[v8,3/8] drivers:input:tsc2007: add iio interface to read external ADC input and temperature
diff mbox

Message ID 99f236df48b03b3188e12f94a20097f8440db7a5.1479823354.git.hns@goldelico.com
State Under Review
Headers show

Commit Message

H. Nikolaus Schaller Nov. 22, 2016, 2:02 p.m. UTC
The tsc2007 chip not only has a resistive touch screen controller but
also an external AUX adc imput which can be used for an ambient
light sensor, battery voltage monitoring or any general purpose.

Additionally it can measure the chip temperature.

This extension provides an iio interface for these adc channels.

Since it is not wasting much resources and is very straightforward,
we simply provide all other adc channels as optional iio interfaces
as weel. This can be used for debugging or special applications.

This patch also splits the tsc2007 driver in several source files:
tsc2007.h -- constants, structs and stubs
tsc2007_core.c -- functional parts of the original driver
tsc2007_iio.c -- the optional iio stuff

Makefile magic allows to conditionally link the iio stuff
if CONFIG_IIO=y or =m in a way that it works with
CONFIG_TOUCHSCREEN_TSC2007=m.

Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
Reviewed-by: Jonathan Cameron <jic23@kernel.org>
---
 drivers/input/touchscreen/Makefile                 |   7 +
 drivers/input/touchscreen/tsc2007.h                | 116 ++++++++++++++++
 .../touchscreen/{tsc2007.c => tsc2007_core.c}      |  95 +++----------
 drivers/input/touchscreen/tsc2007_iio.c            | 150 +++++++++++++++++++++
 4 files changed, 294 insertions(+), 74 deletions(-)
 create mode 100644 drivers/input/touchscreen/tsc2007.h
 rename drivers/input/touchscreen/{tsc2007.c => tsc2007_core.c} (86%)
 create mode 100644 drivers/input/touchscreen/tsc2007_iio.c

Comments

Jonathan Cameron Nov. 24, 2016, 5:38 p.m. UTC | #1
On 22 November 2016 14:02:30 GMT+00:00, "H. Nikolaus Schaller" <hns@goldelico.com> wrote:
>The tsc2007 chip not only has a resistive touch screen controller but
>also an external AUX adc imput which can be used for an ambient
>light sensor, battery voltage monitoring or any general purpose.
>
>Additionally it can measure the chip temperature.
>
>This extension provides an iio interface for these adc channels.
>
>Since it is not wasting much resources and is very straightforward,
>we simply provide all other adc channels as optional iio interfaces
>as weel. This can be used for debugging or special applications.
>
>This patch also splits the tsc2007 driver in several source files:
>tsc2007.h -- constants, structs and stubs
>tsc2007_core.c -- functional parts of the original driver
>tsc2007_iio.c -- the optional iio stuff
>
>Makefile magic allows to conditionally link the iio stuff
>if CONFIG_IIO=y or =m in a way that it works with
>CONFIG_TOUCHSCREEN_TSC2007=m.
>
>Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
>Reviewed-by: Jonathan Cameron <jic23@kernel.org>
>---
> drivers/input/touchscreen/Makefile                 |   7 +
>drivers/input/touchscreen/tsc2007.h                | 116
>++++++++++++++++
> .../touchscreen/{tsc2007.c => tsc2007_core.c}      |  95 +++----------
>drivers/input/touchscreen/tsc2007_iio.c            | 150
>+++++++++++++++++++++
> 4 files changed, 294 insertions(+), 74 deletions(-)
> create mode 100644 drivers/input/touchscreen/tsc2007.h
> rename drivers/input/touchscreen/{tsc2007.c => tsc2007_core.c} (86%)
> create mode 100644 drivers/input/touchscreen/tsc2007_iio.c
>
>diff --git a/drivers/input/touchscreen/Makefile
>b/drivers/input/touchscreen/Makefile
>index 81b8645..3be0d19 100644
>--- a/drivers/input/touchscreen/Makefile
>+++ b/drivers/input/touchscreen/Makefile
>@@ -80,6 +80,13 @@ obj-$(CONFIG_TOUCHSCREEN_TSC_SERIO)	+= tsc40.o
> obj-$(CONFIG_TOUCHSCREEN_TSC200X_CORE)	+= tsc200x-core.o
> obj-$(CONFIG_TOUCHSCREEN_TSC2004)	+= tsc2004.o
> obj-$(CONFIG_TOUCHSCREEN_TSC2005)	+= tsc2005.o
>+tsc2007-y				:= tsc2007_core.o
>+ifeq ($(CONFIG_IIO),y)
>+tsc2007-y				+= tsc2007_iio.o
>+endif
>+ifeq ($(CONFIG_IIO),m)
>+tsc2007-y				+= tsc2007_iio.o

Not tsc2007-m ?

I don't follow how this works!
>+endif
> obj-$(CONFIG_TOUCHSCREEN_TSC2007)	+= tsc2007.o
> obj-$(CONFIG_TOUCHSCREEN_UCB1400)	+= ucb1400_ts.o
> obj-$(CONFIG_TOUCHSCREEN_WACOM_W8001)	+= wacom_w8001.o
>diff --git a/drivers/input/touchscreen/tsc2007.h
>b/drivers/input/touchscreen/tsc2007.h
>new file mode 100644
>index 0000000..c25932f
>--- /dev/null
>+++ b/drivers/input/touchscreen/tsc2007.h
>@@ -0,0 +1,116 @@
>+/*
>+ * Copyright (c) 2008 MtekVision Co., Ltd.
>+ *	Kwangwoo Lee <kwlee@mtekvision.com>
>+ *
>+ * Using code from:
>+ *  - ads7846.c
>+ *	Copyright (c) 2005 David Brownell
>+ *	Copyright (c) 2006 Nokia Corporation
>+ *  - corgi_ts.c
>+ *	Copyright (C) 2004-2005 Richard Purdie
>+ *  - omap_ts.[hc], ads7846.h, ts_osk.c
>+ *	Copyright (C) 2002 MontaVista Software
>+ *	Copyright (C) 2004 Texas Instruments
>+ *	Copyright (C) 2005 Dirk Behme
>+ *
>+ *  This program is free software; you can redistribute it and/or
>modify
>+ *  it under the terms of the GNU General Public License version 2 as
>+ *  published by the Free Software Foundation.
>+ */
>+
>+#include <linux/input/touchscreen.h>
>+
>+#define TSC2007_MEASURE_TEMP0		(0x0 << 4)
>+#define TSC2007_MEASURE_AUX		(0x2 << 4)
>+#define TSC2007_MEASURE_TEMP1		(0x4 << 4)
>+#define TSC2007_ACTIVATE_XN		(0x8 << 4)
>+#define TSC2007_ACTIVATE_YN		(0x9 << 4)
>+#define TSC2007_ACTIVATE_YP_XN		(0xa << 4)
>+#define TSC2007_SETUP			(0xb << 4)
>+#define TSC2007_MEASURE_X		(0xc << 4)
>+#define TSC2007_MEASURE_Y		(0xd << 4)
>+#define TSC2007_MEASURE_Z1		(0xe << 4)
>+#define TSC2007_MEASURE_Z2		(0xf << 4)
>+
>+#define TSC2007_POWER_OFF_IRQ_EN	(0x0 << 2)
>+#define TSC2007_ADC_ON_IRQ_DIS0		(0x1 << 2)
>+#define TSC2007_ADC_OFF_IRQ_EN		(0x2 << 2)
>+#define TSC2007_ADC_ON_IRQ_DIS1		(0x3 << 2)
>+
>+#define TSC2007_12BIT			(0x0 << 1)
>+#define TSC2007_8BIT			(0x1 << 1)
>+
>+#define	MAX_12BIT			((1 << 12) - 1)
>+
>+#define ADC_ON_12BIT	(TSC2007_12BIT | TSC2007_ADC_ON_IRQ_DIS0)
>+
>+#define READ_Y		(ADC_ON_12BIT | TSC2007_MEASURE_Y)
>+#define READ_Z1		(ADC_ON_12BIT | TSC2007_MEASURE_Z1)
>+#define READ_Z2		(ADC_ON_12BIT | TSC2007_MEASURE_Z2)
>+#define READ_X		(ADC_ON_12BIT | TSC2007_MEASURE_X)
>+#define PWRDOWN		(TSC2007_12BIT | TSC2007_POWER_OFF_IRQ_EN)
>+
>+struct ts_event {
>+	u16	x;
>+	u16	y;
>+	u16	z1, z2;
>+};
>+
>+struct tsc2007 {
>+	struct input_dev	*input;
>+	char			phys[32];
>+
>+	struct i2c_client	*client;
>+
>+	u16			model;
>+	u16			x_plate_ohms;
>+
>+	struct touchscreen_properties prop;
>+
>+	bool			report_resistance;
>+	u16			min_x;
>+	u16			min_y;
>+	u16			max_x;
>+	u16			max_y;
>+	u16			max_rt;
>+	unsigned long		poll_period; /* in jiffies */
>+	int			fuzzx;
>+	int			fuzzy;
>+	int			fuzzz;
>+
>+	unsigned int		gpio;
>+	int			irq;
>+
>+	wait_queue_head_t	wait;
>+	bool			stopped;
>+	bool			pendown;
>+
>+	int			(*get_pendown_state)(struct device *);
>+	void			(*clear_penirq)(void);
>+
>+	struct mutex		mlock;
>+	struct iio_dev		*iio_dev;	/* optional */
>+};
>+
>+int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd);
>+u32 tsc2007_calculate_resistance(struct tsc2007 *tsc,
>+					struct ts_event *tc);
>+bool tsc2007_is_pen_down(struct tsc2007 *ts);
>+
>+#if IS_ENABLED(CONFIG_IIO)
>+
>+/* defined in tsc2007_iio.c */
>+int tsc2007_iio_configure(struct tsc2007 *ts);
>+void tsc2007_iio_unconfigure(struct tsc2007 *ts);
>+
>+#else /* CONFIG_IIO */
>+
>+static inline int tsc2007_iio_configure(struct tsc2007 *ts)
>+{
>+	return 0;
>+}
>+static inline void tsc2007_iio_unconfigure(struct tsc2007 *ts)
>+{
>+}
>+
>+#endif /* CONFIG_IIO */
>diff --git a/drivers/input/touchscreen/tsc2007.c
>b/drivers/input/touchscreen/tsc2007_core.c
>similarity index 86%
>rename from drivers/input/touchscreen/tsc2007.c
>rename to drivers/input/touchscreen/tsc2007_core.c
>index 76b462b..812ded8 100644
>--- a/drivers/input/touchscreen/tsc2007.c
>+++ b/drivers/input/touchscreen/tsc2007_core.c
>@@ -27,79 +27,11 @@
> #include <linux/i2c.h>
> #include <linux/i2c/tsc2007.h>
> #include <linux/of_device.h>
>-#include <linux/of.h>
> #include <linux/of_gpio.h>
>-#include <linux/input/touchscreen.h>
>-
>-#define TSC2007_MEASURE_TEMP0		(0x0 << 4)
>-#define TSC2007_MEASURE_AUX		(0x2 << 4)
>-#define TSC2007_MEASURE_TEMP1		(0x4 << 4)
>-#define TSC2007_ACTIVATE_XN		(0x8 << 4)
>-#define TSC2007_ACTIVATE_YN		(0x9 << 4)
>-#define TSC2007_ACTIVATE_YP_XN		(0xa << 4)
>-#define TSC2007_SETUP			(0xb << 4)
>-#define TSC2007_MEASURE_X		(0xc << 4)
>-#define TSC2007_MEASURE_Y		(0xd << 4)
>-#define TSC2007_MEASURE_Z1		(0xe << 4)
>-#define TSC2007_MEASURE_Z2		(0xf << 4)
>-
>-#define TSC2007_POWER_OFF_IRQ_EN	(0x0 << 2)
>-#define TSC2007_ADC_ON_IRQ_DIS0		(0x1 << 2)
>-#define TSC2007_ADC_OFF_IRQ_EN		(0x2 << 2)
>-#define TSC2007_ADC_ON_IRQ_DIS1		(0x3 << 2)
>-
>-#define TSC2007_12BIT			(0x0 << 1)
>-#define TSC2007_8BIT			(0x1 << 1)
>-
>-#define	MAX_12BIT			((1 << 12) - 1)
>-
>-#define ADC_ON_12BIT	(TSC2007_12BIT | TSC2007_ADC_ON_IRQ_DIS0)
>-
>-#define READ_Y		(ADC_ON_12BIT | TSC2007_MEASURE_Y)
>-#define READ_Z1		(ADC_ON_12BIT | TSC2007_MEASURE_Z1)
>-#define READ_Z2		(ADC_ON_12BIT | TSC2007_MEASURE_Z2)
>-#define READ_X		(ADC_ON_12BIT | TSC2007_MEASURE_X)
>-#define PWRDOWN		(TSC2007_12BIT | TSC2007_POWER_OFF_IRQ_EN)
>-
>-struct ts_event {
>-	u16	x;
>-	u16	y;
>-	u16	z1, z2;
>-};
>-
>-struct tsc2007 {
>-	struct input_dev	*input;
>-	char			phys[32];
>-
>-	struct i2c_client	*client;
>-
>-	u16			model;
>-	u16			x_plate_ohms;
>-
>-	struct touchscreen_properties prop;
>-
>-	bool			report_resistance;
>-	u16			min_x;
>-	u16			min_y;
>-	u16			max_x;
>-	u16			max_y;
>-	u16			max_rt;
>-	unsigned long		poll_period; /* in jiffies */
>-	int			fuzzx;
