Patchwork [PATCHv5,1/4] Input: tsc2007: Add device tree support.

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Submitter Denis Carikli
Date Oct. 23, 2013, 12:10 p.m.
Message ID <1382530220-27881-1-git-send-email-denis@eukrea.com>
Download mbox | patch
Permalink /patch/285652/
State New
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Comments

Denis Carikli - Oct. 23, 2013, 12:10 p.m.
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Ian Campbell <ijc+devicetree@hellion.org.uk>
Cc: devicetree@vger.kernel.org
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: linux-input@vger.kernel.org
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Lothar Waßmann <LW@KARO-electronics.de>
Cc: Eric Bénard <eric@eukrea.com>
Signed-off-by: Denis Carikli <denis@eukrea.com>
---
ChangeLog v4->v5:
- Most of the "if (ts->of)" were replaced by wrapping them in the
  tsc2007_is_pen_down_valid and tsc2007_is_pen_down functions.
- Some whitespace cleanups.
- The devm_kzalloc call was fixed to make it compile.
---
 .../bindings/input/touchscreen/tsc2007.txt         |   44 +++++
 drivers/input/touchscreen/tsc2007.c                |  194 +++++++++++++++-----
 2 files changed, 197 insertions(+), 41 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/input/touchscreen/tsc2007.txt
Rob Herring - Oct. 23, 2013, 10:18 p.m.
On 10/23/2013 07:10 AM, Denis Carikli wrote:
> Cc: Rob Herring <rob.herring@calxeda.com>
> Cc: Pawel Moll <pawel.moll@arm.com>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: Stephen Warren <swarren@wwwdotorg.org>
> Cc: Ian Campbell <ijc+devicetree@hellion.org.uk>
> Cc: devicetree@vger.kernel.org
> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
> Cc: linux-input@vger.kernel.org
> Cc: Sascha Hauer <kernel@pengutronix.de>
> Cc: linux-arm-kernel@lists.infradead.org
> Cc: Lothar Waßmann <LW@KARO-electronics.de>
> Cc: Eric Bénard <eric@eukrea.com>
> Signed-off-by: Denis Carikli <denis@eukrea.com>
> ---
> ChangeLog v4->v5:
> - Most of the "if (ts->of)" were replaced by wrapping them in the
>   tsc2007_is_pen_down_valid and tsc2007_is_pen_down functions.
> - Some whitespace cleanups.
> - The devm_kzalloc call was fixed to make it compile.
> ---
>  .../bindings/input/touchscreen/tsc2007.txt         |   44 +++++
>  drivers/input/touchscreen/tsc2007.c                |  194 +++++++++++++++-----
>  2 files changed, 197 insertions(+), 41 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/input/touchscreen/tsc2007.txt
> 
> diff --git a/Documentation/devicetree/bindings/input/touchscreen/tsc2007.txt b/Documentation/devicetree/bindings/input/touchscreen/tsc2007.txt
> new file mode 100644
> index 0000000..fadd3f6
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/input/touchscreen/tsc2007.txt
> @@ -0,0 +1,44 @@
> +* Texas Instruments tsc2007 touchscreen controller
> +
> +Required properties:
> +- compatible: must be "ti,tsc2007".
> +- reg: I2C address of the chip.
> +- pinctrl-0: Should specify pin control groups used for this controller
> +  (see pinctrl bindings[0]).
> +- pinctrl-names: Should contain only one value - "default"
> +  (see pinctrl bindings[0]).

I'm confused why an i2c slave needs pinctl binding?

