[PATCH v5 0/8] Adding support for STMPE811 ADC

[PATCH v5 0/8] Adding support for STMPE811 ADC

[Philippe Schenker]

From: Philippe Schenker <philippe.schenker@toradex.com>

Hello everyone,

This patchset is adding an ADC driver for STMPE811. The STMPE811 is a
Multi-Frontend-Device that supports a touchscreen, ADC, GPIO and a
temperature sensor.

For Touchscreen and GPIO there are already existing drivers in
mainline. This patchset will add support, to read out the ADC and
temperature sensor.
This patchset is also reformatting device tree bindings, so they are
easier to read (PATCH 1/1).
To be able to add this ADC driver it is necessary to move some defines
from the touchscreen driver to the mfd device (PATCH 2/8) so they are
also accessible by mfd and adc driver.
Because the touchscreen driver is also using the internal ADC it makes
sense to put the common adc settings of stmpe-ts.c and stmpe_adc.c to
the MFD. In the MFD there is then also an initialisation for the common
settings of ADC done. The existing initialisation in touchscreen driver
is kept for backwards-compatibility. All of this MFD related changes
are in PATCH 3/8.
In PATCH 4/8 then these settings are removed from stmpe-ts and grabbed
from MFD.
PATCH 5/8 is actually adding the ADC driver that also supports the
built-in temperature sensor.
PATCH 6/8 is then adding the needed devicetree bindings.
PATCH 7/8 and 8/8 is lastly adding the stmpe_adc DT-nodes as found on
Toradex boards.

Changes in v5:
 - Made a one column list
 - Added lee's Acked-for-MFD
 - Changed author of commit to use correct email.
 - Changed author of commit to use correct email
 - Added Lee Jone's Ack
 - Changed author of commit. Previous patch versions author was wrong
   by mistake.
 - Changed author of commit to use correct email.
 - Removed devm_add_action_or_reset
 - Changed iio_device_register to devm_iio_device_register
 - Added Jonathan Cameron's Reviewed-by
 - Added correct author of commit, as this changed by accident
 - Made a one column list
 - Cleared note about precedence
 - Changed example to a full STMPE811 device with MFD, touchscreen, and the new
   stmpe_adc driver.
 - Added Jonathan Cameron's Reviewed-by

Changes in v4:
 - New separate precursor patch for holding reformatting
 - Added Lee Jone's Ack
 - Added Dmitry Torokhov's Ack
 - New patch: split mfd changes into this precursor patch
 - Export the added stmpe811_adc_commmon_init function
 - Disabling adc when mfd is removed
 - New patch: Split changes in stmpe-ts.c to a separate commit
 - Remove common adc settings from init and call the
   stmpe811_adc_common_init function
 - Moved MFD changes to a precursor patch
 - Moved stmpe-ts changes to a precursor patch
 - Created stmpe_read_temp and stmpe_read_voltage functions to make
   read_raw more readable
 - Added local lock instead of using indio_dev's mlock
 - Use be16_to_cpu() macro instead of bitshifting
 - Added stmpe_enable again to stmpe_adc_init_hw
 - Use devm_add_action_or_reset to get rid of the remove function
   (I tested if that actually works)
 - Put reformatting in a separate precursor patch.
 - Moved T30 devicetree settings to separate commit
 - New separate commit to hold T30 devicetree changes

Changes in v3:
 - Undo ADC-settings related code-deletions in stmpe-ts.c that the code
   is backwards-compatible to older devicetrees.
 - Removed COMPILE_TEST from dependings in Kconfig
 - Removed stmpe_adc_get_platform_info() function and integrated the
   few code lines in the other function
 - Reformatted documentation for touchscreen to use tabs and have a better
   overview of the settings.
 - Added note which adc-settings will take precedence.
 - changed typo in sample-time setting from 144 clocks to 124 clocks, as stated
   in the datasheet.
 - None

Changes in v2:
 - This is a new added commit. Separate commit for moving the defines
   out of drivers/input/touchscreen/stmpe-ts.c to overlying mfd-device
   drivers/mfd/stmpe.c
 - Pre-fix defines with STMPE_
 - Move code to setup ADC to MFD device, as it is used by both drivers
   adc and touchscreen
 - Code formatting
 - Removed unused includes
 - Defined the macro STMPE_START_ONE_TEMP_CONV with other macros.
 - Added new macro that defines the channel of the temperature sensor.
   Took new name for STMPE_MAX_ADC->STMPE_ADC_LAST_NR and used it
   throughout the code for better readability.
 - Added mutex_unlock where missing.
 - Moved the bindings for ADC to the overlying mfd.
 - Reformatted for better readability
 - Put common ADC settings in mfd

