[PATCH v5 0/8] drivers: touchscreen: tsc2007 and ads7846/tsc2046 improvements (use common touchscreen bindings, pre-calibration, spi fix and provide iio raw values)

[PATCH v5 0/8] drivers: touchscreen: tsc2007 and ads7846/tsc2046 improvements (use common touchscreen bindings, pre-calibration, spi fix and provide iio raw values)

[H. Nikolaus Schaller]

Changes V5:
* ads7846: remove an empty line (suggested by Andrew F. Davis <afd@ti.com>)
* ads7846: remove MODULE_ALIAS for SPI (suggested by Andrew F. Davis <afd@ti.com>)
* tsc2007: fix a bug from swapping patch 3/n and patch 4/n (found by kbuid test robot)
* refactored tsc2007 into tsc2007_core and tsc2007_iio (asked for by Jonathan Cameron <jic23@kernel.org>)

2016-10-17 16:00:02: Changes V4:
* fix a merge/squash issue resulting in a non-bisectable patch set (suggested by kbuid test robot)
* remove some unnecessary #include (suggested by Jonathan Cameron <jic23@kernel.org>)
* make the iio extension depend on CONFIG_IIO rather than selecting it (suggested by Jonathan Cameron <jic23@kernel.org>)
* swapped patch 3/n and patch 4/n to remove internal dependency

2016-09-23 14:41:23: Changes V3:
* fix an issue with swapping
* remove hard clipping to min/max rectangle - some systems expect to handle negative coordinates
* make use of commit ed7c9870c9bc ("Input: of_touchscreen - add support for inverted / swapped axes")

2015-11-13 21:36:07: Changes V2:
* add a patch to make drivers still recognise the old "ti,swap-xy" property (suggested by Rob Herring)

2015-11-06 16:14:53: This patch series improves the drivers for the tsc2007 and
ads7846/tsc2046 touchscreen controllers which are e.g. used by the GTA04
OpenPandora and Pyra devices.

New common bindings have been defined by
commit b98abe52fa8e ("Input: add common DT binding for touchscreens"):

	Documentation/devicetree/bindings/input/touchscreen/touchscreen.txt

which also defines a helper function to parse the DT. These new parameters
allow to specify the fuzz factors (jitter suppression), inversion of x or y axis and
swapping of x and y to achieve inversion and rotation so that the touch
coordinate axes match the natural orientation of the display panel.

Another improvement is to better use the min/max ADC values and
scale to the screen size as defined by the DT. This allows to coarsely
calibrate the touch to match the LCD to which it is glued on so that the
touch can quite precisely be operated before any user-space fine-calibration
can be (and needs to be) started.

For the adc7846 we fix an issue with the spi module table.

Finally we add an iio interface for the AUX and temperature ADC channels of
the tsc2007 and also provide the touch screen raw values. This allows to read
an optional ambient light sensor installed on the gta04 board and improves
calibration and hardware monitoring.


H. Nikolaus Schaller (8):
  drivers:input:tsc2007: add new common binding names, pre-calibration,
    flipping and rotation
  drivers:input:tsc2007: send pendown and penup only once like
    ads7846(+tsc2046) driver does
  drivers:input:tsc2007: check for presence and power down tsc2007
    during probe
  drivers:input:tsc2007: add iio interface to read external ADC input
    and temperature
  DT:omap3+tsc2007: use new common touchscreen bindings
  drivers:input:ads7846(+tsc2046): add new common binding names,
    pre-calibration and flipping
  drivers:input:ads7846(+tsc2046): fix spi module table
  DT:omap3+ads7846: use new common touchscreen bindings

 .../devicetree/bindings/input/ads7846.txt          |   9 +-
 .../bindings/input/touchscreen/tsc2007.txt         |  20 +-
 arch/arm/boot/dts/omap3-gta04.dtsi                 |  25 ++-
 arch/arm/boot/dts/omap3-lilly-a83x.dtsi            |   2 +-
 arch/arm/boot/dts/omap3-pandora-common.dtsi        |  17 +-
 .../boot/dts/omap3-panel-sharp-ls037v7dw01.dtsi    |   3 +-
 drivers/input/touchscreen/Makefile                 |   2 +
 drivers/input/touchscreen/ads7846.c                |  71 ++++--
 drivers/input/touchscreen/tsc2007.h                | 124 +++++++++++
 .../touchscreen/{tsc2007.c => tsc2007_core.c}      | 240 ++++++++++++---------
 drivers/input/touchscreen/tsc2007_iio.c            | 162 ++++++++++++++
 include/linux/i2c/tsc2007.h                        |   8 +
 12 files changed, 556 insertions(+), 127 deletions(-)
 create mode 100644 drivers/input/touchscreen/tsc2007.h
 rename drivers/input/touchscreen/{tsc2007.c => tsc2007_core.c} (70%)
 create mode 100644 drivers/input/touchscreen/tsc2007_iio.c

-- 
2.7.3

[PATCH v5 1/8] drivers:input:tsc2007: add new common binding names, pre-calibration, flipping and rotation

[H. Nikolaus Schaller]

commit b98abe52fa8e ("Input: add common DT binding for touchscreens")
introduced common DT bindings for touchscreens [1] and a helper function to
parse the DT.

commit ed7c9870c9bc ("Input: of_touchscreen - add support for inverted / swapped axes")
added another helper for parsing axis inversion and swapping
and applying them to x and y coordinates.

Both helpers have been integrated to accommodate any orientation of the
touch panel in relation to the LCD.

A new feature is to introduce scaling the min/max ADC values to the screen
size.

This makes it possible to pre-calibrate the touch so that is (almost)
exactly matches the LCD pixel coordinates it is glued onto. This allows to
well enough operate the touch before a user space calibration step can
improve the precision.

Finally, calculate_pressure has been renamed to calculate_resistance
because that is what it is doing.

[1]: Documentation/devicetree/bindings/input/touchscreen/touchscreen.txt

Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
---
 .../bindings/input/touchscreen/tsc2007.txt         |  20 ++--
 drivers/input/touchscreen/tsc2007.c                | 120 +++++++++++++++++----
 include/linux/i2c/tsc2007.h                        |   8 ++
 3 files changed, 118 insertions(+), 30 deletions(-)

diff --git a/Documentation/devicetree/bindings/input/touchscreen/tsc2007.txt b/Documentation/devicetree/bindings/input/touchscreen/tsc2007.txt
index ec365e1..6e9fd55 100644
--- a/Documentation/devicetree/bindings/input/touchscreen/tsc2007.txt
+++ b/Documentation/devicetree/bindings/input/touchscreen/tsc2007.txt
@@ -6,6 +6,7 @@ Required properties:
 - ti,x-plate-ohms: X-plate resistance in ohms.
 