> +- interrupt-parent: the phandle for the interrupt controller
> +  (see interrupt binding[1]).
> +- interrupts: interrupt to which the chip is connected
> +  (see interrupt binding[1]).
> +- ti,x-plate-ohms: X-plate resistance in ohms.
> +
> +Optional properties:
> +- gpios: the interrupt gpio the chip is connected to (trough the penirq pin)
> +  (see GPIO binding[2] for more details).
> +- max-rt: maximum pressure.
> +- fuzzy: specifies the fuzz value that is used to filter noise from the event
> +  stream.
> +- poll-period: how much time to wait(in millisecond) before reading again the
> +  values from the tsc2007.
> +
> +[0]: Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
> +[1]: Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
> +[2]: Documentation/devicetree/bindings/gpio/gpio.txt
> +
> +Example:
> +	&i2c1 {
> +		/* ... */
> +		tsc2007@49 {
> +			compatible = "ti,tsc2007";
> +			reg = <0x49>;
> +			pinctrl-names = "default";
> +			pinctrl-0 = <&pinctrl_tsc2007_1>;
> +			interrupt-parent = <&gpio4>;
> +			interrupts = <0x0 0x8>;
> +			gpios = <&gpio4 0 0>;
> +			ti,x-plate-ohms = <180>;
> +		};
> +
> +		/* ... */
> +	};
> diff --git a/drivers/input/touchscreen/tsc2007.c b/drivers/input/touchscreen/tsc2007.c
> index 0b67ba4..0625fe1 100644
> --- a/drivers/input/touchscreen/tsc2007.c
> +++ b/drivers/input/touchscreen/tsc2007.c
> @@ -26,6 +26,9 @@
>  #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>
>  
>  #define TSC2007_MEASURE_TEMP0		(0x0 << 4)
>  #define TSC2007_MEASURE_AUX		(0x2 << 4)
> @@ -74,7 +77,10 @@ struct tsc2007 {
>  	u16			max_rt;
>  	unsigned long		poll_delay;
>  	unsigned long		poll_period;
> +	int			fuzzy;
> +	char			of;
>  
> +	unsigned		gpio;
>  	int			irq;
>  
>  	wait_queue_head_t	wait;
> @@ -84,6 +90,11 @@ struct tsc2007 {
>  	void			(*clear_penirq)(void);
>  };
>  
> +static int tsc2007_get_pendown_state_dt(struct tsc2007 *ts)
> +{
> +	return !gpio_get_value(ts->gpio);
> +}
> +
>  static inline int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd)
>  {
>  	s32 data;
> @@ -142,6 +153,14 @@ static u32 tsc2007_calculate_pressure(struct tsc2007 *tsc, struct ts_event *tc)
>  	return rt;
>  }
>  
> +static bool tsc2007_is_pen_down_valid(struct tsc2007 *ts)
> +{
> +	if (ts->of)
> +		return gpio_is_valid(ts->gpio);
> +	else
> +		return ts->get_pendown_state ? true : false;
> +}
> +
>  static bool tsc2007_is_pen_down(struct tsc2007 *ts)
>  {
>  	/*
> @@ -158,10 +177,13 @@ static bool tsc2007_is_pen_down(struct tsc2007 *ts)
>  	 * to fall back on the pressure reading.
>  	 */
>  
> -	if (!ts->get_pendown_state)
> +	if (!tsc2007_is_pen_down_valid(ts))
>  		return true;
>  
> -	return ts->get_pendown_state();
> +	if (ts->of)
> +		return tsc2007_get_pendown_state_dt(ts);
> +	else
> +		return ts->get_pendown_state();
>  }
>  
>  static irqreturn_t tsc2007_soft_irq(int irq, void *handle)
> @@ -178,7 +200,7 @@ static irqreturn_t tsc2007_soft_irq(int irq, void *handle)
>  
>  		rt = tsc2007_calculate_pressure(ts, &tc);
>  
> -		if (rt == 0 && !ts->get_pendown_state) {
> +		if(!rt && !tsc2007_is_pen_down_valid(ts)) {
>  			/*
>  			 * If pressure reported is 0 and we don't have
>  			 * callback to check pendown state, we have to
> @@ -228,7 +250,7 @@ static irqreturn_t tsc2007_hard_irq(int irq, void *handle)
>  {
>  	struct tsc2007 *ts = handle;
>  
> -	if (!ts->get_pendown_state || likely(ts->get_pendown_state()))
> +	if (tsc2007_is_pen_down(ts))
>  		return IRQ_WAKE_THREAD;
>  
>  	if (ts->clear_penirq)
> @@ -273,34 +295,65 @@ static void tsc2007_close(struct input_dev *input_dev)
>  	tsc2007_stop(ts);
>  }
>  
> -static int tsc2007_probe(struct i2c_client *client,
> -				   const struct i2c_device_id *id)
> +#ifdef CONFIG_OF
> +static int tsc2007_probe_dt(struct i2c_client *client, struct tsc2007 *ts,
> +			    struct device_node *np)
>  {
> -	struct tsc2007 *ts;
> -	struct tsc2007_platform_data *pdata = client->dev.platform_data;
> -	struct input_dev *input_dev;
> -	int err;
> -
> -	if (!pdata) {
> -		dev_err(&client->dev, "platform data is required!\n");
> +	int err = 0;
> +	u32 val32;
> +	u64 val64;
> +
> +	if (!of_property_read_u32(np, "max-rt", &val32))
> +		ts->max_rt = val32;
> +	else
> +		ts->max_rt = MAX_12BIT;

