/iio/iio.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/imx25-tsadc.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+
+#define MX25_GCQ_TIMEOUT (msecs_to_jiffies(2000))
+
+static const char * const driver_name = "mx25-gcq";
+
+enum mx25_gcq_cfgs {
+	MX25_CFG_XP = 0,
+	MX25_CFG_YP,
+	MX25_CFG_XN,
+	MX25_CFG_YN,
+	MX25_CFG_WIPER,
+	MX25_CFG_INAUX0,
+	MX25_CFG_INAUX1,
+	MX25_CFG_INAUX2,
+	MX25_NUM_CFGS,
+};
+
+struct mx25_gcq_priv {
+	struct regmap *regs;
+	struct completion completed;
+	struct clk *clk;
+	int irq;
+	struct regulator *vref[4];
+	u32 channel_vref_mv[MX25_NUM_CFGS];
+	/*
+	 * Lock to protect the device state during a potential concurrent
+	 * read access from userspace. Reading a raw value requires a sequence
+	 * of register writes, then a wait for a completion callback,
+	 * and finally a register read, during which userspace could issue
+	 * another read request. This lock protects a read access from
+	 * ocurring before another one has finished.
+	 */
+	struct mutex lock;
+};
+
+#define MX25_CQG_CHAN(chan, id) {\
+	.type = IIO_VOLTAGE,\
+	.indexed = 1,\
+	.channel = chan,\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
+			      BIT(IIO_CHAN_INFO_SCALE),\
+	.datasheet_name = id,\
+}
+
+static const struct iio_chan_spec mx25_gcq_channels[MX25_NUM_CFGS] = {
+	MX25_CQG_CHAN(MX25_CFG_XP, "xp"),
+	MX25_CQG_CHAN(MX25_CFG_YP, "yp"),
+	MX25_CQG_CHAN(MX25_CFG_XN, "xn"),
+	MX25_CQG_CHAN(MX25_CFG_YN, "yn"),
+	MX25_CQG_CHAN(MX25_CFG_WIPER, "wiper"),
+	MX25_CQG_CHAN(MX25_CFG_INAUX0, "inaux0"),
+	MX25_CQG_CHAN(MX25_CFG_INAUX1, "inaux1"),
+	MX25_CQG_CHAN(MX25_CFG_INAUX2, "inaux2"),
+};
+
+static const char * const mx25_gcq_refp_names[] = {
+	[MX25_ADC_REFP_YP] = "yp",
+	[MX25_ADC_REFP_XP] = "xp",
+	[MX25_ADC_REFP_INT] = "int",
+	[MX25_ADC_REFP_EXT] = "ext",
+};
+
+static irqreturn_t mx25_gcq_irq(int irq, void *data)
+{
+	struct mx25_gcq_priv *priv = data;
+	u32 stats;
+
+	regmap_read(priv->regs, MX25_ADCQ_SR, &stats);
+
+	if (stats & MX25_ADCQ_SR_EOQ) {
+		regmap_update_bits(priv->regs, MX25_ADCQ_MR,
+				   MX25_ADCQ_MR_EOQ_IRQ, MX25_ADCQ_MR_EOQ_IRQ);
+		complete(&priv->completed);
+	}
+
+	/* Disable conversion queue run */
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_FQS, 0);
+
+	/* Acknowledge all possible irqs */
+	regmap_write(priv->regs, MX25_ADCQ_SR, MX25_ADCQ_SR_FRR |
+		     MX25_ADCQ_SR_FUR | MX25_ADCQ_SR_FOR |
+		     MX25_ADCQ_SR_EOQ | MX25_ADCQ_SR_PD);
+
+	return IRQ_HANDLED;
+}
+
+static int mx25_gcq_get_raw_value(struct device *dev,
+				  struct iio_chan_spec const *chan,
+				  struct mx25_gcq_priv *priv,
+				  int *val)
+{
+	long timeout;
+	u32 data;
+
+	/* Setup the configuration we want to use */
+	regmap_write(priv->regs, MX25_ADCQ_ITEM_7_0,
+		     MX25_ADCQ_ITEM(0, chan->channel));
+
+	regmap_update_bits(priv->regs, MX25_ADCQ_MR, MX25_ADCQ_MR_EOQ_IRQ, 0);
+
+	/* Trigger queue for one run */
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_FQS,
+			   MX25_ADCQ_CR_FQS);
+
+	timeout = wait_for_completion_interruptible_timeout(
+		&priv->completed, MX25_GCQ_TIMEOUT);
+	if (timeout < 0) {
+		dev_err(dev, "ADC wait for measurement failed\n");
+		return timeout;
+	} else if (timeout == 0) {
+		dev_err(dev, "ADC timed out\n");
+		return -ETIMEDOUT;
+	}
+
+	regmap_read(priv->regs, MX25_ADCQ_FIFO, &data);
+
+	*val = MX25_ADCQ_FIFO_DATA(data);