 Optional properties:
+- generic touch screen properties: see touchscreen binding [2].
 - gpios: the interrupt gpio the chip is connected to (trough the penirq pin).
   The penirq pin goes to low when the panel is touched.
   (see GPIO binding[1] for more details).
@@ -13,17 +14,20 @@ Optional properties:
   (see interrupt binding[0]).
 - interrupts: (gpio) interrupt to which the chip is connected
   (see interrupt binding[0]).
-- ti,max-rt: maximum pressure.
-- ti,fuzzx: specifies the absolute input fuzz x value.
-  If set, it will permit noise in the data up to +- the value given to the fuzz
-  parameter, that is used to filter noise from the event stream.
-- ti,fuzzy: specifies the absolute input fuzz y value.
-- ti,fuzzz: specifies the absolute input fuzz z value.
+- ti,max-rt: maximum pressure resistance above which samples are ignored
+  (default: 4095).
+- ti,report-resistance: report resistance (no pressure = max_rt) instead
+  of pressure (no pressure = 0).
+- ti,min-x: minimum value reported by X axis ADC (default 0).
+- ti,max-x: maximum value reported by X axis ADC (default 4095).
+- ti,min-y: minimum value reported by Y axis ADC (default 0).
+- ti,max-y: maximum value reported by Y axis ADC (default 4095).
 - ti,poll-period: how much time to wait (in milliseconds) before reading again the
-  values from the tsc2007.
+  values from the tsc2007 (default 1).
 
 [0]: Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
 [1]: Documentation/devicetree/bindings/gpio/gpio.txt
+[2]: Documentation/devicetree/bindings/input/touchscreen/touchscreen.txt
 
 Example:
 	&i2c1 {
@@ -35,6 +39,8 @@ Example:
 			interrupts = <0x0 0x8>;
 			gpios = <&gpio4 0 0>;
 			ti,x-plate-ohms = <180>;
+			touchscreen-size-x = <640>;
+			touchscreen-size-y = <480>;
 		};
 
 		/* ... */
diff --git a/drivers/input/touchscreen/tsc2007.c b/drivers/input/touchscreen/tsc2007.c
index 5d0cd51..c1d9593 100644
--- a/drivers/input/touchscreen/tsc2007.c
+++ b/drivers/input/touchscreen/tsc2007.c
@@ -29,6 +29,7 @@
 #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)
@@ -74,6 +75,14 @@ struct tsc2007 {
 
 	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;
@@ -128,7 +137,8 @@ static void tsc2007_read_values(struct tsc2007 *tsc, struct ts_event *tc)
 	tsc2007_xfer(tsc, PWRDOWN);
 }
 
-static u32 tsc2007_calculate_pressure(struct tsc2007 *tsc, struct ts_event *tc)
+static u32 tsc2007_calculate_resistance(struct tsc2007 *tsc,
+					struct ts_event *tc)
 {
 	u32 rt = 0;
 
@@ -177,12 +187,13 @@ static irqreturn_t tsc2007_soft_irq(int irq, void *handle)
 	struct ts_event tc;
 	u32 rt;
 
+	dev_dbg(&ts->client->dev, "soft irq %d\n", irq);
 	while (!ts->stopped && tsc2007_is_pen_down(ts)) {
 
 		/* pen is down, continue with the measurement */
 		tsc2007_read_values(ts, &tc);
 
-		rt = tsc2007_calculate_pressure(ts, &tc);
+		rt = tsc2007_calculate_resistance(ts, &tc);
 
 		if (!rt && !ts->get_pendown_state) {
 			/*
@@ -194,21 +205,41 @@ static irqreturn_t tsc2007_soft_irq(int irq, void *handle)
 		}
 
 		if (rt <= ts->max_rt) {
+			int sx, sy;
+
 			dev_dbg(&ts->client->dev,
 				"DOWN point(%4d,%4d), pressure (%4u)\n",
 				tc.x, tc.y, rt);
 
+			if (!ts->report_resistance)
+				rt = ts->max_rt - rt;
+
+			/* scale ADC values to desired output range */
+			sx = (ts->prop.max_x * (tc.x - ts->min_x))
+				/ (ts->max_x - ts->min_x);
+			sy = (ts->prop.max_y * (tc.y - ts->min_y))
+				/ (ts->max_y - ts->min_y);
+			rt = (input->absinfo[ABS_PRESSURE].maximum * rt) /
+				ts->max_rt;
+
+			dev_dbg(&ts->client->dev,
+				"Scaled point(%4d,%4d), pressure (%4u)\n",
+				sx, sy, rt);
+
+			/* report event */
 			input_report_key(input, BTN_TOUCH, 1);
-			input_report_abs(input, ABS_X, tc.x);
-			input_report_abs(input, ABS_Y, tc.y);
+			touchscreen_report_pos(ts->input, &ts->prop,
+						(unsigned int) sx,
+						(unsigned int) sy,
+						false);
 			input_report_abs(input, ABS_PRESSURE, rt);
 
 			input_sync(input);
 
 		} else {
 			/*
-			 * Sample found inconsistent by debouncing or pressure is
-			 * beyond the maximum. Don't report it to user space,
+			 * Sample found inconsistent by debouncing or resistance
+			 * is beyond the maximum. Don't report it to user space,
 			 * repeat at least once more the measurement.
 			 */
 			dev_dbg(&ts->client->dev, "ignored pressure %d\n", rt);
@@ -233,6 +264,7 @@ static irqreturn_t tsc2007_hard_irq(int irq, void *handle)
 {
 	struct tsc2007 *ts = handle;
 
+	dev_dbg(&ts->client->dev, "hard irq %d\n", irq);
 	if (tsc2007_is_pen_down(ts))
 		return IRQ_WAKE_THREAD;
 
@@ -303,14 +335,24 @@ static int tsc2007_probe_dt(struct i2c_client *client, struct tsc2007 *ts)
 	else
 		ts->max_rt = MAX_12BIT;
 
-	if (!of_property_read_u32(np, "ti,fuzzx", &val32))
-		ts->fuzzx = val32;
+	ts->report_resistance =
+		       of_property_read_bool(np, "ti,report-resistance");
 