These functions don't overwrite the value if the property isn't present.
So you can set the values to the defaults and just pass the variable
(i.e. ts->max_rt) to of_property_read_u32 directly.

Rob
Lothar Waßmann - Oct. 24, 2013, 6:51 a.m.
Hi,

Rob Herring wrote:
> On 10/23/2013 07:10 AM, Denis Carikli wrote:
[...]
> > diff --git
a/Documentation/devicetree/bindings/input/touchscreen/tsc2007.txt
b/Documentation/devicetree/bindings/input/touchscreen/tsc2007.txt
> > new file mode 100644
> > index 0000000..fadd3f6
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/input/touchscreen/tsc2007.txt
> > @@ -0,0 +1,44 @@
> > +* Texas Instruments tsc2007 touchscreen controller
> > +
> > +Required properties:
> > +- compatible: must be "ti,tsc2007".
> > +- reg: I2C address of the chip.
> > +- pinctrl-0: Should specify pin control groups used for this controller
> > +  (see pinctrl bindings[0]).
> > +- pinctrl-names: Should contain only one value - "default"
> > +  (see pinctrl bindings[0]).
> 
> I'm confused why an i2c slave needs pinctl binding?
> 
for the pendetect GPIO.

[...]
> > diff --git a/drivers/input/touchscreen/tsc2007.c b/drivers/input/touchscreen/tsc2007.c
> > index 0b67ba4..0625fe1 100644
> > --- a/drivers/input/touchscreen/tsc2007.c
> > +++ b/drivers/input/touchscreen/tsc2007.c
> > @@ -26,6 +26,9 @@
> >  #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>
> >  
> >  #define TSC2007_MEASURE_TEMP0		(0x0 << 4)
> >  #define TSC2007_MEASURE_AUX		(0x2 << 4)
> > @@ -74,7 +77,10 @@ struct tsc2007 {
> >  	u16			max_rt;
> >  	unsigned long		poll_delay;
> >  	unsigned long		poll_period;
> > +	int			fuzzy;
> > +	char			of;
> >  
> > +	unsigned		gpio;
> >  	int			irq;
> >  
> >  	wait_queue_head_t	wait;
[...]
> > @@ -273,34 +295,65 @@ static void tsc2007_close(struct input_dev *input_dev)
> >  	tsc2007_stop(ts);
> >  }
> >  
> > -static int tsc2007_probe(struct i2c_client *client,
> > -				   const struct i2c_device_id *id)
> > +#ifdef CONFIG_OF
> > +static int tsc2007_probe_dt(struct i2c_client *client, struct tsc2007 *ts,
> > +			    struct device_node *np)
> >  {
> > -	struct tsc2007 *ts;
> > -	struct tsc2007_platform_data *pdata = client->dev.platform_data;
> > -	struct input_dev *input_dev;
> > -	int err;
> > -
> > -	if (!pdata) {
> > -		dev_err(&client->dev, "platform data is required!\n");
> > +	int err = 0;
> > +	u32 val32;
> > +	u64 val64;
> > +
> > +	if (!of_property_read_u32(np, "max-rt", &val32))
> > +		ts->max_rt = val32;
> > +	else
> > +		ts->max_rt = MAX_12BIT;
> 
> These functions don't overwrite the value if the property isn't present.
> So you can set the values to the defaults and just pass the variable
> (i.e. ts->max_rt) to of_property_read_u32 directly.
> 
Not quite. Since max_rt is an u16 you can't pass it to
of_property_read_u32(). And using of_property_read_u16() requires the
abominable DT notation: "/bits/ 16 <value>;"