+
+	return IIO_VAL_INT;
+}
+
+static int mx25_gcq_read_raw(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan, int *val,
+			     int *val2, long mask)
+{
+	struct mx25_gcq_priv *priv = iio_priv(indio_dev);
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		mutex_lock(&priv->lock);
+		ret = mx25_gcq_get_raw_value(&indio_dev->dev, chan, priv, val);
+		mutex_unlock(&priv->lock);
+		return ret;
+
+	case IIO_CHAN_INFO_SCALE:
+		*val = priv->channel_vref_mv[chan->channel];
+		*val2 = 12;
+		return IIO_VAL_FRACTIONAL_LOG2;
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct iio_info mx25_gcq_iio_info = {
+	.read_raw = mx25_gcq_read_raw,
+};
+
+static const struct regmap_config mx25_gcq_regconfig = {
+	.max_register = 0x5c,
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = 4,
+};
+
+static int mx25_gcq_setup_cfgs(struct platform_device *pdev,
+			       struct mx25_gcq_priv *priv)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct device_node *child;
+	struct device *dev = &pdev->dev;
+	unsigned int refp_used[4] = {};
+	int ret, i;
+
+	/*
+	 * Setup all configurations registers with a default conversion
+	 * configuration for each input
+	 */
+	for (i = 0; i < MX25_NUM_CFGS; ++i)
+		regmap_write(priv->regs, MX25_ADCQ_CFG(i),
+			     MX25_ADCQ_CFG_YPLL_OFF |
+			     MX25_ADCQ_CFG_XNUR_OFF |
+			     MX25_ADCQ_CFG_XPUL_OFF |
+			     MX25_ADCQ_CFG_REFP_INT |
+			     MX25_ADCQ_CFG_IN(i) |
+			     MX25_ADCQ_CFG_REFN_NGND2);
+
+	/*
+	 * First get all regulators to store them in channel_vref_mv if
+	 * necessary. Later we use that information for proper IIO scale
+	 * information.
+	 */
+	priv->vref[MX25_ADC_REFP_INT] = NULL;
+	priv->vref[MX25_ADC_REFP_EXT] =
+		devm_regulator_get_optional(&pdev->dev, "vref-ext");
+	priv->vref[MX25_ADC_REFP_XP] =
+		devm_regulator_get_optional(&pdev->dev, "vref-xp");
+	priv->vref[MX25_ADC_REFP_YP] =
+		devm_regulator_get_optional(&pdev->dev, "vref-yp");
+
+	for_each_child_of_node(np, child) {
+		u32 reg;
+		u32 refp = MX25_ADCQ_CFG_REFP_INT;
+		u32 refn = MX25_ADCQ_CFG_REFN_NGND2;
+
+		ret = of_property_read_u32(child, "reg", &reg);
+		if (ret) {
+			dev_err(dev, "Failed to get reg property\n");
+			of_node_put(child);
+			return ret;
+		}
+
+		if (reg >= MX25_NUM_CFGS) {
+			dev_err(dev,
+				"reg value is greater than the number of available configuration registers\n");
+			of_node_put(child);
+			return -EINVAL;
+		}
+
+		of_property_read_u32(child, "fsl,adc-refp", &refp);
+		of_property_read_u32(child, "fsl,adc-refn", &refn);
+
+		switch (refp) {
+		case MX25_ADC_REFP_EXT:
+		case MX25_ADC_REFP_XP:
+		case MX25_ADC_REFP_YP:
+			if (IS_ERR(priv->vref[refp])) {
+				dev_err(dev, "Error, trying to use external voltage reference without a vref-%s regulator.",
+					mx25_gcq_refp_names[refp]);
+				of_node_put(child);
+				return PTR_ERR(priv->vref[refp]);
+			}
+			priv->channel_vref_mv[reg] =
+				regulator_get_voltage(priv->vref[refp]);
+			/* Conversion from uV to mV */
+			priv->channel_vref_mv[reg] /= 1000;
+			break;
+		case MX25_ADC_REFP_INT:
+			priv->channel_vref_mv[reg] = 2500;
+			break;
+		default:
+			dev_err(dev, "Invalid positive reference %d\n", refp);
+			of_node_put(child);
+			return -EINVAL;
+		}
+
+		++refp_used[refp];
+
+		/*
+		 * Shift the read values to the correct positions within the
+		 * register.
