[PATCH v2 0/4] ARM: berlin: ADC support

[PATCH v2 0/4] ARM: berlin: ADC support

[Antoine Tenart]

Hi,

The Berlin ADC provides 8 channels, with one connected to a temperature
sensor. The temperature sensor has its own registers and both the ADC
and the temperature sensor need to be configured when using it.

This series is based on the two Berlin controllers rework series:
- https://lkml.org/lkml/2015/3/6/511
- https://lkml.org/lkml/2015/3/6/535

Antoine

Changes since v1:
        - updated to use regmap_update_bits()
        - fixed mixed berlin/berlin2 and some prefixes
        - reworked channel definitions
        - moved to IIO_CHAN_INFO_PROCESSED for the tsen
        - fixed some typos
        - cosmetic changes

Antoine Tenart (4):
  iio: adc: add support for Berlin
  Documentation: bindings: document the Berlin ADC driver
  ARM: berlin: add an ADC node for the BG2Q
  ARM: berlin: enable the ADC on the BG2Q DMP

 .../devicetree/bindings/iio/adc/berlin2_adc.txt    |  19 ++
 arch/arm/boot/dts/berlin2q-marvell-dmp.dts         |   4 +
 arch/arm/boot/dts/berlin2q.dtsi                    |   8 +
 drivers/iio/adc/Kconfig                            |   7 +
 drivers/iio/adc/Makefile                           |   1 +
 drivers/iio/adc/berlin2-adc.c                      | 379 +++++++++++++++++++++
 6 files changed, 418 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/adc/berlin2_adc.txt
 create mode 100644 drivers/iio/adc/berlin2-adc.c

-- 
2.3.4

[PATCH v2 0/4] ARM: berlin: ADC support

[Antoine Tenart]

Hi,

The Berlin ADC provides 8 channels, with one connected to a temperature
sensor. The temperature sensor has its own registers and both the ADC
and the temperature sensor need to be configured when using it.

This series is based on the two Berlin controllers rework series:
- https://lkml.org/lkml/2015/3/6/511
- https://lkml.org/lkml/2015/3/6/535

Antoine

Changes since v1:
        - updated to use regmap_update_bits()
        - fixed mixed berlin/berlin2 and some prefixes
        - reworked channel definitions
        - moved to IIO_CHAN_INFO_PROCESSED for the tsen
        - fixed some typos
        - cosmetic changes

Antoine Tenart (4):
  iio: adc: add support for Berlin
  Documentation: bindings: document the Berlin ADC driver
  ARM: berlin: add an ADC node for the BG2Q
  ARM: berlin: enable the ADC on the BG2Q DMP

 .../devicetree/bindings/iio/adc/berlin2_adc.txt    |  19 ++
 arch/arm/boot/dts/berlin2q-marvell-dmp.dts         |   4 +
 arch/arm/boot/dts/berlin2q.dtsi                    |   8 +
 drivers/iio/adc/Kconfig                            |   7 +
 drivers/iio/adc/Makefile                           |   1 +
 drivers/iio/adc/berlin2-adc.c                      | 379 +++++++++++++++++++++
 6 files changed, 418 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/adc/berlin2_adc.txt
 create mode 100644 drivers/iio/adc/berlin2-adc.c

-- 
2.3.4

[PATCH v2 1/4] iio: adc: add support for Berlin

[Antoine Tenart]

This patch adds the support of the Berlin ADC, available on Berlin SoCs.
This ADC has 8 channels available, with one connected to a temperature
sensor.

The particularity here, is that the temperature sensor connected to the
ADC has its own registers, and both the ADC and the temperature sensor
must be configured when using it.

Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
---
 drivers/iio/adc/Kconfig       |   7 +
 drivers/iio/adc/Makefile      |   1 +
 drivers/iio/adc/berlin2-adc.c | 379 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 387 insertions(+)
 create mode 100644 drivers/iio/adc/berlin2-adc.c

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 202daf889be2..92cc40fd5e71 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -135,6 +135,13 @@ config AXP288_ADC
 	  device. Depending on platform configuration, this general purpose ADC can
 	  be used for sampling sensors such as thermal resistors.
 
+config BERLIN2_ADC
+	tristate "Marvell Berlin2 ADC driver"
+	depends on ARCH_BERLIN
+	help
+	  Marvell Berlin2 ADC driver. This ADC has 8 channels, with one used for
+	  temperature measurement.
+
 config CC10001_ADC
 	tristate "Cosmic Circuits 10001 ADC driver"
 	depends on HAS_IOMEM || HAVE_CLK || REGULATOR
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index 0315af640866..2b6dadaf7714 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -15,6 +15,7 @@ obj-$(CONFIG_AD7887) += ad7887.o
 obj-$(CONFIG_AD799X) += ad799x.o
 obj-$(CONFIG_AT91_ADC) += at91_adc.o
 obj-$(CONFIG_AXP288_ADC) += axp288_adc.o
+obj-$(CONFIG_BERLIN2_ADC) += berlin2-adc.o
 obj-$(CONFIG_CC10001_ADC) += cc10001_adc.o
 obj-$(CONFIG_EXYNOS_ADC) += exynos_adc.o
 obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o
diff --git a/drivers/iio/adc/berlin2-adc.c b/drivers/iio/adc/berlin2-adc.c
new file mode 100644
index 000000000000..cd21fefc403e
--- /dev/null
+++ b/drivers/iio/adc/berlin2-adc.c
@@ -0,0 +1,379 @@
+/*
+ * Marvell Berlin2 ADC driver
+ *
+ * Copyright (C) 2015 Marvell Technology Group Ltd.
+ *
+ * Antoine Tenart <antoine.tenart@free-electrons.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/iio/iio.h>
+#include <linux/iio/driver.h>
+#include <linux/iio/machine.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+#include <linux/sched.h>
+#include <linux/wait.h>
+
+#define BERLIN2_SM_CTRL				0x14
+#define  BERLIN2_SM_CTRL_SM_SOC_INT		BIT(1)
+#define  BERLIN2_SM_CTRL_SOC_SM_INT		BIT(2)
+#define  BERLIN2_SM_CTRL_ADC_SEL(x)		(BIT(x) << 5)	/* 0-15 */
+#define  BERLIN2_SM_CTRL_ADC_SEL_MASK		(0xf << 5)
+#define  BERLIN2_SM_CTRL_ADC_POWER		BIT(9)
+#define  BERLIN2_SM_CTRL_ADC_CLKSEL_DIV2	(0x0 << 10)
+#define  BERLIN2_SM_CTRL_ADC_CLKSEL_DIV3	(0x1 << 10)
+#define  BERLIN2_SM_CTRL_ADC_CLKSEL_DIV4	(0x2 << 10)
+#define  BERLIN2_SM_CTRL_ADC_CLKSEL_DIV8	(0x3 << 10)
+#define  BERLIN2_SM_CTRL_ADC_CLKSEL_MASK	(0x3 << 10)
+#define  BERLIN2_SM_CTRL_ADC_START		BIT(12)
+#define  BERLIN2_SM_CTRL_ADC_RESET		BIT(13)
+#define  BERLIN2_SM_CTRL_ADC_BANDGAP_RDY	BIT(14)
+#define  BERLIN2_SM_CTRL_ADC_CONT_SINGLE	(0x0 << 15)
+#define  BERLIN2_SM_CTRL_ADC_CONT_CONTINUOUS	(0x1 << 15)
+#define  BERLIN2_SM_CTRL_ADC_BUFFER_EN		BIT(16)
+#define  BERLIN2_SM_CTRL_ADC_VREF_EXT		(0x0 << 17)
+#define  BERLIN2_SM_CTRL_ADC_VREF_INT		(0x1 << 17)
+#define  BERLIN2_SM_CTRL_ADC_ROTATE		BIT(19)
+#define  BERLIN2_SM_CTRL_TSEN_EN		BIT(20)
+#define  BERLIN2_SM_CTRL_TSEN_CLK_SEL_125	(0x0 << 21)	/* 1.25 MHz */
+#define  BERLIN2_SM_CTRL_TSEN_CLK_SEL_250	(0x1 << 21)	/* 2.5 MHz */
+#define  BERLIN2_SM_CTRL_TSEN_MODE_0_125	(0x0 << 22)	/* 0-125 C */
+#define  BERLIN2_SM_CTRL_TSEN_MODE_10_50	(0x1 << 22)	/* 10-50 C */
+#define  BERLIN2_SM_CTRL_TSEN_RESET		BIT(29)
+#define BERLIN2_SM_ADC_DATA			0x20
+#define  BERLIN2_SM_ADC_MASK			0x3ff
+#define BERLIN2_SM_ADC_STATUS			0x1c
+#define  BERLIN2_SM_ADC_STATUS_DATA_RDY(x)	BIT(x)		/* 0-15 */
+#define  BERLIN2_SM_ADC_STATUS_DATA_RDY_MASK	0xf
+#define  BERLIN2_SM_ADC_STATUS_INT_EN(x)	(BIT(x) << 16)	/* 0-15 */
+#define  BERLIN2_SM_ADC_STATUS_INT_EN_MASK	(0xf << 16)
+#define BERLIN2_SM_TSEN_STATUS			0x24
+#define  BERLIN2_SM_TSEN_STATUS_DATA_RDY	BIT(0)
+#define  BERLIN2_SM_TSEN_STATUS_INT_EN		BIT(1)
+#define BERLIN2_SM_TSEN_DATA			0x28
+#define  BERLIN2_SM_TSEN_MASK			0xfff
+#define BERLIN2_SM_TSEN_CTRL			0x74
+#define  BERLIN2_SM_TSEN_CTRL_START		BIT(8)
+#define  BERLIN2_SM_TSEN_CTRL_SETTLING_4	(0x0 << 21)	/* 4 us */
+#define  BERLIN2_SM_TSEN_CTRL_SETTLING_12	(0x1 << 21)	/* 12 us */
+#define  BERLIN2_SM_TSEN_CTRL_SETTLING_MASK	(0x1 << 21)
+#define  BERLIN2_SM_TSEN_CTRL_TRIM(x)		((x) << 22)
+#define  BERLIN2_SM_TSEN_CTRL_TRIM_MASK		(0xf << 22)
+
+struct berlin2_adc_priv {
+	struct regmap		*regmap;
+	struct mutex		lock;
+	wait_queue_head_t	wq;
+	int			irq;
+	int			tsen_irq;
+	bool			data_available;
+	int			data;
+};
+
+#define BERLIN2_ADC_CHANNEL(n, t)					\
+		{							\
+			.channel	= n,				\
+			.datasheet_name	= "channel"#n,			\
+			.type		= t,				\
+			.indexed	= 1,				\