-	if (!of_property_read_u32(np, "ti,fuzzy", &val32))
-		ts->fuzzy = val32;
+	touchscreen_parse_properties(ts->input, false, &ts->prop);
 
-	if (!of_property_read_u32(np, "ti,fuzzz", &val32))
-		ts->fuzzz = val32;
+	if (!of_property_read_u32(np, "ti,min-x", &val32))
+		ts->min_x = val32;
+	if (!of_property_read_u32(np, "ti,max-x", &val32))
+		ts->max_x = val32;
+	else
+		ts->max_x = MAX_12BIT;
+
+	if (!of_property_read_u32(np, "ti,min-y", &val32))
+		ts->min_y = val32;
+	if (!of_property_read_u32(np, "ti,max-y", &val32))
+		ts->max_y = val32;
+	else
+		ts->max_y = MAX_12BIT;
 
 	if (!of_property_read_u64(np, "ti,poll-period", &val64))
 		ts->poll_period = msecs_to_jiffies(val64);
@@ -332,6 +374,22 @@ static int tsc2007_probe_dt(struct i2c_client *client, struct tsc2007 *ts)
 			 "GPIO not specified in DT (of_get_gpio returned %d)\n",
 			 ts->gpio);
 
+	dev_dbg(&client->dev,
+			"min/max_x (%4d,%4d)\n",
+			ts->min_x, ts->max_x);
+	dev_dbg(&client->dev,
+			"min/max_y (%4d,%4d)\n",
+			ts->min_y, ts->max_y);
+	dev_dbg(&client->dev,
+			"max_rt (%4d)\n",
+			ts->max_rt);
+	dev_dbg(&client->dev,
+			"size (%4d,%4d)\n",
+			ts->prop.max_x, ts->prop.max_y);
+	dev_dbg(&client->dev,
+			"ts-gpio: %d\n",
+			ts->gpio);
+
 	return 0;
 }
 #else
@@ -349,6 +407,14 @@ static int tsc2007_probe_pdev(struct i2c_client *client, struct tsc2007 *ts,
 	ts->model             = pdata->model;
 	ts->x_plate_ohms      = pdata->x_plate_ohms;
 	ts->max_rt            = pdata->max_rt ? : MAX_12BIT;
+	ts->prop.swap_x_y     = pdata->swap_xy;
+	ts->prop.invert_x     = pdata->invert_x;
+	ts->prop.invert_y     = pdata->invert_y;
+	ts->report_resistance = pdata->report_resistance;
+	ts->min_x             = pdata->min_x ? : 0;
+	ts->min_y             = pdata->min_y ? : 0;
+	ts->max_x             = pdata->max_x ? : MAX_12BIT;
+	ts->max_y             = pdata->max_y ? : MAX_12BIT;
 	ts->poll_period       = msecs_to_jiffies(pdata->poll_period ? : 1);
 	ts->get_pendown_state = pdata->get_pendown_state;
 	ts->clear_penirq      = pdata->clear_penirq;
@@ -388,13 +454,6 @@ static int tsc2007_probe(struct i2c_client *client,
 	if (!ts)
 		return -ENOMEM;
 
-	if (pdata)
-		err = tsc2007_probe_pdev(client, ts, pdata, id);
-	else
-		err = tsc2007_probe_dt(client, ts);
-	if (err)
-		return err;
-
 	input_dev = devm_input_allocate_device(&client->dev);
 	if (!input_dev)
 		return -ENOMEM;
@@ -419,12 +478,25 @@ static int tsc2007_probe(struct i2c_client *client,
 	input_set_drvdata(input_dev, ts);
 
 	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
+	input_dev->absbit[0] = BIT_MASK(ABS_X) | BIT_MASK(ABS_Y) |
+				BIT_MASK(ABS_PRESSURE);
 	input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
 
-	input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, ts->fuzzx, 0);
-	input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, ts->fuzzy, 0);
-	input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_12BIT,
-			     ts->fuzzz, 0);
+	if (pdata) {
+		err = tsc2007_probe_pdev(client, ts, pdata, id);
+		if (err)
+			return err;
+		input_set_abs_params(input_dev, ABS_X, 0, ts->max_x-ts->min_x,
+							  ts->fuzzx, 0);
+		input_set_abs_params(input_dev, ABS_Y, 0, ts->max_y-ts->min_y,
+							  ts->fuzzy, 0);
+		input_set_abs_params(input_dev, ABS_PRESSURE, 0, ts->max_rt,
+							  ts->fuzzz, 0);
+	} else {
+		err = tsc2007_probe_dt(client, ts);
+		if (err)
+			return err;
+	}
 
 	if (pdata) {
 		if (pdata->exit_platform_hw) {
@@ -443,6 +515,8 @@ static int tsc2007_probe(struct i2c_client *client,
 			pdata->init_platform_hw();
 	}
 
+	dev_dbg(&client->dev, "request irq %d\n",
+			ts->irq);
 	err = devm_request_threaded_irq(&client->dev, ts->irq,
 					tsc2007_hard_irq, tsc2007_soft_irq,
 					IRQF_ONESHOT,
diff --git a/include/linux/i2c/tsc2007.h b/include/linux/i2c/tsc2007.h
index 4f35b6a..632db20 100644
--- a/include/linux/i2c/tsc2007.h
+++ b/include/linux/i2c/tsc2007.h
@@ -6,6 +6,14 @@
 struct tsc2007_platform_data {
 	u16	model;				/* 2007. */
 	u16	x_plate_ohms;	/* must be non-zero value */
+	bool	swap_xy;	/* swap x and y axis */
+	bool	invert_x;
+	bool	invert_y;
+	bool	report_resistance;
+	u16	min_x;	/* min and max values reported by ADC */
+	u16	min_y;
+	u16	max_x;
+	u16	max_y;
 	u16	max_rt; /* max. resistance above which samples are ignored */
 	unsigned long poll_period; /* time (in ms) between samples */
 	int	fuzzx; /* fuzz factor for X, Y and pressure axes */
-- 
2.7.3

[PATCH v5 2/8] drivers:input:tsc2007: send pendown and penup only once like ads7846(+tsc2046) driver does

[H. Nikolaus Schaller]

this should reduce unnecessary input events.

Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
---
 drivers/input/touchscreen/tsc2007.c | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/drivers/input/touchscreen/tsc2007.c b/drivers/input/touchscreen/tsc2007.c
index c1d9593..e9d5086 100644
--- a/drivers/input/touchscreen/tsc2007.c
+++ b/drivers/input/touchscreen/tsc2007.c
@@ -94,6 +94,7 @@ struct tsc2007 {
 
 	wait_queue_head_t	wait;
 	bool			stopped;
+	bool			pendown;
 
 	int			(*get_pendown_state)(struct device *);
 	void			(*clear_penirq)(void);
@@ -227,7 +228,11 @@ static irqreturn_t tsc2007_soft_irq(int irq, void *handle)
 				sx, sy, rt);
 
 			/* report event */
-			input_report_key(input, BTN_TOUCH, 1);
+			if (!ts->pendown) {
+				input_report_key(input, BTN_TOUCH, 1);
+				ts->pendown = true;
+			}
+
 			touchscreen_report_pos(ts->input, &ts->prop,
 						(unsigned int) sx,
 						(unsigned int) sy,
@@ -250,9 +255,13 @@ static irqreturn_t tsc2007_soft_irq(int irq, void *handle)
 
 	dev_dbg(&ts->client->dev, "UP\n");
 
-	input_report_key(input, BTN_TOUCH, 0);
-	input_report_abs(input, ABS_PRESSURE, 0);
-	input_sync(input);
+	if (ts->pendown) {
+		input_report_key(input, BTN_TOUCH, 0);
+		input_report_abs(input, ABS_PRESSURE, 0);
+		input_sync(input);
+
+		ts->pendown = false;
+	}
 
 	if (ts->clear_penirq)
 		ts->clear_penirq();
-- 
2.7.3

[PATCH v5 3/8] drivers:input:tsc2007: check for presence and power down tsc2007 during probe

[H. Nikolaus Schaller]

1. check if chip is really present and don't succeed if it isn't.
2. if it succeeds, power down the chip until accessed

Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
---
 drivers/input/touchscreen/tsc2007.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/input/touchscreen/tsc2007.c b/drivers/input/touchscreen/tsc2007.c
index e9d5086..5e3c4bf 100644
--- a/drivers/input/touchscreen/tsc2007.c
+++ b/drivers/input/touchscreen/tsc2007.c
@@ -538,6 +538,14 @@ static int tsc2007_probe(struct i2c_client *client,
 
 	tsc2007_stop(ts);
 
+	/* power down the chip (TSC2007_SETUP does not ACK on I2C) */
+	err = tsc2007_xfer(ts, PWRDOWN);
+	if (err < 0) {
+		dev_err(&client->dev,
+			"Failed to setup chip: %d\n", err);
+		return err;	/* usually, chip does not respond */
+	}
+
 	err = input_register_device(input_dev);
 	if (err) {
 		dev_err(&client->dev,
-- 
2.7.3

[PATCH v5 4/8] drivers:input:tsc2007: add iio interface to read external ADC input and temperature

[H. Nikolaus Schaller]

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 in a way that it works with
CONFIG_TOUCHSCREEN_TSC2007=m.

Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
---
 drivers/input/touchscreen/Makefile                 |   2 +
 drivers/input/touchscreen/tsc2007.h                | 124 ++++++++++++++++
 .../touchscreen/{tsc2007.c => tsc2007_core.c}      | 119 +++++----------
 drivers/input/touchscreen/tsc2007_iio.c            | 162 +++++++++++++++++++++
 4 files changed, 323 insertions(+), 84 deletions(-)
 create mode 100644 drivers/input/touchscreen/tsc2007.h
 rename drivers/input/touchscreen/{tsc2007.c => tsc2007_core.c} (85%)
 create mode 100644 drivers/input/touchscreen/tsc2007_iio.c

diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 81b8645..d932e2d 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -80,6 +80,8 @@ 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
+tsc2007-$(CONFIG_IIO)			+= tsc2007_iio.o
 obj-$(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..7153bf3
--- /dev/null
+++ b/drivers/input/touchscreen/tsc2007.h
@@ -0,0 +1,124 @@
+/*
+ * drivers/input/touchscreen/tsc2007.h
+ *
+ * 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/module.h>
+#include <linux/slab.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#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 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;
+#ifdef CONFIG_IIO
+	void			*private;
+#endif
+};
+
+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);
+
+#ifdef 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) { }
+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 85%
rename from drivers/input/touchscreen/tsc2007.c
rename to drivers/input/touchscreen/tsc2007_core.c
index 5e3c4bf..19dfc9b 100644
--- a/drivers/input/touchscreen/tsc2007.c
+++ b/drivers/input/touchscreen/tsc2007_core.c
@@ -20,87 +20,9 @@
  *  published by the Free Software Foundation.
  */
 
-#include <linux/module.h>
-#include <linux/slab.h>
-#include <linux/input.h>
-#include <linux/interrupt.h>
-#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;
+#include "tsc2007.h"
 
-	unsigned		gpio;
-	int			irq;
-
-	wait_queue_head_t	wait;
-	bool			stopped;
-	bool			pendown;
-
-	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;
@@ -121,6 +43,7 @@ static inline int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd)
 
 	return val;
 }
+EXPORT_SYMBOL(tsc2007_xfer);
 
 static void tsc2007_read_values(struct tsc2007 *tsc, struct ts_event *tc)
 {
@@ -138,7 +61,7 @@ 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;
@@ -158,8 +81,9 @@ static u32 tsc2007_calculate_resistance(struct tsc2007 *tsc,
 
 	return rt;
 }
+EXPORT_SYMBOL(tsc2007_calculate_resistance);
 
-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
@@ -180,6 +104,7 @@ static bool tsc2007_is_pen_down(struct tsc2007 *ts)
 
 	return ts->get_pendown_state(&ts->client->dev);
 }
+EXPORT_SYMBOL(tsc2007_is_pen_down);
 
 static irqreturn_t tsc2007_soft_irq(int irq, void *handle)
 {
@@ -192,7 +117,10 @@ 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);
 