Lothar Waßmann
Thierry Reding - Oct. 24, 2013, 7:46 a.m.
On Thu, Oct 24, 2013 at 08:51:50AM +0200, Lothar Waßmann wrote:
> Hi,
> 
> Rob Herring wrote:
> > On 10/23/2013 07:10 AM, Denis Carikli wrote:
> [...]
> > > diff --git
> a/Documentation/devicetree/bindings/input/touchscreen/tsc2007.txt
> b/Documentation/devicetree/bindings/input/touchscreen/tsc2007.txt
> > > new file mode 100644
> > > index 0000000..fadd3f6
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/input/touchscreen/tsc2007.txt
> > > @@ -0,0 +1,44 @@
> > > +* Texas Instruments tsc2007 touchscreen controller
> > > +
> > > +Required properties:
> > > +- compatible: must be "ti,tsc2007".
> > > +- reg: I2C address of the chip.
> > > +- pinctrl-0: Should specify pin control groups used for this controller
> > > +  (see pinctrl bindings[0]).
> > > +- pinctrl-names: Should contain only one value - "default"
> > > +  (see pinctrl bindings[0]).
> > 
> > I'm confused why an i2c slave needs pinctl binding?
> > 
> for the pendetect GPIO.

Shouldn't that be done transparently to users of the GPIO API? I was
under the impression that gpio_request() would set everything up (or
return an error if unable to do so) so that the GPIO can be used,
including any required pinmuxing.

> [...]
> > > diff --git a/drivers/input/touchscreen/tsc2007.c b/drivers/input/touchscreen/tsc2007.c
> > > index 0b67ba4..0625fe1 100644
> > > --- a/drivers/input/touchscreen/tsc2007.c
> > > +++ b/drivers/input/touchscreen/tsc2007.c
> > > @@ -26,6 +26,9 @@
> > >  #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>
> > >  
> > >  #define TSC2007_MEASURE_TEMP0		(0x0 << 4)
> > >  #define TSC2007_MEASURE_AUX		(0x2 << 4)
> > > @@ -74,7 +77,10 @@ struct tsc2007 {
> > >  	u16			max_rt;
> > >  	unsigned long		poll_delay;
> > >  	unsigned long		poll_period;
> > > +	int			fuzzy;
> > > +	char			of;
> > >  
> > > +	unsigned		gpio;
> > >  	int			irq;
> > >  
> > >  	wait_queue_head_t	wait;
> [...]
> > > @@ -273,34 +295,65 @@ static void tsc2007_close(struct input_dev *input_dev)
> > >  	tsc2007_stop(ts);
> > >  }
> > >  
> > > -static int tsc2007_probe(struct i2c_client *client,
> > > -				   const struct i2c_device_id *id)
> > > +#ifdef CONFIG_OF
> > > +static int tsc2007_probe_dt(struct i2c_client *client, struct tsc2007 *ts,
> > > +			    struct device_node *np)
> > >  {
> > > -	struct tsc2007 *ts;
> > > -	struct tsc2007_platform_data *pdata = client->dev.platform_data;
> > > -	struct input_dev *input_dev;
> > > -	int err;
> > > -
> > > -	if (!pdata) {
> > > -		dev_err(&client->dev, "platform data is required!\n");
> > > +	int err = 0;
> > > +	u32 val32;
> > > +	u64 val64;
> > > +
> > > +	if (!of_property_read_u32(np, "max-rt", &val32))
> > > +		ts->max_rt = val32;
> > > +	else
> > > +		ts->max_rt = MAX_12BIT;
> > 
> > These functions don't overwrite the value if the property isn't present.
> > So you can set the values to the defaults and just pass the variable
> > (i.e. ts->max_rt) to of_property_read_u32 directly.
> > 
> Not quite. Since max_rt is an u16 you can't pass it to
> of_property_read_u32(). And using of_property_read_u16() requires the
> abominable DT notation: "/bits/ 16 <value>;"

In that case perhaps you need to check that whatever u32 value you read
from DT is actually in the expected range before assigning to u16?