>-	int			fuzzy;
>-	int			fuzzz;
>-
>-	unsigned		gpio;
>-	int			irq;
>-
>-	wait_queue_head_t	wait;
>-	bool			stopped;
>+#include "tsc2007.h"
> 
>-	int			(*get_pendown_state)(struct device *);
>-	void			(*clear_penirq)(void);
>-};
> 
>-static inline int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd)
>+int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd)
> {
> 	s32 data;
> 	u16 val;
>@@ -137,7 +69,7 @@ static void tsc2007_read_values(struct tsc2007 *tsc,
>struct ts_event *tc)
> 	tsc2007_xfer(tsc, PWRDOWN);
> }
> 
>-static u32 tsc2007_calculate_resistance(struct tsc2007 *tsc,
>+u32 tsc2007_calculate_resistance(struct tsc2007 *tsc,
> 					struct ts_event *tc)
> {
> 	u32 rt = 0;
>@@ -158,7 +90,7 @@ static u32 tsc2007_calculate_resistance(struct
>tsc2007 *tsc,
> 	return rt;
> }
> 
>-static bool tsc2007_is_pen_down(struct tsc2007 *ts)
>+bool tsc2007_is_pen_down(struct tsc2007 *ts)
> {
> 	/*
> 	 * NOTE: We can't rely on the pressure to determine the pen down
>@@ -191,7 +123,10 @@ static irqreturn_t tsc2007_soft_irq(int irq, void
>*handle)
> 	while (!ts->stopped && tsc2007_is_pen_down(ts)) {
> 
> 		/* pen is down, continue with the measurement */
>+
>+		mutex_lock(&ts->mlock);
> 		tsc2007_read_values(ts, &tc);
>+		mutex_unlock(&ts->mlock);
> 
> 		rt = tsc2007_calculate_resistance(ts, &tc);
> 
>@@ -441,7 +376,8 @@ static void tsc2007_call_exit_platform_hw(void
>*data)
> static int tsc2007_probe(struct i2c_client *client,
> 			 const struct i2c_device_id *id)
> {
>-	const struct tsc2007_platform_data *pdata =
>dev_get_platdata(&client->dev);
>+	const struct tsc2007_platform_data *pdata =
>+		dev_get_platdata(&client->dev);
> 	struct tsc2007 *ts;
> 	struct input_dev *input_dev;
> 	int err;
>@@ -463,7 +399,9 @@ static int tsc2007_probe(struct i2c_client *client,
> 	ts->client = client;
> 	ts->irq = client->irq;
> 	ts->input = input_dev;
>+
> 	init_waitqueue_head(&ts->wait);
>+	mutex_init(&ts->mlock);
> 
> 	snprintf(ts->phys, sizeof(ts->phys),
> 		 "%s/input0", dev_name(&client->dev));
>@@ -534,7 +472,7 @@ static int tsc2007_probe(struct i2c_client *client,
> 	if (err < 0) {
> 		dev_err(&client->dev,
> 			"Failed to setup chip: %d\n", err);
>-		return err;	/* usually, chip does not respond */
>+		return err;	/* chip does not respond */
> 	}
> 
> 	err = input_register_device(input_dev);
>@@ -544,6 +482,14 @@ static int tsc2007_probe(struct i2c_client
>*client,
> 		return err;
> 	}
> 
>+	return tsc2007_iio_configure(ts);
>+}
>+
>+static int tsc2007_remove(struct i2c_client *client)
>+{
>+	struct tsc2007 *ts = i2c_get_clientdata(client);
>+
>+	tsc2007_iio_unconfigure(ts);
> 	return 0;
> }
> 
>@@ -569,6 +515,7 @@ static struct i2c_driver tsc2007_driver = {
> 	},
> 	.id_table	= tsc2007_idtable,
> 	.probe		= tsc2007_probe,
>+	.remove		= tsc2007_remove,
> };
> 
> module_i2c_driver(tsc2007_driver);
>diff --git a/drivers/input/touchscreen/tsc2007_iio.c
>b/drivers/input/touchscreen/tsc2007_iio.c
>new file mode 100644
>index 0000000..ed79944
>--- /dev/null
>+++ b/drivers/input/touchscreen/tsc2007_iio.c
>@@ -0,0 +1,150 @@
>+/*
>+ * Copyright (c) 2016 Golden Delicious Comp. GmbH&Co. KG
>+ *	Nikolaus Schaller <hns@goldelico.com>
>+ *
>+ *  This program is free software; you can redistribute it and/or
>modify
>+ *  it under the terms of the GNU General Public License version 2 as
>+ *  published by the Free Software Foundation.
>+ */
>+
>+#include <linux/i2c.h>
>+#include <linux/iio/iio.h>
>+#include "tsc2007.h"
>+
>+struct tsc2007_iio {
>+	struct tsc2007 *ts;
>+};
>+
>+#define TSC2007_CHAN_IIO(_chan, _name, _type, _chan_info) \
>+{ \
>+	.datasheet_name = _name, \
>+	.type = _type, \
>+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |	\
>+			BIT(_chan_info), \
>+	.indexed = 1, \
>+	.channel = _chan, \
>+}
>+
>+static const struct iio_chan_spec tsc2007_iio_channel[] = {
>+	TSC2007_CHAN_IIO(0, "x", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
>+	TSC2007_CHAN_IIO(1, "y", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
>+	TSC2007_CHAN_IIO(2, "z1", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
>+	TSC2007_CHAN_IIO(3, "z2", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
>+	TSC2007_CHAN_IIO(4, "adc", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
>+	TSC2007_CHAN_IIO(5, "rt", IIO_VOLTAGE, IIO_CHAN_INFO_RAW), /* Ohms?
>*/
>+	TSC2007_CHAN_IIO(6, "pen", IIO_PRESSURE, IIO_CHAN_INFO_RAW),
>+	TSC2007_CHAN_IIO(7, "temp0", IIO_TEMP, IIO_CHAN_INFO_RAW),
>+	TSC2007_CHAN_IIO(8, "temp1", IIO_TEMP, IIO_CHAN_INFO_RAW),
>+};
>+
>+static int tsc2007_read_raw(struct iio_dev *indio_dev,
>+	struct iio_chan_spec const *chan, int *val, int *val2, long mask)
>+{
>+	struct tsc2007_iio *iio = iio_priv(indio_dev);
>+	struct tsc2007 *tsc = iio->ts;
>+	int adc_chan = chan->channel;
>+	int ret = 0;
>+
>+	if (adc_chan >= ARRAY_SIZE(tsc2007_iio_channel))
>+		return -EINVAL;
>+
>+	if (mask != IIO_CHAN_INFO_RAW)
>+		return -EINVAL;
>+
>+	mutex_lock(&tsc->mlock);
>+
>+	switch (chan->channel) {
>+	case 0:
>+		*val = tsc2007_xfer(tsc, READ_X);
>+		break;
>+	case 1:
>+		*val = tsc2007_xfer(tsc, READ_Y);
>+		break;
>+	case 2:
>+		*val = tsc2007_xfer(tsc, READ_Z1);
>+		break;
>+	case 3:
>+		*val = tsc2007_xfer(tsc, READ_Z2);
>+		break;
>+	case 4:
>+		*val = tsc2007_xfer(tsc, (ADC_ON_12BIT | TSC2007_MEASURE_AUX));
>+		break;
>+	case 5: {
>+		struct ts_event tc;
>+
>+		tc.x = tsc2007_xfer(tsc, READ_X);
>+		tc.z1 = tsc2007_xfer(tsc, READ_Z1);
>+		tc.z2 = tsc2007_xfer(tsc, READ_Z2);
>+		*val = tsc2007_calculate_resistance(tsc, &tc);
>+		break;
>+	}
>+	case 6:
>+		*val = tsc2007_is_pen_down(tsc);
>+		break;
>+	case 7:
>+		*val = tsc2007_xfer(tsc,
>+				    (ADC_ON_12BIT | TSC2007_MEASURE_TEMP0));
>+		break;
>+	case 8:
>+		*val = tsc2007_xfer(tsc,
>+				    (ADC_ON_12BIT | TSC2007_MEASURE_TEMP1));
>+		break;
>+	}
>+
>+	/* Prepare for next touch reading - power down ADC, enable PENIRQ */
>+	tsc2007_xfer(tsc, PWRDOWN);
>+
>+	mutex_unlock(&tsc->mlock);
>+
>+	ret = IIO_VAL_INT;
>+
>+	return ret;
>+}
>+
>+static const struct iio_info tsc2007_iio_info = {
>+	.read_raw = tsc2007_read_raw,
>+	.driver_module = THIS_MODULE,
>+};
>+
>+int tsc2007_iio_configure(struct tsc2007 *ts)
>+{
>+	int err;
>+	struct iio_dev *indio_dev;
>+	struct tsc2007_iio *iio;
>+
>+	indio_dev = devm_iio_device_alloc(&ts->client->dev,
>+		sizeof(struct tsc2007_iio));
>+	if (!indio_dev) {
>+		dev_err(&ts->client->dev, "iio_device_alloc failed\n");
>+		return -ENOMEM;
>+	}
>+
>+	iio = iio_priv(indio_dev);
>+	iio->ts = ts;
>+	ts->iio_dev = (void *) indio_dev;
>+
>+	indio_dev->name = "tsc2007";
>+	indio_dev->dev.parent = &ts->client->dev;
>+	indio_dev->info = &tsc2007_iio_info;
>+	indio_dev->modes = INDIO_DIRECT_MODE;
>+	indio_dev->channels = tsc2007_iio_channel;
>+	indio_dev->num_channels = ARRAY_SIZE(tsc2007_iio_channel);
>+
>+	err = iio_device_register(indio_dev);
>+	if (err < 0) {
>+		dev_err(&ts->client->dev, "iio_device_register() failed: %d\n",
>+			err);
>+		return err;
>+	}
>+
>+	return 0;
>+}
>+EXPORT_SYMBOL(tsc2007_iio_configure);
>+
>+void tsc2007_iio_unconfigure(struct tsc2007 *ts)
>+{
>+	struct iio_dev *indio_dev = ts->iio_dev;
>+
>+	iio_device_unregister(indio_dev);
>+}
>+EXPORT_SYMBOL(tsc2007_iio_unconfigure);
H. Nikolaus Schaller Nov. 24, 2016, 6:05 p.m. UTC | #2
> Am 24.11.2016 um 18:38 schrieb Jonathan Cameron <jic23@jic23.retrosnub.co.uk>:
> 
> 
> 
> On 22 November 2016 14:02:30 GMT+00:00, "H. Nikolaus Schaller" <hns@goldelico.com> wrote:
>> The tsc2007 chip not only has a resistive touch screen controller but
>> also an external AUX adc imput which can be used for an ambient
>> light sensor, battery voltage monitoring or any general purpose.
>> 
>> Additionally it can measure the chip temperature.
>> 
>> This extension provides an iio interface for these adc channels.
>> 
>> Since it is not wasting much resources and is very straightforward,
>> we simply provide all other adc channels as optional iio interfaces
>> as weel. This can be used for debugging or special applications.
>> 
>> This patch also splits the tsc2007 driver in several source files:
>> tsc2007.h -- constants, structs and stubs
>> tsc2007_core.c -- functional parts of the original driver
>> tsc2007_iio.c -- the optional iio stuff
>> 
>> Makefile magic allows to conditionally link the iio stuff
>> if CONFIG_IIO=y or =m in a way that it works with
>> CONFIG_TOUCHSCREEN_TSC2007=m.
>> 
>> Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
>> Reviewed-by: Jonathan Cameron <jic23@kernel.org>
>> ---
>> drivers/input/touchscreen/Makefile                 |   7 +
>> drivers/input/touchscreen/tsc2007.h                | 116
>> ++++++++++++++++
>> .../touchscreen/{tsc2007.c => tsc2007_core.c}      |  95 +++----------
>> drivers/input/touchscreen/tsc2007_iio.c            | 150
>> +++++++++++++++++++++
>> 4 files changed, 294 insertions(+), 74 deletions(-)
>> create mode 100644 drivers/input/touchscreen/tsc2007.h
>> rename drivers/input/touchscreen/{tsc2007.c => tsc2007_core.c} (86%)
>> create mode 100644 drivers/input/touchscreen/tsc2007_iio.c
>> 
>> diff --git a/drivers/input/touchscreen/Makefile
>> b/drivers/input/touchscreen/Makefile
>> index 81b8645..3be0d19 100644
>> --- a/drivers/input/touchscreen/Makefile
>> +++ b/drivers/input/touchscreen/Makefile
>> @@ -80,6 +80,13 @@ obj-$(CONFIG_TOUCHSCREEN_TSC_SERIO)	+= tsc40.o
>> obj-$(CONFIG_TOUCHSCREEN_TSC200X_CORE)	+= tsc200x-core.o
>> obj-$(CONFIG_TOUCHSCREEN_TSC2004)	+= tsc2004.o
>> obj-$(CONFIG_TOUCHSCREEN_TSC2005)	+= tsc2005.o
>> +tsc2007-y				:= tsc2007_core.o
>> +ifeq ($(CONFIG_IIO),y)
>> +tsc2007-y				+= tsc2007_iio.o
>> +endif
>> +ifeq ($(CONFIG_IIO),m)
>> +tsc2007-y				+= tsc2007_iio.o
> 
> Not tsc2007-m ?
> 
> I don't follow how this works!