+		 */
+		refp = MX25_ADCQ_CFG_REFP(refp);
+		refn = MX25_ADCQ_CFG_REFN(refn);
+
+		if ((refp & MX25_ADCQ_CFG_REFP_MASK) != refp) {
+			dev_err(dev, "Invalid fsl,adc-refp property value\n");
+			of_node_put(child);
+			return -EINVAL;
+		}
+		if ((refn & MX25_ADCQ_CFG_REFN_MASK) != refn) {
+			dev_err(dev, "Invalid fsl,adc-refn property value\n");
+			of_node_put(child);
+			return -EINVAL;
+		}
+
+		regmap_update_bits(priv->regs, MX25_ADCQ_CFG(reg),
+				   MX25_ADCQ_CFG_REFP_MASK |
+				   MX25_ADCQ_CFG_REFN_MASK,
+				   refp | refn);
+	}
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR,
+			   MX25_ADCQ_CR_FRST | MX25_ADCQ_CR_QRST,
+			   MX25_ADCQ_CR_FRST | MX25_ADCQ_CR_QRST);
+
+	regmap_write(priv->regs, MX25_ADCQ_CR,
+		     MX25_ADCQ_CR_PDMSK | MX25_ADCQ_CR_QSM_FQS);
+
+	/* Remove unused regulators */
+	for (i = 0; i != 4; ++i) {
+		if (!refp_used[i]) {
+			if (!IS_ERR_OR_NULL(priv->vref[i]))
+				devm_regulator_put(priv->vref[i]);
+			priv->vref[i] = NULL;
+		}
+	}
+
+	return 0;
+}
+
+static int mx25_gcq_probe(struct platform_device *pdev)
+{
+	struct iio_dev *indio_dev;
+	struct mx25_gcq_priv *priv;
+	struct mx25_tsadc *tsadc = dev_get_drvdata(pdev->dev.parent);
+	struct device *dev = &pdev->dev;
+	void __iomem *mem;
+	int ret;
+	int i;
+
+	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*priv));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	priv = iio_priv(indio_dev);
+
+	mem = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(mem))
+		return PTR_ERR(mem);
+
+	priv->regs = devm_regmap_init_mmio(dev, mem, &mx25_gcq_regconfig);
+	if (IS_ERR(priv->regs)) {
+		dev_err(dev, "Failed to initialize regmap\n");
+		return PTR_ERR(priv->regs);
+	}
+
+	mutex_init(&priv->lock);
+
+	init_completion(&priv->completed);
+
+	ret = mx25_gcq_setup_cfgs(pdev, priv);
+	if (ret)
+		return ret;
+
+	for (i = 0; i != 4; ++i) {
+		if (!priv->vref[i])
+			continue;
+
+		ret = regulator_enable(priv->vref[i]);
+		if (ret)
+			goto err_regulator_disable;
+	}
+
+	priv->clk = tsadc->clk;
+	ret = clk_prepare_enable(priv->clk);
+	if (ret) {
+		dev_err(dev, "Failed to enable clock\n");
+		goto err_vref_disable;
+	}
+
+	priv->irq = platform_get_irq(pdev, 0);
+	if (priv->irq <= 0) {
+		ret = priv->irq;
+		if (!ret)
+			ret = -ENXIO;
+		goto err_clk_unprepare;
+	}
+
+	ret = request_irq(priv->irq, mx25_gcq_irq, 0, pdev->name, priv);
+	if (ret) {
+		dev_err(dev, "Failed requesting IRQ\n");
+		goto err_clk_unprepare;
+	}
+
+	indio_dev->channels = mx25_gcq_channels;
+	indio_dev->num_channels = ARRAY_SIZE(mx25_gcq_channels);
+	indio_dev->info = &mx25_gcq_iio_info;
+	indio_dev->name = driver_name;
+
+	ret = iio_device_register(indio_dev);
+	if (ret) {
+		dev_err(dev, "Failed to register iio device\n");
+		goto err_irq_free;
+	}
+
+	platform_set_drvdata(pdev, indio_dev);
+
+	return 0;
+
+err_irq_free:
+	free_irq(priv->irq, priv);
+err_clk_unprepare:
+	clk_disable_unprepare(priv->clk);
+err_vref_disable:
+	i = 4;
+err_regulator_disable:
+	for (; i-- > 0;) {
+		if (priv->vref[i])
+			regulator_disable(priv->vref[i]);
+	}
+	return ret;
+}
+
+static int mx25_gcq_remove(struct platform_device *pdev)
+{
+	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+	struct mx25_gcq_priv *priv = iio_priv(indio_dev);
+	int i;
+
+	iio_device_unregister(indio_dev);
+	free_irq(priv->irq, priv);
+	clk_disable_unprepare(priv->clk);
+	for (i = 4; i-- > 0;) {
+		if (priv->vref[i])
+			regulator_disable(priv->vref[i]);
+	}
+
+	return 0;
+}
+
+static const struct of_device_id mx25_gcq_ids[] = {
+	{ .compatible = "fsl,imx25-gcq", },
+	{ /* Sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, mx25_gcq_ids);
+
+static struct platform_driver mx25_gcq_driver = {
+	.driver		= {
+		.name	= "mx25-gcq",
+		.of_match_table = mx25_gcq_ids,
+	},
+	.probe		= mx25_gcq_probe,
+	.remove		= mx25_gcq_remove,
+};
+module_platform_driver(mx25_gcq_driver);
+
+MODULE_DESCRIPTION("ADC driver for Freescale mx25");
+MODULE_AUTHOR("Markus Pargmann <mpa@pengutronix.de>");
+MODULE_LICENSE("GPL v2");