+			.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),	\
+		}
+
+static struct iio_chan_spec berlin2_adc_channels[] = {
+	BERLIN2_ADC_CHANNEL(0, IIO_VOLTAGE),	/* external input */
+	BERLIN2_ADC_CHANNEL(1, IIO_VOLTAGE),	/* external input */
+	BERLIN2_ADC_CHANNEL(2, IIO_VOLTAGE),	/* external input */
+	BERLIN2_ADC_CHANNEL(3, IIO_VOLTAGE),	/* external input */
+	BERLIN2_ADC_CHANNEL(4, IIO_VOLTAGE),	/* reserved */
+	BERLIN2_ADC_CHANNEL(5, IIO_VOLTAGE),	/* reserved */
+	{					/* temperature sensor */
+		.channel		= 6,
+		.datasheet_name		= "channel6",
+		.type			= IIO_TEMP,
+		.indexed		= 0,
+		.info_mask_separate	= BIT(IIO_CHAN_INFO_PROCESSED),
+	},
+	BERLIN2_ADC_CHANNEL(7, IIO_VOLTAGE),	/* reserved */
+	IIO_CHAN_SOFT_TIMESTAMP(8),		/* timestamp */
+};
+#define BERLIN2_N_CHANNELS	ARRAY_SIZE(berlin2_adc_channels)
+
+static int berlin2_adc_read(struct iio_dev *indio_dev, int channel)
+{
+	struct berlin2_adc_priv *priv = iio_priv(indio_dev);
+	int data, ret;
+
+	mutex_lock(&priv->lock);
+
+	/* Configure the ADC */
+	regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
+			BERLIN2_SM_CTRL_ADC_RESET | BERLIN2_SM_CTRL_ADC_SEL_MASK
+			| BERLIN2_SM_CTRL_ADC_START,
+			BERLIN2_SM_CTRL_ADC_SEL(channel) | BERLIN2_SM_CTRL_ADC_START);
+
+	/* Enable the interrupts */
+	regmap_write(priv->regmap, BERLIN2_SM_ADC_STATUS,
+			BERLIN2_SM_ADC_STATUS_INT_EN(channel));
+
+	ret = wait_event_interruptible_timeout(priv->wq, priv->data_available,
+			msecs_to_jiffies(1000));
+
+	/* Disable the interrupts */
+	regmap_update_bits(priv->regmap, BERLIN2_SM_ADC_STATUS,
+			BERLIN2_SM_ADC_STATUS_INT_EN(channel), 0);
+
+	if (ret == 0)
+		ret = -ETIMEDOUT;
+	if (ret < 0) {
+		mutex_unlock(&priv->lock);
+		return ret;
+	}
+
+	regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
+			BERLIN2_SM_CTRL_ADC_START, 0);
+
+	data = priv->data;
+	priv->data = -1;
+	priv->data_available = false;
+
+	mutex_unlock(&priv->lock);
+
+	return data;
+}
+
+static int berlin2_adc_tsen_read(struct iio_dev *indio_dev)
+{
+	struct berlin2_adc_priv *priv = iio_priv(indio_dev);
+	int data, ret;
+
+	mutex_lock(&priv->lock);
+
+	/* Configure the ADC */
+	regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
+			BERLIN2_SM_CTRL_TSEN_RESET | BERLIN2_SM_CTRL_ADC_ROTATE,
+			BERLIN2_SM_CTRL_ADC_ROTATE);
+
+	/* Configure the temperature sensor */
+	regmap_update_bits(priv->regmap, BERLIN2_SM_TSEN_CTRL,
+			BERLIN2_SM_TSEN_CTRL_TRIM_MASK | BERLIN2_SM_TSEN_CTRL_SETTLING_MASK
+			| BERLIN2_SM_TSEN_CTRL_START,
+			BERLIN2_SM_TSEN_CTRL_TRIM(3) | BERLIN2_SM_TSEN_CTRL_SETTLING_12
+			| BERLIN2_SM_TSEN_CTRL_START);
+
+	/* Enable interrupts */
+	regmap_write(priv->regmap, BERLIN2_SM_TSEN_STATUS,
+			BERLIN2_SM_TSEN_STATUS_INT_EN);
+
+	ret = wait_event_interruptible_timeout(priv->wq, priv->data_available,
+			msecs_to_jiffies(1000));
+
+	/* Disable interrupts */
+	regmap_update_bits(priv->regmap, BERLIN2_SM_TSEN_STATUS,
+			BERLIN2_SM_TSEN_STATUS_INT_EN, 0);
+
+	if (ret == 0)
+		ret = -ETIMEDOUT;
+	if (ret < 0) {
+		mutex_unlock(&priv->lock);
+		return ret;
+	}
+
+	regmap_update_bits(priv->regmap, BERLIN2_SM_TSEN_CTRL,
+			BERLIN2_SM_TSEN_CTRL_START, 0);
+
+	data = priv->data;
+	priv->data = -1;
+	priv->data_available = false;
+
+	mutex_unlock(&priv->lock);
+
+	return data;
+}
+
+static int berlin2_adc_read_raw(struct iio_dev *indio_dev,
+		struct iio_chan_spec const *chan, int *val, int *val2,
+		long mask)
+{
+	int temp;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		if (chan->type != IIO_VOLTAGE)
+			return -EINVAL;
+
+		*val = berlin2_adc_read(indio_dev, chan->channel);
+		if (*val < 0)
+			return *val;
+
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_PROCESSED:
+		if (chan->type != IIO_TEMP)
+			return -EINVAL;
+
+		temp = berlin2_adc_tsen_read(indio_dev);
+		if (temp < 0)
+			return temp;
+
+		if (temp > 2047)
+			temp = -(4096 - temp);
+
+		/* Convert to Celsius */
+		*val = (temp * 100) / 264 - 270;
+		return IIO_VAL_INT;
+	default:
+		break;
+	}
+
+	return -EINVAL;
+}
+
+static irqreturn_t berlin2_adc_irq(int irq, void *private)
+{
+	struct iio_dev *indio_dev = private;
+	struct berlin2_adc_priv *priv = iio_priv(indio_dev);
+	unsigned val;
+
+	regmap_read(priv->regmap, BERLIN2_SM_ADC_STATUS, &val);
+	if (val & BERLIN2_SM_ADC_STATUS_DATA_RDY_MASK) {
+		regmap_read(priv->regmap, BERLIN2_SM_ADC_DATA, &priv->data);
+		priv->data &= BERLIN2_SM_ADC_MASK;
+
+		val &= ~BERLIN2_SM_ADC_STATUS_DATA_RDY_MASK;
+		regmap_write(priv->regmap, BERLIN2_SM_ADC_STATUS, val);
+
+		priv->data_available = true;
+		wake_up_interruptible(&priv->wq);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t berlin2_adc_tsen_irq(int irq, void *private)
+{
+	struct iio_dev *indio_dev = private;
+	struct berlin2_adc_priv *priv = iio_priv(indio_dev);
+	unsigned val;
+
+	regmap_read(priv->regmap, BERLIN2_SM_TSEN_STATUS, &val);
+	if (val & BERLIN2_SM_TSEN_STATUS_DATA_RDY) {
+		regmap_read(priv->regmap, BERLIN2_SM_TSEN_DATA, &priv->data);
+		priv->data &= BERLIN2_SM_TSEN_MASK;
+
+		val &= ~BERLIN2_SM_TSEN_STATUS_DATA_RDY;
+		regmap_write(priv->regmap, BERLIN2_SM_TSEN_STATUS, val);
+
+		priv->data_available = true;
+		wake_up_interruptible(&priv->wq);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static const struct iio_info berlin2_adc_info = {
+	.driver_module	= THIS_MODULE,
+	.read_raw	= berlin2_adc_read_raw,
+};
+
+static int berlin2_adc_probe(struct platform_device *pdev)
+{
+	struct iio_dev *indio_dev;
+	struct berlin2_adc_priv *priv;
+	struct device_node *parent_np = of_get_parent(pdev->dev.of_node);
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(&pdev->dev,
+					  sizeof(struct berlin2_adc_priv));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	priv = iio_priv(indio_dev);
+	platform_set_drvdata(pdev, indio_dev);
+
+	priv->regmap = syscon_node_to_regmap(parent_np);
+	of_node_put(parent_np);
+	if (IS_ERR(priv->regmap))
+		return PTR_ERR(priv->regmap);
+
+	priv->irq = platform_get_irq_byname(pdev, "adc");
+	if (priv->irq < 0)
+		return -ENODEV;
+
+	priv->tsen_irq = platform_get_irq_byname(pdev, "tsen");
+	if (priv->tsen_irq < 0)
+		return -ENODEV;
+
+	ret = devm_request_irq(&pdev->dev, priv->irq, berlin2_adc_irq, 0,
+			pdev->dev.driver->name, indio_dev);
+	if (ret)
+		return ret;
+
+	ret = devm_request_irq(&pdev->dev, priv->tsen_irq, berlin2_adc_tsen_irq,
+			0, pdev->dev.driver->name, indio_dev);
+	if (ret)
+		return ret;
+
+	init_waitqueue_head(&priv->wq);
+	mutex_init(&priv->lock);
+
+	indio_dev->dev.parent = &pdev->dev;
+	indio_dev->name = dev_name(&pdev->dev);
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->info = &berlin2_adc_info;
+
+	indio_dev->num_channels = BERLIN2_N_CHANNELS;
+	indio_dev->channels = berlin2_adc_channels;
+
+	/* Power up the ADC */
+	regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
+			BERLIN2_SM_CTRL_ADC_POWER, BERLIN2_SM_CTRL_ADC_POWER);
+
+	return devm_iio_device_register(&pdev->dev, indio_dev);
+}
+
+static int berlin2_adc_remove(struct platform_device *pdev)
+{
+	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+	struct berlin2_adc_priv *priv = iio_priv(indio_dev);
+
+	iio_device_unregister(indio_dev);
+
+	/* Power down the ADC */
+	regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
+			BERLIN2_SM_CTRL_ADC_POWER, 0);
+
+	free_irq(priv->irq, indio_dev);
+	free_irq(priv->tsen_irq, indio_dev);
+
+	iio_device_free(indio_dev);
+
+	return 0;
+}
+
+static const struct of_device_id berlin2_adc_match[] = {
+	{ .compatible = "marvell,berlin2-adc", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, berlin2q_adc_match);
+
+static struct platform_driver berlin2_adc_driver = {
+	.driver	= {
+		.name		= "berlin2-adc",
+		.of_match_table	= berlin2_adc_match,
+	},
+	.probe	= berlin2_adc_probe,
+	.remove	= berlin2_adc_remove,
+};
+module_platform_driver(berlin2_adc_driver);
+
+MODULE_AUTHOR("Antoine Tenart <antoine.tenart@free-electrons.com>");
+MODULE_DESCRIPTION("Marvell Berlin2 ADC driver");
+MODULE_LICENSE("GPL v2");
-- 
2.3.4