Thierry

Patch

diff --git a/Documentation/devicetree/bindings/input/touchscreen/tsc2007.txt b/Documentation/devicetree/bindings/input/touchscreen/tsc2007.txt
new file mode 100644
index 0000000..fadd3f6
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/touchscreen/tsc2007.txt
@@ -0,0 +1,44 @@ 
+* Texas Instruments tsc2007 touchscreen controller
+
+Required properties:
+- compatible: must be "ti,tsc2007".
+- reg: I2C address of the chip.
+- pinctrl-0: Should specify pin control groups used for this controller
+  (see pinctrl bindings[0]).
+- pinctrl-names: Should contain only one value - "default"
+  (see pinctrl bindings[0]).
+- interrupt-parent: the phandle for the interrupt controller
+  (see interrupt binding[1]).
+- interrupts: interrupt to which the chip is connected
+  (see interrupt binding[1]).
+- ti,x-plate-ohms: X-plate resistance in ohms.
+
+Optional properties:
+- gpios: the interrupt gpio the chip is connected to (trough the penirq pin)
+  (see GPIO binding[2] for more details).
+- max-rt: maximum pressure.
+- fuzzy: specifies the fuzz value that is used to filter noise from the event
+  stream.
+- poll-period: how much time to wait(in millisecond) before reading again the
+  values from the tsc2007.
+
+[0]: Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
+[1]: Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
+[2]: Documentation/devicetree/bindings/gpio/gpio.txt
+
+Example:
+	&i2c1 {
+		/* ... */
+		tsc2007@49 {
+			compatible = "ti,tsc2007";
+			reg = <0x49>;
+			pinctrl-names = "default";
+			pinctrl-0 = <&pinctrl_tsc2007_1>;
+			interrupt-parent = <&gpio4>;
+			interrupts = <0x0 0x8>;
+			gpios = <&gpio4 0 0>;
+			ti,x-plate-ohms = <180>;
+		};
+
+		/* ... */
+	};
diff --git a/drivers/input/touchscreen/tsc2007.c b/drivers/input/touchscreen/tsc2007.c
index 0b67ba4..0625fe1 100644
--- a/drivers/input/touchscreen/tsc2007.c
+++ b/drivers/input/touchscreen/tsc2007.c
@@ -26,6 +26,9 @@ 
 #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>
 
 #define TSC2007_MEASURE_TEMP0		(0x0 << 4)
 #define TSC2007_MEASURE_AUX		(0x2 << 4)
@@ -74,7 +77,10 @@  struct tsc2007 {
 	u16			max_rt;
 	unsigned long		poll_delay;
 	unsigned long		poll_period;
+	int			fuzzy;
+	char			of;
 
+	unsigned		gpio;
 	int			irq;
 
 	wait_queue_head_t	wait;
@@ -84,6 +90,11 @@  struct tsc2007 {
 	void			(*clear_penirq)(void);
 };
 
+static int tsc2007_get_pendown_state_dt(struct tsc2007 *ts)
+{
+	return !gpio_get_value(ts->gpio);
+}
+
 static inline int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd)
 {
 	s32 data;
@@ -142,6 +153,14 @@  static u32 tsc2007_calculate_pressure(struct tsc2007 *tsc, struct ts_event *tc)
 	return rt;
 }
 
+static bool tsc2007_is_pen_down_valid(struct tsc2007 *ts)
+{
+	if (ts->of)
+		return gpio_is_valid(ts->gpio);
+	else
+		return ts->get_pendown_state ? true : false;
+}
+
 static bool tsc2007_is_pen_down(struct tsc2007 *ts)
 {
 	/*
@@ -158,10 +177,13 @@  static bool tsc2007_is_pen_down(struct tsc2007 *ts)
 	 * to fall back on the pressure reading.
 	 */
 