Philippe Schenker (5):
  dt-bindings: stmpe: reformatting parameter list and use tabs only
  mfd: stmpe: Move ADC related defines to header of mfd
  Input: stmpe-ts: preparations for STMPE ADC driver
  ARM: dts: Add stmpe-adc DT node to Toradex iMX6 modules
  ARM: dts: Add stmpe-adc DT node to Toradex T30 modules

Stefan Agner (3):
  mfd: stmpe: preparations for STMPE ADC driver
  iio: adc: add STMPE ADC driver using IIO framework
  iio: adc: add STMPE ADC devicetree bindings

 .../devicetree/bindings/iio/adc/stmpe-adc.txt |  21 +
 .../bindings/input/touchscreen/stmpe.txt      | 116 ++++--
 .../devicetree/bindings/mfd/stmpe.txt         |  28 +-
 arch/arm/boot/dts/imx6qdl-apalis.dtsi         |  22 +-
 arch/arm/boot/dts/imx6qdl-colibri.dtsi        |  23 +-
 arch/arm/boot/dts/tegra30-apalis.dtsi         |  22 +-
 arch/arm/boot/dts/tegra30-colibri.dtsi        |  22 +-
 drivers/iio/adc/Kconfig                       |   7 +
 drivers/iio/adc/Makefile                      |   1 +
 drivers/iio/adc/stmpe-adc.c                   | 363 ++++++++++++++++++
 drivers/input/touchscreen/stmpe-ts.c          |  66 +---
 drivers/mfd/Kconfig                           |   3 +-
 drivers/mfd/stmpe.c                           |  68 ++++
 include/linux/mfd/stmpe.h                     |  21 +
 14 files changed, 667 insertions(+), 116 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/iio/adc/stmpe-adc.txt
 create mode 100644 drivers/iio/adc/stmpe-adc.c

-- 
2.19.2

[PATCH v5 5/8] iio: adc: add STMPE ADC driver using IIO framework

[Philippe Schenker]

From: Stefan Agner <stefan@agner.ch>

This adds an ADC driver for the STMPE device using the industrial
input/output interface. The driver supports raw reading of values.
The driver depends on the MFD STMPE driver. If the touchscreen
block is enabled too, only four of the 8 ADC channels are available.

Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com>
Signed-off-by: Philippe Schenker <philippe.schenker@toradex.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

---

Changes in v5:
 - Removed devm_add_action_or_reset
 - Changed iio_device_register to devm_iio_device_register
 - Added Jonathan Cameron's Reviewed-by
 - Added correct author of commit, as this changed by accident

Changes in v4:
 - Moved MFD changes to a precursor patch
 - Moved stmpe-ts changes to a precursor patch
 - Created stmpe_read_temp and stmpe_read_voltage functions to make
   read_raw more readable
 - Added local lock instead of using indio_dev's mlock
 - Use be16_to_cpu() macro instead of bitshifting
 - Added stmpe_enable again to stmpe_adc_init_hw
 - Use devm_add_action_or_reset to get rid of the remove function
   (I tested if that actually works)

Changes in v3:
 - Removed COMPILE_TEST from dependings in Kconfig
 - Removed stmpe_adc_get_platform_info() function and integrated the
   few code lines in the other function

Changes in v2:
 - Code formatting
 - Removed unused includes
 - Defined the macro STMPE_START_ONE_TEMP_CONV with other macros.
 - Added new macro that defines the channel of the temperature sensor.
   Took new name for STMPE_MAX_ADC->STMPE_ADC_LAST_NR and used it
   throughout the code for better readability.
 - Added mutex_unlock where missing.

 drivers/iio/adc/Kconfig     |   7 +
 drivers/iio/adc/Makefile    |   1 +
 drivers/iio/adc/stmpe-adc.c | 363 ++++++++++++++++++++++++++++++++++++
 3 files changed, 371 insertions(+)
 create mode 100644 drivers/iio/adc/stmpe-adc.c

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index a52fea8749a9..224f2067494d 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -734,6 +734,13 @@ config STM32_DFSDM_ADC
 	  This driver can also be built as a module.  If so, the module
 	  will be called stm32-dfsdm-adc.
 