[PATCH v2 1/4] iio: adc: add support for Berlin

[Antoine Tenart]

This patch adds the support of the Berlin ADC, available on Berlin SoCs.
This ADC has 8 channels available, with one connected to a temperature
sensor.

The particularity here, is that the temperature sensor connected to the
ADC has its own registers, and both the ADC and the temperature sensor
must be configured when using it.

Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
---
 drivers/iio/adc/Kconfig       |   7 +
 drivers/iio/adc/Makefile      |   1 +
 drivers/iio/adc/berlin2-adc.c | 379 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 387 insertions(+)
 create mode 100644 drivers/iio/adc/berlin2-adc.c

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 202daf889be2..92cc40fd5e71 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -135,6 +135,13 @@ config AXP288_ADC
 	  device. Depending on platform configuration, this general purpose ADC can
 	  be used for sampling sensors such as thermal resistors.
 
+config BERLIN2_ADC
+	tristate "Marvell Berlin2 ADC driver"
+	depends on ARCH_BERLIN
+	help
+	  Marvell Berlin2 ADC driver. This ADC has 8 channels, with one used for
+	  temperature measurement.
+
 config CC10001_ADC
 	tristate "Cosmic Circuits 10001 ADC driver"
 	depends on HAS_IOMEM || HAVE_CLK || REGULATOR
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index 0315af640866..2b6dadaf7714 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -15,6 +15,7 @@ obj-$(CONFIG_AD7887) += ad7887.o
 obj-$(CONFIG_AD799X) += ad799x.o
 obj-$(CONFIG_AT91_ADC) += at91_adc.o
 obj-$(CONFIG_AXP288_ADC) += axp288_adc.o
+obj-$(CONFIG_BERLIN2_ADC) += berlin2-adc.o
 obj-$(CONFIG_CC10001_ADC) += cc10001_adc.o
 obj-$(CONFIG_EXYNOS_ADC) += exynos_adc.o
 obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o
diff --git a/drivers/iio/adc/berlin2-adc.c b/drivers/iio/adc/berlin2-adc.c
new file mode 100644
index 000000000000..cd21fefc403e
--- /dev/null
+++ b/drivers/iio/adc/berlin2-adc.c
@@ -0,0 +1,379 @@
+/*
+ * Marvell Berlin2 ADC driver
+ *
+ * Copyright (C) 2015 Marvell Technology Group Ltd.
+ *
+ * Antoine Tenart <antoine.tenart@free-electrons.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/iio/iio.h>
+#include <linux/iio/driver.h>
+#include <linux/iio/machine.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+#include <linux/sched.h>
+#include <linux/wait.h>
+
+#define BERLIN2_SM_CTRL				0x14
+#define  BERLIN2_SM_CTRL_SM_SOC_INT		BIT(1)
+#define  BERLIN2_SM_CTRL_SOC_SM_INT		BIT(2)
+#define  BERLIN2_SM_CTRL_ADC_SEL(x)		(BIT(x) << 5)	/* 0-15 */
+#define  BERLIN2_SM_CTRL_ADC_SEL_MASK		(0xf << 5)
+#define  BERLIN2_SM_CTRL_ADC_POWER		BIT(9)
+#define  BERLIN2_SM_CTRL_ADC_CLKSEL_DIV2	(0x0 << 10)
+#define  BERLIN2_SM_CTRL_ADC_CLKSEL_DIV3	(0x1 << 10)
+#define  BERLIN2_SM_CTRL_ADC_CLKSEL_DIV4	(0x2 << 10)
+#define  BERLIN2_SM_CTRL_ADC_CLKSEL_DIV8	(0x3 << 10)
+#define  BERLIN2_SM_CTRL_ADC_CLKSEL_MASK	(0x3 << 10)
+#define  BERLIN2_SM_CTRL_ADC_START		BIT(12)
+#define  BERLIN2_SM_CTRL_ADC_RESET		BIT(13)
+#define  BERLIN2_SM_CTRL_ADC_BANDGAP_RDY	BIT(14)
+#define  BERLIN2_SM_CTRL_ADC_CONT_SINGLE	(0x0 << 15)
+#define  BERLIN2_SM_CTRL_ADC_CONT_CONTINUOUS	(0x1 << 15)
+#define  BERLIN2_SM_CTRL_ADC_BUFFER_EN		BIT(16)
+#define  BERLIN2_SM_CTRL_ADC_VREF_EXT		(0x0 << 17)
+#define  BERLIN2_SM_CTRL_ADC_VREF_INT		(0x1 << 17)
+#define  BERLIN2_SM_CTRL_ADC_ROTATE		BIT(19)
+#define  BERLIN2_SM_CTRL_TSEN_EN		BIT(20)
+#define  BERLIN2_SM_CTRL_TSEN_CLK_SEL_125	(0x0 << 21)	/* 1.25 MHz */
+#define  BERLIN2_SM_CTRL_TSEN_CLK_SEL_250	(0x1 << 21)	/* 2.5 MHz */
+#define  BERLIN2_SM_CTRL_TSEN_MODE_0_125	(0x0 << 22)	/* 0-125 C */
+#define  BERLIN2_SM_CTRL_TSEN_MODE_10_50	(0x1 << 22)	/* 10-50 C */
+#define  BERLIN2_SM_CTRL_TSEN_RESET		BIT(29)
+#define BERLIN2_SM_ADC_DATA			0x20
+#define  BERLIN2_SM_ADC_MASK			0x3ff
+#define BERLIN2_SM_ADC_STATUS			0x1c
+#define  BERLIN2_SM_ADC_STATUS_DATA_RDY(x)	BIT(x)		/* 0-15 */
+#define  BERLIN2_SM_ADC_STATUS_DATA_RDY_MASK	0xf
+#define  BERLIN2_SM_ADC_STATUS_INT_EN(x)	(BIT(x) << 16)	/* 0-15 */
+#define  BERLIN2_SM_ADC_STATUS_INT_EN_MASK	(0xf << 16)
+#define BERLIN2_SM_TSEN_STATUS			0x24
+#define  BERLIN2_SM_TSEN_STATUS_DATA_RDY	BIT(0)
+#define  BERLIN2_SM_TSEN_STATUS_INT_EN		BIT(1)
+#define BERLIN2_SM_TSEN_DATA			0x28
+#define  BERLIN2_SM_TSEN_MASK			0xfff
+#define BERLIN2_SM_TSEN_CTRL			0x74
+#define  BERLIN2_SM_TSEN_CTRL_START		BIT(8)
+#define  BERLIN2_SM_TSEN_CTRL_SETTLING_4	(0x0 << 21)	/* 4 us */
+#define  BERLIN2_SM_TSEN_CTRL_SETTLING_12	(0x1 << 21)	/* 12 us */
+#define  BERLIN2_SM_TSEN_CTRL_SETTLING_MASK	(0x1 << 21)
+#define  BERLIN2_SM_TSEN_CTRL_TRIM(x)		((x) << 22)
+#define  BERLIN2_SM_TSEN_CTRL_TRIM_MASK		(0xf << 22)
+
+struct berlin2_adc_priv {
+	struct regmap		*regmap;
+	struct mutex		lock;
+	wait_queue_head_t	wq;
+	int			irq;
+	int			tsen_irq;
+	bool			data_available;
+	int			data;
+};
+
+#define BERLIN2_ADC_CHANNEL(n, t)					\
+		{							\
+			.channel	= n,				\
+			.datasheet_name	= "channel"#n,			\
+			.type		= t,				\
+			.indexed	= 1,				\
+			.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),	\
+		}
+
+static struct iio_chan_spec berlin2_adc_channels[] = {
+	BERLIN2_ADC_CHANNEL(0, IIO_VOLTAGE),	/* external input */
+	BERLIN2_ADC_CHANNEL(1, IIO_VOLTAGE),	/* external input */
+	BERLIN2_ADC_CHANNEL(2, IIO_VOLTAGE),	/* external input */
+	BERLIN2_ADC_CHANNEL(3, IIO_VOLTAGE),	/* external input */
+	BERLIN2_ADC_CHANNEL(4, IIO_VOLTAGE),	/* reserved */
+	BERLIN2_ADC_CHANNEL(5, IIO_VOLTAGE),	/* reserved */
+	{					/* temperature sensor */
+		.channel		= 6,
+		.datasheet_name		= "channel6",
+		.type			= IIO_TEMP,
+		.indexed		= 0,
+		.info_mask_separate	= BIT(IIO_CHAN_INFO_PROCESSED),
+	},
+	BERLIN2_ADC_CHANNEL(7, IIO_VOLTAGE),	/* reserved */
+	IIO_CHAN_SOFT_TIMESTAMP(8),		/* timestamp */
+};
+#define BERLIN2_N_CHANNELS	ARRAY_SIZE(berlin2_adc_channels)
+
+static int berlin2_adc_read(struct iio_dev *indio_dev, int channel)
+{
+	struct berlin2_adc_priv *priv = iio_priv(indio_dev);
+	int data, ret;
+
+	mutex_lock(&priv->lock);
+
+	/* Configure the ADC */
+	regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
+			BERLIN2_SM_CTRL_ADC_RESET | BERLIN2_SM_CTRL_ADC_SEL_MASK
+			| BERLIN2_SM_CTRL_ADC_START,
+			BERLIN2_SM_CTRL_ADC_SEL(channel) | BERLIN2_SM_CTRL_ADC_START);
+
+	/* Enable the interrupts */
+	regmap_write(priv->regmap, BERLIN2_SM_ADC_STATUS,
+			BERLIN2_SM_ADC_STATUS_INT_EN(channel));
+
+	ret = wait_event_interruptible_timeout(priv->wq, priv->data_available,
+			msecs_to_jiffies(1000));
+
+	/* Disable the interrupts */
+	regmap_update_bits(priv->regmap, BERLIN2_SM_ADC_STATUS,
+			BERLIN2_SM_ADC_STATUS_INT_EN(channel), 0);
+
+	if (ret == 0)
+		ret = -ETIMEDOUT;
+	if (ret < 0) {
+		mutex_unlock(&priv->lock);
+		return ret;
+	}
+
+	regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
+			BERLIN2_SM_CTRL_ADC_START, 0);
+
+	data = priv->data;
+	priv->data = -1;
+	priv->data_available = false;
+
+	mutex_unlock(&priv->lock);
+
+	return data;
+}
+
+static int berlin2_adc_tsen_read(struct iio_dev *indio_dev)
+{
+	struct berlin2_adc_priv *priv = iio_priv(indio_dev);
+	int data, ret;
+
+	mutex_lock(&priv->lock);
+
+	/* Configure the ADC */
+	regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
+			BERLIN2_SM_CTRL_TSEN_RESET | BERLIN2_SM_CTRL_ADC_ROTATE,
+			BERLIN2_SM_CTRL_ADC_ROTATE);
+
+	/* Configure the temperature sensor */
+	regmap_update_bits(priv->regmap, BERLIN2_SM_TSEN_CTRL,
+			BERLIN2_SM_TSEN_CTRL_TRIM_MASK | BERLIN2_SM_TSEN_CTRL_SETTLING_MASK
+			| BERLIN2_SM_TSEN_CTRL_START,
+			BERLIN2_SM_TSEN_CTRL_TRIM(3) | BERLIN2_SM_TSEN_CTRL_SETTLING_12
+			| BERLIN2_SM_TSEN_CTRL_START);
+
+	/* Enable interrupts */
+	regmap_write(priv->regmap, BERLIN2_SM_TSEN_STATUS,
+			BERLIN2_SM_TSEN_STATUS_INT_EN);
+
+	ret = wait_event_interruptible_timeout(priv->wq, priv->data_available,
+			msecs_to_jiffies(1000));
+
+	/* Disable interrupts */
+	regmap_update_bits(priv->regmap, BERLIN2_SM_TSEN_STATUS,
+			BERLIN2_SM_TSEN_STATUS_INT_EN, 0);
+
+	if (ret == 0)
+		ret = -ETIMEDOUT;
+	if (ret < 0) {
+		mutex_unlock(&priv->lock);
+		return ret;
+	}
+
+	regmap_update_bits(priv->regmap, BERLIN2_SM_TSEN_CTRL,
+			BERLIN2_SM_TSEN_CTRL_START, 0);
+
+	data = priv->data;
+	priv->data = -1;
+	priv->data_available = false;
+
+	mutex_unlock(&priv->lock);
+
+	return data;
+}
+
+static int berlin2_adc_read_raw(struct iio_dev *indio_dev,
+		struct iio_chan_spec const *chan, int *val, int *val2,
+		long mask)
+{
+	int temp;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		if (chan->type != IIO_VOLTAGE)
+			return -EINVAL;
+
+		*val = berlin2_adc_read(indio_dev, chan->channel);
+		if (*val < 0)
+			return *val;
+
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_PROCESSED:
+		if (chan->type != IIO_TEMP)
+			return -EINVAL;
+
+		temp = berlin2_adc_tsen_read(indio_dev);
+		if (temp < 0)
+			return temp;
+
+		if (temp > 2047)
+			temp = -(4096 - temp);
+
+		/* Convert to Celsius */
+		*val = (temp * 100) / 264 - 270;
+		return IIO_VAL_INT;
+	default:
+		break;
+	}
+
+	return -EINVAL;
+}
+
+static irqreturn_t berlin2_adc_irq(int irq, void *private)
+{
+	struct iio_dev *indio_dev = private;
+	struct berlin2_adc_priv *priv = iio_priv(indio_dev);
+	unsigned val;
+
+	regmap_read(priv->regmap, BERLIN2_SM_ADC_STATUS, &val);
+	if (val & BERLIN2_SM_ADC_STATUS_DATA_RDY_MASK) {
+		regmap_read(priv->regmap, BERLIN2_SM_ADC_DATA, &priv->data);
+		priv->data &= BERLIN2_SM_ADC_MASK;
+
+		val &= ~BERLIN2_SM_ADC_STATUS_DATA_RDY_MASK;
+		regmap_write(priv->regmap, BERLIN2_SM_ADC_STATUS, val);
+
+		priv->data_available = true;
+		wake_up_interruptible(&priv->wq);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t berlin2_adc_tsen_irq(int irq, void *private)
+{
+	struct iio_dev *indio_dev = private;
+	struct berlin2_adc_priv *priv = iio_priv(indio_dev);
+	unsigned val;
+
+	regmap_read(priv->regmap, BERLIN2_SM_TSEN_STATUS, &val);
+	if (val & BERLIN2_SM_TSEN_STATUS_DATA_RDY) {
+		regmap_read(priv->regmap, BERLIN2_SM_TSEN_DATA, &priv->data);
+		priv->data &= BERLIN2_SM_TSEN_MASK;
+
+		val &= ~BERLIN2_SM_TSEN_STATUS_DATA_RDY;
+		regmap_write(priv->regmap, BERLIN2_SM_TSEN_STATUS, val);
+
+		priv->data_available = true;
+		wake_up_interruptible(&priv->wq);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static const struct iio_info berlin2_adc_info = {
+	.driver_module	= THIS_MODULE,
+	.read_raw	= berlin2_adc_read_raw,
+};
+
+static int berlin2_adc_probe(struct platform_device *pdev)
+{
+	struct iio_dev *indio_dev;
+	struct berlin2_adc_priv *priv;
+	struct device_node *parent_np = of_get_parent(pdev->dev.of_node);
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(&pdev->dev,
+					  sizeof(struct berlin2_adc_priv));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	priv = iio_priv(indio_dev);
+	platform_set_drvdata(pdev, indio_dev);
+
+	priv->regmap = syscon_node_to_regmap(parent_np);
+	of_node_put(parent_np);
+	if (IS_ERR(priv->regmap))
+		return PTR_ERR(priv->regmap);
+
+	priv->irq = platform_get_irq_byname(pdev, "adc");
+	if (priv->irq < 0)
+		return -ENODEV;
+
+	priv->tsen_irq = platform_get_irq_byname(pdev, "tsen");
+	if (priv->tsen_irq < 0)
+		return -ENODEV;
+
+	ret = devm_request_irq(&pdev->dev, priv->irq, berlin2_adc_irq, 0,
+			pdev->dev.driver->name, indio_dev);
+	if (ret)
+		return ret;
+
+	ret = devm_request_irq(&pdev->dev, priv->tsen_irq, berlin2_adc_tsen_irq,
+			0, pdev->dev.driver->name, indio_dev);
+	if (ret)
+		return ret;
+
+	init_waitqueue_head(&priv->wq);
+	mutex_init(&priv->lock);
+
+	indio_dev->dev.parent = &pdev->dev;
+	indio_dev->name = dev_name(&pdev->dev);
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->info = &berlin2_adc_info;
+
+	indio_dev->num_channels = BERLIN2_N_CHANNELS;
+	indio_dev->channels = berlin2_adc_channels;
+
+	/* Power up the ADC */
+	regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
+			BERLIN2_SM_CTRL_ADC_POWER, BERLIN2_SM_CTRL_ADC_POWER);
+
+	return devm_iio_device_register(&pdev->dev, indio_dev);
+}
+
+static int berlin2_adc_remove(struct platform_device *pdev)
+{
+	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+	struct berlin2_adc_priv *priv = iio_priv(indio_dev);
+
+	iio_device_unregister(indio_dev);
+
+	/* Power down the ADC */
+	regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
+			BERLIN2_SM_CTRL_ADC_POWER, 0);
+
+	free_irq(priv->irq, indio_dev);
+	free_irq(priv->tsen_irq, indio_dev);
+
+	iio_device_free(indio_dev);
+
+	return 0;
+}
+
+static const struct of_device_id berlin2_adc_match[] = {
+	{ .compatible = "marvell,berlin2-adc", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, berlin2q_adc_match);
+
+static struct platform_driver berlin2_adc_driver = {
+	.driver	= {
+		.name		= "berlin2-adc",
+		.of_match_table	= berlin2_adc_match,
+	},
+	.probe	= berlin2_adc_probe,
+	.remove	= berlin2_adc_remove,
+};
+module_platform_driver(berlin2_adc_driver);
+
+MODULE_AUTHOR("Antoine Tenart <antoine.tenart@free-electrons.com>");
+MODULE_DESCRIPTION("Marvell Berlin2 ADC driver");
+MODULE_LICENSE("GPL v2");
-- 
2.3.4

[PATCH v2 2/4] Documentation: bindings: document the Berlin ADC driver

[Antoine Tenart]

Following the addition of a Berlin ADC driver, this patch adds the
corresponding bindings documentation.

Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
---
 .../devicetree/bindings/iio/adc/berlin2_adc.txt       | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/adc/berlin2_adc.txt

diff --git a/Documentation/devicetree/bindings/iio/adc/berlin2_adc.txt b/Documentation/devicetree/bindings/iio/adc/berlin2_adc.txt
new file mode 100644
index 000000000000..908334c6b07f
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/adc/berlin2_adc.txt
@@ -0,0 +1,19 @@
+* Berlin Analog to Digital Converter (ADC)
+
+The Berlin ADC has 8 channels, with one connected to a temperature sensor.
+It is part of the system controller register set. The ADC node should be a
+sub-node of the system controller node.
+
+Required properties:
+- compatible: must be "marvell,berlin2-adc"
+- interrupts: the interrupts for the ADC and the temperature sensor
+- interrupt-names: should be "adc" and "tsen"
+
+Example:
+
+adc: adc {
+	compatible = "marvell,berlin2-adc";
+	interrupt-parent = <&sic>;
+	interrupts = <12>, <14>;
+	interrupt-names = "adc", "tsen";
+};
-- 
2.3.4

[PATCH v2 2/4] Documentation: bindings: document the Berlin ADC driver

[Antoine Tenart]

Following the addition of a Berlin ADC driver, this patch adds the
corresponding bindings documentation.

Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
---
 .../devicetree/bindings/iio/adc/berlin2_adc.txt       | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/adc/berlin2_adc.txt

diff --git a/Documentation/devicetree/bindings/iio/adc/berlin2_adc.txt b/Documentation/devicetree/bindings/iio/adc/berlin2_adc.txt
new file mode 100644
index 000000000000..908334c6b07f
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/adc/berlin2_adc.txt
@@ -0,0 +1,19 @@
+* Berlin Analog to Digital Converter (ADC)
+
+The Berlin ADC has 8 channels, with one connected to a temperature sensor.
+It is part of the system controller register set. The ADC node should be a
+sub-node of the system controller node.
+
+Required properties:
+- compatible: must be "marvell,berlin2-adc"
+- interrupts: the interrupts for the ADC and the temperature sensor
+- interrupt-names: should be "adc" and "tsen"
+
+Example:
+
+adc: adc {
+	compatible = "marvell,berlin2-adc";
+	interrupt-parent = <&sic>;
+	interrupts = <12>, <14>;
+	interrupt-names = "adc", "tsen";
+};
-- 
2.3.4

[PATCH v2 3/4] ARM: berlin: add an ADC node for the BG2Q

[Antoine Tenart]

This patch adds the ADC node for the Berlin BG2Q, using the newly added
Berlin IIO ADC driver.

Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
---
 arch/arm/boot/dts/berlin2q.dtsi | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/arch/arm/boot/dts/berlin2q.dtsi b/arch/arm/boot/dts/berlin2q.dtsi
index 187d056f7ad2..72b1c969a99d 100644
--- a/arch/arm/boot/dts/berlin2q.dtsi
+++ b/arch/arm/boot/dts/berlin2q.dtsi
@@ -565,6 +565,14 @@
 						function = "twsi3";
 					};
 				};
+
+				adc: adc {
+					compatible = "marvell,berlin2-adc";
+					interrupt-parent = <&sic>;
+					interrupts = <12>, <14>;
+					interrupt-names = "adc", "tsen";
+					status = "disabled";
+				};
 			};
 
 			sic: interrupt-controller@e000 {
-- 
2.3.4

[PATCH v2 3/4] ARM: berlin: add an ADC node for the BG2Q

[Antoine Tenart]

This patch adds the ADC node for the Berlin BG2Q, using the newly added
Berlin IIO ADC driver.

Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
---
 arch/arm/boot/dts/berlin2q.dtsi | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/arch/arm/boot/dts/berlin2q.dtsi b/arch/arm/boot/dts/berlin2q.dtsi
index 187d056f7ad2..72b1c969a99d 100644
--- a/arch/arm/boot/dts/berlin2q.dtsi
+++ b/arch/arm/boot/dts/berlin2q.dtsi
@@ -565,6 +565,14 @@
 						function = "twsi3";
 					};
 				};
+
+				adc: adc {
+					compatible = "marvell,berlin2-adc";
+					interrupt-parent = <&sic>;
+					interrupts = <12>, <14>;
+					interrupt-names = "adc", "tsen";
+					status = "disabled";
+				};
 			};
 
 			sic: interrupt-controller at e000 {
-- 
2.3.4

[PATCH v2 4/4] ARM: berlin: enable the ADC on the BG2Q DMP

[Antoine Tenart]

An ADC node is now available in the BG2Q SoC device tree. Enable it on
the BG2Q DMP board.

Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
---
 arch/arm/boot/dts/berlin2q-marvell-dmp.dts | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/arm/boot/dts/berlin2q-marvell-dmp.dts b/arch/arm/boot/dts/berlin2q-marvell-dmp.dts
index a98ac1bd8f65..a6de0039e5bc 100644
--- a/arch/arm/boot/dts/berlin2q-marvell-dmp.dts
+++ b/arch/arm/boot/dts/berlin2q-marvell-dmp.dts
@@ -112,3 +112,7 @@
 &sata_phy {
 	status = "okay";
 };
+
+&adc {
+	status = "okay";
+};
-- 
2.3.4

[PATCH v2 4/4] ARM: berlin: enable the ADC on the BG2Q DMP

[Antoine Tenart]

An ADC node is now available in the BG2Q SoC device tree. Enable it on
the BG2Q DMP board.

Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
---
 arch/arm/boot/dts/berlin2q-marvell-dmp.dts | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/arm/boot/dts/berlin2q-marvell-dmp.dts b/arch/arm/boot/dts/berlin2q-marvell-dmp.dts
index a98ac1bd8f65..a6de0039e5bc 100644
--- a/arch/arm/boot/dts/berlin2q-marvell-dmp.dts
+++ b/arch/arm/boot/dts/berlin2q-marvell-dmp.dts
@@ -112,3 +112,7 @@
 &sata_phy {
 	status = "okay";
 };
+
+&adc {
+	status = "okay";
+};
-- 
2.3.4

Re: [PATCH v2 3/4] ARM: berlin: add an ADC node for the BG2Q

[Sebastian Hesselbarth]

On 03.04.2015 15:06, Antoine Tenart wrote:
> This patch adds the ADC node for the Berlin BG2Q, using the newly added
> Berlin IIO ADC driver.
>
> Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
> ---
>   arch/arm/boot/dts/berlin2q.dtsi | 8 ++++++++
>   1 file changed, 8 insertions(+)
>
> diff --git a/arch/arm/boot/dts/berlin2q.dtsi b/arch/arm/boot/dts/berlin2q.dtsi
> index 187d056f7ad2..72b1c969a99d 100644
> --- a/arch/arm/boot/dts/berlin2q.dtsi
> +++ b/arch/arm/boot/dts/berlin2q.dtsi
> @@ -565,6 +565,14 @@
>   						function = "twsi3";
>   					};
>   				};
> +
> +				adc: adc {
> +					compatible = "marvell,berlin2-adc";
> +					interrupt-parent = <&sic>;
> +					interrupts = <12>, <14>;
> +					interrupt-names = "adc", "tsen";
> +					status = "disabled";
> +				};

Antoine,

nit: there is no gated clock for the ADC, I guess we can just always
enable it. That will save you the last patch of the series.

BTW, I have the strong feeling that moving berlin's clk drivers to
regmap will block any subsequent patches you are preparing. How about
we target the next merge window for moving the clk node but not the
drivers (except of_iomap of the _parent's_ reg property) and push the
less controversal patches (pinctrl, reset) with regmap/syscon forward?

Sebastian

>   			};
>
>   			sic: interrupt-controller@e000 {
>

[PATCH v2 3/4] ARM: berlin: add an ADC node for the BG2Q

[Sebastian Hesselbarth]

On 03.04.2015 15:06, Antoine Tenart wrote:
> This patch adds the ADC node for the Berlin BG2Q, using the newly added
> Berlin IIO ADC driver.
>
> Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
> ---
>   arch/arm/boot/dts/berlin2q.dtsi | 8 ++++++++
>   1 file changed, 8 insertions(+)
>
> diff --git a/arch/arm/boot/dts/berlin2q.dtsi b/arch/arm/boot/dts/berlin2q.dtsi
> index 187d056f7ad2..72b1c969a99d 100644
> --- a/arch/arm/boot/dts/berlin2q.dtsi
> +++ b/arch/arm/boot/dts/berlin2q.dtsi
> @@ -565,6 +565,14 @@
>   						function = "twsi3";
>   					};
>   				};
> +
> +				adc: adc {
> +					compatible = "marvell,berlin2-adc";
> +					interrupt-parent = <&sic>;
> +					interrupts = <12>, <14>;
> +					interrupt-names = "adc", "tsen";
> +					status = "disabled";
> +				};

Antoine,

nit: there is no gated clock for the ADC, I guess we can just always
enable it. That will save you the last patch of the series.

BTW, I have the strong feeling that moving berlin's clk drivers to
regmap will block any subsequent patches you are preparing. How about
we target the next merge window for moving the clk node but not the
drivers (except of_iomap of the _parent's_ reg property) and push the
less controversal patches (pinctrl, reset) with regmap/syscon forward?

Sebastian

>   			};
>
>   			sic: interrupt-controller at e000 {
>

Re: [PATCH v2 3/4] ARM: berlin: add an ADC node for the BG2Q

[Antoine Tenart]

Sebastian,

On Sat, Apr 04, 2015 at 12:25:56PM +0200, Sebastian Hesselbarth wrote:
> On 03.04.2015 15:06, Antoine Tenart wrote:
> >This patch adds the ADC node for the Berlin BG2Q, using the newly added
> >Berlin IIO ADC driver.
> >
> >Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
> >---
> >  arch/arm/boot/dts/berlin2q.dtsi | 8 ++++++++
> >  1 file changed, 8 insertions(+)
> >
> >diff --git a/arch/arm/boot/dts/berlin2q.dtsi b/arch/arm/boot/dts/berlin2q.dtsi
> >index 187d056f7ad2..72b1c969a99d 100644
> >--- a/arch/arm/boot/dts/berlin2q.dtsi
> >+++ b/arch/arm/boot/dts/berlin2q.dtsi
> >@@ -565,6 +565,14 @@
> >  						function = "twsi3";
> >  					};
> >  				};
> >+
> >+				adc: adc {
> >+					compatible = "marvell,berlin2-adc";
> >+					interrupt-parent = <&sic>;
> >+					interrupts = <12>, <14>;
> >+					interrupt-names = "adc", "tsen";
> >+					status = "disabled";
> >+				};
> 
> nit: there is no gated clock for the ADC, I guess we can just always
> enable it. That will save you the last patch of the series.

Sure, we can just drop the last patch (and the status property).

> BTW, I have the strong feeling that moving berlin's clk drivers to
> regmap will block any subsequent patches you are preparing. How about
> we target the next merge window for moving the clk node but not the
> drivers (except of_iomap of the _parent's_ reg property) and push the
> less controversal patches (pinctrl, reset) with regmap/syscon forward?

The entire clock rework series does not affect this ADC series or any
other on going series. It can be merged latter, without breaking
anything. I just realized I mentioned the clock rework series as a
dependency in the cover letter of this series but it is not, my bad.

So, we can target the next merge window for all series but the clock
rework. In addition to this, I can send a series moving the clock node,
with minor modifications to the driver so we have a proper dt. And then
we can see if moving to a regmap aware clock driver can be done.

To sum up:
- chip/system controller series can be pushed
- this ADC series too, as it does not depend on the clock rework (as
  soon as we have the needed acked-by)
- I need to make a new series to move the clock node
- the clock driver rework series can live in parallel

Agreed?

Antoine

-- 
Antoine Ténart, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

[PATCH v2 3/4] ARM: berlin: add an ADC node for the BG2Q

[Antoine Tenart]

Sebastian,

On Sat, Apr 04, 2015 at 12:25:56PM +0200, Sebastian Hesselbarth wrote:
> On 03.04.2015 15:06, Antoine Tenart wrote:
> >This patch adds the ADC node for the Berlin BG2Q, using the newly added
> >Berlin IIO ADC driver.
> >
> >Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
> >---
> >  arch/arm/boot/dts/berlin2q.dtsi | 8 ++++++++
> >  1 file changed, 8 insertions(+)
> >
> >diff --git a/arch/arm/boot/dts/berlin2q.dtsi b/arch/arm/boot/dts/berlin2q.dtsi
> >index 187d056f7ad2..72b1c969a99d 100644
> >--- a/arch/arm/boot/dts/berlin2q.dtsi
> >+++ b/arch/arm/boot/dts/berlin2q.dtsi
> >@@ -565,6 +565,14 @@
> >  						function = "twsi3";
> >  					};
> >  				};
> >+
> >+				adc: adc {
> >+					compatible = "marvell,berlin2-adc";
> >+					interrupt-parent = <&sic>;
> >+					interrupts = <12>, <14>;
> >+					interrupt-names = "adc", "tsen";
> >+					status = "disabled";
> >+				};
> 
> nit: there is no gated clock for the ADC, I guess we can just always
> enable it. That will save you the last patch of the series.