-	if (!ts->get_pendown_state)
+	if (!tsc2007_is_pen_down_valid(ts))
 		return true;
 
-	return ts->get_pendown_state();
+	if (ts->of)
+		return tsc2007_get_pendown_state_dt(ts);
+	else
+		return ts->get_pendown_state();
 }
 
 static irqreturn_t tsc2007_soft_irq(int irq, void *handle)
@@ -178,7 +200,7 @@  static irqreturn_t tsc2007_soft_irq(int irq, void *handle)
 
 		rt = tsc2007_calculate_pressure(ts, &tc);
 
-		if (rt == 0 && !ts->get_pendown_state) {
+		if(!rt && !tsc2007_is_pen_down_valid(ts)) {
 			/*
 			 * If pressure reported is 0 and we don't have
 			 * callback to check pendown state, we have to
@@ -228,7 +250,7 @@  static irqreturn_t tsc2007_hard_irq(int irq, void *handle)
 {
 	struct tsc2007 *ts = handle;
 
-	if (!ts->get_pendown_state || likely(ts->get_pendown_state()))
+	if (tsc2007_is_pen_down(ts))
 		return IRQ_WAKE_THREAD;
 
 	if (ts->clear_penirq)
@@ -273,34 +295,65 @@  static void tsc2007_close(struct input_dev *input_dev)
 	tsc2007_stop(ts);
 }
 
-static int tsc2007_probe(struct i2c_client *client,
-				   const struct i2c_device_id *id)
+#ifdef CONFIG_OF
+static int tsc2007_probe_dt(struct i2c_client *client, struct tsc2007 *ts,
+			    struct device_node *np)
 {
-	struct tsc2007 *ts;
-	struct tsc2007_platform_data *pdata = client->dev.platform_data;
-	struct input_dev *input_dev;
-	int err;
-
-	if (!pdata) {
-		dev_err(&client->dev, "platform data is required!\n");
+	int err = 0;
+	u32 val32;
+	u64 val64;
+
+	if (!of_property_read_u32(np, "max-rt", &val32))
+		ts->max_rt = val32;
+	else
+		ts->max_rt = MAX_12BIT;
+
+	if (!of_property_read_u32(np, "fuzzy", &val32))
+		ts->fuzzy = val32;
+
+	if (!of_property_read_u64(np, "poll-period", &val64))
+		ts->poll_period = val64;
+	else
+		ts->poll_period = 1;
+
+	if (!of_property_read_u32(np, "ti,x-plate-ohms", &val32)) {
+		ts->x_plate_ohms = val32;
+	} else {
+		dev_err(&client->dev,
+			"Error: lacking ti,x-plate-ohms devicetree property. (err %d).",
+			err);
 		return -EINVAL;
 	}
 
-	if (!i2c_check_functionality(client->adapter,
-				     I2C_FUNC_SMBUS_READ_WORD_DATA))
-		return -EIO;
+	ts->gpio = of_get_gpio(np, 0);
+	if (!gpio_is_valid(ts->gpio))
+		dev_err(&client->dev,
+			"GPIO not found (of_get_gpio returned %d)\n",
+			ts->gpio);
 
-	ts = kzalloc(sizeof(struct tsc2007), GFP_KERNEL);
-	input_dev = input_allocate_device();
-	if (!ts || !input_dev) {
-		err = -ENOMEM;
-		goto err_free_mem;
-	}
+	/* Used to detect if it is probed trough the device tree,
+	 * in order to be able to use that information in the IRQ handler.
+	 */
+	ts->of = 1;
 