+config STMPE_ADC
+	tristate "STMicroelectronics STMPE ADC driver"
+	depends on OF && MFD_STMPE
+	help
+	  Say yes here to build support for ST Microelectronics STMPE
+	  built-in ADC block (stmpe811).
+
 config STX104
 	tristate "Apex Embedded Systems STX104 driver"
 	depends on PC104 && X86
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index a6e6a0b659e2..cba889c30bf9 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -69,6 +69,7 @@ obj-$(CONFIG_STM32_ADC_CORE) += stm32-adc-core.o
 obj-$(CONFIG_STM32_ADC) += stm32-adc.o
 obj-$(CONFIG_STM32_DFSDM_CORE) += stm32-dfsdm-core.o
 obj-$(CONFIG_STM32_DFSDM_ADC) += stm32-dfsdm-adc.o
+obj-$(CONFIG_STMPE_ADC) += stmpe-adc.o
 obj-$(CONFIG_TI_ADC081C) += ti-adc081c.o
 obj-$(CONFIG_TI_ADC0832) += ti-adc0832.o
 obj-$(CONFIG_TI_ADC084S021) += ti-adc084s021.o
diff --git a/drivers/iio/adc/stmpe-adc.c b/drivers/iio/adc/stmpe-adc.c
new file mode 100644
index 000000000000..37f4b74a5d32
--- /dev/null
+++ b/drivers/iio/adc/stmpe-adc.c
@@ -0,0 +1,363 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  STMicroelectronics STMPE811 IIO ADC Driver
+ *
+ *  4 channel, 10/12-bit ADC
+ *
+ *  Copyright (C) 2013-2018 Toradex AG <stefan.agner@toradex.com>
+ */
+
+#include <linux/completion.h>
+#include <linux/err.h>
+#include <linux/iio/iio.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/mfd/stmpe.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/device.h>
+
+#define STMPE_REG_INT_STA		0x0B
+#define STMPE_REG_ADC_INT_EN		0x0E
+#define STMPE_REG_ADC_INT_STA		0x0F
+
+#define STMPE_REG_ADC_CTRL1		0x20
+#define STMPE_REG_ADC_CTRL2		0x21
+#define STMPE_REG_ADC_CAPT		0x22
+#define STMPE_REG_ADC_DATA_CH(channel)	(0x30 + 2 * (channel))
+
+#define STMPE_REG_TEMP_CTRL		0x60
+#define STMPE_TEMP_CTRL_ENABLE		BIT(0)
+#define STMPE_TEMP_CTRL_ACQ		BIT(1)
+#define STMPE_TEMP_CTRL_THRES_EN	BIT(3)
+#define STMPE_START_ONE_TEMP_CONV	(STMPE_TEMP_CTRL_ENABLE | \
+					STMPE_TEMP_CTRL_ACQ | \
+					STMPE_TEMP_CTRL_THRES_EN)
+#define STMPE_REG_TEMP_DATA		0x61
+#define STMPE_REG_TEMP_TH		0x63
+#define STMPE_ADC_LAST_NR		7
+#define STMPE_TEMP_CHANNEL		(STMPE_ADC_LAST_NR + 1)
+
+#define STMPE_ADC_CH(channel)		((1 << (channel)) & 0xff)
+
+#define STMPE_ADC_TIMEOUT		msecs_to_jiffies(1000)
+
+struct stmpe_adc {
+	struct stmpe *stmpe;
+	struct clk *clk;
+	struct device *dev;
+	struct mutex lock;
+
+	/* We are allocating plus one for the temperature channel */
+	struct iio_chan_spec stmpe_adc_iio_channels[STMPE_ADC_LAST_NR + 2];
+
+	struct completion completion;
+
+	u8 channel;
+	u32 value;
+};
+
+static int stmpe_read_voltage(struct stmpe_adc *info,
+		struct iio_chan_spec const *chan, int *val)
+{
+	long ret;
+
+	mutex_lock(&info->lock);
+
+	info->channel = (u8)chan->channel;
+
+	if (info->channel > STMPE_ADC_LAST_NR) {
+		mutex_unlock(&info->lock);
+		return -EINVAL;
+	}
+
+	stmpe_reg_write(info->stmpe, STMPE_REG_ADC_INT_EN,
+			STMPE_ADC_CH(info->channel));
+
+	stmpe_reg_write(info->stmpe, STMPE_REG_ADC_CAPT,
+			STMPE_ADC_CH(info->channel));
+
+	*val = info->value;
+
+	ret = wait_for_completion_interruptible_timeout
+		(&info->completion, STMPE_ADC_TIMEOUT);
+
+	if (ret <= 0) {
+		mutex_unlock(&info->lock);
+		if (ret == 0)