Sure, we can just drop the last patch (and the status property).

> BTW, I have the strong feeling that moving berlin's clk drivers to
> regmap will block any subsequent patches you are preparing. How about
> we target the next merge window for moving the clk node but not the
> drivers (except of_iomap of the _parent's_ reg property) and push the
> less controversal patches (pinctrl, reset) with regmap/syscon forward?

The entire clock rework series does not affect this ADC series or any
other on going series. It can be merged latter, without breaking
anything. I just realized I mentioned the clock rework series as a
dependency in the cover letter of this series but it is not, my bad.

So, we can target the next merge window for all series but the clock
rework. In addition to this, I can send a series moving the clock node,
with minor modifications to the driver so we have a proper dt. And then
we can see if moving to a regmap aware clock driver can be done.

To sum up:
- chip/system controller series can be pushed
- this ADC series too, as it does not depend on the clock rework (as
  soon as we have the needed acked-by)
- I need to make a new series to move the clock node
- the clock driver rework series can live in parallel

Agreed?

Antoine

-- 
Antoine T?nart, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

Re: [PATCH v2 3/4] ARM: berlin: add an ADC node for the BG2Q

[Sebastian Hesselbarth]

On 07.04.2015 12:20, Antoine Tenart wrote:
> On Sat, Apr 04, 2015 at 12:25:56PM +0200, Sebastian Hesselbarth wrote:
>> On 03.04.2015 15:06, Antoine Tenart wrote:
>>> This patch adds the ADC node for the Berlin BG2Q, using the newly added
>>> Berlin IIO ADC driver.
>>>
>>> Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
>>> ---
>>>   arch/arm/boot/dts/berlin2q.dtsi | 8 ++++++++
>>>   1 file changed, 8 insertions(+)
>>>
>>> diff --git a/arch/arm/boot/dts/berlin2q.dtsi b/arch/arm/boot/dts/berlin2q.dtsi
>>> index 187d056f7ad2..72b1c969a99d 100644
>>> --- a/arch/arm/boot/dts/berlin2q.dtsi
>>> +++ b/arch/arm/boot/dts/berlin2q.dtsi
>>> @@ -565,6 +565,14 @@
>>>   						function = "twsi3";
>>>   					};
>>>   				};
>>> +
>>> +				adc: adc {
>>> +					compatible = "marvell,berlin2-adc";
>>> +					interrupt-parent = <&sic>;
>>> +					interrupts = <12>, <14>;
>>> +					interrupt-names = "adc", "tsen";
>>> +					status = "disabled";
>>> +				};
>>
>> nit: there is no gated clock for the ADC, I guess we can just always
>> enable it. That will save you the last patch of the series.
>
> Sure, we can just drop the last patch (and the status property).

Ok.

>> BTW, I have the strong feeling that moving berlin's clk drivers to
>> regmap will block any subsequent patches you are preparing. How about
>> we target the next merge window for moving the clk node but not the
>> drivers (except of_iomap of the _parent's_ reg property) and push the
>> less controversal patches (pinctrl, reset) with regmap/syscon forward?
>
> The entire clock rework series does not affect this ADC series or any
> other on going series. It can be merged latter, without breaking
> anything. I just realized I mentioned the clock rework series as a
> dependency in the cover letter of this series but it is not, my bad.
>
> So, we can target the next merge window for all series but the clock
> rework. In addition to this, I can send a series moving the clock node,
> with minor modifications to the driver so we have a proper dt. And then
> we can see if moving to a regmap aware clock driver can be done.
>
> To sum up:
> - chip/system controller series can be pushed

Ok, I'll pick it up once 4.0 drops.

> - this ADC series too, as it does not depend on the clock rework (as
>    soon as we have the needed acked-by)

Ok, once the ACKs are there, I'll pick it up too.

> - I need to make a new series to move the clock node

Great.

> - the clock driver rework series can live in parallel

Good.

> Agreed?

Definitely :)

Sebastian

[PATCH v2 3/4] ARM: berlin: add an ADC node for the BG2Q

[Sebastian Hesselbarth]

On 07.04.2015 12:20, Antoine Tenart wrote:
> On Sat, Apr 04, 2015 at 12:25:56PM +0200, Sebastian Hesselbarth wrote:
>> On 03.04.2015 15:06, Antoine Tenart wrote:
>>> This patch adds the ADC node for the Berlin BG2Q, using the newly added
>>> Berlin IIO ADC driver.
>>>
>>> Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
>>> ---
>>>   arch/arm/boot/dts/berlin2q.dtsi | 8 ++++++++
>>>   1 file changed, 8 insertions(+)
>>>
>>> diff --git a/arch/arm/boot/dts/berlin2q.dtsi b/arch/arm/boot/dts/berlin2q.dtsi
>>> index 187d056f7ad2..72b1c969a99d 100644
>>> --- a/arch/arm/boot/dts/berlin2q.dtsi
>>> +++ b/arch/arm/boot/dts/berlin2q.dtsi
>>> @@ -565,6 +565,14 @@
>>>   						function = "twsi3";
>>>   					};
>>>   				};
>>> +
>>> +				adc: adc {
>>> +					compatible = "marvell,berlin2-adc";
>>> +					interrupt-parent = <&sic>;
>>> +					interrupts = <12>, <14>;
>>> +					interrupt-names = "adc", "tsen";
>>> +					status = "disabled";
>>> +				};
>>
>> nit: there is no gated clock for the ADC, I guess we can just always
>> enable it. That will save you the last patch of the series.
>
> Sure, we can just drop the last patch (and the status property).

Ok.

>> BTW, I have the strong feeling that moving berlin's clk drivers to
>> regmap will block any subsequent patches you are preparing. How about
>> we target the next merge window for moving the clk node but not the
>> drivers (except of_iomap of the _parent's_ reg property) and push the
>> less controversal patches (pinctrl, reset) with regmap/syscon forward?
>
> The entire clock rework series does not affect this ADC series or any
> other on going series. It can be merged latter, without breaking
> anything. I just realized I mentioned the clock rework series as a
> dependency in the cover letter of this series but it is not, my bad.
>
> So, we can target the next merge window for all series but the clock
> rework. In addition to this, I can send a series moving the clock node,
> with minor modifications to the driver so we have a proper dt. And then
> we can see if moving to a regmap aware clock driver can be done.
>
> To sum up:
> - chip/system controller series can be pushed

Ok, I'll pick it up once 4.0 drops.

> - this ADC series too, as it does not depend on the clock rework (as
>    soon as we have the needed acked-by)

Ok, once the ACKs are there, I'll pick it up too.

> - I need to make a new series to move the clock node

Great.

> - the clock driver rework series can live in parallel

Good.

> Agreed?

Definitely :)

Sebastian

Re: [PATCH v2 1/4] iio: adc: add support for Berlin

[Jonathan Cameron]

On 03/04/15 14:06, Antoine Tenart wrote:
> This patch adds the support of the Berlin ADC, available on Berlin SoCs.
> This ADC has 8 channels available, with one connected to a temperature
> sensor.
> 
> The particularity here, is that the temperature sensor connected to the
> ADC has its own registers, and both the ADC and the temperature sensor
> must be configured when using it.
> 
> Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
Few bits and bobs inline.  However, big one is that you've gotten
confused on how the devm managed allocations work....
Also a lot of care is needed with using devm_iio_device_register.
It only makes sense in really simple devices where there really is nothing
to do on device removal...