I guess tsc2007-y is an internal collector variable name
for multiple .o components. Sort of a "library" object.

While

obj-y += tsc2007.o adds it to the kernel
obj-m += tsc2007.o adds it to the modules

I am not sure if my explanation is correct but it appears
to work that way.

Anyways what shall we do? If CONFIG_TOUCHSCREEN_TSC2007=y
and IIO=m we have a problem that we need dynamic binding.

>> +endif
>> obj-$(CONFIG_TOUCHSCREEN_TSC2007)	+= tsc2007.o
>> obj-$(CONFIG_TOUCHSCREEN_UCB1400)	+= ucb1400_ts.o
>> obj-$(CONFIG_TOUCHSCREEN_WACOM_W8001)	+= wacom_w8001.o
>> diff --git a/drivers/input/touchscreen/tsc2007.h
>> b/drivers/input/touchscreen/tsc2007.h
>> new file mode 100644
>> index 0000000..c25932f
>> --- /dev/null
>> +++ b/drivers/input/touchscreen/tsc2007.h
>> @@ -0,0 +1,116 @@
>> +/*
>> + * Copyright (c) 2008 MtekVision Co., Ltd.
>> + *	Kwangwoo Lee <kwlee@mtekvision.com>
>> + *
>> + * Using code from:
>> + *  - ads7846.c
>> + *	Copyright (c) 2005 David Brownell
>> + *	Copyright (c) 2006 Nokia Corporation
>> + *  - corgi_ts.c
>> + *	Copyright (C) 2004-2005 Richard Purdie
>> + *  - omap_ts.[hc], ads7846.h, ts_osk.c
>> + *	Copyright (C) 2002 MontaVista Software
>> + *	Copyright (C) 2004 Texas Instruments
>> + *	Copyright (C) 2005 Dirk Behme
>> + *
>> + *  This program is free software; you can redistribute it and/or
>> modify
>> + *  it under the terms of the GNU General Public License version 2 as
>> + *  published by the Free Software Foundation.
>> + */
>> +
>> +#include <linux/input/touchscreen.h>
>> +
>> +#define TSC2007_MEASURE_TEMP0		(0x0 << 4)
>> +#define TSC2007_MEASURE_AUX		(0x2 << 4)
>> +#define TSC2007_MEASURE_TEMP1		(0x4 << 4)
>> +#define TSC2007_ACTIVATE_XN		(0x8 << 4)
>> +#define TSC2007_ACTIVATE_YN		(0x9 << 4)
>> +#define TSC2007_ACTIVATE_YP_XN		(0xa << 4)
>> +#define TSC2007_SETUP			(0xb << 4)
>> +#define TSC2007_MEASURE_X		(0xc << 4)
>> +#define TSC2007_MEASURE_Y		(0xd << 4)
>> +#define TSC2007_MEASURE_Z1		(0xe << 4)
>> +#define TSC2007_MEASURE_Z2		(0xf << 4)
>> +
>> +#define TSC2007_POWER_OFF_IRQ_EN	(0x0 << 2)
>> +#define TSC2007_ADC_ON_IRQ_DIS0		(0x1 << 2)
>> +#define TSC2007_ADC_OFF_IRQ_EN		(0x2 << 2)
>> +#define TSC2007_ADC_ON_IRQ_DIS1		(0x3 << 2)
>> +
>> +#define TSC2007_12BIT			(0x0 << 1)
>> +#define TSC2007_8BIT			(0x1 << 1)
>> +
>> +#define	MAX_12BIT			((1 << 12) - 1)
>> +
>> +#define ADC_ON_12BIT	(TSC2007_12BIT | TSC2007_ADC_ON_IRQ_DIS0)
>> +
>> +#define READ_Y		(ADC_ON_12BIT | TSC2007_MEASURE_Y)
>> +#define READ_Z1		(ADC_ON_12BIT | TSC2007_MEASURE_Z1)
>> +#define READ_Z2		(ADC_ON_12BIT | TSC2007_MEASURE_Z2)
>> +#define READ_X		(ADC_ON_12BIT | TSC2007_MEASURE_X)
>> +#define PWRDOWN		(TSC2007_12BIT | TSC2007_POWER_OFF_IRQ_EN)
>> +
>> +struct ts_event {
>> +	u16	x;
>> +	u16	y;
>> +	u16	z1, z2;
>> +};
>> +
>> +struct tsc2007 {
>> +	struct input_dev	*input;
>> +	char			phys[32];
>> +
>> +	struct i2c_client	*client;
>> +
>> +	u16			model;
>> +	u16			x_plate_ohms;
>> +
>> +	struct touchscreen_properties prop;
>> +
>> +	bool			report_resistance;
>> +	u16			min_x;
>> +	u16			min_y;
>> +	u16			max_x;
>> +	u16			max_y;
>> +	u16			max_rt;
>> +	unsigned long		poll_period; /* in jiffies */
>> +	int			fuzzx;
>> +	int			fuzzy;
>> +	int			fuzzz;
>> +
>> +	unsigned int		gpio;
>> +	int			irq;
>> +
>> +	wait_queue_head_t	wait;
>> +	bool			stopped;
>> +	bool			pendown;
>> +
>> +	int			(*get_pendown_state)(struct device *);
>> +	void			(*clear_penirq)(void);
>> +
>> +	struct mutex		mlock;
>> +	struct iio_dev		*iio_dev;	/* optional */
>> +};
>> +
>> +int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd);
>> +u32 tsc2007_calculate_resistance(struct tsc2007 *tsc,
>> +					struct ts_event *tc);
>> +bool tsc2007_is_pen_down(struct tsc2007 *ts);
>> +
>> +#if IS_ENABLED(CONFIG_IIO)
>> +
>> +/* defined in tsc2007_iio.c */
>> +int tsc2007_iio_configure(struct tsc2007 *ts);
>> +void tsc2007_iio_unconfigure(struct tsc2007 *ts);
>> +
>> +#else /* CONFIG_IIO */
>> +
>> +static inline int tsc2007_iio_configure(struct tsc2007 *ts)
>> +{
>> +	return 0;
>> +}
>> +static inline void tsc2007_iio_unconfigure(struct tsc2007 *ts)
>> +{
>> +}
>> +
>> +#endif /* CONFIG_IIO */
>> diff --git a/drivers/input/touchscreen/tsc2007.c
>> b/drivers/input/touchscreen/tsc2007_core.c
>> similarity index 86%
>> rename from drivers/input/touchscreen/tsc2007.c
>> rename to drivers/input/touchscreen/tsc2007_core.c
>> index 76b462b..812ded8 100644
>> --- a/drivers/input/touchscreen/tsc2007.c
>> +++ b/drivers/input/touchscreen/tsc2007_core.c
>> @@ -27,79 +27,11 @@
>> #include <linux/i2c.h>
>> #include <linux/i2c/tsc2007.h>
>> #include <linux/of_device.h>
>> -#include <linux/of.h>
>> #include <linux/of_gpio.h>
>> -#include <linux/input/touchscreen.h>
>> -
>> -#define TSC2007_MEASURE_TEMP0		(0x0 << 4)
>> -#define TSC2007_MEASURE_AUX		(0x2 << 4)
>> -#define TSC2007_MEASURE_TEMP1		(0x4 << 4)
>> -#define TSC2007_ACTIVATE_XN		(0x8 << 4)
>> -#define TSC2007_ACTIVATE_YN		(0x9 << 4)
>> -#define TSC2007_ACTIVATE_YP_XN		(0xa << 4)
>> -#define TSC2007_SETUP			(0xb << 4)
>> -#define TSC2007_MEASURE_X		(0xc << 4)
>> -#define TSC2007_MEASURE_Y		(0xd << 4)
>> -#define TSC2007_MEASURE_Z1		(0xe << 4)
>> -#define TSC2007_MEASURE_Z2		(0xf << 4)
>> -
>> -#define TSC2007_POWER_OFF_IRQ_EN	(0x0 << 2)
>> -#define TSC2007_ADC_ON_IRQ_DIS0		(0x1 << 2)
>> -#define TSC2007_ADC_OFF_IRQ_EN		(0x2 << 2)
>> -#define TSC2007_ADC_ON_IRQ_DIS1		(0x3 << 2)
>> -
>> -#define TSC2007_12BIT			(0x0 << 1)
>> -#define TSC2007_8BIT			(0x1 << 1)
>> -
>> -#define	MAX_12BIT			((1 << 12) - 1)
>> -
>> -#define ADC_ON_12BIT	(TSC2007_12BIT | TSC2007_ADC_ON_IRQ_DIS0)
>> -
>> -#define READ_Y		(ADC_ON_12BIT | TSC2007_MEASURE_Y)
>> -#define READ_Z1		(ADC_ON_12BIT | TSC2007_MEASURE_Z1)
>> -#define READ_Z2		(ADC_ON_12BIT | TSC2007_MEASURE_Z2)
>> -#define READ_X		(ADC_ON_12BIT | TSC2007_MEASURE_X)
>> -#define PWRDOWN		(TSC2007_12BIT | TSC2007_POWER_OFF_IRQ_EN)
>> -
>> -struct ts_event {
>> -	u16	x;
>> -	u16	y;
>> -	u16	z1, z2;
>> -};
>> -
>> -struct tsc2007 {
>> -	struct input_dev	*input;
>> -	char			phys[32];
>> -
>> -	struct i2c_client	*client;
>> -
>> -	u16			model;
>> -	u16			x_plate_ohms;
>> -
>> -	struct touchscreen_properties prop;
>> -
>> -	bool			report_resistance;
>> -	u16			min_x;
>> -	u16			min_y;
>> -	u16			max_x;
>> -	u16			max_y;
>> -	u16			max_rt;
>> -	unsigned long		poll_period; /* in jiffies */
>> -	int			fuzzx;
>> -	int			fuzzy;
>> -	int			fuzzz;
>> -
>> -	unsigned		gpio;
>> -	int			irq;
>> -
>> -	wait_queue_head_t	wait;
>> -	bool			stopped;
>> +#include "tsc2007.h"
>> 
>> -	int			(*get_pendown_state)(struct device *);
>> -	void			(*clear_penirq)(void);
>> -};
>> 
>> -static inline int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd)
>> +int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd)
>> {
>> 	s32 data;
>> 	u16 val;
>> @@ -137,7 +69,7 @@ static void tsc2007_read_values(struct tsc2007 *tsc,
>> struct ts_event *tc)
>> 	tsc2007_xfer(tsc, PWRDOWN);
>> }
>> 
>> -static u32 tsc2007_calculate_resistance(struct tsc2007 *tsc,
>> +u32 tsc2007_calculate_resistance(struct tsc2007 *tsc,
>> 					struct ts_event *tc)
>> {
>> 	u32 rt = 0;
>> @@ -158,7 +90,7 @@ static u32 tsc2007_calculate_resistance(struct
>> tsc2007 *tsc,
>> 	return rt;
>> }
>> 
>> -static bool tsc2007_is_pen_down(struct tsc2007 *ts)
>> +bool tsc2007_is_pen_down(struct tsc2007 *ts)
>> {
>> 	/*
>> 	 * NOTE: We can't rely on the pressure to determine the pen down
>> @@ -191,7 +123,10 @@ static irqreturn_t tsc2007_soft_irq(int irq, void
>> *handle)
>> 	while (!ts->stopped && tsc2007_is_pen_down(ts)) {
>> 
>> 		/* pen is down, continue with the measurement */
>> +
>> +		mutex_lock(&ts->mlock);
>> 		tsc2007_read_values(ts, &tc);
>> +		mutex_unlock(&ts->mlock);
>> 
>> 		rt = tsc2007_calculate_resistance(ts, &tc);
>> 
>> @@ -441,7 +376,8 @@ static void tsc2007_call_exit_platform_hw(void
>> *data)
>> static int tsc2007_probe(struct i2c_client *client,
>> 			 const struct i2c_device_id *id)
>> {
>> -	const struct tsc2007_platform_data *pdata =
>> dev_get_platdata(&client->dev);
>> +	const struct tsc2007_platform_data *pdata =
>> +		dev_get_platdata(&client->dev);
>> 	struct tsc2007 *ts;
>> 	struct input_dev *input_dev;
>> 	int err;
>> @@ -463,7 +399,9 @@ static int tsc2007_probe(struct i2c_client *client,
>> 	ts->client = client;
>> 	ts->irq = client->irq;
>> 	ts->input = input_dev;
>> +
>> 	init_waitqueue_head(&ts->wait);
>> +	mutex_init(&ts->mlock);
>> 
>> 	snprintf(ts->phys, sizeof(ts->phys),
>> 		 "%s/input0", dev_name(&client->dev));
>> @@ -534,7 +472,7 @@ static int tsc2007_probe(struct i2c_client *client,
>> 	if (err < 0) {
>> 		dev_err(&client->dev,
>> 			"Failed to setup chip: %d\n", err);
>> -		return err;	/* usually, chip does not respond */
>> +		return err;	/* chip does not respond */
>> 	}
>> 
>> 	err = input_register_device(input_dev);
>> @@ -544,6 +482,14 @@ static int tsc2007_probe(struct i2c_client
>> *client,
>> 		return err;
>> 	}
>> 
>> +	return tsc2007_iio_configure(ts);
>> +}
>> +
>> +static int tsc2007_remove(struct i2c_client *client)
>> +{
>> +	struct tsc2007 *ts = i2c_get_clientdata(client);
>> +
>> +	tsc2007_iio_unconfigure(ts);
>> 	return 0;
>> }
>> 
>> @@ -569,6 +515,7 @@ static struct i2c_driver tsc2007_driver = {
>> 	},
>> 	.id_table	= tsc2007_idtable,
>> 	.probe		= tsc2007_probe,
>> +	.remove		= tsc2007_remove,
>> };
>> 
>> module_i2c_driver(tsc2007_driver);
>> diff --git a/drivers/input/touchscreen/tsc2007_iio.c
>> b/drivers/input/touchscreen/tsc2007_iio.c
>> new file mode 100644
>> index 0000000..ed79944
>> --- /dev/null
>> +++ b/drivers/input/touchscreen/tsc2007_iio.c
>> @@ -0,0 +1,150 @@
>> +/*
>> + * Copyright (c) 2016 Golden Delicious Comp. GmbH&Co. KG
>> + *	Nikolaus Schaller <hns@goldelico.com>
>> + *
>> + *  This program is free software; you can redistribute it and/or
>> modify
>> + *  it under the terms of the GNU General Public License version 2 as
>> + *  published by the Free Software Foundation.
>> + */
>> +
>> +#include <linux/i2c.h>
>> +#include <linux/iio/iio.h>
>> +#include "tsc2007.h"
>> +
>> +struct tsc2007_iio {
>> +	struct tsc2007 *ts;
>> +};
>> +
>> +#define TSC2007_CHAN_IIO(_chan, _name, _type, _chan_info) \
>> +{ \
>> +	.datasheet_name = _name, \
>> +	.type = _type, \
>> +	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |	\
>> +			BIT(_chan_info), \
>> +	.indexed = 1, \
>> +	.channel = _chan, \
>> +}
>> +
>> +static const struct iio_chan_spec tsc2007_iio_channel[] = {
>> +	TSC2007_CHAN_IIO(0, "x", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
>> +	TSC2007_CHAN_IIO(1, "y", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
>> +	TSC2007_CHAN_IIO(2, "z1", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
>> +	TSC2007_CHAN_IIO(3, "z2", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
>> +	TSC2007_CHAN_IIO(4, "adc", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
>> +	TSC2007_CHAN_IIO(5, "rt", IIO_VOLTAGE, IIO_CHAN_INFO_RAW), /* Ohms?
>> */
>> +	TSC2007_CHAN_IIO(6, "pen", IIO_PRESSURE, IIO_CHAN_INFO_RAW),
>> +	TSC2007_CHAN_IIO(7, "temp0", IIO_TEMP, IIO_CHAN_INFO_RAW),
>> +	TSC2007_CHAN_IIO(8, "temp1", IIO_TEMP, IIO_CHAN_INFO_RAW),
>> +};
>> +
>> +static int tsc2007_read_raw(struct iio_dev *indio_dev,
>> +	struct iio_chan_spec const *chan, int *val, int *val2, long mask)
>> +{
>> +	struct tsc2007_iio *iio = iio_priv(indio_dev);
>> +	struct tsc2007 *tsc = iio->ts;
>> +	int adc_chan = chan->channel;
>> +	int ret = 0;
>> +
>> +	if (adc_chan >= ARRAY_SIZE(tsc2007_iio_channel))
>> +		return -EINVAL;
>> +
>> +	if (mask != IIO_CHAN_INFO_RAW)
>> +		return -EINVAL;
>> +
>> +	mutex_lock(&tsc->mlock);
>> +
>> +	switch (chan->channel) {
>> +	case 0:
>> +		*val = tsc2007_xfer(tsc, READ_X);
>> +		break;
>> +	case 1:
>> +		*val = tsc2007_xfer(tsc, READ_Y);
>> +		break;
>> +	case 2:
>> +		*val = tsc2007_xfer(tsc, READ_Z1);
>> +		break;
>> +	case 3:
>> +		*val = tsc2007_xfer(tsc, READ_Z2);
>> +		break;
>> +	case 4:
>> +		*val = tsc2007_xfer(tsc, (ADC_ON_12BIT | TSC2007_MEASURE_AUX));
>> +		break;
>> +	case 5: {
>> +		struct ts_event tc;
>> +
>> +		tc.x = tsc2007_xfer(tsc, READ_X);
>> +		tc.z1 = tsc2007_xfer(tsc, READ_Z1);
>> +		tc.z2 = tsc2007_xfer(tsc, READ_Z2);
>> +		*val = tsc2007_calculate_resistance(tsc, &tc);
>> +		break;
>> +	}
>> +	case 6:
>> +		*val = tsc2007_is_pen_down(tsc);
>> +		break;
>> +	case 7:
>> +		*val = tsc2007_xfer(tsc,
>> +				    (ADC_ON_12BIT | TSC2007_MEASURE_TEMP0));
>> +		break;
>> +	case 8:
>> +		*val = tsc2007_xfer(tsc,
>> +				    (ADC_ON_12BIT | TSC2007_MEASURE_TEMP1));
>> +		break;
>> +	}
>> +
>> +	/* Prepare for next touch reading - power down ADC, enable PENIRQ */
>> +	tsc2007_xfer(tsc, PWRDOWN);
>> +
>> +	mutex_unlock(&tsc->mlock);
>> +
>> +	ret = IIO_VAL_INT;
>> +
>> +	return ret;
>> +}
>> +
>> +static const struct iio_info tsc2007_iio_info = {
>> +	.read_raw = tsc2007_read_raw,
>> +	.driver_module = THIS_MODULE,
>> +};
>> +
>> +int tsc2007_iio_configure(struct tsc2007 *ts)
>> +{
>> +	int err;
>> +	struct iio_dev *indio_dev;
>> +	struct tsc2007_iio *iio;
>> +
>> +	indio_dev = devm_iio_device_alloc(&ts->client->dev,
>> +		sizeof(struct tsc2007_iio));
>> +	if (!indio_dev) {
>> +		dev_err(&ts->client->dev, "iio_device_alloc failed\n");
>> +		return -ENOMEM;
>> +	}
>> +
>> +	iio = iio_priv(indio_dev);
>> +	iio->ts = ts;
>> +	ts->iio_dev = (void *) indio_dev;
>> +
>> +	indio_dev->name = "tsc2007";
>> +	indio_dev->dev.parent = &ts->client->dev;
>> +	indio_dev->info = &tsc2007_iio_info;
>> +	indio_dev->modes = INDIO_DIRECT_MODE;
>> +	indio_dev->channels = tsc2007_iio_channel;
>> +	indio_dev->num_channels = ARRAY_SIZE(tsc2007_iio_channel);
>> +
>> +	err = iio_device_register(indio_dev);
>> +	if (err < 0) {
>> +		dev_err(&ts->client->dev, "iio_device_register() failed: %d\n",
>> +			err);
>> +		return err;
>> +	}
>> +
>> +	return 0;
>> +}
>> +EXPORT_SYMBOL(tsc2007_iio_configure);
>> +
>> +void tsc2007_iio_unconfigure(struct tsc2007 *ts)
>> +{
>> +	struct iio_dev *indio_dev = ts->iio_dev;
>> +
>> +	iio_device_unregister(indio_dev);
>> +}
>> +EXPORT_SYMBOL(tsc2007_iio_unconfigure);
> 
> -- 
> Sent from my Android device with K-9 Mail. Please excuse my brevity.