+			return -ETIMEDOUT;
+		else
+			return ret;
+	}
+
+	*val = info->value;
+
+	mutex_unlock(&info->lock);
+
+	return 0;
+}
+
+static int stmpe_read_temp(struct stmpe_adc *info,
+		struct iio_chan_spec const *chan, int *val)
+{
+	long ret;
+
+	mutex_lock(&info->lock);
+
+	info->channel = (u8)chan->channel;
+
+	if (info->channel != STMPE_TEMP_CHANNEL) {
+		mutex_unlock(&info->lock);
+		return -EINVAL;
+	}
+
+	stmpe_reg_write(info->stmpe, STMPE_REG_TEMP_CTRL,
+			STMPE_START_ONE_TEMP_CONV);
+
+	ret = wait_for_completion_interruptible_timeout
+		(&info->completion, STMPE_ADC_TIMEOUT);
+
+	if (ret <= 0) {
+		mutex_unlock(&info->lock);
+		if (ret == 0)
+			return -ETIMEDOUT;
+		else
+			return ret;
+	}
+
+	/*
+	 * absolute temp = +V3.3 * value /7.51 [K]
+	 * scale to [milli °C]
+	 */
+	*val = ((449960l * info->value) / 1024l) - 273150;
+
+	mutex_unlock(&info->lock);
+
+	return 0;
+}
+
+static int stmpe_read_raw(struct iio_dev *indio_dev,
+			  struct iio_chan_spec const *chan,
+			  int *val,
+			  int *val2,
+			  long mask)
+{
+	struct stmpe_adc *info = iio_priv(indio_dev);
+	long ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+	case IIO_CHAN_INFO_PROCESSED:
+
+		switch (chan->type) {
+		case IIO_VOLTAGE:
+			ret = stmpe_read_voltage(info, chan, val);
+			break;
+
+		case IIO_TEMP:
+			ret = stmpe_read_temp(info, chan, val);
+			break;
+		default:
+			return -EINVAL;
+		}
+
+		if (ret < 0)
+			return ret;
+
+		return IIO_VAL_INT;
+
+	case IIO_CHAN_INFO_SCALE:
+		*val = 3300;
+		*val2 = info->stmpe->mod_12b ? 12 : 10;
+		return IIO_VAL_FRACTIONAL_LOG2;
+
+	default:
+		break;
+	}
+
+	return -EINVAL;
+}
+
+static irqreturn_t stmpe_adc_isr(int irq, void *dev_id)
+{
+	struct stmpe_adc *info = (struct stmpe_adc *)dev_id;
+	u16 data;
+
+	if (info->channel > STMPE_TEMP_CHANNEL)
+		return IRQ_NONE;
+
+	if (info->channel <= STMPE_ADC_LAST_NR) {
+		int int_sta;
+
+		int_sta = stmpe_reg_read(info->stmpe, STMPE_REG_ADC_INT_STA);
+
+		/* Is the interrupt relevant */
+		if (!(int_sta & STMPE_ADC_CH(info->channel)))
+			return IRQ_NONE;
+
+		/* Read value */
+		stmpe_block_read(info->stmpe,
+			STMPE_REG_ADC_DATA_CH(info->channel), 2, (u8 *) &data);
+
+		stmpe_reg_write(info->stmpe, STMPE_REG_ADC_INT_STA, int_sta);
+	} else if (info->channel == STMPE_TEMP_CHANNEL) {
+		/* Read value */
+		stmpe_block_read(info->stmpe, STMPE_REG_TEMP_DATA, 2,
+				(u8 *) &data);
+	}
+
+	info->value = (u32) be16_to_cpu(data);
+	complete(&info->completion);
+
+	return IRQ_HANDLED;
+}
+
+static const struct iio_info stmpe_adc_iio_info = {
+	.read_raw = &stmpe_read_raw,
+};
+
+static void stmpe_adc_voltage_chan(struct iio_chan_spec *ics, int chan)
+{
+	ics->type = IIO_VOLTAGE;
+	ics->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
+	ics->info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE);
+	ics->indexed = 1;
+	ics->channel = chan;
+}
+
+static void stmpe_adc_temp_chan(struct iio_chan_spec *ics, int chan)
+{
+	ics->type = IIO_TEMP;
+	ics->info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED);
+	ics->indexed = 1;
+	ics->channel = chan;
+}
+
+static int stmpe_adc_init_hw(struct stmpe_adc *adc)
+{
+	int ret;
+	struct stmpe *stmpe = adc->stmpe;