> ---
>  drivers/iio/adc/Kconfig       |   7 +
>  drivers/iio/adc/Makefile      |   1 +
>  drivers/iio/adc/berlin2-adc.c | 379 ++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 387 insertions(+)
>  create mode 100644 drivers/iio/adc/berlin2-adc.c
> 
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index 202daf889be2..92cc40fd5e71 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -135,6 +135,13 @@ config AXP288_ADC
>  	  device. Depending on platform configuration, this general purpose ADC can
>  	  be used for sampling sensors such as thermal resistors.
>  
> +config BERLIN2_ADC
> +	tristate "Marvell Berlin2 ADC driver"
> +	depends on ARCH_BERLIN
> +	help
> +	  Marvell Berlin2 ADC driver. This ADC has 8 channels, with one used for
> +	  temperature measurement.
> +
>  config CC10001_ADC
>  	tristate "Cosmic Circuits 10001 ADC driver"
>  	depends on HAS_IOMEM || HAVE_CLK || REGULATOR
> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
> index 0315af640866..2b6dadaf7714 100644
> --- a/drivers/iio/adc/Makefile
> +++ b/drivers/iio/adc/Makefile
> @@ -15,6 +15,7 @@ obj-$(CONFIG_AD7887) += ad7887.o
>  obj-$(CONFIG_AD799X) += ad799x.o
>  obj-$(CONFIG_AT91_ADC) += at91_adc.o
>  obj-$(CONFIG_AXP288_ADC) += axp288_adc.o
> +obj-$(CONFIG_BERLIN2_ADC) += berlin2-adc.o
>  obj-$(CONFIG_CC10001_ADC) += cc10001_adc.o
>  obj-$(CONFIG_EXYNOS_ADC) += exynos_adc.o
>  obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o
> diff --git a/drivers/iio/adc/berlin2-adc.c b/drivers/iio/adc/berlin2-adc.c
> new file mode 100644
> index 000000000000..cd21fefc403e
> --- /dev/null
> +++ b/drivers/iio/adc/berlin2-adc.c
> @@ -0,0 +1,379 @@
> +/*
> + * Marvell Berlin2 ADC driver
> + *
> + * Copyright (C) 2015 Marvell Technology Group Ltd.
> + *
> + * Antoine Tenart <antoine.tenart@free-electrons.com>
> + *
> + * This file is licensed under the terms of the GNU General Public
> + * License version 2. This program is licensed "as is" without any
> + * warranty of any kind, whether express or implied.
> + */
> +
> +#include <linux/iio/iio.h>
> +#include <linux/iio/driver.h>
> +#include <linux/iio/machine.h>
> +#include <linux/interrupt.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/regmap.h>
> +#include <linux/sched.h>
> +#include <linux/wait.h>
> +
> +#define BERLIN2_SM_CTRL				0x14
> +#define  BERLIN2_SM_CTRL_SM_SOC_INT		BIT(1)
> +#define  BERLIN2_SM_CTRL_SOC_SM_INT		BIT(2)
> +#define  BERLIN2_SM_CTRL_ADC_SEL(x)		(BIT(x) << 5)	/* 0-15 */
> +#define  BERLIN2_SM_CTRL_ADC_SEL_MASK		(0xf << 5)
> +#define  BERLIN2_SM_CTRL_ADC_POWER		BIT(9)
> +#define  BERLIN2_SM_CTRL_ADC_CLKSEL_DIV2	(0x0 << 10)
> +#define  BERLIN2_SM_CTRL_ADC_CLKSEL_DIV3	(0x1 << 10)
> +#define  BERLIN2_SM_CTRL_ADC_CLKSEL_DIV4	(0x2 << 10)
> +#define  BERLIN2_SM_CTRL_ADC_CLKSEL_DIV8	(0x3 << 10)
> +#define  BERLIN2_SM_CTRL_ADC_CLKSEL_MASK	(0x3 << 10)
> +#define  BERLIN2_SM_CTRL_ADC_START		BIT(12)
> +#define  BERLIN2_SM_CTRL_ADC_RESET		BIT(13)
> +#define  BERLIN2_SM_CTRL_ADC_BANDGAP_RDY	BIT(14)
> +#define  BERLIN2_SM_CTRL_ADC_CONT_SINGLE	(0x0 << 15)
> +#define  BERLIN2_SM_CTRL_ADC_CONT_CONTINUOUS	(0x1 << 15)
> +#define  BERLIN2_SM_CTRL_ADC_BUFFER_EN		BIT(16)
> +#define  BERLIN2_SM_CTRL_ADC_VREF_EXT		(0x0 << 17)
> +#define  BERLIN2_SM_CTRL_ADC_VREF_INT		(0x1 << 17)
> +#define  BERLIN2_SM_CTRL_ADC_ROTATE		BIT(19)
> +#define  BERLIN2_SM_CTRL_TSEN_EN		BIT(20)
> +#define  BERLIN2_SM_CTRL_TSEN_CLK_SEL_125	(0x0 << 21)	/* 1.25 MHz */
> +#define  BERLIN2_SM_CTRL_TSEN_CLK_SEL_250	(0x1 << 21)	/* 2.5 MHz */
> +#define  BERLIN2_SM_CTRL_TSEN_MODE_0_125	(0x0 << 22)	/* 0-125 C */
> +#define  BERLIN2_SM_CTRL_TSEN_MODE_10_50	(0x1 << 22)	/* 10-50 C */
> +#define  BERLIN2_SM_CTRL_TSEN_RESET		BIT(29)
> +#define BERLIN2_SM_ADC_DATA			0x20
> +#define  BERLIN2_SM_ADC_MASK			0x3ff
> +#define BERLIN2_SM_ADC_STATUS			0x1c
> +#define  BERLIN2_SM_ADC_STATUS_DATA_RDY(x)	BIT(x)		/* 0-15 */
> +#define  BERLIN2_SM_ADC_STATUS_DATA_RDY_MASK	0xf
> +#define  BERLIN2_SM_ADC_STATUS_INT_EN(x)	(BIT(x) << 16)	/* 0-15 */
> +#define  BERLIN2_SM_ADC_STATUS_INT_EN_MASK	(0xf << 16)
> +#define BERLIN2_SM_TSEN_STATUS			0x24
> +#define  BERLIN2_SM_TSEN_STATUS_DATA_RDY	BIT(0)
> +#define  BERLIN2_SM_TSEN_STATUS_INT_EN		BIT(1)
> +#define BERLIN2_SM_TSEN_DATA			0x28
> +#define  BERLIN2_SM_TSEN_MASK			0xfff
> +#define BERLIN2_SM_TSEN_CTRL			0x74
> +#define  BERLIN2_SM_TSEN_CTRL_START		BIT(8)
> +#define  BERLIN2_SM_TSEN_CTRL_SETTLING_4	(0x0 << 21)	/* 4 us */
> +#define  BERLIN2_SM_TSEN_CTRL_SETTLING_12	(0x1 << 21)	/* 12 us */
> +#define  BERLIN2_SM_TSEN_CTRL_SETTLING_MASK	(0x1 << 21)
> +#define  BERLIN2_SM_TSEN_CTRL_TRIM(x)		((x) << 22)
> +#define  BERLIN2_SM_TSEN_CTRL_TRIM_MASK		(0xf << 22)
> +
> +struct berlin2_adc_priv {
> +	struct regmap		*regmap;
> +	struct mutex		lock;
> +	wait_queue_head_t	wq;
> +	int			irq;
> +	int			tsen_irq;
> +	bool			data_available;
> +	int			data;
> +};
> +
> +#define BERLIN2_ADC_CHANNEL(n, t)					\
> +		{							\
> +			.channel	= n,				\
> +			.datasheet_name	= "channel"#n,			\
> +			.type		= t,				\
> +			.indexed	= 1,				\
> +			.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),	\
> +		}
> +
> +static struct iio_chan_spec berlin2_adc_channels[] = {
> +	BERLIN2_ADC_CHANNEL(0, IIO_VOLTAGE),	/* external input */
> +	BERLIN2_ADC_CHANNEL(1, IIO_VOLTAGE),	/* external input */
> +	BERLIN2_ADC_CHANNEL(2, IIO_VOLTAGE),	/* external input */
> +	BERLIN2_ADC_CHANNEL(3, IIO_VOLTAGE),	/* external input */
> +	BERLIN2_ADC_CHANNEL(4, IIO_VOLTAGE),	/* reserved */
> +	BERLIN2_ADC_CHANNEL(5, IIO_VOLTAGE),	/* reserved */
> +	{					/* temperature sensor */
> +		.channel		= 6,
> +		.datasheet_name		= "channel6",
> +		.type			= IIO_TEMP,
> +		.indexed		= 0,
> +		.info_mask_separate	= BIT(IIO_CHAN_INFO_PROCESSED),
> +	},
> +	BERLIN2_ADC_CHANNEL(7, IIO_VOLTAGE),	/* reserved */
> +	IIO_CHAN_SOFT_TIMESTAMP(8),		/* timestamp */
> +};
> +#define BERLIN2_N_CHANNELS	ARRAY_SIZE(berlin2_adc_channels)
> +
> +static int berlin2_adc_read(struct iio_dev *indio_dev, int channel)
> +{
> +	struct berlin2_adc_priv *priv = iio_priv(indio_dev);
> +	int data, ret;
> +
> +	mutex_lock(&priv->lock);
> +
> +	/* Configure the ADC */
> +	regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
> +			BERLIN2_SM_CTRL_ADC_RESET | BERLIN2_SM_CTRL_ADC_SEL_MASK
> +			| BERLIN2_SM_CTRL_ADC_START,
> +			BERLIN2_SM_CTRL_ADC_SEL(channel) | BERLIN2_SM_CTRL_ADC_START);
> +
> +	/* Enable the interrupts */
> +	regmap_write(priv->regmap, BERLIN2_SM_ADC_STATUS,
> +			BERLIN2_SM_ADC_STATUS_INT_EN(channel));
> +
> +	ret = wait_event_interruptible_timeout(priv->wq, priv->data_available,
> +			msecs_to_jiffies(1000));
> +
> +	/* Disable the interrupts */
> +	regmap_update_bits(priv->regmap, BERLIN2_SM_ADC_STATUS,
> +			BERLIN2_SM_ADC_STATUS_INT_EN(channel), 0);
> +
> +	if (ret == 0)
> +		ret = -ETIMEDOUT;
> +	if (ret < 0) {
> +		mutex_unlock(&priv->lock);
> +		return ret;
> +	}
> +
> +	regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
> +			BERLIN2_SM_CTRL_ADC_START, 0);
> +
> +	data = priv->data;
> +	priv->data = -1;
> +	priv->data_available = false;
> +
> +	mutex_unlock(&priv->lock);
> +
> +	return data;
> +}
> +
> +static int berlin2_adc_tsen_read(struct iio_dev *indio_dev)
> +{
> +	struct berlin2_adc_priv *priv = iio_priv(indio_dev);
> +	int data, ret;
> +
> +	mutex_lock(&priv->lock);
> +
> +	/* Configure the ADC */
> +	regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
> +			BERLIN2_SM_CTRL_TSEN_RESET | BERLIN2_SM_CTRL_ADC_ROTATE,
> +			BERLIN2_SM_CTRL_ADC_ROTATE);
> +
> +	/* Configure the temperature sensor */
> +	regmap_update_bits(priv->regmap, BERLIN2_SM_TSEN_CTRL,
> +			BERLIN2_SM_TSEN_CTRL_TRIM_MASK | BERLIN2_SM_TSEN_CTRL_SETTLING_MASK
> +			| BERLIN2_SM_TSEN_CTRL_START,
> +			BERLIN2_SM_TSEN_CTRL_TRIM(3) | BERLIN2_SM_TSEN_CTRL_SETTLING_12
> +			| BERLIN2_SM_TSEN_CTRL_START);
> +
> +	/* Enable interrupts */
> +	regmap_write(priv->regmap, BERLIN2_SM_TSEN_STATUS,
> +			BERLIN2_SM_TSEN_STATUS_INT_EN);
Is there a possible race here?  Depends on whether this is a level interrupt
or an edge triggered one... Would probably expect this just before the
call to start the read.
> +
> +	ret = wait_event_interruptible_timeout(priv->wq, priv->data_available,
> +			msecs_to_jiffies(1000));
> +
> +	/* Disable interrupts */
> +	regmap_update_bits(priv->regmap, BERLIN2_SM_TSEN_STATUS,
> +			BERLIN2_SM_TSEN_STATUS_INT_EN, 0);
> +
> +	if (ret == 0)
> +		ret = -ETIMEDOUT;
> +	if (ret < 0) {
> +		mutex_unlock(&priv->lock);
> +		return ret;
> +	}
> +
> +	regmap_update_bits(priv->regmap, BERLIN2_SM_TSEN_CTRL,
> +			BERLIN2_SM_TSEN_CTRL_START, 0);
> +
> +	data = priv->data;
> +	priv->data = -1;
> +	priv->data_available = false;
> +
> +	mutex_unlock(&priv->lock);
> +
> +	return data;
> +}
> +
> +static int berlin2_adc_read_raw(struct iio_dev *indio_dev,
> +		struct iio_chan_spec const *chan, int *val, int *val2,
> +		long mask)
> +{
> +	int temp;
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_RAW:
> +		if (chan->type != IIO_VOLTAGE)
> +			return -EINVAL;
> +
> +		*val = berlin2_adc_read(indio_dev, chan->channel);
> +		if (*val < 0)
> +			return *val;
> +
> +		return IIO_VAL_INT;
> +	case IIO_CHAN_INFO_PROCESSED:
> +		if (chan->type != IIO_TEMP)
> +			return -EINVAL;
> +
> +		temp = berlin2_adc_tsen_read(indio_dev);
> +		if (temp < 0)
> +			return temp;
> +
> +		if (temp > 2047)
> +			temp = -(4096 - temp);
> +
> +		/* Convert to Celsius */
> +		*val = (temp * 100) / 264 - 270;
> +		return IIO_VAL_INT;
> +	default:
> +		break;
> +	}
> +
> +	return -EINVAL;
> +}
> +
> +static irqreturn_t berlin2_adc_irq(int irq, void *private)
> +{
> +	struct iio_dev *indio_dev = private;
> +	struct berlin2_adc_priv *priv = iio_priv(indio_dev);
> +	unsigned val;
> +
> +	regmap_read(priv->regmap, BERLIN2_SM_ADC_STATUS, &val);
> +	if (val & BERLIN2_SM_ADC_STATUS_DATA_RDY_MASK) {
> +		regmap_read(priv->regmap, BERLIN2_SM_ADC_DATA, &priv->data);
> +		priv->data &= BERLIN2_SM_ADC_MASK;
> +
> +		val &= ~BERLIN2_SM_ADC_STATUS_DATA_RDY_MASK;
> +		regmap_write(priv->regmap, BERLIN2_SM_ADC_STATUS, val);
> +
> +		priv->data_available = true;
> +		wake_up_interruptible(&priv->wq);
> +	}
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static irqreturn_t berlin2_adc_tsen_irq(int irq, void *private)
> +{
> +	struct iio_dev *indio_dev = private;
> +	struct berlin2_adc_priv *priv = iio_priv(indio_dev);
I'd roll the above two lines into one.
struct berlin2_adc_priv *priv = iio_priv(private);

> +	unsigned val;
> +
> +	regmap_read(priv->regmap, BERLIN2_SM_TSEN_STATUS, &val);
> +	if (val & BERLIN2_SM_TSEN_STATUS_DATA_RDY) {
> +		regmap_read(priv->regmap, BERLIN2_SM_TSEN_DATA, &priv->data);
> +		priv->data &= BERLIN2_SM_TSEN_MASK;
> +
> +		val &= ~BERLIN2_SM_TSEN_STATUS_DATA_RDY;
> +		regmap_write(priv->regmap, BERLIN2_SM_TSEN_STATUS, val);
> +
> +		priv->data_available = true;
> +		wake_up_interruptible(&priv->wq);
> +	}
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static const struct iio_info berlin2_adc_info = {
> +	.driver_module	= THIS_MODULE,
> +	.read_raw	= berlin2_adc_read_raw,
> +};
> +
> +static int berlin2_adc_probe(struct platform_device *pdev)
> +{
> +	struct iio_dev *indio_dev;
> +	struct berlin2_adc_priv *priv;
> +	struct device_node *parent_np = of_get_parent(pdev->dev.of_node);
> +	int ret;
> +
> +	indio_dev = devm_iio_device_alloc(&pdev->dev,
> +					  sizeof(struct berlin2_adc_priv));
> +	if (!indio_dev)
> +		return -ENOMEM;
> +
> +	priv = iio_priv(indio_dev);
> +	platform_set_drvdata(pdev, indio_dev);
> +
> +	priv->regmap = syscon_node_to_regmap(parent_np);
> +	of_node_put(parent_np);
> +	if (IS_ERR(priv->regmap))
> +		return PTR_ERR(priv->regmap);
> +
> +	priv->irq = platform_get_irq_byname(pdev, "adc");
> +	if (priv->irq < 0)
> +		return -ENODEV;
> +
> +	priv->tsen_irq = platform_get_irq_byname(pdev, "tsen");
> +	if (priv->tsen_irq < 0)
> +		return -ENODEV;
> +
> +	ret = devm_request_irq(&pdev->dev, priv->irq, berlin2_adc_irq, 0,
> +			pdev->dev.driver->name, indio_dev);
> +	if (ret)
> +		return ret;
> +
> +	ret = devm_request_irq(&pdev->dev, priv->tsen_irq, berlin2_adc_tsen_irq,
> +			0, pdev->dev.driver->name, indio_dev);
> +	if (ret)
> +		return ret;
> +
> +	init_waitqueue_head(&priv->wq);
> +	mutex_init(&priv->lock);
> +
> +	indio_dev->dev.parent = &pdev->dev;
> +	indio_dev->name = dev_name(&pdev->dev);
> +	indio_dev->modes = INDIO_DIRECT_MODE;
> +	indio_dev->info = &berlin2_adc_info;
> +
> +	indio_dev->num_channels = BERLIN2_N_CHANNELS;
> +	indio_dev->channels = berlin2_adc_channels;
> +
> +	/* Power up the ADC */
> +	regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
> +			BERLIN2_SM_CTRL_ADC_POWER, BERLIN2_SM_CTRL_ADC_POWER);
> +
> +	return devm_iio_device_register(&pdev->dev, indio_dev);
you are mixing devm requests with explicit removes in the remove.
You are going to get double frees.