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Jonathan Cameron Nov. 27, 2016, 11:02 a.m. UTC | #3
On 24/11/16 18:05, H. Nikolaus Schaller wrote:
> 
>> Am 24.11.2016 um 18:38 schrieb Jonathan Cameron <jic23@jic23.retrosnub.co.uk>:
>>
>>
>>
>> On 22 November 2016 14:02:30 GMT+00:00, "H. Nikolaus Schaller" <hns@goldelico.com> wrote:
>>> The tsc2007 chip not only has a resistive touch screen controller but
>>> also an external AUX adc imput which can be used for an ambient
>>> light sensor, battery voltage monitoring or any general purpose.
>>>
>>> Additionally it can measure the chip temperature.
>>>
>>> This extension provides an iio interface for these adc channels.
>>>
>>> Since it is not wasting much resources and is very straightforward,
>>> we simply provide all other adc channels as optional iio interfaces
>>> as weel. This can be used for debugging or special applications.
>>>
>>> This patch also splits the tsc2007 driver in several source files:
>>> tsc2007.h -- constants, structs and stubs
>>> tsc2007_core.c -- functional parts of the original driver
>>> tsc2007_iio.c -- the optional iio stuff
>>>
>>> Makefile magic allows to conditionally link the iio stuff
>>> if CONFIG_IIO=y or =m in a way that it works with
>>> CONFIG_TOUCHSCREEN_TSC2007=m.
>>>
>>> Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
>>> Reviewed-by: Jonathan Cameron <jic23@kernel.org>
>>> ---
>>> drivers/input/touchscreen/Makefile                 |   7 +
>>> drivers/input/touchscreen/tsc2007.h                | 116
>>> ++++++++++++++++
>>> .../touchscreen/{tsc2007.c => tsc2007_core.c}      |  95 +++----------
>>> drivers/input/touchscreen/tsc2007_iio.c            | 150
>>> +++++++++++++++++++++
>>> 4 files changed, 294 insertions(+), 74 deletions(-)
>>> create mode 100644 drivers/input/touchscreen/tsc2007.h
>>> rename drivers/input/touchscreen/{tsc2007.c => tsc2007_core.c} (86%)
>>> create mode 100644 drivers/input/touchscreen/tsc2007_iio.c
>>>
>>> diff --git a/drivers/input/touchscreen/Makefile
>>> b/drivers/input/touchscreen/Makefile
>>> index 81b8645..3be0d19 100644
>>> --- a/drivers/input/touchscreen/Makefile
>>> +++ b/drivers/input/touchscreen/Makefile
>>> @@ -80,6 +80,13 @@ obj-$(CONFIG_TOUCHSCREEN_TSC_SERIO)	+= tsc40.o
>>> obj-$(CONFIG_TOUCHSCREEN_TSC200X_CORE)	+= tsc200x-core.o
>>> obj-$(CONFIG_TOUCHSCREEN_TSC2004)	+= tsc2004.o
>>> obj-$(CONFIG_TOUCHSCREEN_TSC2005)	+= tsc2005.o
>>> +tsc2007-y				:= tsc2007_core.o
>>> +ifeq ($(CONFIG_IIO),y)
>>> +tsc2007-y				+= tsc2007_iio.o
>>> +endif
>>> +ifeq ($(CONFIG_IIO),m)
>>> +tsc2007-y				+= tsc2007_iio.o
>>
>> Not tsc2007-m ?
>>
>> I don't follow how this works!
> 
> I guess tsc2007-y is an internal collector variable name
> for multiple .o components. Sort of a "library" object.
> 
> While
> 
> obj-y += tsc2007.o adds it to the kernel
> obj-m += tsc2007.o adds it to the modules
> 
> I am not sure if my explanation is correct but it appears
> to work that way.
> 
> Anyways what shall we do? If CONFIG_TOUCHSCREEN_TSC2007=y
> and IIO=m we have a problem that we need dynamic binding.
Yes, we just need to block that particular combination. Only build in the IIO support
if it is also built in.  That's way I thought we'd want to add it tsc2007-m which would
only be used if tsc2007 as a whole was built as a module.
Otherwise it would be ignored (I think!)

I'm not seeing this structure anywhere else in kernel - hence cc'd Yann and the Kbuild list
to see if they can offer some advices.

As a quick summary, we are looking to add IIO support to this driver in the following circumstances.

IIO and this driver are modules.  (ideally handling the dependencies nicely)
IIO and this driver are both built in.

Problem case is driver built in and IIO as a module.

Jonathan
> 
>>> +endif
>>> obj-$(CONFIG_TOUCHSCREEN_TSC2007)	+= tsc2007.o
>>> obj-$(CONFIG_TOUCHSCREEN_UCB1400)	+= ucb1400_ts.o
>>> obj-$(CONFIG_TOUCHSCREEN_WACOM_W8001)	+= wacom_w8001.o
>>> diff --git a/drivers/input/touchscreen/tsc2007.h
>>> b/drivers/input/touchscreen/tsc2007.h
>>> new file mode 100644
>>> index 0000000..c25932f
>>> --- /dev/null
>>> +++ b/drivers/input/touchscreen/tsc2007.h
>>> @@ -0,0 +1,116 @@
>>> +/*
>>> + * Copyright (c) 2008 MtekVision Co., Ltd.
>>> + *	Kwangwoo Lee <kwlee@mtekvision.com>
>>> + *
>>> + * Using code from:
>>> + *  - ads7846.c
>>> + *	Copyright (c) 2005 David Brownell
>>> + *	Copyright (c) 2006 Nokia Corporation
>>> + *  - corgi_ts.c
>>> + *	Copyright (C) 2004-2005 Richard Purdie
>>> + *  - omap_ts.[hc], ads7846.h, ts_osk.c
>>> + *	Copyright (C) 2002 MontaVista Software
>>> + *	Copyright (C) 2004 Texas Instruments
>>> + *	Copyright (C) 2005 Dirk Behme
>>> + *
>>> + *  This program is free software; you can redistribute it and/or
>>> modify
>>> + *  it under the terms of the GNU General Public License version 2 as
>>> + *  published by the Free Software Foundation.
>>> + */
>>> +
>>> +#include <linux/input/touchscreen.h>
>>> +
>>> +#define TSC2007_MEASURE_TEMP0		(0x0 << 4)
>>> +#define TSC2007_MEASURE_AUX		(0x2 << 4)
>>> +#define TSC2007_MEASURE_TEMP1		(0x4 << 4)
>>> +#define TSC2007_ACTIVATE_XN		(0x8 << 4)
>>> +#define TSC2007_ACTIVATE_YN		(0x9 << 4)
>>> +#define TSC2007_ACTIVATE_YP_XN		(0xa << 4)
>>> +#define TSC2007_SETUP			(0xb << 4)
>>> +#define TSC2007_MEASURE_X		(0xc << 4)
>>> +#define TSC2007_MEASURE_Y		(0xd << 4)
>>> +#define TSC2007_MEASURE_Z1		(0xe << 4)
>>> +#define TSC2007_MEASURE_Z2		(0xf << 4)
>>> +
>>> +#define TSC2007_POWER_OFF_IRQ_EN	(0x0 << 2)
>>> +#define TSC2007_ADC_ON_IRQ_DIS0		(0x1 << 2)
>>> +#define TSC2007_ADC_OFF_IRQ_EN		(0x2 << 2)
>>> +#define TSC2007_ADC_ON_IRQ_DIS1		(0x3 << 2)
>>> +
>>> +#define TSC2007_12BIT			(0x0 << 1)
>>> +#define TSC2007_8BIT			(0x1 << 1)
>>> +
>>> +#define	MAX_12BIT			((1 << 12) - 1)
>>> +
>>> +#define ADC_ON_12BIT	(TSC2007_12BIT | TSC2007_ADC_ON_IRQ_DIS0)
>>> +
>>> +#define READ_Y		(ADC_ON_12BIT | TSC2007_MEASURE_Y)
>>> +#define READ_Z1		(ADC_ON_12BIT | TSC2007_MEASURE_Z1)
>>> +#define READ_Z2		(ADC_ON_12BIT | TSC2007_MEASURE_Z2)
>>> +#define READ_X		(ADC_ON_12BIT | TSC2007_MEASURE_X)
>>> +#define PWRDOWN		(TSC2007_12BIT | TSC2007_POWER_OFF_IRQ_EN)
>>> +
>>> +struct ts_event {
>>> +	u16	x;
>>> +	u16	y;
>>> +	u16	z1, z2;
>>> +};
>>> +
>>> +struct tsc2007 {
>>> +	struct input_dev	*input;
>>> +	char			phys[32];
>>> +
>>> +	struct i2c_client	*client;
>>> +
>>> +	u16			model;
>>> +	u16			x_plate_ohms;
>>> +
>>> +	struct touchscreen_properties prop;
>>> +
>>> +	bool			report_resistance;
>>> +	u16			min_x;
>>> +	u16			min_y;
>>> +	u16			max_x;
>>> +	u16			max_y;
>>> +	u16			max_rt;
>>> +	unsigned long		poll_period; /* in jiffies */
>>> +	int			fuzzx;
>>> +	int			fuzzy;
>>> +	int			fuzzz;
>>> +
>>> +	unsigned int		gpio;
>>> +	int			irq;
>>> +
>>> +	wait_queue_head_t	wait;
>>> +	bool			stopped;
>>> +	bool			pendown;
>>> +
>>> +	int			(*get_pendown_state)(struct device *);
>>> +	void			(*clear_penirq)(void);
>>> +
>>> +	struct mutex		mlock;
>>> +	struct iio_dev		*iio_dev;	/* optional */
>>> +};
>>> +
>>> +int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd);
>>> +u32 tsc2007_calculate_resistance(struct tsc2007 *tsc,
>>> +					struct ts_event *tc);
>>> +bool tsc2007_is_pen_down(struct tsc2007 *ts);
>>> +
>>> +#if IS_ENABLED(CONFIG_IIO)
>>> +
>>> +/* defined in tsc2007_iio.c */
>>> +int tsc2007_iio_configure(struct tsc2007 *ts);
>>> +void tsc2007_iio_unconfigure(struct tsc2007 *ts);
>>> +
>>> +#else /* CONFIG_IIO */
>>> +
>>> +static inline int tsc2007_iio_configure(struct tsc2007 *ts)
>>> +{
>>> +	return 0;
>>> +}
>>> +static inline void tsc2007_iio_unconfigure(struct tsc2007 *ts)
>>> +{
>>> +}
>>> +
>>> +#endif /* CONFIG_IIO */
>>> diff --git a/drivers/input/touchscreen/tsc2007.c
>>> b/drivers/input/touchscreen/tsc2007_core.c
>>> similarity index 86%
>>> rename from drivers/input/touchscreen/tsc2007.c
>>> rename to drivers/input/touchscreen/tsc2007_core.c
>>> index 76b462b..812ded8 100644
>>> --- a/drivers/input/touchscreen/tsc2007.c
>>> +++ b/drivers/input/touchscreen/tsc2007_core.c
>>> @@ -27,79 +27,11 @@
>>> #include <linux/i2c.h>
>>> #include <linux/i2c/tsc2007.h>
>>> #include <linux/of_device.h>
>>> -#include <linux/of.h>
>>> #include <linux/of_gpio.h>
>>> -#include <linux/input/touchscreen.h>
>>> -
>>> -#define TSC2007_MEASURE_TEMP0		(0x0 << 4)
>>> -#define TSC2007_MEASURE_AUX		(0x2 << 4)
>>> -#define TSC2007_MEASURE_TEMP1		(0x4 << 4)
>>> -#define TSC2007_ACTIVATE_XN		(0x8 << 4)
>>> -#define TSC2007_ACTIVATE_YN		(0x9 << 4)
>>> -#define TSC2007_ACTIVATE_YP_XN		(0xa << 4)
>>> -#define TSC2007_SETUP			(0xb << 4)
>>> -#define TSC2007_MEASURE_X		(0xc << 4)
>>> -#define TSC2007_MEASURE_Y		(0xd << 4)
>>> -#define TSC2007_MEASURE_Z1		(0xe << 4)
>>> -#define TSC2007_MEASURE_Z2		(0xf << 4)
>>> -
>>> -#define TSC2007_POWER_OFF_IRQ_EN	(0x0 << 2)
>>> -#define TSC2007_ADC_ON_IRQ_DIS0		(0x1 << 2)
>>> -#define TSC2007_ADC_OFF_IRQ_EN		(0x2 << 2)
>>> -#define TSC2007_ADC_ON_IRQ_DIS1		(0x3 << 2)
>>> -
>>> -#define TSC2007_12BIT			(0x0 << 1)
>>> -#define TSC2007_8BIT			(0x1 << 1)
>>> -
>>> -#define	MAX_12BIT			((1 << 12) - 1)
>>> -
>>> -#define ADC_ON_12BIT	(TSC2007_12BIT | TSC2007_ADC_ON_IRQ_DIS0)
>>> -
>>> -#define READ_Y		(ADC_ON_12BIT | TSC2007_MEASURE_Y)
>>> -#define READ_Z1		(ADC_ON_12BIT | TSC2007_MEASURE_Z1)
>>> -#define READ_Z2		(ADC_ON_12BIT | TSC2007_MEASURE_Z2)
>>> -#define READ_X		(ADC_ON_12BIT | TSC2007_MEASURE_X)
>>> -#define PWRDOWN		(TSC2007_12BIT | TSC2007_POWER_OFF_IRQ_EN)
>>> -
>>> -struct ts_event {
>>> -	u16	x;
>>> -	u16	y;
>>> -	u16	z1, z2;
>>> -};
>>> -
>>> -struct tsc2007 {
>>> -	struct input_dev	*input;
>>> -	char			phys[32];
>>> -
>>> -	struct i2c_client	*client;
>>> -
>>> -	u16			model;
>>> -	u16			x_plate_ohms;
>>> -
>>> -	struct touchscreen_properties prop;
>>> -
>>> -	bool			report_resistance;
>>> -	u16			min_x;
>>> -	u16			min_y;
>>> -	u16			max_x;
>>> -	u16			max_y;
>>> -	u16			max_rt;
>>> -	unsigned long		poll_period; /* in jiffies */
>>> -	int			fuzzx;
>>> -	int			fuzzy;
>>> -	int			fuzzz;
>>> -
>>> -	unsigned		gpio;
>>> -	int			irq;
>>> -
>>> -	wait_queue_head_t	wait;
>>> -	bool			stopped;
>>> +#include "tsc2007.h"
>>>
>>> -	int			(*get_pendown_state)(struct device *);
>>> -	void			(*clear_penirq)(void);
>>> -};
>>>
>>> -static inline int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd)
>>> +int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd)
>>> {
>>> 	s32 data;
>>> 	u16 val;
>>> @@ -137,7 +69,7 @@ static void tsc2007_read_values(struct tsc2007 *tsc,
>>> struct ts_event *tc)
>>> 	tsc2007_xfer(tsc, PWRDOWN);
>>> }
>>>
>>> -static u32 tsc2007_calculate_resistance(struct tsc2007 *tsc,
>>> +u32 tsc2007_calculate_resistance(struct tsc2007 *tsc,
>>> 					struct ts_event *tc)
>>> {
>>> 	u32 rt = 0;
>>> @@ -158,7 +90,7 @@ static u32 tsc2007_calculate_resistance(struct
>>> tsc2007 *tsc,
>>> 	return rt;
>>> }
>>>
>>> -static bool tsc2007_is_pen_down(struct tsc2007 *ts)
>>> +bool tsc2007_is_pen_down(struct tsc2007 *ts)
>>> {
>>> 	/*
>>> 	 * NOTE: We can't rely on the pressure to determine the pen down
>>> @@ -191,7 +123,10 @@ static irqreturn_t tsc2007_soft_irq(int irq, void
>>> *handle)
>>> 	while (!ts->stopped && tsc2007_is_pen_down(ts)) {
>>>
>>> 		/* pen is down, continue with the measurement */
>>> +
>>> +		mutex_lock(&ts->mlock);
>>> 		tsc2007_read_values(ts, &tc);
>>> +		mutex_unlock(&ts->mlock);
>>>
>>> 		rt = tsc2007_calculate_resistance(ts, &tc);
>>>
>>> @@ -441,7 +376,8 @@ static void tsc2007_call_exit_platform_hw(void
>>> *data)
>>> static int tsc2007_probe(struct i2c_client *client,
>>> 			 const struct i2c_device_id *id)
>>> {
>>> -	const struct tsc2007_platform_data *pdata =
>>> dev_get_platdata(&client->dev);
>>> +	const struct tsc2007_platform_data *pdata =
>>> +		dev_get_platdata(&client->dev);
>>> 	struct tsc2007 *ts;
>>> 	struct input_dev *input_dev;
>>> 	int err;
>>> @@ -463,7 +399,9 @@ static int tsc2007_probe(struct i2c_client *client,
>>> 	ts->client = client;
>>> 	ts->irq = client->irq;
>>> 	ts->input = input_dev;
>>> +
>>> 	init_waitqueue_head(&ts->wait);
>>> +	mutex_init(&ts->mlock);
>>>
>>> 	snprintf(ts->phys, sizeof(ts->phys),
>>> 		 "%s/input0", dev_name(&client->dev));
>>> @@ -534,7 +472,7 @@ static int tsc2007_probe(struct i2c_client *client,
>>> 	if (err < 0) {
>>> 		dev_err(&client->dev,
>>> 			"Failed to setup chip: %d\n", err);
>>> -		return err;	/* usually, chip does not respond */
>>> +		return err;	/* chip does not respond */
>>> 	}
>>>
>>> 	err = input_register_device(input_dev);
>>> @@ -544,6 +482,14 @@ static int tsc2007_probe(struct i2c_client
>>> *client,
>>> 		return err;
>>> 	}
>>>
>>> +	return tsc2007_iio_configure(ts);
>>> +}
>>> +
>>> +static int tsc2007_remove(struct i2c_client *client)
>>> +{
>>> +	struct tsc2007 *ts = i2c_get_clientdata(client);
>>> +
>>> +	tsc2007_iio_unconfigure(ts);
>>> 	return 0;
>>> }
>>>
>>> @@ -569,6 +515,7 @@ static struct i2c_driver tsc2007_driver = {
>>> 	},
>>> 	.id_table	= tsc2007_idtable,
>>> 	.probe		= tsc2007_probe,
>>> +	.remove		= tsc2007_remove,
>>> };
>>>
>>> module_i2c_driver(tsc2007_driver);
>>> diff --git a/drivers/input/touchscreen/tsc2007_iio.c
>>> b/drivers/input/touchscreen/tsc2007_iio.c
>>> new file mode 100644
>>> index 0000000..ed79944
>>> --- /dev/null
>>> +++ b/drivers/input/touchscreen/tsc2007_iio.c
>>> @@ -0,0 +1,150 @@
>>> +/*
>>> + * Copyright (c) 2016 Golden Delicious Comp. GmbH&Co. KG
>>> + *	Nikolaus Schaller <hns@goldelico.com>
>>> + *
>>> + *  This program is free software; you can redistribute it and/or
>>> modify
>>> + *  it under the terms of the GNU General Public License version 2 as
>>> + *  published by the Free Software Foundation.
>>> + */
>>> +
>>> +#include <linux/i2c.h>
>>> +#include <linux/iio/iio.h>
>>> +#include "tsc2007.h"
>>> +
>>> +struct tsc2007_iio {
>>> +	struct tsc2007 *ts;
>>> +};
>>> +
>>> +#define TSC2007_CHAN_IIO(_chan, _name, _type, _chan_info) \
>>> +{ \
>>> +	.datasheet_name = _name, \
>>> +	.type = _type, \
>>> +	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |	\
>>> +			BIT(_chan_info), \
>>> +	.indexed = 1, \
>>> +	.channel = _chan, \
>>> +}
>>> +
>>> +static const struct iio_chan_spec tsc2007_iio_channel[] = {
>>> +	TSC2007_CHAN_IIO(0, "x", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
>>> +	TSC2007_CHAN_IIO(1, "y", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
>>> +	TSC2007_CHAN_IIO(2, "z1", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
>>> +	TSC2007_CHAN_IIO(3, "z2", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
>>> +	TSC2007_CHAN_IIO(4, "adc", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
>>> +	TSC2007_CHAN_IIO(5, "rt", IIO_VOLTAGE, IIO_CHAN_INFO_RAW), /* Ohms?
>>> */
>>> +	TSC2007_CHAN_IIO(6, "pen", IIO_PRESSURE, IIO_CHAN_INFO_RAW),
>>> +	TSC2007_CHAN_IIO(7, "temp0", IIO_TEMP, IIO_CHAN_INFO_RAW),
>>> +	TSC2007_CHAN_IIO(8, "temp1", IIO_TEMP, IIO_CHAN_INFO_RAW),
>>> +};
>>> +
>>> +static int tsc2007_read_raw(struct iio_dev *indio_dev,
>>> +	struct iio_chan_spec const *chan, int *val, int *val2, long mask)
>>> +{
>>> +	struct tsc2007_iio *iio = iio_priv(indio_dev);
>>> +	struct tsc2007 *tsc = iio->ts;
>>> +	int adc_chan = chan->channel;
>>> +	int ret = 0;
>>> +
>>> +	if (adc_chan >= ARRAY_SIZE(tsc2007_iio_channel))
>>> +		return -EINVAL;
>>> +
>>> +	if (mask != IIO_CHAN_INFO_RAW)
>>> +		return -EINVAL;
>>> +
>>> +	mutex_lock(&tsc->mlock);
>>> +
>>> +	switch (chan->channel) {
>>> +	case 0:
>>> +		*val = tsc2007_xfer(tsc, READ_X);
>>> +		break;
>>> +	case 1:
>>> +		*val = tsc2007_xfer(tsc, READ_Y);
>>> +		break;
>>> +	case 2:
>>> +		*val = tsc2007_xfer(tsc, READ_Z1);
>>> +		break;
>>> +	case 3:
>>> +		*val = tsc2007_xfer(tsc, READ_Z2);
>>> +		break;
>>> +	case 4:
>>> +		*val = tsc2007_xfer(tsc, (ADC_ON_12BIT | TSC2007_MEASURE_AUX));
>>> +		break;
>>> +	case 5: {
>>> +		struct ts_event tc;
>>> +
>>> +		tc.x = tsc2007_xfer(tsc, READ_X);
>>> +		tc.z1 = tsc2007_xfer(tsc, READ_Z1);
>>> +		tc.z2 = tsc2007_xfer(tsc, READ_Z2);
>>> +		*val = tsc2007_calculate_resistance(tsc, &tc);
>>> +		break;
>>> +	}
>>> +	case 6:
>>> +		*val = tsc2007_is_pen_down(tsc);
>>> +		break;
>>> +	case 7:
>>> +		*val = tsc2007_xfer(tsc,
>>> +				    (ADC_ON_12BIT | TSC2007_MEASURE_TEMP0));
>>> +		break;
>>> +	case 8:
>>> +		*val = tsc2007_xfer(tsc,
>>> +				    (ADC_ON_12BIT | TSC2007_MEASURE_TEMP1));
>>> +		break;
>>> +	}
>>> +
>>> +	/* Prepare for next touch reading - power down ADC, enable PENIRQ */
>>> +	tsc2007_xfer(tsc, PWRDOWN);
>>> +
>>> +	mutex_unlock(&tsc->mlock);
>>> +
>>> +	ret = IIO_VAL_INT;
>>> +
>>> +	return ret;
>>> +}
>>> +
>>> +static const struct iio_info tsc2007_iio_info = {
>>> +	.read_raw = tsc2007_read_raw,
>>> +	.driver_module = THIS_MODULE,
>>> +};
>>> +
>>> +int tsc2007_iio_configure(struct tsc2007 *ts)
>>> +{
>>> +	int err;
>>> +	struct iio_dev *indio_dev;
>>> +	struct tsc2007_iio *iio;
>>> +
>>> +	indio_dev = devm_iio_device_alloc(&ts->client->dev,
>>> +		sizeof(struct tsc2007_iio));
>>> +	if (!indio_dev) {
>>> +		dev_err(&ts->client->dev, "iio_device_alloc failed\n");
>>> +		return -ENOMEM;
>>> +	}
>>> +
>>> +	iio = iio_priv(indio_dev);
>>> +	iio->ts = ts;
>>> +	ts->iio_dev = (void *) indio_dev;
>>> +
>>> +	indio_dev->name = "tsc2007";
>>> +	indio_dev->dev.parent = &ts->client->dev;
>>> +	indio_dev->info = &tsc2007_iio_info;
>>> +	indio_dev->modes = INDIO_DIRECT_MODE;
>>> +	indio_dev->channels = tsc2007_iio_channel;
>>> +	indio_dev->num_channels = ARRAY_SIZE(tsc2007_iio_channel);
>>> +
>>> +	err = iio_device_register(indio_dev);
>>> +	if (err < 0) {
>>> +		dev_err(&ts->client->dev, "iio_device_register() failed: %d\n",
>>> +			err);
>>> +		return err;
>>> +	}
>>> +
>>> +	return 0;
>>> +}
>>> +EXPORT_SYMBOL(tsc2007_iio_configure);
>>> +
>>> +void tsc2007_iio_unconfigure(struct tsc2007 *ts)
>>> +{
>>> +	struct iio_dev *indio_dev = ts->iio_dev;
>>> +
>>> +	iio_device_unregister(indio_dev);
>>> +}
>>> +EXPORT_SYMBOL(tsc2007_iio_unconfigure);
>>
>> -- 
>> Sent from my Android device with K-9 Mail. Please excuse my brevity.
> 