@@ -450,7 +378,8 @@ 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;
@@ -472,7 +401,13 @@ static int tsc2007_probe(struct i2c_client *client,
 	ts->client = client;
 	ts->irq = client->irq;
 	ts->input = input_dev;
+
+	err = tsc2007_iio_configure(ts);
+	if (err < 0)
+		return err;
+
 	init_waitqueue_head(&ts->wait);
+	mutex_init(&ts->mlock);
 
 	snprintf(ts->phys, sizeof(ts->phys),
 		 "%s/input0", dev_name(&client->dev));
@@ -503,8 +438,10 @@ static int tsc2007_probe(struct i2c_client *client,
 							  ts->fuzzz, 0);
 	} else {
 		err = tsc2007_probe_dt(client, ts);
-		if (err)
+		if (err) {
+			tsc2007_iio_unconfigure(ts);
 			return err;
+		}
 	}
 
 	if (pdata) {
@@ -516,6 +453,7 @@ static int tsc2007_probe(struct i2c_client *client,
 				dev_err(&client->dev,
 					"Failed to register exit_platform_hw action, %d\n",
 					err);
+				tsc2007_iio_unconfigure(ts);
 				return err;
 			}
 		}
@@ -533,6 +471,7 @@ static int tsc2007_probe(struct i2c_client *client,
 	if (err) {
 		dev_err(&client->dev, "Failed to request irq %d: %d\n",
 			ts->irq, err);
+		tsc2007_iio_unconfigure(ts);
 		return err;
 	}
 
@@ -543,6 +482,7 @@ static int tsc2007_probe(struct i2c_client *client,
 	if (err < 0) {
 		dev_err(&client->dev,
 			"Failed to setup chip: %d\n", err);
+		tsc2007_iio_unconfigure(ts);
 		return err;	/* usually, chip does not respond */
 	}
 
@@ -550,12 +490,22 @@ static int tsc2007_probe(struct i2c_client *client,
 	if (err) {
 		dev_err(&client->dev,
 			"Failed to register input device: %d\n", err);
+		tsc2007_iio_unconfigure(ts);
 		return err;
 	}
 
 	return 0;
 }
 
+static int tsc2007_remove(struct i2c_client *client)
+{
+	struct tsc2007 *ts = i2c_get_clientdata(client);
+
+	tsc2007_iio_unconfigure(ts);
+	input_unregister_device(ts->input);
+	return 0;
+}
+
 static const struct i2c_device_id tsc2007_idtable[] = {
 	{ "tsc2007", 0 },
 	{ }
@@ -578,6 +528,7 @@ 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..608db45
--- /dev/null
+++ b/drivers/input/touchscreen/tsc2007_iio.c
@@ -0,0 +1,162 @@
+/*
+ * drivers/input/touchscreen/tsc2007_iio.c
+ *
+ * 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 "tsc2007.h"
+#include <linux/iio/iio.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->private = (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->private;
+
+	iio_device_unregister(indio_dev);
+}
+EXPORT_SYMBOL(tsc2007_iio_unconfigure);
-- 
2.7.3

[PATCH v5 5/8] DT:omap3+tsc2007: use new common touchscreen bindings

[H. Nikolaus Schaller]

While we fix the GTA04 we add proper pinmux for the
penirq gpio.

Tested on: GTA04A4 and Pyra-Handheld

Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
---
 arch/arm/boot/dts/omap3-gta04.dtsi | 25 +++++++++++++++++++++++--
 1 file changed, 23 insertions(+), 2 deletions(-)

diff --git a/arch/arm/boot/dts/omap3-gta04.dtsi b/arch/arm/boot/dts/omap3-gta04.dtsi
index b3a8b1f..64d6ee3 100644
--- a/arch/arm/boot/dts/omap3-gta04.dtsi
+++ b/arch/arm/boot/dts/omap3-gta04.dtsi
@@ -273,6 +273,13 @@
 			OMAP3_CORE1_IOPAD(0x2134, PIN_INPUT_PULLUP | MUX_MODE4) /* gpio112 */
 		>;
 	};
+
+	penirq_pins: pinmux_penirq_pins {
+		pinctrl-single,pins = <
+			/* here we could enable to wakeup the cpu from suspend by a pen touch */
+			OMAP3_CORE1_IOPAD(0x2194, PIN_INPUT_PULLUP | MUX_MODE4) /* gpio160 */
+		>;
+	};
 };
 
 &omap3_pmx_core2 {
@@ -410,10 +417,24 @@
 	tsc2007@48 {
 		compatible = "ti,tsc2007";
 		reg = <0x48>;
+		pinctrl-names = "default";
+		pinctrl-0 = <&penirq_pins>;
 		interrupt-parent = <&gpio6>;
 		interrupts = <0 IRQ_TYPE_EDGE_FALLING>; /* GPIO_160 */
-		gpios = <&gpio6 0 GPIO_ACTIVE_LOW>;
-		ti,x-plate-ohms = <600>;
+		gpios = <&gpio6 0 GPIO_ACTIVE_LOW>;	/* GPIO_160 */
+		touchscreen-size-x = <480>;
+		touchscreen-size-y = <640>;
+		touchscreen-max-pressure = <1000>;
+		touchscreen-fuzz-x = <3>;
+		touchscreen-fuzz-y = <8>;
+		touchscreen-fuzz-pressure = <10>;
+		touchscreen-inverted-y;
+		ti,min-x = <0x100>;
+		ti,max-x = <0xf00>;
+		ti,min-y = <0x100>;
+		ti,max-y = <0xf00>;
+		ti,max-rt = <4096>;
+		ti,x-plate-ohms = <550>;
 	};
 
 	/* RFID EEPROM */
-- 
2.7.3

[PATCH v5 6/8] drivers:input:ads7846(+tsc2046): add new common binding names, pre-calibration and flipping

[H. Nikolaus Schaller]

commit b98abe52fa8e ("Input: add common DT binding for touchscreens")
introduced common DT bindings for touchscreens [1] and a helper function to
parse the DT.

commit ed7c9870c9bc ("Input: of_touchscreen - add support for inverted / swapped axes")
added another helper for parsing axis inversion and swapping
and applying them to x and y coordinates.

Both helpers have been integrated to accommodate any orientation of the
touch panel in relation to the LCD.

A new feature is to introduce scaling the min/max ADC values to the screen
size.

This makes it possible to pre-calibrate the touch so that is (almost)
exactly matches the LCD pixel coordinates it is glued onto. This allows to
well enough operate the touch before a user space calibration step can
improve the precision.