You'll also want to catch any errors from iio_device_register and power down
the device (via the regmap call) if the register fails.

> +}
> +
> +static int berlin2_adc_remove(struct platform_device *pdev)
> +{
> +	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
> +	struct berlin2_adc_priv *priv = iio_priv(indio_dev);
> +
> +	iio_device_unregister(indio_dev);
As you used devm_iio_device_register you don't need to explicitly unregister.
However...
> +
> +	/* Power down the ADC */
> +	regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
> +			BERLIN2_SM_CTRL_ADC_POWER, 0);
If you do use the devm register above then the userspace access to the
hardware will only be removed AFTER the regmap_update_bits here. Hence
there will be a nasty window.  I would suggest not using the
devm_iio_device_register but rather iio_device_register and then keep
the explicit unregister here.

> +
> +	free_irq(priv->irq, indio_dev);
> +	free_irq(priv->tsen_irq, indio_dev);
> +
> +	iio_device_free(indio_dev);
You used devm versions of the irq requests and iio_device alloc.  These
frees should not be here and will result in a double free.
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id berlin2_adc_match[] = {
> +	{ .compatible = "marvell,berlin2-adc", },
> +	{ },
> +};
> +MODULE_DEVICE_TABLE(of, berlin2q_adc_match);
> +
> +static struct platform_driver berlin2_adc_driver = {
> +	.driver	= {
> +		.name		= "berlin2-adc",
> +		.of_match_table	= berlin2_adc_match,
> +	},
> +	.probe	= berlin2_adc_probe,
> +	.remove	= berlin2_adc_remove,
> +};
> +module_platform_driver(berlin2_adc_driver);
> +
> +MODULE_AUTHOR("Antoine Tenart <antoine.tenart@free-electrons.com>");
> +MODULE_DESCRIPTION("Marvell Berlin2 ADC driver");
> +MODULE_LICENSE("GPL v2");
> 

[PATCH v2 1/4] iio: adc: add support for Berlin

[Jonathan Cameron]

On 03/04/15 14:06, Antoine Tenart wrote:
> This patch adds the support of the Berlin ADC, available on Berlin SoCs.
> This ADC has 8 channels available, with one connected to a temperature
> sensor.
> 
> The particularity here, is that the temperature sensor connected to the
> ADC has its own registers, and both the ADC and the temperature sensor
> must be configured when using it.
> 
> Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
Few bits and bobs inline.  However, big one is that you've gotten
confused on how the devm managed allocations work....
Also a lot of care is needed with using devm_iio_device_register.
It only makes sense in really simple devices where there really is nothing
to do on device removal...

> ---
>  drivers/iio/adc/Kconfig       |   7 +
>  drivers/iio/adc/Makefile      |   1 +
>  drivers/iio/adc/berlin2-adc.c | 379 ++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 387 insertions(+)
>  create mode 100644 drivers/iio/adc/berlin2-adc.c
> 
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index 202daf889be2..92cc40fd5e71 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -135,6 +135,13 @@ config AXP288_ADC
>  	  device. Depending on platform configuration, this general purpose ADC can
>  	  be used for sampling sensors such as thermal resistors.
>  
> +config BERLIN2_ADC
> +	tristate "Marvell Berlin2 ADC driver"
> +	depends on ARCH_BERLIN
> +	help
> +	  Marvell Berlin2 ADC driver. This ADC has 8 channels, with one used for
> +	  temperature measurement.
> +
>  config CC10001_ADC
>  	tristate "Cosmic Circuits 10001 ADC driver"
>  	depends on HAS_IOMEM || HAVE_CLK || REGULATOR
> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
> index 0315af640866..2b6dadaf7714 100644
> --- a/drivers/iio/adc/Makefile
> +++ b/drivers/iio/adc/Makefile
> @@ -15,6 +15,7 @@ obj-$(CONFIG_AD7887) += ad7887.o
>  obj-$(CONFIG_AD799X) += ad799x.o
>  obj-$(CONFIG_AT91_ADC) += at91_adc.o
>  obj-$(CONFIG_AXP288_ADC) += axp288_adc.o
> +obj-$(CONFIG_BERLIN2_ADC) += berlin2-adc.o
>  obj-$(CONFIG_CC10001_ADC) += cc10001_adc.o
>  obj-$(CONFIG_EXYNOS_ADC) += exynos_adc.o
>  obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o
> diff --git a/drivers/iio/adc/berlin2-adc.c b/drivers/iio/adc/berlin2-adc.c
> new file mode 100644
> index 000000000000..cd21fefc403e
> --- /dev/null
> +++ b/drivers/iio/adc/berlin2-adc.c
> @@ -0,0 +1,379 @@
> +/*
> + * Marvell Berlin2 ADC driver
> + *
> + * Copyright (C) 2015 Marvell Technology Group Ltd.
> + *
> + * Antoine Tenart <antoine.tenart@free-electrons.com>
> + *
> + * This file is licensed under the terms of the GNU General Public
> + * License version 2. This program is licensed "as is" without any
> + * warranty of any kind, whether express or implied.
> + */
> +
> +#include <linux/iio/iio.h>
> +#include <linux/iio/driver.h>
> +#include <linux/iio/machine.h>
> +#include <linux/interrupt.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/regmap.h>
> +#include <linux/sched.h>
> +#include <linux/wait.h>
> +
> +#define BERLIN2_SM_CTRL				0x14
> +#define  BERLIN2_SM_CTRL_SM_SOC_INT		BIT(1)
> +#define  BERLIN2_SM_CTRL_SOC_SM_INT		BIT(2)
> +#define  BERLIN2_SM_CTRL_ADC_SEL(x)		(BIT(x) << 5)	/* 0-15 */
> +#define  BERLIN2_SM_CTRL_ADC_SEL_MASK		(0xf << 5)
> +#define  BERLIN2_SM_CTRL_ADC_POWER		BIT(9)
> +#define  BERLIN2_SM_CTRL_ADC_CLKSEL_DIV2	(0x0 << 10)
> +#define  BERLIN2_SM_CTRL_ADC_CLKSEL_DIV3	(0x1 << 10)
> +#define  BERLIN2_SM_CTRL_ADC_CLKSEL_DIV4	(0x2 << 10)
> +#define  BERLIN2_SM_CTRL_ADC_CLKSEL_DIV8	(0x3 << 10)
> +#define  BERLIN2_SM_CTRL_ADC_CLKSEL_MASK	(0x3 << 10)
> +#define  BERLIN2_SM_CTRL_ADC_START		BIT(12)
> +#define  BERLIN2_SM_CTRL_ADC_RESET		BIT(13)
> +#define  BERLIN2_SM_CTRL_ADC_BANDGAP_RDY	BIT(14)
> +#define  BERLIN2_SM_CTRL_ADC_CONT_SINGLE	(0x0 << 15)
> +#define  BERLIN2_SM_CTRL_ADC_CONT_CONTINUOUS	(0x1 << 15)
> +#define  BERLIN2_SM_CTRL_ADC_BUFFER_EN		BIT(16)
> +#define  BERLIN2_SM_CTRL_ADC_VREF_EXT		(0x0 << 17)
> +#define  BERLIN2_SM_CTRL_ADC_VREF_INT		(0x1 << 17)
> +#define  BERLIN2_SM_CTRL_ADC_ROTATE		BIT(19)
> +#define  BERLIN2_SM_CTRL_TSEN_EN		BIT(20)
> +#define  BERLIN2_SM_CTRL_TSEN_CLK_SEL_125	(0x0 << 21)	/* 1.25 MHz */
> +#define  BERLIN2_SM_CTRL_TSEN_CLK_SEL_250	(0x1 << 21)	/* 2.5 MHz */
> +#define  BERLIN2_SM_CTRL_TSEN_MODE_0_125	(0x0 << 22)	/* 0-125 C */
> +#define  BERLIN2_SM_CTRL_TSEN_MODE_10_50	(0x1 << 22)	/* 10-50 C */
> +#define  BERLIN2_SM_CTRL_TSEN_RESET		BIT(29)
> +#define BERLIN2_SM_ADC_DATA			0x20
> +#define  BERLIN2_SM_ADC_MASK			0x3ff
> +#define BERLIN2_SM_ADC_STATUS			0x1c
> +#define  BERLIN2_SM_ADC_STATUS_DATA_RDY(x)	BIT(x)		/* 0-15 */
> +#define  BERLIN2_SM_ADC_STATUS_DATA_RDY_MASK	0xf
> +#define  BERLIN2_SM_ADC_STATUS_INT_EN(x)	(BIT(x) << 16)	/* 0-15 */
> +#define  BERLIN2_SM_ADC_STATUS_INT_EN_MASK	(0xf << 16)
> +#define BERLIN2_SM_TSEN_STATUS			0x24
> +#define  BERLIN2_SM_TSEN_STATUS_DATA_RDY	BIT(0)
> +#define  BERLIN2_SM_TSEN_STATUS_INT_EN		BIT(1)
> +#define BERLIN2_SM_TSEN_DATA			0x28
> +#define  BERLIN2_SM_TSEN_MASK			0xfff
> +#define BERLIN2_SM_TSEN_CTRL			0x74
> +#define  BERLIN2_SM_TSEN_CTRL_START		BIT(8)
> +#define  BERLIN2_SM_TSEN_CTRL_SETTLING_4	(0x0 << 21)	/* 4 us */
> +#define  BERLIN2_SM_TSEN_CTRL_SETTLING_12	(0x1 << 21)	/* 12 us */
> +#define  BERLIN2_SM_TSEN_CTRL_SETTLING_MASK	(0x1 << 21)
> +#define  BERLIN2_SM_TSEN_CTRL_TRIM(x)		((x) << 22)
> +#define  BERLIN2_SM_TSEN_CTRL_TRIM_MASK		(0xf << 22)
> +
> +struct berlin2_adc_priv {
> +	struct regmap		*regmap;
> +	struct mutex		lock;
> +	wait_queue_head_t	wq;
> +	int			irq;
> +	int			tsen_irq;
> +	bool			data_available;
> +	int			data;
> +};
> +
> +#define BERLIN2_ADC_CHANNEL(n, t)					\
> +		{							\
> +			.channel	= n,				\
> +			.datasheet_name	= "channel"#n,			\
> +			.type		= t,				\
> +			.indexed	= 1,				\
> +			.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),	\
> +		}
> +
> +static struct iio_chan_spec berlin2_adc_channels[] = {
> +	BERLIN2_ADC_CHANNEL(0, IIO_VOLTAGE),	/* external input */
> +	BERLIN2_ADC_CHANNEL(1, IIO_VOLTAGE),	/* external input */
> +	BERLIN2_ADC_CHANNEL(2, IIO_VOLTAGE),	/* external input */
> +	BERLIN2_ADC_CHANNEL(3, IIO_VOLTAGE),	/* external input */
> +	BERLIN2_ADC_CHANNEL(4, IIO_VOLTAGE),	/* reserved */
> +	BERLIN2_ADC_CHANNEL(5, IIO_VOLTAGE),	/* reserved */
> +	{					/* temperature sensor */
> +		.channel		= 6,
> +		.datasheet_name		= "channel6",
> +		.type			= IIO_TEMP,
> +		.indexed		= 0,
> +		.info_mask_separate	= BIT(IIO_CHAN_INFO_PROCESSED),
> +	},
> +	BERLIN2_ADC_CHANNEL(7, IIO_VOLTAGE),	/* reserved */
> +	IIO_CHAN_SOFT_TIMESTAMP(8),		/* timestamp */
> +};
> +#define BERLIN2_N_CHANNELS	ARRAY_SIZE(berlin2_adc_channels)
> +
> +static int berlin2_adc_read(struct iio_dev *indio_dev, int channel)
> +{
> +	struct berlin2_adc_priv *priv = iio_priv(indio_dev);
> +	int data, ret;
> +
> +	mutex_lock(&priv->lock);
> +
> +	/* Configure the ADC */
> +	regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
> +			BERLIN2_SM_CTRL_ADC_RESET | BERLIN2_SM_CTRL_ADC_SEL_MASK
> +			| BERLIN2_SM_CTRL_ADC_START,
> +			BERLIN2_SM_CTRL_ADC_SEL(channel) | BERLIN2_SM_CTRL_ADC_START);
> +
> +	/* Enable the interrupts */
> +	regmap_write(priv->regmap, BERLIN2_SM_ADC_STATUS,
> +			BERLIN2_SM_ADC_STATUS_INT_EN(channel));
> +
> +	ret = wait_event_interruptible_timeout(priv->wq, priv->data_available,
> +			msecs_to_jiffies(1000));
> +
> +	/* Disable the interrupts */
> +	regmap_update_bits(priv->regmap, BERLIN2_SM_ADC_STATUS,
> +			BERLIN2_SM_ADC_STATUS_INT_EN(channel), 0);
> +
> +	if (ret == 0)
> +		ret = -ETIMEDOUT;
> +	if (ret < 0) {
> +		mutex_unlock(&priv->lock);
> +		return ret;
> +	}
> +
> +	regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
> +			BERLIN2_SM_CTRL_ADC_START, 0);
> +
> +	data = priv->data;
> +	priv->data = -1;
> +	priv->data_available = false;
> +
> +	mutex_unlock(&priv->lock);
> +
> +	return data;
> +}
> +
> +static int berlin2_adc_tsen_read(struct iio_dev *indio_dev)
> +{
> +	struct berlin2_adc_priv *priv = iio_priv(indio_dev);
> +	int data, ret;
> +
> +	mutex_lock(&priv->lock);
> +
> +	/* Configure the ADC */
> +	regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
> +			BERLIN2_SM_CTRL_TSEN_RESET | BERLIN2_SM_CTRL_ADC_ROTATE,
> +			BERLIN2_SM_CTRL_ADC_ROTATE);
> +
> +	/* Configure the temperature sensor */
> +	regmap_update_bits(priv->regmap, BERLIN2_SM_TSEN_CTRL,
> +			BERLIN2_SM_TSEN_CTRL_TRIM_MASK | BERLIN2_SM_TSEN_CTRL_SETTLING_MASK
> +			| BERLIN2_SM_TSEN_CTRL_START,
> +			BERLIN2_SM_TSEN_CTRL_TRIM(3) | BERLIN2_SM_TSEN_CTRL_SETTLING_12
> +			| BERLIN2_SM_TSEN_CTRL_START);
> +
> +	/* Enable interrupts */
> +	regmap_write(priv->regmap, BERLIN2_SM_TSEN_STATUS,
> +			BERLIN2_SM_TSEN_STATUS_INT_EN);
Is there a possible race here?  Depends on whether this is a level interrupt
or an edge triggered one... Would probably expect this just before the
call to start the read.
> +
> +	ret = wait_event_interruptible_timeout(priv->wq, priv->data_available,
> +			msecs_to_jiffies(1000));
> +
> +	/* Disable interrupts */
> +	regmap_update_bits(priv->regmap, BERLIN2_SM_TSEN_STATUS,
> +			BERLIN2_SM_TSEN_STATUS_INT_EN, 0);
> +
> +	if (ret == 0)
> +		ret = -ETIMEDOUT;
> +	if (ret < 0) {
> +		mutex_unlock(&priv->lock);
> +		return ret;
> +	}
> +
> +	regmap_update_bits(priv->regmap, BERLIN2_SM_TSEN_CTRL,
> +			BERLIN2_SM_TSEN_CTRL_START, 0);
> +
> +	data = priv->data;
> +	priv->data = -1;
> +	priv->data_available = false;
> +
> +	mutex_unlock(&priv->lock);
> +
> +	return data;
> +}
> +
> +static int berlin2_adc_read_raw(struct iio_dev *indio_dev,
> +		struct iio_chan_spec const *chan, int *val, int *val2,
> +		long mask)
> +{
> +	int temp;
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_RAW:
> +		if (chan->type != IIO_VOLTAGE)
> +			return -EINVAL;
> +
> +		*val = berlin2_adc_read(indio_dev, chan->channel);
> +		if (*val < 0)
> +			return *val;
> +
> +		return IIO_VAL_INT;
> +	case IIO_CHAN_INFO_PROCESSED:
> +		if (chan->type != IIO_TEMP)
> +			return -EINVAL;
> +
> +		temp = berlin2_adc_tsen_read(indio_dev);
> +		if (temp < 0)
> +			return temp;
> +
> +		if (temp > 2047)
> +			temp = -(4096 - temp);
> +
> +		/* Convert to Celsius */
> +		*val = (temp * 100) / 264 - 270;
> +		return IIO_VAL_INT;
> +	default:
> +		break;
> +	}
> +
> +	return -EINVAL;
> +}
> +
> +static irqreturn_t berlin2_adc_irq(int irq, void *private)
> +{
> +	struct iio_dev *indio_dev = private;
> +	struct berlin2_adc_priv *priv = iio_priv(indio_dev);
> +	unsigned val;
> +
> +	regmap_read(priv->regmap, BERLIN2_SM_ADC_STATUS, &val);
> +	if (val & BERLIN2_SM_ADC_STATUS_DATA_RDY_MASK) {
> +		regmap_read(priv->regmap, BERLIN2_SM_ADC_DATA, &priv->data);
> +		priv->data &= BERLIN2_SM_ADC_MASK;
> +
> +		val &= ~BERLIN2_SM_ADC_STATUS_DATA_RDY_MASK;
> +		regmap_write(priv->regmap, BERLIN2_SM_ADC_STATUS, val);
> +
> +		priv->data_available = true;
> +		wake_up_interruptible(&priv->wq);
> +	}
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static irqreturn_t berlin2_adc_tsen_irq(int irq, void *private)
> +{
> +	struct iio_dev *indio_dev = private;
> +	struct berlin2_adc_priv *priv = iio_priv(indio_dev);
I'd roll the above two lines into one.
struct berlin2_adc_priv *priv = iio_priv(private);