+
+	ret = stmpe_enable(stmpe, STMPE_BLOCK_ADC);
+	if (ret) {
+		dev_err(stmpe->dev, "Could not enable clock for ADC\n");
+		return ret;
+	}
+
+	ret = stmpe811_adc_common_init(stmpe);
+	if (ret) {
+		stmpe_disable(stmpe, STMPE_BLOCK_ADC);
+		return ret;
+	}
+
+	/* use temp irq for each conversion completion */
+	stmpe_reg_write(stmpe, STMPE_REG_TEMP_TH, 0);
+	stmpe_reg_write(stmpe, STMPE_REG_TEMP_TH + 1, 0);
+
+	return 0;
+}
+
+static int stmpe_adc_probe(struct platform_device *pdev)
+{
+	struct iio_dev *indio_dev;
+	struct stmpe_adc *info;
+	struct device_node *np;
+	u32 norequest_mask = 0;
+	int irq_temp, irq_adc;
+	int num_chan = 0;
+	int i = 0;
+	int ret;
+
+	irq_adc = platform_get_irq_byname(pdev, "STMPE_ADC");
+	if (irq_adc < 0)
+		return irq_adc;
+
+	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(struct stmpe_adc));
+	if (!indio_dev) {
+		dev_err(&pdev->dev, "failed allocating iio device\n");
+		return -ENOMEM;
+	}
+
+	info = iio_priv(indio_dev);
+	mutex_init(&info->lock);
+
+	init_completion(&info->completion);
+	ret = devm_request_threaded_irq(&pdev->dev, irq_adc, NULL,
+					stmpe_adc_isr, IRQF_ONESHOT,
+					"stmpe-adc", info);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "failed requesting irq, irq = %d\n",
+				irq_adc);
+		return ret;
+	}
+
+	irq_temp = platform_get_irq_byname(pdev, "STMPE_TEMP_SENS");
+	if (irq_temp >= 0) {
+		ret = devm_request_threaded_irq(&pdev->dev, irq_temp, NULL,
+						stmpe_adc_isr, IRQF_ONESHOT,
+						"stmpe-adc", info);
+		if (ret < 0)
+			dev_warn(&pdev->dev, "failed requesting irq for"
+				 " temp sensor, irq = %d\n", irq_temp);
+	}
+
+	platform_set_drvdata(pdev, indio_dev);
+
+	indio_dev->name		= dev_name(&pdev->dev);
+	indio_dev->dev.parent	= &pdev->dev;
+	indio_dev->info		= &stmpe_adc_iio_info;
+	indio_dev->modes	= INDIO_DIRECT_MODE;
+
+	info->stmpe = dev_get_drvdata(pdev->dev.parent);
+
+	np = pdev->dev.of_node;
+
+	if (!np)
+		dev_err(&pdev->dev, "no device tree node found\n");
+
+	of_property_read_u32(np, "st,norequest-mask", &norequest_mask);
+
+	for_each_clear_bit(i, (unsigned long *) &norequest_mask,
+			   (STMPE_ADC_LAST_NR + 1)) {
+		stmpe_adc_voltage_chan(&info->stmpe_adc_iio_channels[num_chan], i);
+		num_chan++;
+	}
+	stmpe_adc_temp_chan(&info->stmpe_adc_iio_channels[num_chan], i);
+	num_chan++;
+	indio_dev->channels = info->stmpe_adc_iio_channels;
+	indio_dev->num_channels = num_chan;
+
+	ret = stmpe_adc_init_hw(info);
+	if (ret)
+		return ret;
+
+	return devm_iio_device_register(&pdev->dev, indio_dev);
+}
+
+static int __maybe_unused stmpe_adc_resume(struct device *dev)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct stmpe_adc *info = iio_priv(indio_dev);
+
+	stmpe_adc_init_hw(info);
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(stmpe_adc_pm_ops, NULL, stmpe_adc_resume);
+
+static struct platform_driver stmpe_adc_driver = {
+	.probe		= stmpe_adc_probe,
+	.driver		= {
+		.name	= "stmpe-adc",
+		.pm	= &stmpe_adc_pm_ops,
+	},
+};
+
+module_platform_driver(stmpe_adc_driver);
+
+MODULE_AUTHOR("Stefan Agner <stefan.agner@toradex.com>");
+MODULE_DESCRIPTION("STMPEXXX ADC driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:stmpe-adc");
-- 
2.19.2