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H. Nikolaus Schaller Nov. 27, 2016, 3:47 p.m. UTC | #4
Hi Jonathan,

> Am 27.11.2016 um 12:02 schrieb Jonathan Cameron <jic23@kernel.org>:
> 
> On 24/11/16 18:05, H. Nikolaus Schaller wrote:
>> 
>>> Am 24.11.2016 um 18:38 schrieb Jonathan Cameron <jic23@jic23.retrosnub.co.uk>:
>>> 
>>> 
>>> 
>>> On 22 November 2016 14:02:30 GMT+00:00, "H. Nikolaus Schaller" <hns@goldelico.com> wrote:
>>>> The tsc2007 chip not only has a resistive touch screen controller but
>>>> also an external AUX adc imput which can be used for an ambient
>>>> light sensor, battery voltage monitoring or any general purpose.
>>>> 
>>>> Additionally it can measure the chip temperature.
>>>> 
>>>> This extension provides an iio interface for these adc channels.
>>>> 
>>>> Since it is not wasting much resources and is very straightforward,
>>>> we simply provide all other adc channels as optional iio interfaces
>>>> as weel. This can be used for debugging or special applications.
>>>> 
>>>> This patch also splits the tsc2007 driver in several source files:
>>>> tsc2007.h -- constants, structs and stubs
>>>> tsc2007_core.c -- functional parts of the original driver
>>>> tsc2007_iio.c -- the optional iio stuff
>>>> 
>>>> Makefile magic allows to conditionally link the iio stuff
>>>> if CONFIG_IIO=y or =m in a way that it works with
>>>> CONFIG_TOUCHSCREEN_TSC2007=m.
>>>> 
>>>> Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
>>>> Reviewed-by: Jonathan Cameron <jic23@kernel.org>
>>>> ---
>>>> drivers/input/touchscreen/Makefile                 |   7 +
>>>> drivers/input/touchscreen/tsc2007.h                | 116
>>>> ++++++++++++++++
>>>> .../touchscreen/{tsc2007.c => tsc2007_core.c}      |  95 +++----------
>>>> drivers/input/touchscreen/tsc2007_iio.c            | 150
>>>> +++++++++++++++++++++
>>>> 4 files changed, 294 insertions(+), 74 deletions(-)
>>>> create mode 100644 drivers/input/touchscreen/tsc2007.h
>>>> rename drivers/input/touchscreen/{tsc2007.c => tsc2007_core.c} (86%)
>>>> create mode 100644 drivers/input/touchscreen/tsc2007_iio.c
>>>> 
>>>> diff --git a/drivers/input/touchscreen/Makefile
>>>> b/drivers/input/touchscreen/Makefile
>>>> index 81b8645..3be0d19 100644
>>>> --- a/drivers/input/touchscreen/Makefile
>>>> +++ b/drivers/input/touchscreen/Makefile
>>>> @@ -80,6 +80,13 @@ obj-$(CONFIG_TOUCHSCREEN_TSC_SERIO)	+= tsc40.o
>>>> obj-$(CONFIG_TOUCHSCREEN_TSC200X_CORE)	+= tsc200x-core.o
>>>> obj-$(CONFIG_TOUCHSCREEN_TSC2004)	+= tsc2004.o
>>>> obj-$(CONFIG_TOUCHSCREEN_TSC2005)	+= tsc2005.o
>>>> +tsc2007-y				:= tsc2007_core.o
>>>> +ifeq ($(CONFIG_IIO),y)
>>>> +tsc2007-y				+= tsc2007_iio.o
>>>> +endif
>>>> +ifeq ($(CONFIG_IIO),m)
>>>> +tsc2007-y				+= tsc2007_iio.o
>>> 
>>> Not tsc2007-m ?
>>> 
>>> I don't follow how this works!
>> 
>> I guess tsc2007-y is an internal collector variable name
>> for multiple .o components. Sort of a "library" object.
>> 
>> While
>> 
>> obj-y += tsc2007.o adds it to the kernel
>> obj-m += tsc2007.o adds it to the modules
>> 
>> I am not sure if my explanation is correct but it appears
>> to work that way.
>> 
>> Anyways what shall we do? If CONFIG_TOUCHSCREEN_TSC2007=y
>> and IIO=m we have a problem that we need dynamic binding.
> Yes, we just need to block that particular combination. Only build in the IIO support
> if it is also built in.  That's way I thought we'd want to add it tsc2007-m which would
> only be used if tsc2007 as a whole was built as a module.

Yes, that is what one could expect.

> Otherwise it would be ignored (I think!)
> 
> I'm not seeing this structure anywhere else in kernel

It is also not described in that way:

http://lxr.free-electrons.com/source/Documentation/kbuild/modules.txt#L146

it only talks about obj-m and <module_name>-y but not <module_name>-m

> - hence cc'd Yann and the Kbuild list
> to see if they can offer some advices.

Thanks!

BTW, the other tsc2007 and ads7846 patches could already be merged (if there
are no more changes needed) since this one only depends on the result of applying
all others before.