[1]: Documentation/devicetree/bindings/input/touchscreen/touchscreen.txt

Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
---
 .../devicetree/bindings/input/ads7846.txt          |  9 +++-
 drivers/input/touchscreen/ads7846.c                | 60 ++++++++++++++++++----
 2 files changed, 57 insertions(+), 12 deletions(-)

diff --git a/Documentation/devicetree/bindings/input/ads7846.txt b/Documentation/devicetree/bindings/input/ads7846.txt
index 9fc47b0..29f91ed 100644
--- a/Documentation/devicetree/bindings/input/ads7846.txt
+++ b/Documentation/devicetree/bindings/input/ads7846.txt
@@ -26,6 +26,12 @@ Additional required properties:
 
 Optional properties:
 
+You can optionally specify any of the touchscreen parameters described in
+
+	Documentation/devicetree/bindings/input/touchscreen/touchscreen.txt
+
+This allows to scale, invert or swap coordinates and define the fuzz factors.
+
 	ti,vref-delay-usecs		vref supply delay in usecs, 0 for
 					external vref (u16).
 	ti,vref-mv			The VREF voltage, in millivolts (u16).
@@ -33,7 +39,7 @@ Optional properties:
 					(ADS7846).
 	ti,keep-vref-on			set to keep vref on for differential
 					measurements as well
-	ti,swap-xy			swap x and y axis
+	ti,swap-xy			deprecated name for touchscreen-swapped-x-y
 	ti,settle-delay-usec		Settling time of the analog signals;
 					a function of Vcc and the capacitance
 					on the X/Y drivers.  If set to non-zero,
@@ -82,6 +88,7 @@ Example for a TSC2046 chip connected to an McSPI controller of an OMAP SoC::
 			pendown-gpio = <&gpio1 8 0>;
 			vcc-supply = <&reg_vcc3>;
 
+			touchscreen-swapped-x-y;
 			ti,x-min = /bits/ 16 <0>;
 			ti,x-max = /bits/ 16 <8000>;
 			ti,y-min = /bits/ 16 <0>;
diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
index 1ce3ecb..400e421 100644
--- a/drivers/input/touchscreen/ads7846.c
+++ b/drivers/input/touchscreen/ads7846.c
@@ -34,6 +34,7 @@
 #include <linux/spi/ads7846.h>
 #include <linux/regulator/consumer.h>
 #include <linux/module.h>
+#include <linux/input/touchscreen.h>
 #include <asm/irq.h>
 
 /*
@@ -109,8 +110,13 @@ struct ads7846 {
 	u16			vref_delay_usecs;
 	u16			x_plate_ohms;
 	u16			pressure_max;
+	u16			x_min;
+	u16			x_max;
+	u16			y_min;
+	u16			y_max;
+
+	struct touchscreen_properties prop;
 
-	bool			swap_xy;
 	bool			use_internal;
 
 	struct ads7846_packet	*packet;
@@ -825,22 +831,36 @@ static void ads7846_report_state(struct ads7846 *ts)
 	 */
 	if (Rt) {
 		struct input_dev *input = ts->input;
+		int sx, sy;
+
+		dev_dbg(&ts->spi->dev,
+			"Raw point(%4d,%4d), pressure (%4u)\n",
+				x, y, Rt);
+
+		/* scale ADC values to desired output range */
+		sx = (ts->prop.max_x * (x - ts->x_min))
+			/ (ts->x_max - ts->x_min);
+		sy = (ts->prop.max_y * (y - ts->y_min))
+			/ (ts->y_max - ts->y_min);
 
-		if (ts->swap_xy)
-			swap(x, y);
+		dev_dbg(&ts->spi->dev,
+			"Scaled point(%4d,%4d), pressure (%4u)\n",
+				sx, sy, Rt);
 
+		/* report event */
 		if (!ts->pendown) {
 			input_report_key(input, BTN_TOUCH, 1);
 			ts->pendown = true;
 			dev_vdbg(&ts->spi->dev, "DOWN\n");
 		}
 
-		input_report_abs(input, ABS_X, x);
-		input_report_abs(input, ABS_Y, y);
+		touchscreen_report_pos(ts->input, &ts->prop,
+				       (unsigned int) sx, (unsigned int) sy,
+				       false);
 		input_report_abs(input, ABS_PRESSURE, ts->pressure_max - Rt);
 
 		input_sync(input);
-		dev_vdbg(&ts->spi->dev, "%4d/%4d/%4d\n", x, y, Rt);
+		dev_vdbg(&ts->spi->dev, "%4d/%4d/%4d\n", sx, sy, Rt);
 	}
 }
 
@@ -1212,6 +1232,8 @@ static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev)
 	pdata->keep_vref_on = of_property_read_bool(node, "ti,keep-vref-on");
 
 	pdata->swap_xy = of_property_read_bool(node, "ti,swap-xy");
+	if (pdata->swap_xy)
+		dev_notice(dev, "please update device tree to use touchscreen-swapped-x-y");
 
 	of_property_read_u16(node, "ti,settle-delay-usec",
 			     &pdata->settle_delay_usecs);
@@ -1315,7 +1337,6 @@ static int ads7846_probe(struct spi_device *spi)
 	ts->pressure_max = pdata->pressure_max ? : ~0;
 
 	ts->vref_mv = pdata->vref_mv;
-	ts->swap_xy = pdata->swap_xy;
 
 	if (pdata->filter != NULL) {
 		if (pdata->filter_init != NULL) {
@@ -1355,18 +1376,35 @@ static int ads7846_probe(struct spi_device *spi)
 	input_dev->dev.parent = &spi->dev;
 
 	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
+	input_dev->absbit[0] = BIT_MASK(ABS_X) | BIT_MASK(ABS_Y) |
+				BIT_MASK(ABS_PRESSURE);
 	input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
+
+	ts->x_min = pdata->x_min ? : 0;
+	ts->x_max = pdata->x_max ? : MAX_12BIT;
+	ts->y_min = pdata->y_min ? : 0;
+	ts->y_max = pdata->y_max ? : MAX_12BIT;
+
 	input_set_abs_params(input_dev, ABS_X,
-			pdata->x_min ? : 0,
-			pdata->x_max ? : MAX_12BIT,
+			ts->x_min,
+			ts->x_max,
 			0, 0);
 	input_set_abs_params(input_dev, ABS_Y,
-			pdata->y_min ? : 0,
-			pdata->y_max ? : MAX_12BIT,
+			ts->y_min,
+			ts->y_max,
 			0, 0);
 	input_set_abs_params(input_dev, ABS_PRESSURE,
 			pdata->pressure_min, pdata->pressure_max, 0, 0);
 
+	if (spi->dev.of_node) {
+		input_abs_set_min(input_dev, ABS_X, 0);
+		input_abs_set_min(input_dev, ABS_Y, 0);
+
+		touchscreen_parse_properties(ts->input, false, &ts->prop);
+	}
+
+	ts->prop.swap_x_y |= pdata->swap_xy;
+
 	ads7846_setup_spi_msg(ts, pdata);
 
 	ts->reg = regulator_get(&spi->dev, "vcc");
-- 
2.7.3

[PATCH v5 7/8] drivers:input:ads7846(+tsc2046): fix spi module table

[H. Nikolaus Schaller]

Fix module table so that the driver is loaded if compiled
as module and requested by DT.

Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
---
 drivers/input/touchscreen/ads7846.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
index 400e421..50c85d2 100644
--- a/drivers/input/touchscreen/ads7846.c
+++ b/drivers/input/touchscreen/ads7846.c
@@ -1532,6 +1532,16 @@ static int ads7846_remove(struct spi_device *spi)
 	return 0;
 }
 
+static const struct spi_device_id ads7846_idtable[] = {
+	{ "tsc2046", 0 },
+	{ "ads7843", 0 },
+	{ "ads7845", 0 },
+	{ "ads7846", 0 },
+	{ "ads7873", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(spi, ads7846_idtable);
+
 static struct spi_driver ads7846_driver = {
 	.driver = {
 		.name	= "ads7846",
@@ -1546,4 +1556,3 @@ module_spi_driver(ads7846_driver);
 
 MODULE_DESCRIPTION("ADS7846 TouchScreen Driver");
 MODULE_LICENSE("GPL");
-MODULE_ALIAS("spi:ads7846");
-- 
2.7.3

[PATCH v5 8/8] DT:omap3+ads7846: use new common touchscreen bindings

[H. Nikolaus Schaller]

The standard touch screen bindings [1] replace the private ti,swap-xy
with touchscreen-swaped-x-y. And for the Openpandora we use
touchscreen-size etc. to match the LCD screen size.

[1]: Documentation/devicetree/bindings/input/touchscreen/touchscreen.txt

Tested with OpenPandora.

Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
---
 arch/arm/boot/dts/omap3-lilly-a83x.dtsi              |  2 +-
 arch/arm/boot/dts/omap3-pandora-common.dtsi          | 17 +++++++++++++----
 arch/arm/boot/dts/omap3-panel-sharp-ls037v7dw01.dtsi |  3 ++-
 3 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/arch/arm/boot/dts/omap3-lilly-a83x.dtsi b/arch/arm/boot/dts/omap3-lilly-a83x.dtsi
index fa611a5..b8b3864 100644
--- a/arch/arm/boot/dts/omap3-lilly-a83x.dtsi
+++ b/arch/arm/boot/dts/omap3-lilly-a83x.dtsi
@@ -325,7 +325,7 @@
 		ti,y-max = /bits/ 16 <3600>;
 		ti,x-plate-ohms = /bits/ 16 <80>;
 		ti,pressure-max = /bits/ 16 <255>;
-		ti,swap-xy;
+		touchscreen-swapped-x-y;
 
 		wakeup-source;
 	};
diff --git a/arch/arm/boot/dts/omap3-pandora-common.dtsi b/arch/arm/boot/dts/omap3-pandora-common.dtsi
index b0d1551..d12008a 100644
--- a/arch/arm/boot/dts/omap3-pandora-common.dtsi
+++ b/arch/arm/boot/dts/omap3-pandora-common.dtsi
@@ -700,10 +700,19 @@
 		pendown-gpio = <&gpio3 30 GPIO_ACTIVE_HIGH>;
 		vcc-supply = <&vaux4>;
 
-		ti,x-min = /bits/ 16 <0>;
-		ti,x-max = /bits/ 16 <8000>;
-		ti,y-min = /bits/ 16 <0>;
-		ti,y-max = /bits/ 16 <4800>;
+		touchscreen-size-x = <800>;
+		touchscreen-size-y = <480>;
+		touchscreen-max-pressure = <1000>;
+		touchscreen-fuzz-x = <16>;
+		touchscreen-fuzz-y = <16>;
+		touchscreen-fuzz-pressure = <10>;
+		touchscreen-inverted-x;
+		touchscreen-inverted-y;
+
+		ti,x-min = /bits/ 16 <160>;
+		ti,x-max = /bits/ 16 <3900>;
+		ti,y-min = /bits/ 16 <220>;
+		ti,y-max = /bits/ 16 <3750>;
 		ti,x-plate-ohms = /bits/ 16 <40>;
 		ti,pressure-max = /bits/ 16 <255>;
 
diff --git a/arch/arm/boot/dts/omap3-panel-sharp-ls037v7dw01.dtsi b/arch/arm/boot/dts/omap3-panel-sharp-ls037v7dw01.dtsi
index 157345b..3627a63 100644
--- a/arch/arm/boot/dts/omap3-panel-sharp-ls037v7dw01.dtsi
+++ b/arch/arm/boot/dts/omap3-panel-sharp-ls037v7dw01.dtsi
@@ -66,6 +66,7 @@
 		ti,x-plate-ohms = /bits/ 16 <40>;
 		ti,pressure-max = /bits/ 16 <255>;
 		ti,swap-xy;
-		wakeup-source;
+		touchscreen-swapped-x-y;
+		linux,wakeup;
 	};
 };
-- 
2.7.3

Re: [PATCH v5 4/8] drivers:input:tsc2007: add iio interface to read external ADC input and temperature

[Jonathan Cameron]

On 25/10/16 20:26, H. Nikolaus Schaller 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.
well
> 
> 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 in a way that it works with
> CONFIG_TOUCHSCREEN_TSC2007=m.
> 
> Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
Basically sound, just a few minor bits inline.  In particular the point
about including iio.h (and it applies to input.h etc) in your header.

You can define a pointer to a struct iio_dev without having to let the compiler
know what is actually in it - as long as you don't dereference it in any
place where the compiler needs to know.

Couple of examples in for example drivers/iio/adc/xilinx-xadc.h
The struct clk; stuff is just what we need here for example.

All about keeping internal structures opaque where we don't need to know
what is in them.

