staging:iio:adc:lpc32xx Move out of staging.

There are a few more little cleanups that could be done on this driver, but
I don't think any are sufficient to justify not moving it out of staging.

It's a very simple driver (presumably for a simple part) so not much that can
go wrong.  I think it was only ever in staging because that's where IIO was
as a whole at the time and then we forgot about it!

Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Cc: Roland Stigge <stigge@antcom.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/iio/adc/Kconfig

@@ -305,6 +305,18 @@ config LPC18XX_ADC
 	  To compile this driver as a module, choose M here: the module will be
 	  called lpc18xx_adc.
 
+config LPC32XX_ADC
+	tristate "NXP LPC32XX ADC"
+	depends on ARCH_LPC32XX || COMPILE_TEST
+	depends on HAS_IOMEM
+	help
+	  Say yes here to build support for the integrated ADC inside the
+	  LPC32XX SoC. Note that this feature uses the same hardware as the
+	  touchscreen driver, so you should either select only one of the two
+	  drivers (lpc32xx_adc or lpc32xx_ts) or, in the OpenFirmware case,
+	  activate only one via device tree selection.  Provides direct access
+	  via sysfs.
+
 config LTC2485
 	tristate "Linear Technology LTC2485 ADC driver"
 	depends on I2C

drivers/iio/adc/Makefile

@@ -30,6 +30,7 @@ obj-$(CONFIG_IMX7D_ADC) += imx7d_adc.o
 obj-$(CONFIG_INA2XX_ADC) += ina2xx-adc.o
 obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o
 obj-$(CONFIG_LPC18XX_ADC) += lpc18xx_adc.o
+obj-$(CONFIG_LPC32XX_ADC) += lpc32xx_adc.o
 obj-$(CONFIG_LTC2485) += ltc2485.o
 obj-$(CONFIG_MAX1027) += max1027.o
 obj-$(CONFIG_MAX11100) += max11100.o