> +	unsigned val;
> +
> +	regmap_read(priv->regmap, BERLIN2_SM_TSEN_STATUS, &val);
> +	if (val & BERLIN2_SM_TSEN_STATUS_DATA_RDY) {
> +		regmap_read(priv->regmap, BERLIN2_SM_TSEN_DATA, &priv->data);
> +		priv->data &= BERLIN2_SM_TSEN_MASK;
> +
> +		val &= ~BERLIN2_SM_TSEN_STATUS_DATA_RDY;
> +		regmap_write(priv->regmap, BERLIN2_SM_TSEN_STATUS, val);
> +
> +		priv->data_available = true;
> +		wake_up_interruptible(&priv->wq);
> +	}
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static const struct iio_info berlin2_adc_info = {
> +	.driver_module	= THIS_MODULE,
> +	.read_raw	= berlin2_adc_read_raw,
> +};
> +
> +static int berlin2_adc_probe(struct platform_device *pdev)
> +{
> +	struct iio_dev *indio_dev;
> +	struct berlin2_adc_priv *priv;
> +	struct device_node *parent_np = of_get_parent(pdev->dev.of_node);
> +	int ret;
> +
> +	indio_dev = devm_iio_device_alloc(&pdev->dev,
> +					  sizeof(struct berlin2_adc_priv));
> +	if (!indio_dev)
> +		return -ENOMEM;
> +
> +	priv = iio_priv(indio_dev);
> +	platform_set_drvdata(pdev, indio_dev);
> +
> +	priv->regmap = syscon_node_to_regmap(parent_np);
> +	of_node_put(parent_np);
> +	if (IS_ERR(priv->regmap))
> +		return PTR_ERR(priv->regmap);
> +
> +	priv->irq = platform_get_irq_byname(pdev, "adc");
> +	if (priv->irq < 0)
> +		return -ENODEV;
> +
> +	priv->tsen_irq = platform_get_irq_byname(pdev, "tsen");
> +	if (priv->tsen_irq < 0)
> +		return -ENODEV;
> +
> +	ret = devm_request_irq(&pdev->dev, priv->irq, berlin2_adc_irq, 0,
> +			pdev->dev.driver->name, indio_dev);
> +	if (ret)
> +		return ret;
> +
> +	ret = devm_request_irq(&pdev->dev, priv->tsen_irq, berlin2_adc_tsen_irq,
> +			0, pdev->dev.driver->name, indio_dev);
> +	if (ret)
> +		return ret;
> +
> +	init_waitqueue_head(&priv->wq);
> +	mutex_init(&priv->lock);
> +
> +	indio_dev->dev.parent = &pdev->dev;
> +	indio_dev->name = dev_name(&pdev->dev);
> +	indio_dev->modes = INDIO_DIRECT_MODE;
> +	indio_dev->info = &berlin2_adc_info;
> +
> +	indio_dev->num_channels = BERLIN2_N_CHANNELS;
> +	indio_dev->channels = berlin2_adc_channels;
> +
> +	/* Power up the ADC */
> +	regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
> +			BERLIN2_SM_CTRL_ADC_POWER, BERLIN2_SM_CTRL_ADC_POWER);
> +
> +	return devm_iio_device_register(&pdev->dev, indio_dev);
you are mixing devm requests with explicit removes in the remove.
You are going to get double frees.

You'll also want to catch any errors from iio_device_register and power down
the device (via the regmap call) if the register fails.

> +}
> +
> +static int berlin2_adc_remove(struct platform_device *pdev)
> +{
> +	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
> +	struct berlin2_adc_priv *priv = iio_priv(indio_dev);
> +
> +	iio_device_unregister(indio_dev);
As you used devm_iio_device_register you don't need to explicitly unregister.
However...
> +
> +	/* Power down the ADC */
> +	regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL,
> +			BERLIN2_SM_CTRL_ADC_POWER, 0);
If you do use the devm register above then the userspace access to the
hardware will only be removed AFTER the regmap_update_bits here. Hence
there will be a nasty window.  I would suggest not using the
devm_iio_device_register but rather iio_device_register and then keep
the explicit unregister here.

> +
> +	free_irq(priv->irq, indio_dev);
> +	free_irq(priv->tsen_irq, indio_dev);
> +
> +	iio_device_free(indio_dev);
You used devm versions of the irq requests and iio_device alloc.  These
frees should not be here and will result in a double free.
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id berlin2_adc_match[] = {
> +	{ .compatible = "marvell,berlin2-adc", },
> +	{ },
> +};
> +MODULE_DEVICE_TABLE(of, berlin2q_adc_match);
> +
> +static struct platform_driver berlin2_adc_driver = {
> +	.driver	= {
> +		.name		= "berlin2-adc",
> +		.of_match_table	= berlin2_adc_match,
> +	},
> +	.probe	= berlin2_adc_probe,
> +	.remove	= berlin2_adc_remove,
> +};
> +module_platform_driver(berlin2_adc_driver);
> +
> +MODULE_AUTHOR("Antoine Tenart <antoine.tenart@free-electrons.com>");
> +MODULE_DESCRIPTION("Marvell Berlin2 ADC driver");
> +MODULE_LICENSE("GPL v2");
> 

Re: [PATCH v2 2/4] Documentation: bindings: document the Berlin ADC driver

[Jonathan Cameron]

On 03/04/15 14:06, Antoine Tenart wrote:
> Following the addition of a Berlin ADC driver, this patch adds the
> corresponding bindings documentation.
> 
> Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
About as straightfoward as they come.

Acked-by: Jonathan Cameron <jic23@kernel.org>
> ---
>  .../devicetree/bindings/iio/adc/berlin2_adc.txt       | 19 +++++++++++++++++++
>  1 file changed, 19 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iio/adc/berlin2_adc.txt
> 
> diff --git a/Documentation/devicetree/bindings/iio/adc/berlin2_adc.txt b/Documentation/devicetree/bindings/iio/adc/berlin2_adc.txt
> new file mode 100644
> index 000000000000..908334c6b07f
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/adc/berlin2_adc.txt
> @@ -0,0 +1,19 @@
> +* Berlin Analog to Digital Converter (ADC)
> +
> +The Berlin ADC has 8 channels, with one connected to a temperature sensor.
> +It is part of the system controller register set. The ADC node should be a
> +sub-node of the system controller node.
> +
> +Required properties:
> +- compatible: must be "marvell,berlin2-adc"
> +- interrupts: the interrupts for the ADC and the temperature sensor
> +- interrupt-names: should be "adc" and "tsen"
> +
> +Example:
> +
> +adc: adc {
> +	compatible = "marvell,berlin2-adc";
> +	interrupt-parent = <&sic>;
> +	interrupts = <12>, <14>;
> +	interrupt-names = "adc", "tsen";
> +};
> 

[PATCH v2 2/4] Documentation: bindings: document the Berlin ADC driver

[Jonathan Cameron]

On 03/04/15 14:06, Antoine Tenart wrote:
> Following the addition of a Berlin ADC driver, this patch adds the
> corresponding bindings documentation.
> 
> Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
About as straightfoward as they come.

Acked-by: Jonathan Cameron <jic23@kernel.org>
> ---
>  .../devicetree/bindings/iio/adc/berlin2_adc.txt       | 19 +++++++++++++++++++
>  1 file changed, 19 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iio/adc/berlin2_adc.txt
> 
> diff --git a/Documentation/devicetree/bindings/iio/adc/berlin2_adc.txt b/Documentation/devicetree/bindings/iio/adc/berlin2_adc.txt
> new file mode 100644
> index 000000000000..908334c6b07f
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/adc/berlin2_adc.txt
> @@ -0,0 +1,19 @@
> +* Berlin Analog to Digital Converter (ADC)
> +
> +The Berlin ADC has 8 channels, with one connected to a temperature sensor.
> +It is part of the system controller register set. The ADC node should be a
> +sub-node of the system controller node.
> +
> +Required properties:
> +- compatible: must be "marvell,berlin2-adc"
> +- interrupts: the interrupts for the ADC and the temperature sensor
> +- interrupt-names: should be "adc" and "tsen"
> +
> +Example:
> +
> +adc: adc {
> +	compatible = "marvell,berlin2-adc";
> +	interrupt-parent = <&sic>;
> +	interrupts = <12>, <14>;
> +	interrupt-names = "adc", "tsen";
> +};
>