Anyhow, nearly there! (as far as I'm concerned anyway)

Thanks,

Jonathan
> ---
>  drivers/input/touchscreen/Makefile                 |   2 +
>  drivers/input/touchscreen/tsc2007.h                | 124 ++++++++++++++++
>  .../touchscreen/{tsc2007.c => tsc2007_core.c}      | 119 +++++----------
>  drivers/input/touchscreen/tsc2007_iio.c            | 162 +++++++++++++++++++++
>  4 files changed, 323 insertions(+), 84 deletions(-)
>  create mode 100644 drivers/input/touchscreen/tsc2007.h
>  rename drivers/input/touchscreen/{tsc2007.c => tsc2007_core.c} (85%)
>  create mode 100644 drivers/input/touchscreen/tsc2007_iio.c
> 
> diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
> index 81b8645..d932e2d 100644
> --- a/drivers/input/touchscreen/Makefile
> +++ b/drivers/input/touchscreen/Makefile
> @@ -80,6 +80,8 @@ 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
> +tsc2007-$(CONFIG_IIO)			+= tsc2007_iio.o
>  obj-$(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..7153bf3
> --- /dev/null
> +++ b/drivers/input/touchscreen/tsc2007.h
> @@ -0,0 +1,124 @@
> +/*
> + * drivers/input/touchscreen/tsc2007.h
> + *
> + * 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/module.h>
> +#include <linux/slab.h>
> +#include <linux/input.h>
You shouldn't need to include input.h in here...
(see below comment on the struct iio_dev *
> +#include <linux/interrupt.h>
> +#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>
Not sure why this is included either here.
> +
> +#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;
> +#ifdef CONFIG_IIO
I don't like this.  Nothing stops you using a struct iio_dev * pointer
without including iio.h.  It's a commmon thing to do.  Just put
struct *iio_dev above and don't ever dereference it without having include
iio.h in the file.
> +	void			*private;
> +#endif
> +};
> +
> +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);
> +
> +#ifdef 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) { }
should 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 85%
> rename from drivers/input/touchscreen/tsc2007.c
> rename to drivers/input/touchscreen/tsc2007_core.c
> index 5e3c4bf..19dfc9b 100644
> --- a/drivers/input/touchscreen/tsc2007.c
> +++ b/drivers/input/touchscreen/tsc2007_core.c
> @@ -20,87 +20,9 @@
>   *  published by the Free Software Foundation.
>   */
>  
> -#include <linux/module.h>
> -#include <linux/slab.h>
> -#include <linux/input.h>
> -#include <linux/interrupt.h>
> -#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;
> +#include "tsc2007.h"
>  
> -	unsigned		gpio;
> -	int			irq;
> -
> -	wait_queue_head_t	wait;
> -	bool			stopped;
> -	bool			pendown;
> -
> -	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;
> @@ -121,6 +43,7 @@ static inline int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd)
>  
>  	return val;
>  }
> +EXPORT_SYMBOL(tsc2007_xfer);
>  
>  static void tsc2007_read_values(struct tsc2007 *tsc, struct ts_event *tc)
>  {
> @@ -138,7 +61,7 @@ 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;
> @@ -158,8 +81,9 @@ static u32 tsc2007_calculate_resistance(struct tsc2007 *tsc,
>  
>  	return rt;
>  }
> +EXPORT_SYMBOL(tsc2007_calculate_resistance);
>  
> -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
> @@ -180,6 +104,7 @@ static bool tsc2007_is_pen_down(struct tsc2007 *ts)
>  
>  	return ts->get_pendown_state(&ts->client->dev);
>  }
> +EXPORT_SYMBOL(tsc2007_is_pen_down);
>  
>  static irqreturn_t tsc2007_soft_irq(int irq, void *handle)
>  {
> @@ -192,7 +117,10 @@ 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);
>  
> @@ -450,7 +378,8 @@ 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;
> @@ -472,7 +401,13 @@ static int tsc2007_probe(struct i2c_client *client,
>  	ts->client = client;
>  	ts->irq = client->irq;
>  	ts->input = input_dev;
> +
> +	err = tsc2007_iio_configure(ts);
> +	if (err < 0)
> +		return err;
> +
>  	init_waitqueue_head(&ts->wait);
> +	mutex_init(&ts->mlock);
>  
>  	snprintf(ts->phys, sizeof(ts->phys),
>  		 "%s/input0", dev_name(&client->dev));
> @@ -503,8 +438,10 @@ static int tsc2007_probe(struct i2c_client *client,
>  							  ts->fuzzz, 0);
>  	} else {
>  		err = tsc2007_probe_dt(client, ts);
> -		if (err)
> +		if (err) {
> +			tsc2007_iio_unconfigure(ts);
>  			return err;
> +		}
>  	}
>  
>  	if (pdata) {
> @@ -516,6 +453,7 @@ static int tsc2007_probe(struct i2c_client *client,
>  				dev_err(&client->dev,
>  					"Failed to register exit_platform_hw action, %d\n",
>  					err);
> +				tsc2007_iio_unconfigure(ts);
>  				return err;
>  			}
>  		}
> @@ -533,6 +471,7 @@ static int tsc2007_probe(struct i2c_client *client,
>  	if (err) {
>  		dev_err(&client->dev, "Failed to request irq %d: %d\n",
>  			ts->irq, err);
> +		tsc2007_iio_unconfigure(ts);
>  		return err;
>  	}
>  
> @@ -543,6 +482,7 @@ static int tsc2007_probe(struct i2c_client *client,
>  	if (err < 0) {
>  		dev_err(&client->dev,
>  			"Failed to setup chip: %d\n", err);
> +		tsc2007_iio_unconfigure(ts);
>  		return err;	/* usually, chip does not respond */
>  	}
>  
> @@ -550,12 +490,22 @@ static int tsc2007_probe(struct i2c_client *client,
>  	if (err) {
>  		dev_err(&client->dev,
>  			"Failed to register input device: %d\n", err);
> +		tsc2007_iio_unconfigure(ts);
>  		return err;
>  	}
>  
>  	return 0;
>  }
>  
> +static int tsc2007_remove(struct i2c_client *client)
> +{
> +	struct tsc2007 *ts = i2c_get_clientdata(client);
> +
> +	tsc2007_iio_unconfigure(ts);
> +	input_unregister_device(ts->input);
> +	return 0;
> +}
> +
>  static const struct i2c_device_id tsc2007_idtable[] = {
>  	{ "tsc2007", 0 },
>  	{ }
> @@ -578,6 +528,7 @@ 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..608db45
> --- /dev/null
> +++ b/drivers/input/touchscreen/tsc2007_iio.c
> @@ -0,0 +1,162 @@
> +/*
> + * drivers/input/touchscreen/tsc2007_iio.c
> + *
> + * 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 "tsc2007.h"
> +#include <linux/iio/iio.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;
return IIO_VAL_INT;

Though feels like tsc2007_xfer might return an error and should
be handled...
> +}
> +
> +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->private = (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->private;
> +
> +	iio_device_unregister(indio_dev);
> +}
> +EXPORT_SYMBOL(tsc2007_iio_unconfigure);
>