drivers/iio/adc/lpc32xx_adc.c

@@ -0,0 +1,219 @@
+/*
+ *  lpc32xx_adc.c - Support for ADC in LPC32XX
+ *
+ *  3-channel, 10-bit ADC
+ *
+ *  Copyright (C) 2011, 2012 Roland Stigge <stigge@antcom.de>
+ *
+ *  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.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/completion.h>
+#include <linux/of.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+/*
+ * LPC32XX registers definitions
+ */
+#define LPC32XXAD_SELECT(x)	((x) + 0x04)
+#define LPC32XXAD_CTRL(x)	((x) + 0x08)
+#define LPC32XXAD_VALUE(x)	((x) + 0x48)
+
+/* Bit definitions for LPC32XXAD_SELECT: */
+/* constant, always write this value! */
+#define LPC32XXAD_REFm         0x00000200
+/* constant, always write this value! */
+#define LPC32XXAD_REFp		0x00000080
+ /* multiple of this is the channel number: 0, 1, 2 */
+#define LPC32XXAD_IN		0x00000010
+/* constant, always write this value! */
+#define LPC32XXAD_INTERNAL	0x00000004
+
+/* Bit definitions for LPC32XXAD_CTRL: */
+#define LPC32XXAD_STROBE	0x00000002
+#define LPC32XXAD_PDN_CTRL	0x00000004
+
+/* Bit definitions for LPC32XXAD_VALUE: */
+#define LPC32XXAD_VALUE_MASK	0x000003FF
+
+#define LPC32XXAD_NAME "lpc32xx-adc"
+
+struct lpc32xx_adc_state {
+	void __iomem *adc_base;
+	struct clk *clk;
+	struct completion completion;
+
+	u32 value;
+};
+
+static int lpc32xx_read_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan,
+			    int *val,
+			    int *val2,
+			    long mask)
+{
+	struct lpc32xx_adc_state *st = iio_priv(indio_dev);
+
+	if (mask == IIO_CHAN_INFO_RAW) {
+		mutex_lock(&indio_dev->mlock);
+		clk_prepare_enable(st->clk);
+		/* Measurement setup */
+		__raw_writel(LPC32XXAD_INTERNAL | (chan->address) |
+			     LPC32XXAD_REFp | LPC32XXAD_REFm,
+			     LPC32XXAD_SELECT(st->adc_base));
+		/* Trigger conversion */
+		__raw_writel(LPC32XXAD_PDN_CTRL | LPC32XXAD_STROBE,
+			     LPC32XXAD_CTRL(st->adc_base));
+		wait_for_completion(&st->completion); /* set by ISR */
+		clk_disable_unprepare(st->clk);
+		*val = st->value;
+		mutex_unlock(&indio_dev->mlock);
+
+		return IIO_VAL_INT;
+	}
+
+	return -EINVAL;
+}
+
+static const struct iio_info lpc32xx_adc_iio_info = {
+	.read_raw = &lpc32xx_read_raw,
+	.driver_module = THIS_MODULE,
+};
+
+#define LPC32XX_ADC_CHANNEL(_index) {			\
+	.type = IIO_VOLTAGE,				\
+	.indexed = 1,					\
+	.channel = _index,				\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),	\
+	.address = LPC32XXAD_IN * _index,		\
+	.scan_index = _index,				\
+}
+
+static const struct iio_chan_spec lpc32xx_adc_iio_channels[] = {
+	LPC32XX_ADC_CHANNEL(0),
+	LPC32XX_ADC_CHANNEL(1),
+	LPC32XX_ADC_CHANNEL(2),
+};
+
+static irqreturn_t lpc32xx_adc_isr(int irq, void *dev_id)
+{
+	struct lpc32xx_adc_state *st = dev_id;
+
+	/* Read value and clear irq */
+	st->value = __raw_readl(LPC32XXAD_VALUE(st->adc_base)) &
+		LPC32XXAD_VALUE_MASK;
+	complete(&st->completion);
+
+	return IRQ_HANDLED;
+}
+
+static int lpc32xx_adc_probe(struct platform_device *pdev)
+{
+	struct lpc32xx_adc_state *st = NULL;
+	struct resource *res;
+	int retval = -ENODEV;
+	struct iio_dev *iodev = NULL;
+	int irq;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "failed to get platform I/O memory\n");
+		return -ENXIO;
+	}
+
+	iodev = devm_iio_device_alloc(&pdev->dev, sizeof(*st));
+	if (!iodev)
+		return -ENOMEM;
+
+	st = iio_priv(iodev);
+
+	st->adc_base = devm_ioremap(&pdev->dev, res->start,
+				    resource_size(res));
+	if (!st->adc_base) {
+		dev_err(&pdev->dev, "failed mapping memory\n");
+		return -EBUSY;
+	}
+
+	st->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(st->clk)) {
+		dev_err(&pdev->dev, "failed getting clock\n");
+		return PTR_ERR(st->clk);
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq <= 0) {
+		dev_err(&pdev->dev, "failed getting interrupt resource\n");
+		return -ENXIO;
+	}
+
+	retval = devm_request_irq(&pdev->dev, irq, lpc32xx_adc_isr, 0,
+				  LPC32XXAD_NAME, st);
+	if (retval < 0) {
+		dev_err(&pdev->dev, "failed requesting interrupt\n");
+		return retval;
+	}
+
+	platform_set_drvdata(pdev, iodev);
+
+	init_completion(&st->completion);
+
+	iodev->name = LPC32XXAD_NAME;
+	iodev->dev.parent = &pdev->dev;
+	iodev->info = &lpc32xx_adc_iio_info;
+	iodev->modes = INDIO_DIRECT_MODE;
+	iodev->channels = lpc32xx_adc_iio_channels;
+	iodev->num_channels = ARRAY_SIZE(lpc32xx_adc_iio_channels);
+
+	retval = devm_iio_device_register(&pdev->dev, iodev);
+	if (retval)
+		return retval;
+
+	dev_info(&pdev->dev, "LPC32XX ADC driver loaded, IRQ %d\n", irq);
+
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id lpc32xx_adc_match[] = {
+	{ .compatible = "nxp,lpc3220-adc" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, lpc32xx_adc_match);
+#endif
+
+static struct platform_driver lpc32xx_adc_driver = {
+	.probe		= lpc32xx_adc_probe,
+	.driver		= {
+		.name	= LPC32XXAD_NAME,
+		.of_match_table = of_match_ptr(lpc32xx_adc_match),
+	},
+};
+
+module_platform_driver(lpc32xx_adc_driver);
+
+MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
+MODULE_DESCRIPTION("LPC32XX ADC driver");
+MODULE_LICENSE("GPL");