[PATCH v5 6/8] iio: adc: add STMPE ADC devicetree bindings

[Philippe Schenker]

From: Stefan Agner <stefan@agner.ch>

This adds the devicetree bindings for the STMPE ADC. This also corrects
a typo in st,sample-time it is rather "6 -> 124 clocks" according
to the datasheet and not 144.
We need to use the naming stmpe_adc in devicetree because this is given
by the mfd device.

Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com>
Signed-off-by: Philippe Schenker <philippe.schenker@toradex.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

---

Changes in v5:
 - Made a one column list
 - Cleared note about precedence
 - Changed example to a full STMPE811 device with MFD, touchscreen, and the new
   stmpe_adc driver.
 - Added Jonathan Cameron's Reviewed-by

Changes in v4:
 - Put reformatting in a separate precursor patch.

Changes in v3:
 - Reformatted documentation for touchscreen to use tabs and have a better
   overview of the settings.
 - Added note which adc-settings will take precedence.
 - changed typo in sample-time setting from 144 clocks to 124 clocks, as stated
   in the datasheet.

Changes in v2:
 - Moved the bindings for ADC to the overlying mfd.
 - Reformatted for better readability

 .../devicetree/bindings/iio/adc/stmpe-adc.txt | 21 +++++
 .../bindings/input/touchscreen/stmpe.txt      | 88 +++++++++++++------
 .../devicetree/bindings/mfd/stmpe.txt         | 14 +++
 3 files changed, 98 insertions(+), 25 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/iio/adc/stmpe-adc.txt

diff --git a/Documentation/devicetree/bindings/iio/adc/stmpe-adc.txt b/Documentation/devicetree/bindings/iio/adc/stmpe-adc.txt
new file mode 100644
index 000000000000..480e66422625
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/adc/stmpe-adc.txt
@@ -0,0 +1,21 @@
+STMPE ADC driver
+----------------
+
+Required properties:
+ - compatible: "st,stmpe-adc"
+
+Optional properties:
+Note that the ADC is shared with the STMPE touchscreen. ADC related settings
+have to be done in the mfd.
+- st,norequest-mask: bitmask specifying which ADC channels should _not_ be
+  requestable due to different usage (e.g. touch)
+
+Node name must be stmpe_adc and should be child node of stmpe node to
+which it belongs.
+
+Example:
+
+	stmpe_adc {
+		compatible = "st,stmpe-adc";
+		st,norequest-mask = <0x0F>; /* dont use ADC CH3-0 */
+	};
diff --git a/Documentation/devicetree/bindings/input/touchscreen/stmpe.txt b/Documentation/devicetree/bindings/input/touchscreen/stmpe.txt
index bf66a55a7de5..c549924603d2 100644
--- a/Documentation/devicetree/bindings/input/touchscreen/stmpe.txt
+++ b/Documentation/devicetree/bindings/input/touchscreen/stmpe.txt
@@ -5,24 +5,6 @@ Required properties:
  - compatible: "st,stmpe-ts"
 
 Optional properties:
-- st,sample-time	: ADC conversion time in number of clock.
-				0 -> 36 clocks
-				1 -> 44 clocks
-				2 -> 56 clocks
-				3 -> 64 clocks
-				4 -> 80 clocks (recommended)
-				5 -> 96 clocks
-				6 -> 144 clocks
-- st,mod-12b		: ADC Bit mode
-				0 -> 10bit ADC
-				1 -> 12bit ADC
-- st,ref-sel		: ADC reference source
-				0 -> internal
-				1 -> external
-- st,adc-freq		: ADC Clock speed
-				0 -> 1.625 MHz
-				1 -> 3.25 MHz
-				2 || 3 -> 6.5 MHz
 - st,ave-ctrl		: Sample average control
 				0 -> 1 sample
 				1 -> 2 samples
@@ -52,20 +34,76 @@ Optional properties:
 				0 -> 20 mA (typical 35mA max)
 				1 -> 50 mA (typical 80 mA max)
 