> 
> As a quick summary, we are looking to add IIO support to this driver in the following circumstances.
> 
> IIO and this driver are modules.  (ideally handling the dependencies nicely)
> IIO and this driver are both built in.
> 
> Problem case is driver built in and IIO as a module.
> 
> Jonathan
>> 
>>>> +endif
>>>> obj-$(CONFIG_TOUCHSCREEN_TSC2007)	+= tsc2007.o
>>>> obj-$(CONFIG_TOUCHSCREEN_UCB1400)	+= ucb1400_ts.o
>>>> obj-$(CONFIG_TOUCHSCREEN_WACOM_W8001)	+= wacom_w8001.o
>>>> diff --git a/drivers/input/touchscreen/tsc2007.h
>>>> b/drivers/input/touchscreen/tsc2007.h
>>>> new file mode 100644
>>>> index 0000000..c25932f
>>>> --- /dev/null
>>>> +++ b/drivers/input/touchscreen/tsc2007.h
>>>> @@ -0,0 +1,116 @@
>>>> +/*
>>>> + * Copyright (c) 2008 MtekVision Co., Ltd.
>>>> + *	Kwangwoo Lee <kwlee@mtekvision.com>
>>>> + *
>>>> + * Using code from:
>>>> + *  - ads7846.c
>>>> + *	Copyright (c) 2005 David Brownell
>>>> + *	Copyright (c) 2006 Nokia Corporation
>>>> + *  - corgi_ts.c
>>>> + *	Copyright (C) 2004-2005 Richard Purdie
>>>> + *  - omap_ts.[hc], ads7846.h, ts_osk.c
>>>> + *	Copyright (C) 2002 MontaVista Software
>>>> + *	Copyright (C) 2004 Texas Instruments
>>>> + *	Copyright (C) 2005 Dirk Behme
>>>> + *
>>>> + *  This program is free software; you can redistribute it and/or
>>>> modify
>>>> + *  it under the terms of the GNU General Public License version 2 as
>>>> + *  published by the Free Software Foundation.
>>>> + */
>>>> +
>>>> +#include <linux/input/touchscreen.h>
>>>> +
>>>> +#define TSC2007_MEASURE_TEMP0		(0x0 << 4)
>>>> +#define TSC2007_MEASURE_AUX		(0x2 << 4)
>>>> +#define TSC2007_MEASURE_TEMP1		(0x4 << 4)
>>>> +#define TSC2007_ACTIVATE_XN		(0x8 << 4)
>>>> +#define TSC2007_ACTIVATE_YN		(0x9 << 4)
>>>> +#define TSC2007_ACTIVATE_YP_XN		(0xa << 4)
>>>> +#define TSC2007_SETUP			(0xb << 4)
>>>> +#define TSC2007_MEASURE_X		(0xc << 4)
>>>> +#define TSC2007_MEASURE_Y		(0xd << 4)
>>>> +#define TSC2007_MEASURE_Z1		(0xe << 4)
>>>> +#define TSC2007_MEASURE_Z2		(0xf << 4)
>>>> +
>>>> +#define TSC2007_POWER_OFF_IRQ_EN	(0x0 << 2)
>>>> +#define TSC2007_ADC_ON_IRQ_DIS0		(0x1 << 2)
>>>> +#define TSC2007_ADC_OFF_IRQ_EN		(0x2 << 2)
>>>> +#define TSC2007_ADC_ON_IRQ_DIS1		(0x3 << 2)
>>>> +
>>>> +#define TSC2007_12BIT			(0x0 << 1)
>>>> +#define TSC2007_8BIT			(0x1 << 1)
>>>> +
>>>> +#define	MAX_12BIT			((1 << 12) - 1)
>>>> +
>>>> +#define ADC_ON_12BIT	(TSC2007_12BIT | TSC2007_ADC_ON_IRQ_DIS0)
>>>> +
>>>> +#define READ_Y		(ADC_ON_12BIT | TSC2007_MEASURE_Y)
>>>> +#define READ_Z1		(ADC_ON_12BIT | TSC2007_MEASURE_Z1)
>>>> +#define READ_Z2		(ADC_ON_12BIT | TSC2007_MEASURE_Z2)
>>>> +#define READ_X		(ADC_ON_12BIT | TSC2007_MEASURE_X)
>>>> +#define PWRDOWN		(TSC2007_12BIT | TSC2007_POWER_OFF_IRQ_EN)
>>>> +
>>>> +struct ts_event {
>>>> +	u16	x;
>>>> +	u16	y;
>>>> +	u16	z1, z2;
>>>> +};
>>>> +
>>>> +struct tsc2007 {
>>>> +	struct input_dev	*input;
>>>> +	char			phys[32];
>>>> +
>>>> +	struct i2c_client	*client;
>>>> +
>>>> +	u16			model;
>>>> +	u16			x_plate_ohms;
>>>> +
>>>> +	struct touchscreen_properties prop;
>>>> +
>>>> +	bool			report_resistance;
>>>> +	u16			min_x;
>>>> +	u16			min_y;
>>>> +	u16			max_x;
>>>> +	u16			max_y;
>>>> +	u16			max_rt;
>>>> +	unsigned long		poll_period; /* in jiffies */
>>>> +	int			fuzzx;
>>>> +	int			fuzzy;
>>>> +	int			fuzzz;
>>>> +
>>>> +	unsigned int		gpio;
>>>> +	int			irq;
>>>> +
>>>> +	wait_queue_head_t	wait;
>>>> +	bool			stopped;
>>>> +	bool			pendown;
>>>> +
>>>> +	int			(*get_pendown_state)(struct device *);
>>>> +	void			(*clear_penirq)(void);
>>>> +
>>>> +	struct mutex		mlock;
>>>> +	struct iio_dev		*iio_dev;	/* optional */
>>>> +};
>>>> +
>>>> +int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd);
>>>> +u32 tsc2007_calculate_resistance(struct tsc2007 *tsc,
>>>> +					struct ts_event *tc);
>>>> +bool tsc2007_is_pen_down(struct tsc2007 *ts);
>>>> +
>>>> +#if IS_ENABLED(CONFIG_IIO)
>>>> +
>>>> +/* defined in tsc2007_iio.c */
>>>> +int tsc2007_iio_configure(struct tsc2007 *ts);
>>>> +void tsc2007_iio_unconfigure(struct tsc2007 *ts);
>>>> +
>>>> +#else /* CONFIG_IIO */
>>>> +
>>>> +static inline int tsc2007_iio_configure(struct tsc2007 *ts)
>>>> +{
>>>> +	return 0;
>>>> +}
>>>> +static inline void tsc2007_iio_unconfigure(struct tsc2007 *ts)
>>>> +{
>>>> +}
>>>> +
>>>> +#endif /* CONFIG_IIO */
>>>> diff --git a/drivers/input/touchscreen/tsc2007.c
>>>> b/drivers/input/touchscreen/tsc2007_core.c
>>>> similarity index 86%
>>>> rename from drivers/input/touchscreen/tsc2007.c
>>>> rename to drivers/input/touchscreen/tsc2007_core.c
>>>> index 76b462b..812ded8 100644
>>>> --- a/drivers/input/touchscreen/tsc2007.c
>>>> +++ b/drivers/input/touchscreen/tsc2007_core.c
>>>> @@ -27,79 +27,11 @@
>>>> #include <linux/i2c.h>
>>>> #include <linux/i2c/tsc2007.h>
>>>> #include <linux/of_device.h>
>>>> -#include <linux/of.h>
>>>> #include <linux/of_gpio.h>
>>>> -#include <linux/input/touchscreen.h>
>>>> -
>>>> -#define TSC2007_MEASURE_TEMP0		(0x0 << 4)
>>>> -#define TSC2007_MEASURE_AUX		(0x2 << 4)
>>>> -#define TSC2007_MEASURE_TEMP1		(0x4 << 4)
>>>> -#define TSC2007_ACTIVATE_XN		(0x8 << 4)
>>>> -#define TSC2007_ACTIVATE_YN		(0x9 << 4)
>>>> -#define TSC2007_ACTIVATE_YP_XN		(0xa << 4)
>>>> -#define TSC2007_SETUP			(0xb << 4)
>>>> -#define TSC2007_MEASURE_X		(0xc << 4)
>>>> -#define TSC2007_MEASURE_Y		(0xd << 4)
>>>> -#define TSC2007_MEASURE_Z1		(0xe << 4)
>>>> -#define TSC2007_MEASURE_Z2		(0xf << 4)
>>>> -
>>>> -#define TSC2007_POWER_OFF_IRQ_EN	(0x0 << 2)
>>>> -#define TSC2007_ADC_ON_IRQ_DIS0		(0x1 << 2)
>>>> -#define TSC2007_ADC_OFF_IRQ_EN		(0x2 << 2)
>>>> -#define TSC2007_ADC_ON_IRQ_DIS1		(0x3 << 2)
>>>> -
>>>> -#define TSC2007_12BIT			(0x0 << 1)
>>>> -#define TSC2007_8BIT			(0x1 << 1)
>>>> -
>>>> -#define	MAX_12BIT			((1 << 12) - 1)
>>>> -
>>>> -#define ADC_ON_12BIT	(TSC2007_12BIT | TSC2007_ADC_ON_IRQ_DIS0)
>>>> -
>>>> -#define READ_Y		(ADC_ON_12BIT | TSC2007_MEASURE_Y)
>>>> -#define READ_Z1		(ADC_ON_12BIT | TSC2007_MEASURE_Z1)
>>>> -#define READ_Z2		(ADC_ON_12BIT | TSC2007_MEASURE_Z2)
>>>> -#define READ_X		(ADC_ON_12BIT | TSC2007_MEASURE_X)
>>>> -#define PWRDOWN		(TSC2007_12BIT | TSC2007_POWER_OFF_IRQ_EN)
>>>> -
>>>> -struct ts_event {
>>>> -	u16	x;
>>>> -	u16	y;
>>>> -	u16	z1, z2;
>>>> -};
>>>> -
>>>> -struct tsc2007 {
>>>> -	struct input_dev	*input;
>>>> -	char			phys[32];
>>>> -
>>>> -	struct i2c_client	*client;
>>>> -
>>>> -	u16			model;
>>>> -	u16			x_plate_ohms;
>>>> -
>>>> -	struct touchscreen_properties prop;
>>>> -
>>>> -	bool			report_resistance;
>>>> -	u16			min_x;
>>>> -	u16			min_y;
>>>> -	u16			max_x;
>>>> -	u16			max_y;
>>>> -	u16			max_rt;
>>>> -	unsigned long		poll_period; /* in jiffies */
>>>> -	int			fuzzx;
>>>> -	int			fuzzy;
>>>> -	int			fuzzz;
>>>> -
>>>> -	unsigned		gpio;
>>>> -	int			irq;
>>>> -
>>>> -	wait_queue_head_t	wait;
>>>> -	bool			stopped;
>>>> +#include "tsc2007.h"
>>>> 
>>>> -	int			(*get_pendown_state)(struct device *);
>>>> -	void			(*clear_penirq)(void);
>>>> -};
>>>> 
>>>> -static inline int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd)
>>>> +int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd)
>>>> {
>>>> 	s32 data;
>>>> 	u16 val;
>>>> @@ -137,7 +69,7 @@ static void tsc2007_read_values(struct tsc2007 *tsc,
>>>> struct ts_event *tc)
>>>> 	tsc2007_xfer(tsc, PWRDOWN);
>>>> }
>>>> 
>>>> -static u32 tsc2007_calculate_resistance(struct tsc2007 *tsc,
>>>> +u32 tsc2007_calculate_resistance(struct tsc2007 *tsc,
>>>> 					struct ts_event *tc)
>>>> {
>>>> 	u32 rt = 0;
>>>> @@ -158,7 +90,7 @@ static u32 tsc2007_calculate_resistance(struct
>>>> tsc2007 *tsc,
>>>> 	return rt;
>>>> }
>>>> 
>>>> -static bool tsc2007_is_pen_down(struct tsc2007 *ts)
>>>> +bool tsc2007_is_pen_down(struct tsc2007 *ts)
>>>> {
>>>> 	/*
>>>> 	 * NOTE: We can't rely on the pressure to determine the pen down
>>>> @@ -191,7 +123,10 @@ static irqreturn_t tsc2007_soft_irq(int irq, void
>>>> *handle)
>>>> 	while (!ts->stopped && tsc2007_is_pen_down(ts)) {
>>>> 
>>>> 		/* pen is down, continue with the measurement */
>>>> +
>>>> +		mutex_lock(&ts->mlock);
>>>> 		tsc2007_read_values(ts, &tc);
>>>> +		mutex_unlock(&ts->mlock);
>>>> 
>>>> 		rt = tsc2007_calculate_resistance(ts, &tc);
>>>> 
>>>> @@ -441,7 +376,8 @@ static void tsc2007_call_exit_platform_hw(void
>>>> *data)
>>>> static int tsc2007_probe(struct i2c_client *client,
>>>> 			 const struct i2c_device_id *id)
>>>> {
>>>> -	const struct tsc2007_platform_data *pdata =
>>>> dev_get_platdata(&client->dev);
>>>> +	const struct tsc2007_platform_data *pdata =
>>>> +		dev_get_platdata(&client->dev);
>>>> 	struct tsc2007 *ts;
>>>> 	struct input_dev *input_dev;
>>>> 	int err;
>>>> @@ -463,7 +399,9 @@ static int tsc2007_probe(struct i2c_client *client,
>>>> 	ts->client = client;
>>>> 	ts->irq = client->irq;
>>>> 	ts->input = input_dev;
>>>> +
>>>> 	init_waitqueue_head(&ts->wait);
>>>> +	mutex_init(&ts->mlock);
>>>> 
>>>> 	snprintf(ts->phys, sizeof(ts->phys),
>>>> 		 "%s/input0", dev_name(&client->dev));
>>>> @@ -534,7 +472,7 @@ static int tsc2007_probe(struct i2c_client *client,
>>>> 	if (err < 0) {
>>>> 		dev_err(&client->dev,
>>>> 			"Failed to setup chip: %d\n", err);
>>>> -		return err;	/* usually, chip does not respond */
>>>> +		return err;	/* chip does not respond */
>>>> 	}
>>>> 
>>>> 	err = input_register_device(input_dev);
>>>> @@ -544,6 +482,14 @@ static int tsc2007_probe(struct i2c_client
>>>> *client,
>>>> 		return err;
>>>> 	}
>>>> 
>>>> +	return tsc2007_iio_configure(ts);
>>>> +}
>>>> +
>>>> +static int tsc2007_remove(struct i2c_client *client)
>>>> +{
>>>> +	struct tsc2007 *ts = i2c_get_clientdata(client);
>>>> +
>>>> +	tsc2007_iio_unconfigure(ts);
>>>> 	return 0;
>>>> }
>>>> 
>>>> @@ -569,6 +515,7 @@ static struct i2c_driver tsc2007_driver = {
>>>> 	},
>>>> 	.id_table	= tsc2007_idtable,
>>>> 	.probe		= tsc2007_probe,
>>>> +	.remove		= tsc2007_remove,
>>>> };
>>>> 
>>>> module_i2c_driver(tsc2007_driver);
>>>> diff --git a/drivers/input/touchscreen/tsc2007_iio.c
>>>> b/drivers/input/touchscreen/tsc2007_iio.c
>>>> new file mode 100644
>>>> index 0000000..ed79944
>>>> --- /dev/null
>>>> +++ b/drivers/input/touchscreen/tsc2007_iio.c
>>>> @@ -0,0 +1,150 @@
>>>> +/*
>>>> + * Copyright (c) 2016 Golden Delicious Comp. GmbH&Co. KG
>>>> + *	Nikolaus Schaller <hns@goldelico.com>
>>>> + *
>>>> + *  This program is free software; you can redistribute it and/or
>>>> modify
>>>> + *  it under the terms of the GNU General Public License version 2 as
>>>> + *  published by the Free Software Foundation.
>>>> + */
>>>> +
>>>> +#include <linux/i2c.h>
>>>> +#include <linux/iio/iio.h>
>>>> +#include "tsc2007.h"
>>>> +
>>>> +struct tsc2007_iio {
>>>> +	struct tsc2007 *ts;
>>>> +};
>>>> +
>>>> +#define TSC2007_CHAN_IIO(_chan, _name, _type, _chan_info) \
>>>> +{ \
>>>> +	.datasheet_name = _name, \
>>>> +	.type = _type, \
>>>> +	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |	\
>>>> +			BIT(_chan_info), \
>>>> +	.indexed = 1, \
>>>> +	.channel = _chan, \
>>>> +}
>>>> +
>>>> +static const struct iio_chan_spec tsc2007_iio_channel[] = {
>>>> +	TSC2007_CHAN_IIO(0, "x", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
>>>> +	TSC2007_CHAN_IIO(1, "y", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
>>>> +	TSC2007_CHAN_IIO(2, "z1", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
>>>> +	TSC2007_CHAN_IIO(3, "z2", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
>>>> +	TSC2007_CHAN_IIO(4, "adc", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
>>>> +	TSC2007_CHAN_IIO(5, "rt", IIO_VOLTAGE, IIO_CHAN_INFO_RAW), /* Ohms?
>>>> */
>>>> +	TSC2007_CHAN_IIO(6, "pen", IIO_PRESSURE, IIO_CHAN_INFO_RAW),
>>>> +	TSC2007_CHAN_IIO(7, "temp0", IIO_TEMP, IIO_CHAN_INFO_RAW),
>>>> +	TSC2007_CHAN_IIO(8, "temp1", IIO_TEMP, IIO_CHAN_INFO_RAW),
>>>> +};
>>>> +
>>>> +static int tsc2007_read_raw(struct iio_dev *indio_dev,
>>>> +	struct iio_chan_spec const *chan, int *val, int *val2, long mask)
>>>> +{
>>>> +	struct tsc2007_iio *iio = iio_priv(indio_dev);
>>>> +	struct tsc2007 *tsc = iio->ts;
>>>> +	int adc_chan = chan->channel;
>>>> +	int ret = 0;
>>>> +
>>>> +	if (adc_chan >= ARRAY_SIZE(tsc2007_iio_channel))
>>>> +		return -EINVAL;
>>>> +
>>>> +	if (mask != IIO_CHAN_INFO_RAW)
>>>> +		return -EINVAL;
>>>> +
>>>> +	mutex_lock(&tsc->mlock);
>>>> +
>>>> +	switch (chan->channel) {
>>>> +	case 0:
>>>> +		*val = tsc2007_xfer(tsc, READ_X);
>>>> +		break;
>>>> +	case 1:
>>>> +		*val = tsc2007_xfer(tsc, READ_Y);
>>>> +		break;
>>>> +	case 2:
>>>> +		*val = tsc2007_xfer(tsc, READ_Z1);
>>>> +		break;
>>>> +	case 3:
>>>> +		*val = tsc2007_xfer(tsc, READ_Z2);
>>>> +		break;
>>>> +	case 4:
>>>> +		*val = tsc2007_xfer(tsc, (ADC_ON_12BIT | TSC2007_MEASURE_AUX));
>>>> +		break;
>>>> +	case 5: {
>>>> +		struct ts_event tc;
>>>> +
>>>> +		tc.x = tsc2007_xfer(tsc, READ_X);
>>>> +		tc.z1 = tsc2007_xfer(tsc, READ_Z1);
>>>> +		tc.z2 = tsc2007_xfer(tsc, READ_Z2);
>>>> +		*val = tsc2007_calculate_resistance(tsc, &tc);
>>>> +		break;
>>>> +	}
>>>> +	case 6:
>>>> +		*val = tsc2007_is_pen_down(tsc);
>>>> +		break;
>>>> +	case 7:
>>>> +		*val = tsc2007_xfer(tsc,
>>>> +				    (ADC_ON_12BIT | TSC2007_MEASURE_TEMP0));
>>>> +		break;
>>>> +	case 8:
>>>> +		*val = tsc2007_xfer(tsc,
>>>> +				    (ADC_ON_12BIT | TSC2007_MEASURE_TEMP1));
>>>> +		break;
>>>> +	}
>>>> +
>>>> +	/* Prepare for next touch reading - power down ADC, enable PENIRQ */
>>>> +	tsc2007_xfer(tsc, PWRDOWN);
>>>> +
>>>> +	mutex_unlock(&tsc->mlock);
>>>> +
>>>> +	ret = IIO_VAL_INT;
>>>> +
>>>> +	return ret;
>>>> +}
>>>> +
>>>> +static const struct iio_info tsc2007_iio_info = {
>>>> +	.read_raw = tsc2007_read_raw,
>>>> +	.driver_module = THIS_MODULE,
>>>> +};
>>>> +
>>>> +int tsc2007_iio_configure(struct tsc2007 *ts)
>>>> +{
>>>> +	int err;
>>>> +	struct iio_dev *indio_dev;
>>>> +	struct tsc2007_iio *iio;
>>>> +
>>>> +	indio_dev = devm_iio_device_alloc(&ts->client->dev,
>>>> +		sizeof(struct tsc2007_iio));
>>>> +	if (!indio_dev) {
>>>> +		dev_err(&ts->client->dev, "iio_device_alloc failed\n");
>>>> +		return -ENOMEM;
>>>> +	}
>>>> +
>>>> +	iio = iio_priv(indio_dev);
>>>> +	iio->ts = ts;
>>>> +	ts->iio_dev = (void *) indio_dev;
>>>> +
>>>> +	indio_dev->name = "tsc2007";
>>>> +	indio_dev->dev.parent = &ts->client->dev;
>>>> +	indio_dev->info = &tsc2007_iio_info;
>>>> +	indio_dev->modes = INDIO_DIRECT_MODE;
>>>> +	indio_dev->channels = tsc2007_iio_channel;
>>>> +	indio_dev->num_channels = ARRAY_SIZE(tsc2007_iio_channel);
>>>> +
>>>> +	err = iio_device_register(indio_dev);
>>>> +	if (err < 0) {
>>>> +		dev_err(&ts->client->dev, "iio_device_register() failed: %d\n",
>>>> +			err);
>>>> +		return err;
>>>> +	}
>>>> +
>>>> +	return 0;
>>>> +}
>>>> +EXPORT_SYMBOL(tsc2007_iio_configure);
>>>> +
>>>> +void tsc2007_iio_unconfigure(struct tsc2007 *ts)
>>>> +{
>>>> +	struct iio_dev *indio_dev = ts->iio_dev;
>>>> +
>>>> +	iio_device_unregister(indio_dev);
>>>> +}
>>>> +EXPORT_SYMBOL(tsc2007_iio_unconfigure);
>>> 
>>> -- 
>>> Sent from my Android device with K-9 Mail. Please excuse my brevity.
>> 
> 