+Optional properties common with MFD (deprecated):
+ - st,sample-time	: ADC conversion time in number of clock.
+				0 -> 36 clocks
+				1 -> 44 clocks
+				2 -> 56 clocks
+				3 -> 64 clocks
+				4 -> 80 clocks (recommended)
+				5 -> 96 clocks
+				6 -> 124 clocks
+ - st,mod-12b		: ADC Bit mode
+				0 -> 10bit ADC
+				1 -> 12bit ADC
+ - st,ref-sel		: ADC reference source
+				0 -> internal
+				1 -> external
+ - st,adc-freq		: ADC Clock speed
+				0 -> 1.625 MHz
+				1 -> 3.25 MHz
+				2 || 3 -> 6.5 MHz
+
 Node name must be stmpe_touchscreen and should be child node of stmpe node to
 which it belongs.
 
+Note that common ADC settings of stmpe_touchscreen (child) will take precedence
+over the settings done in MFD.
+
 Example:
 
+stmpe811@41 {
+	compatible = "st,stmpe811";
+	pinctrl-names = "default";
+	pinctrl-0 = <&pinctrl_touch_int>;
+	#address-cells = <1>;
+	#size-cells = <0>;
+	reg = <0x41>;
+	interrupts = <10 IRQ_TYPE_LEVEL_LOW>;
+	interrupt-parent = <&gpio4>;
+	interrupt-controller;
+	id = <0>;
+	blocks = <0x5>;
+	irq-trigger = <0x1>;
+	/* Common ADC settings */
+	/* 3.25 MHz ADC clock speed */
+	st,adc-freq = <1>;
+	/* 12-bit ADC */
+	st,mod-12b = <1>;
+	/* internal ADC reference */
+	st,ref-sel = <0>;
+	/* ADC converstion time: 80 clocks */
+	st,sample-time = <4>;
+
 	stmpe_touchscreen {
 		compatible = "st,stmpe-ts";
-		st,sample-time = <4>;
-		st,mod-12b = <1>;
-		st,ref-sel = <0>;
-		st,adc-freq = <1>;
-		st,ave-ctrl = <1>;
-		st,touch-det-delay = <2>;
-		st,settling = <2>;
+		reg = <0>;
+		/* 8 sample average control */
+		st,ave-ctrl = <3>;
+		/* 5 ms touch detect interrupt delay */
+		st,touch-det-delay = <5>;
+		/* 1 ms panel driver settling time */
+		st,settling = <3>;
+		/* 7 length fractional part in z */
 		st,fraction-z = <7>;
+		/*
+		 * 50 mA typical 80 mA max touchscreen drivers
+		 * current limit value
+		 */
 		st,i-drive = <1>;
 	};
+	stmpe_adc {
+		compatible = "st,stmpe-adc";
+		st,norequest-mask = <0x0F>;
+	};
+};
diff --git a/Documentation/devicetree/bindings/mfd/stmpe.txt b/Documentation/devicetree/bindings/mfd/stmpe.txt
index a46e7177195d..d4408a417193 100644
--- a/Documentation/devicetree/bindings/mfd/stmpe.txt
+++ b/Documentation/devicetree/bindings/mfd/stmpe.txt
@@ -14,6 +14,20 @@ Optional properties:
  - st,autosleep-timeout		: Valid entries (ms); 4, 16, 32, 64, 128, 256, 512 and 1024
  - irq-gpio			: If present, which GPIO to use for event IRQ
 
+Optional properties for devices with touch and ADC (STMPE811|STMPE610):
+ - st,sample-time		: ADC conversion time in number of clock.
+					0 -> 36 clocks		4 -> 80 clocks (recommended)
+					1 -> 44 clocks		5 -> 96 clocks
+					2 -> 56 clocks		6 -> 124 clocks
+					3 -> 64 clocks
+ - st,mod-12b			: ADC Bit mode
+					0 -> 10bit ADC		1 -> 12bit ADC
+ - st,ref-sel			: ADC reference source
+					0 -> internal		1 -> external
+ - st,adc-freq			: ADC Clock speed
+					0 -> 1.625 MHz		2 || 3 -> 6.5 MHz
+					1 -> 3.25 MHz
+
 Example:
 
 	stmpe1601: stmpe1601@40 {
-- 
2.19.2

Re: [PATCH v5 6/8] iio: adc: add STMPE ADC devicetree bindings

[Rob Herring]