BR,
Nikolaus

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H. Nikolaus Schaller Dec. 12, 2016, 9:21 p.m. UTC | #5
Hi,


> Am 27.11.2016 um 16:47 schrieb H. Nikolaus Schaller <hns@goldelico.com>:
> 
> Hi Jonathan,
> 
>> Am 27.11.2016 um 12:02 schrieb Jonathan Cameron <jic23@kernel.org>:
>> 
>> On 24/11/16 18:05, H. Nikolaus Schaller wrote:
>>> 
>>>> Am 24.11.2016 um 18:38 schrieb Jonathan Cameron <jic23@jic23.retrosnub.co.uk>:
>>>> 
>>>> 
>>>> 
>>>> On 22 November 2016 14:02:30 GMT+00:00, "H. Nikolaus Schaller" <hns@goldelico.com> wrote:

> 
>> - hence cc'd Yann and the Kbuild list
>> to see if they can offer some advices.

no response / advice so far.

> 
> Thanks!
> 
> BTW, the other tsc2007 and ads7846 patches could already be merged (if there
> are no more changes needed) since this one only depends on the result of applying
> all others before.

I wonder if input maintainers can already merge the other patches of this patch series?

BR and thanks,
Nikolaus--
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H. Nikolaus Schaller Dec. 27, 2016, 7:08 p.m. UTC | #6
ping.

> Am 12.12.2016 um 22:21 schrieb H. Nikolaus Schaller <hns@goldelico.com>:
> 
> Hi,
> 
> 
>> Am 27.11.2016 um 16:47 schrieb H. Nikolaus Schaller <hns@goldelico.com>:
>> 
>> Hi Jonathan,
>> 
>>> Am 27.11.2016 um 12:02 schrieb Jonathan Cameron <jic23@kernel.org>:
>>> 
>>> On 24/11/16 18:05, H. Nikolaus Schaller wrote:
>>>> 
>>>>> Am 24.11.2016 um 18:38 schrieb Jonathan Cameron <jic23@jic23.retrosnub.co.uk>:
>>>>> 
>>>>> 
>>>>> 
>>>>> On 22 November 2016 14:02:30 GMT+00:00, "H. Nikolaus Schaller" <hns@goldelico.com> wrote:
> 
>> 
>>> - hence cc'd Yann and the Kbuild list
>>> to see if they can offer some advices.
> 
> no response / advice so far.
> 
>> 
>> Thanks!
>> 
>> BTW, the other tsc2007 and ads7846 patches could already be merged (if there
>> are no more changes needed) since this one only depends on the result of applying
>> all others before.
> 
> I wonder if input maintainers can already merge the other patches of this patch series?

series: https://lkml.org/lkml/2016/11/22/309

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Dmitry Torokhov Dec. 27, 2016, 9:54 p.m. UTC | #7
On Mon, Dec 12, 2016 at 10:21:25PM +0100, H. Nikolaus Schaller wrote:
> Hi,
> 
> 
> > Am 27.11.2016 um 16:47 schrieb H. Nikolaus Schaller <hns@goldelico.com>:
> > 
> > Hi Jonathan,
> > 
> >> Am 27.11.2016 um 12:02 schrieb Jonathan Cameron <jic23@kernel.org>:
> >> 
> >> On 24/11/16 18:05, H. Nikolaus Schaller wrote:
> >>> 
> >>>> Am 24.11.2016 um 18:38 schrieb Jonathan Cameron <jic23@jic23.retrosnub.co.uk>:
> >>>> 
> >>>> 
> >>>> 
> >>>> On 22 November 2016 14:02:30 GMT+00:00, "H. Nikolaus Schaller" <hns@goldelico.com> wrote:
> 
> > 
> >> - hence cc'd Yann and the Kbuild list
> >> to see if they can offer some advices.
> 
> no response / advice so far.

Since you are saying that IIO stuff is optional, add it to Kconfig
explicitly:

config "TOUCHSCREEN_TSC2007_IIO"
	bool "IIO interface for external ADC input and temperature"
	depends on TOUCHSCREEN_TSC2007
	depends on IIO=y || IIO=TOUCHSCREEN_TSC2007
	help
	  ...

and use this symbols in makefile:

and in Makefile:

obj-$(CONFIG_TOUCHSCREEN_TSC2007) += tsc2007.o
tsc2007-y := tsc2007-core.o ...
tsc2007-$(CONFIG_TOUCHSCREEN_TSC2007_IIO) += tsc2007_iio.o

Thanks.
H. Nikolaus Schaller Dec. 28, 2016, 2:52 p.m. UTC | #8
Hi Dmitry,

> Am 27.12.2016 um 22:54 schrieb Dmitry Torokhov <dmitry.torokhov@gmail.com>:
> 
> On Mon, Dec 12, 2016 at 10:21:25PM +0100, H. Nikolaus Schaller wrote:
>> Hi,
>> 
>> 
>>> Am 27.11.2016 um 16:47 schrieb H. Nikolaus Schaller <hns@goldelico.com>:
>>> 
>>> Hi Jonathan,
>>> 
>>>> Am 27.11.2016 um 12:02 schrieb Jonathan Cameron <jic23@kernel.org>:
>>>> 
>>>> On 24/11/16 18:05, H. Nikolaus Schaller wrote:
>>>>> 
>>>>>> Am 24.11.2016 um 18:38 schrieb Jonathan Cameron <jic23@jic23.retrosnub.co.uk>:
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> On 22 November 2016 14:02:30 GMT+00:00, "H. Nikolaus Schaller" <hns@goldelico.com> wrote:
>> 
>>> 
>>>> - hence cc'd Yann and the Kbuild list
>>>> to see if they can offer some advices.
>> 
>> no response / advice so far.
> 
> Since you are saying that IIO stuff is optional, add it to Kconfig
> explicitly:
> 
> config "TOUCHSCREEN_TSC2007_IIO"
> 	bool "IIO interface for external ADC input and temperature"
> 	depends on TOUCHSCREEN_TSC2007
> 	depends on IIO=y || IIO=TOUCHSCREEN_TSC2007
> 	help
> 	  ...
> 
> and use this symbols in makefile:
> 
> and in Makefile:
> 
> obj-$(CONFIG_TOUCHSCREEN_TSC2007) += tsc2007.o
> tsc2007-y := tsc2007-core.o ...
> tsc2007-$(CONFIG_TOUCHSCREEN_TSC2007_IIO) += tsc2007_iio.o

Ah, ok. Well, we tried to make it without an explicit config option
but it does not hurt to have one.

Your proposal works fine for 3 out of the 4 possible combinations.

I think it is unlikely that the combination TOUCHSCREEN_TSC2007=y IIO=m
is needed at all (we configure as much as possible as =m in our kernel).

Patch v9 will come next (where I have also moved this iio driver
patch to be 8/8).

BR and thanks,
Nikolaus--
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Jonathan Cameron Dec. 30, 2016, 8:17 p.m. UTC | #9
On 28/12/16 14:52, H. Nikolaus Schaller wrote:
> Hi Dmitry,
> 
>> Am 27.12.2016 um 22:54 schrieb Dmitry Torokhov <dmitry.torokhov@gmail.com>:
>>
>> On Mon, Dec 12, 2016 at 10:21:25PM +0100, H. Nikolaus Schaller wrote:
>>> Hi,
>>>
>>>
>>>> Am 27.11.2016 um 16:47 schrieb H. Nikolaus Schaller <hns@goldelico.com>:
>>>>
>>>> Hi Jonathan,
>>>>
>>>>> Am 27.11.2016 um 12:02 schrieb Jonathan Cameron <jic23@kernel.org>:
>>>>>
>>>>> On 24/11/16 18:05, H. Nikolaus Schaller wrote:
>>>>>>
>>>>>>> Am 24.11.2016 um 18:38 schrieb Jonathan Cameron <jic23@jic23.retrosnub.co.uk>:
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> On 22 November 2016 14:02:30 GMT+00:00, "H. Nikolaus Schaller" <hns@goldelico.com> wrote:
>>>
>>>>
>>>>> - hence cc'd Yann and the Kbuild list
>>>>> to see if they can offer some advices.
>>>
>>> no response / advice so far.
>>
>> Since you are saying that IIO stuff is optional, add it to Kconfig
>> explicitly:
>>
>> config "TOUCHSCREEN_TSC2007_IIO"
>> 	bool "IIO interface for external ADC input and temperature"
>> 	depends on TOUCHSCREEN_TSC2007
>> 	depends on IIO=y || IIO=TOUCHSCREEN_TSC2007
>> 	help
>> 	  ...
>>
>> and use this symbols in makefile:
>>
>> and in Makefile:
>>
>> obj-$(CONFIG_TOUCHSCREEN_TSC2007) += tsc2007.o
>> tsc2007-y := tsc2007-core.o ...
>> tsc2007-$(CONFIG_TOUCHSCREEN_TSC2007_IIO) += tsc2007_iio.o
> 
> Ah, ok. Well, we tried to make it without an explicit config option
> but it does not hurt to have one.
> 
> Your proposal works fine for 3 out of the 4 possible combinations.
> 
> I think it is unlikely that the combination TOUCHSCREEN_TSC2007=y IIO=m
> is needed at all (we configure as much as possible as =m in our kernel).
Indeed - that shouldn't work and is blocked by the above which is good.
> 
> Patch v9 will come next (where I have also moved this iio driver
> patch to be 8/8).
Wise move ;)
> 
> BR and thanks,
> Nikolaus
> 