On Fri, 21 Dec 2018 14:46:35 +0100, Philippe Schenker wrote:
> From: Stefan Agner <stefan@agner.ch>
> 
> This adds the devicetree bindings for the STMPE ADC. This also corrects
> a typo in st,sample-time it is rather "6 -> 124 clocks" according
> to the datasheet and not 144.
> We need to use the naming stmpe_adc in devicetree because this is given
> by the mfd device.
> 
> Signed-off-by: Stefan Agner <stefan@agner.ch>
> Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com>
> Signed-off-by: Philippe Schenker <philippe.schenker@toradex.com>
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> 
> ---
> 
> Changes in v5:
>  - Made a one column list
>  - Cleared note about precedence
>  - Changed example to a full STMPE811 device with MFD, touchscreen, and the new
>    stmpe_adc driver.
>  - Added Jonathan Cameron's Reviewed-by
> 
> Changes in v4:
>  - Put reformatting in a separate precursor patch.
> 
> Changes in v3:
>  - Reformatted documentation for touchscreen to use tabs and have a better
>    overview of the settings.
>  - Added note which adc-settings will take precedence.
>  - changed typo in sample-time setting from 144 clocks to 124 clocks, as stated
>    in the datasheet.
> 
> Changes in v2:
>  - Moved the bindings for ADC to the overlying mfd.
>  - Reformatted for better readability
> 
>  .../devicetree/bindings/iio/adc/stmpe-adc.txt | 21 +++++
>  .../bindings/input/touchscreen/stmpe.txt      | 88 +++++++++++++------
>  .../devicetree/bindings/mfd/stmpe.txt         | 14 +++
>  3 files changed, 98 insertions(+), 25 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/iio/adc/stmpe-adc.txt
> 

Reviewed-by: Rob Herring <robh@kernel.org>

[GIT PULL] Immutable branch between MFD, IIO and Input due for the v5.1 merge window

[Lee Jones]

Taken all but the ARM patches.

These need to be reviewed and go in via ARM-SoC.

The following changes since commit bfeffd155283772bbe78c6a05dec7c0128ee500c:

  Linux 5.0-rc1 (2019-01-06 17:08:20 -0800)

are available in the Git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd.git ib-mfd-iio-input-v5.1

for you to fetch changes up to 81cdab79818988d27d8aeb162b7988c9e6dde936:

  iio: adc: add STMPE ADC devicetree bindings (2019-01-16 12:37:36 +0000)

----------------------------------------------------------------
Immutable branch between MFD, IIO and Input due for the v5.1 merge window

----------------------------------------------------------------
Philippe Schenker (3):
      dt-bindings: stmpe: Reformatting parameter list and use tabs only
      mfd: stmpe: Move ADC related defines to MFD header
      Input: stmpe-ts: preparations for STMPE ADC driver

Stefan Agner (3):
      mfd: stmpe: Preparations for STMPE ADC driver
      iio: adc: add STMPE ADC driver using IIO framework
      iio: adc: add STMPE ADC devicetree bindings

 .../devicetree/bindings/iio/adc/stmpe-adc.txt      |  21 ++
 .../bindings/input/touchscreen/stmpe.txt           | 116 +++++--
 Documentation/devicetree/bindings/mfd/stmpe.txt    |  28 +-
 drivers/iio/adc/Kconfig                            |   7 +
 drivers/iio/adc/Makefile                           |   1 +
 drivers/iio/adc/stmpe-adc.c                        | 363 +++++++++++++++++++++
 drivers/input/touchscreen/stmpe-ts.c               |  66 +---
 drivers/mfd/Kconfig                                |   3 +-
 drivers/mfd/stmpe.c                                |  68 ++++
 include/linux/mfd/stmpe.h                          |  21 ++
 10 files changed, 610 insertions(+), 84 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/iio/adc/stmpe-adc.txt
 create mode 100644 drivers/iio/adc/stmpe-adc.c

-- 
Lee Jones [李琼斯]
Linaro Services Technical Lead
Linaro.org │ Open source software for ARM SoCs
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