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Patch
diff mbox

diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 81b8645..3be0d19 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -80,6 +80,13 @@  obj-$(CONFIG_TOUCHSCREEN_TSC_SERIO)	+= tsc40.o
 obj-$(CONFIG_TOUCHSCREEN_TSC200X_CORE)	+= tsc200x-core.o
 obj-$(CONFIG_TOUCHSCREEN_TSC2004)	+= tsc2004.o
 obj-$(CONFIG_TOUCHSCREEN_TSC2005)	+= tsc2005.o
+tsc2007-y				:= tsc2007_core.o
+ifeq ($(CONFIG_IIO),y)
+tsc2007-y				+= tsc2007_iio.o
+endif
+ifeq ($(CONFIG_IIO),m)
+tsc2007-y				+= tsc2007_iio.o
+endif
 obj-$(CONFIG_TOUCHSCREEN_TSC2007)	+= tsc2007.o
 obj-$(CONFIG_TOUCHSCREEN_UCB1400)	+= ucb1400_ts.o
 obj-$(CONFIG_TOUCHSCREEN_WACOM_W8001)	+= wacom_w8001.o
diff --git a/drivers/input/touchscreen/tsc2007.h b/drivers/input/touchscreen/tsc2007.h
new file mode 100644
index 0000000..c25932f
--- /dev/null
+++ b/drivers/input/touchscreen/tsc2007.h
@@ -0,0 +1,116 @@ 
+/*
+ * Copyright (c) 2008 MtekVision Co., Ltd.
+ *	Kwangwoo Lee <kwlee@mtekvision.com>
+ *
+ * Using code from:
+ *  - ads7846.c
+ *	Copyright (c) 2005 David Brownell
+ *	Copyright (c) 2006 Nokia Corporation
+ *  - corgi_ts.c
+ *	Copyright (C) 2004-2005 Richard Purdie
+ *  - omap_ts.[hc], ads7846.h, ts_osk.c
+ *	Copyright (C) 2002 MontaVista Software
+ *	Copyright (C) 2004 Texas Instruments
+ *	Copyright (C) 2005 Dirk Behme
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ */
+
+#include <linux/input/touchscreen.h>
+
+#define TSC2007_MEASURE_TEMP0		(0x0 << 4)
+#define TSC2007_MEASURE_AUX		(0x2 << 4)
+#define TSC2007_MEASURE_TEMP1		(0x4 << 4)
+#define TSC2007_ACTIVATE_XN		(0x8 << 4)
+#define TSC2007_ACTIVATE_YN		(0x9 << 4)
+#define TSC2007_ACTIVATE_YP_XN		(0xa << 4)
+#define TSC2007_SETUP			(0xb << 4)
+#define TSC2007_MEASURE_X		(0xc << 4)
+#define TSC2007_MEASURE_Y		(0xd << 4)
+#define TSC2007_MEASURE_Z1		(0xe << 4)
+#define TSC2007_MEASURE_Z2		(0xf << 4)
+
+#define TSC2007_POWER_OFF_IRQ_EN	(0x0 << 2)
+#define TSC2007_ADC_ON_IRQ_DIS0		(0x1 << 2)
+#define TSC2007_ADC_OFF_IRQ_EN		(0x2 << 2)
+#define TSC2007_ADC_ON_IRQ_DIS1		(0x3 << 2)
+
+#define TSC2007_12BIT			(0x0 << 1)
+#define TSC2007_8BIT			(0x1 << 1)
+
+#define	MAX_12BIT			((1 << 12) - 1)
+
+#define ADC_ON_12BIT	(TSC2007_12BIT | TSC2007_ADC_ON_IRQ_DIS0)
+
+#define READ_Y		(ADC_ON_12BIT | TSC2007_MEASURE_Y)
+#define READ_Z1		(ADC_ON_12BIT | TSC2007_MEASURE_Z1)
+#define READ_Z2		(ADC_ON_12BIT | TSC2007_MEASURE_Z2)
+#define READ_X		(ADC_ON_12BIT | TSC2007_MEASURE_X)
+#define PWRDOWN		(TSC2007_12BIT | TSC2007_POWER_OFF_IRQ_EN)
+
+struct ts_event {
+	u16	x;
+	u16	y;
+	u16	z1, z2;
+};
+
+struct tsc2007 {
+	struct input_dev	*input;
+	char			phys[32];
+
+	struct i2c_client	*client;
+
+	u16			model;
+	u16			x_plate_ohms;
+
+	struct touchscreen_properties prop;
+
+	bool			report_resistance;
+	u16			min_x;
+	u16			min_y;
+	u16			max_x;
+	u16			max_y;
+	u16			max_rt;
+	unsigned long		poll_period; /* in jiffies */
+	int			fuzzx;
+	int			fuzzy;
+	int			fuzzz;
+
+	unsigned int		gpio;
+	int			irq;
+
+	wait_queue_head_t	wait;
+	bool			stopped;
+	bool			pendown;
+
+	int			(*get_pendown_state)(struct device *);
+	void			(*clear_penirq)(void);
+
+	struct mutex		mlock;
+	struct iio_dev		*iio_dev;	/* optional */
+};
+
+int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd);
+u32 tsc2007_calculate_resistance(struct tsc2007 *tsc,
+					struct ts_event *tc);
+bool tsc2007_is_pen_down(struct tsc2007 *ts);
+
+#if IS_ENABLED(CONFIG_IIO)
+
+/* defined in tsc2007_iio.c */
+int tsc2007_iio_configure(struct tsc2007 *ts);
+void tsc2007_iio_unconfigure(struct tsc2007 *ts);
+
+#else /* CONFIG_IIO */
+
+static inline int tsc2007_iio_configure(struct tsc2007 *ts)
+{
+	return 0;
+}
+static inline void tsc2007_iio_unconfigure(struct tsc2007 *ts)
+{
+}
+
+#endif /* CONFIG_IIO */
diff --git a/drivers/input/touchscreen/tsc2007.c b/drivers/input/touchscreen/tsc2007_core.c
similarity index 86%
rename from drivers/input/touchscreen/tsc2007.c
rename to drivers/input/touchscreen/tsc2007_core.c
index 76b462b..812ded8 100644
--- a/drivers/input/touchscreen/tsc2007.c
+++ b/drivers/input/touchscreen/tsc2007_core.c
@@ -27,79 +27,11 @@ 
 #include <linux/i2c.h>
 #include <linux/i2c/tsc2007.h>
 #include <linux/of_device.h>
-#include <linux/of.h>
 #include <linux/of_gpio.h>
-#include <linux/input/touchscreen.h>
-
-#define TSC2007_MEASURE_TEMP0		(0x0 << 4)
-#define TSC2007_MEASURE_AUX		(0x2 << 4)
-#define TSC2007_MEASURE_TEMP1		(0x4 << 4)
-#define TSC2007_ACTIVATE_XN		(0x8 << 4)
-#define TSC2007_ACTIVATE_YN		(0x9 << 4)
-#define TSC2007_ACTIVATE_YP_XN		(0xa << 4)
-#define TSC2007_SETUP			(0xb << 4)
-#define TSC2007_MEASURE_X		(0xc << 4)
-#define TSC2007_MEASURE_Y		(0xd << 4)
-#define TSC2007_MEASURE_Z1		(0xe << 4)
-#define TSC2007_MEASURE_Z2		(0xf << 4)
-
-#define TSC2007_POWER_OFF_IRQ_EN	(0x0 << 2)
-#define TSC2007_ADC_ON_IRQ_DIS0		(0x1 << 2)
-#define TSC2007_ADC_OFF_IRQ_EN		(0x2 << 2)
-#define TSC2007_ADC_ON_IRQ_DIS1		(0x3 << 2)
-
-#define TSC2007_12BIT			(0x0 << 1)
-#define TSC2007_8BIT			(0x1 << 1)
-
-#define	MAX_12BIT			((1 << 12) - 1)
-
-#define ADC_ON_12BIT	(TSC2007_12BIT | TSC2007_ADC_ON_IRQ_DIS0)
-
-#define READ_Y		(ADC_ON_12BIT | TSC2007_MEASURE_Y)
-#define READ_Z1		(ADC_ON_12BIT | TSC2007_MEASURE_Z1)
-#define READ_Z2		(ADC_ON_12BIT | TSC2007_MEASURE_Z2)
-#define READ_X		(ADC_ON_12BIT | TSC2007_MEASURE_X)
-#define PWRDOWN		(TSC2007_12BIT | TSC2007_POWER_OFF_IRQ_EN)
-
-struct ts_event {
-	u16	x;
-	u16	y;
-	u16	z1, z2;
-};
-
-struct tsc2007 {
-	struct input_dev	*input;
-	char			phys[32];
-
-	struct i2c_client	*client;
-
-	u16			model;
-	u16			x_plate_ohms;
-
-	struct touchscreen_properties prop;
-
-	bool			report_resistance;
-	u16			min_x;
-	u16			min_y;
-	u16			max_x;
-	u16			max_y;
-	u16			max_rt;
-	unsigned long		poll_period; /* in jiffies */
-	int			fuzzx;
-	int			fuzzy;
-	int			fuzzz;
-
-	unsigned		gpio;
-	int			irq;
-
-	wait_queue_head_t	wait;
-	bool			stopped;
+#include "tsc2007.h"
 
-	int			(*get_pendown_state)(struct device *);
-	void			(*clear_penirq)(void);
-};
 
-static inline int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd)
+int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd)
 {
 	s32 data;
 	u16 val;
@@ -137,7 +69,7 @@  static void tsc2007_read_values(struct tsc2007 *tsc, struct ts_event *tc)
 	tsc2007_xfer(tsc, PWRDOWN);
 }
 
-static u32 tsc2007_calculate_resistance(struct tsc2007 *tsc,
+u32 tsc2007_calculate_resistance(struct tsc2007 *tsc,
 					struct ts_event *tc)
 {
 	u32 rt = 0;
@@ -158,7 +90,7 @@  static u32 tsc2007_calculate_resistance(struct tsc2007 *tsc,
 	return rt;
 }
 
-static bool tsc2007_is_pen_down(struct tsc2007 *ts)
+bool tsc2007_is_pen_down(struct tsc2007 *ts)
 {
 	/*
 	 * NOTE: We can't rely on the pressure to determine the pen down
@@ -191,7 +123,10 @@  static irqreturn_t tsc2007_soft_irq(int irq, void *handle)
 	while (!ts->stopped && tsc2007_is_pen_down(ts)) {
 
 		/* pen is down, continue with the measurement */
+
+		mutex_lock(&ts->mlock);
 		tsc2007_read_values(ts, &tc);
+		mutex_unlock(&ts->mlock);
 
 		rt = tsc2007_calculate_resistance(ts, &tc);
 
@@ -441,7 +376,8 @@  static void tsc2007_call_exit_platform_hw(void *data)
 static int tsc2007_probe(struct i2c_client *client,
 			 const struct i2c_device_id *id)
 {
-	const struct tsc2007_platform_data *pdata = dev_get_platdata(&client->dev);
+	const struct tsc2007_platform_data *pdata =
+		dev_get_platdata(&client->dev);
 	struct tsc2007 *ts;
 	struct input_dev *input_dev;
 	int err;
@@ -463,7 +399,9 @@  static int tsc2007_probe(struct i2c_client *client,
 	ts->client = client;
 	ts->irq = client->irq;
 	ts->input = input_dev;
+
 	init_waitqueue_head(&ts->wait);
+	mutex_init(&ts->mlock);
 
 	snprintf(ts->phys, sizeof(ts->phys),
 		 "%s/input0", dev_name(&client->dev));
@@ -534,7 +472,7 @@  static int tsc2007_probe(struct i2c_client *client,
 	if (err < 0) {
 		dev_err(&client->dev,
 			"Failed to setup chip: %d\n", err);
-		return err;	/* usually, chip does not respond */
+		return err;	/* chip does not respond */
 	}
 
 	err = input_register_device(input_dev);
@@ -544,6 +482,14 @@  static int tsc2007_probe(struct i2c_client *client,
 		return err;
 	}
 
+	return tsc2007_iio_configure(ts);
+}
+
+static int tsc2007_remove(struct i2c_client *client)
+{
+	struct tsc2007 *ts = i2c_get_clientdata(client);
+
+	tsc2007_iio_unconfigure(ts);
 	return 0;
 }
 
@@ -569,6 +515,7 @@  static struct i2c_driver tsc2007_driver = {
 	},
 	.id_table	= tsc2007_idtable,
 	.probe		= tsc2007_probe,
+	.remove		= tsc2007_remove,
 };
 
 module_i2c_driver(tsc2007_driver);
diff --git a/drivers/input/touchscreen/tsc2007_iio.c b/drivers/input/touchscreen/tsc2007_iio.c
new file mode 100644
index 0000000..ed79944
--- /dev/null
+++ b/drivers/input/touchscreen/tsc2007_iio.c
@@ -0,0 +1,150 @@ 
+/*
+ * Copyright (c) 2016 Golden Delicious Comp. GmbH&Co. KG
+ *	Nikolaus Schaller <hns@goldelico.com>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ */
+
+#include <linux/i2c.h>
+#include <linux/iio/iio.h>
+#include "tsc2007.h"
+
+struct tsc2007_iio {
+	struct tsc2007 *ts;
+};
+
+#define TSC2007_CHAN_IIO(_chan, _name, _type, _chan_info) \
+{ \
+	.datasheet_name = _name, \
+	.type = _type, \
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |	\
+			BIT(_chan_info), \
+	.indexed = 1, \
+	.channel = _chan, \
+}
+
+static const struct iio_chan_spec tsc2007_iio_channel[] = {
+	TSC2007_CHAN_IIO(0, "x", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
+	TSC2007_CHAN_IIO(1, "y", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
+	TSC2007_CHAN_IIO(2, "z1", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
+	TSC2007_CHAN_IIO(3, "z2", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
+	TSC2007_CHAN_IIO(4, "adc", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
+	TSC2007_CHAN_IIO(5, "rt", IIO_VOLTAGE, IIO_CHAN_INFO_RAW), /* Ohms? */
+	TSC2007_CHAN_IIO(6, "pen", IIO_PRESSURE, IIO_CHAN_INFO_RAW),
+	TSC2007_CHAN_IIO(7, "temp0", IIO_TEMP, IIO_CHAN_INFO_RAW),
+	TSC2007_CHAN_IIO(8, "temp1", IIO_TEMP, IIO_CHAN_INFO_RAW),
+};
+
+static int tsc2007_read_raw(struct iio_dev *indio_dev,
+	struct iio_chan_spec const *chan, int *val, int *val2, long mask)
+{
+	struct tsc2007_iio *iio = iio_priv(indio_dev);
+	struct tsc2007 *tsc = iio->ts;
+	int adc_chan = chan->channel;
+	int ret = 0;
+
+	if (adc_chan >= ARRAY_SIZE(tsc2007_iio_channel))
+		return -EINVAL;
+
+	if (mask != IIO_CHAN_INFO_RAW)
+		return -EINVAL;
+
+	mutex_lock(&tsc->mlock);
+
+	switch (chan->channel) {
+	case 0:
+		*val = tsc2007_xfer(tsc, READ_X);
+		break;
+	case 1:
+		*val = tsc2007_xfer(tsc, READ_Y);
+		break;
+	case 2:
+		*val = tsc2007_xfer(tsc, READ_Z1);
+		break;
+	case 3:
+		*val = tsc2007_xfer(tsc, READ_Z2);
+		break;
+	case 4:
+		*val = tsc2007_xfer(tsc, (ADC_ON_12BIT | TSC2007_MEASURE_AUX));
+		break;
+	case 5: {
+		struct ts_event tc;
+
+		tc.x = tsc2007_xfer(tsc, READ_X);
+		tc.z1 = tsc2007_xfer(tsc, READ_Z1);
+		tc.z2 = tsc2007_xfer(tsc, READ_Z2);
+		*val = tsc2007_calculate_resistance(tsc, &tc);
+		break;
+	}
+	case 6:
+		*val = tsc2007_is_pen_down(tsc);
+		break;
+	case 7:
+		*val = tsc2007_xfer(tsc,
+				    (ADC_ON_12BIT | TSC2007_MEASURE_TEMP0));
+		break;
+	case 8:
+		*val = tsc2007_xfer(tsc,
+				    (ADC_ON_12BIT | TSC2007_MEASURE_TEMP1));
+		break;
+	}
+
+	/* Prepare for next touch reading - power down ADC, enable PENIRQ */
+	tsc2007_xfer(tsc, PWRDOWN);
+
+	mutex_unlock(&tsc->mlock);
+
+	ret = IIO_VAL_INT;
+
+	return ret;
+}
+
+static const struct iio_info tsc2007_iio_info = {
+	.read_raw = tsc2007_read_raw,
+	.driver_module = THIS_MODULE,
+};
+
+int tsc2007_iio_configure(struct tsc2007 *ts)
+{
+	int err;
+	struct iio_dev *indio_dev;
+	struct tsc2007_iio *iio;
+
+	indio_dev = devm_iio_device_alloc(&ts->client->dev,
+		sizeof(struct tsc2007_iio));
+	if (!indio_dev) {
+		dev_err(&ts->client->dev, "iio_device_alloc failed\n");
+		return -ENOMEM;
+	}
+
+	iio = iio_priv(indio_dev);
+	iio->ts = ts;
+	ts->iio_dev = (void *) indio_dev;
+
+	indio_dev->name = "tsc2007";
+	indio_dev->dev.parent = &ts->client->dev;
+	indio_dev->info = &tsc2007_iio_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = tsc2007_iio_channel;
+	indio_dev->num_channels = ARRAY_SIZE(tsc2007_iio_channel);
+
+	err = iio_device_register(indio_dev);
+	if (err < 0) {
+		dev_err(&ts->client->dev, "iio_device_register() failed: %d\n",
+			err);
+		return err;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(tsc2007_iio_configure);
+
+void tsc2007_iio_unconfigure(struct tsc2007 *ts)
+{
+	struct iio_dev *indio_dev = ts->iio_dev;
+
+	iio_device_unregister(indio_dev);
+}
+EXPORT_SYMBOL(tsc2007_iio_unconfigure);