-	ts->client = client;
-	ts->irq = client->irq;
-	ts->input = input_dev;
-	init_waitqueue_head(&ts->wait);
+	return 0;
+}
+#else
+static int tsc2007_probe_dt(struct i2c_client *client, struct tsc2007 *ts,
+			    struct device_node *np)
+{
+	return -ENODEV;
+}
+#endif
+
+static int tsc2007_probe_pdev(struct i2c_client *client, struct tsc2007 *ts,
+			      struct tsc2007_platform_data *pdata,
+			      const struct i2c_device_id *id)
+{
+	if (!pdata) {
+		dev_err(&client->dev, "platform data is required!\n");
+		return -EINVAL;
+	}
 
 	ts->model             = pdata->model;
 	ts->x_plate_ohms      = pdata->x_plate_ohms;
@@ -309,13 +362,57 @@  static int tsc2007_probe(struct i2c_client *client,
 	ts->poll_period       = pdata->poll_period ? : 1;
 	ts->get_pendown_state = pdata->get_pendown_state;
 	ts->clear_penirq      = pdata->clear_penirq;
+	ts->fuzzy             = pdata->fuzzy;
 
 	if (pdata->x_plate_ohms == 0) {
 		dev_err(&client->dev, "x_plate_ohms is not set up in platform data");
-		err = -EINVAL;
-		goto err_free_mem;
+		return -EINVAL;
 	}
 
+	/* Used to detect if it is probed trough the device tree,
+	 * in order to be able to use that information in the IRQ handler.
+	 */
+	ts->of = 0;
+
+	return 0;
+}
+
+static int tsc2007_probe(struct i2c_client *client,
+			 const struct i2c_device_id *id)
+{
+	struct device_node *np = client->dev.of_node;
+	struct tsc2007_platform_data *pdata = client->dev.platform_data;
+	struct tsc2007 *ts;
+	struct input_dev *input_dev;
+	int err = 0;
+
+	ts = devm_kzalloc(&client->dev, sizeof(struct tsc2007), GFP_KERNEL);
+	if (!ts)
+		return -ENOMEM;
+
+	if (np)
+		err = tsc2007_probe_dt(client, ts, np);
+	else
+		err = tsc2007_probe_pdev(client, ts, pdata, id);
+
+	if (err)
+		return err;
+
+	if (!i2c_check_functionality(client->adapter,
+				     I2C_FUNC_SMBUS_READ_WORD_DATA))
+		return -EIO;
+
+	input_dev = input_allocate_device();
+	if (!input_dev) {
+		err = -ENOMEM;
+		goto err_free_input;
+	};
+
+	ts->client = client;
+	ts->irq = client->irq;
+	ts->input = input_dev;
+	init_waitqueue_head(&ts->wait);
+
 	snprintf(ts->phys, sizeof(ts->phys),
 		 "%s/input0", dev_name(&client->dev));
 
@@ -331,19 +428,21 @@  static int tsc2007_probe(struct i2c_client *client,
 	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
 	input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
 
-	input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, pdata->fuzzx, 0);
-	input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, pdata->fuzzy, 0);
+	input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, ts->fuzzy, 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,
-			pdata->fuzzz, 0);
+			     ts->fuzzy, 0);
 
-	if (pdata->init_platform_hw)
-		pdata->init_platform_hw();
+	if (!np) {
+		if (pdata->init_platform_hw)
+			pdata->init_platform_hw();
+	}
 
 	err = request_threaded_irq(ts->irq, tsc2007_hard_irq, tsc2007_soft_irq,
 				   IRQF_ONESHOT, client->dev.driver->name, ts);
 	if (err < 0) {
 		dev_err(&client->dev, "irq %d busy?\n", ts->irq);
-		goto err_free_mem;
+		goto err_free_input;
 	}
 
 	tsc2007_stop(ts);
@@ -358,23 +457,27 @@  static int tsc2007_probe(struct i2c_client *client,
 
  err_free_irq:
 	free_irq(ts->irq, ts);
-	if (pdata->exit_platform_hw)
-		pdata->exit_platform_hw();
- err_free_mem:
+	if (!np) {
+		if (pdata->exit_platform_hw)
+			pdata->exit_platform_hw();
+	}
+ err_free_input:
 	input_free_device(input_dev);
-	kfree(ts);
 	return err;
 }
 
 static int tsc2007_remove(struct i2c_client *client)
 {
+	struct device_node *np = client->dev.of_node;
 	struct tsc2007	*ts = i2c_get_clientdata(client);
 	struct tsc2007_platform_data *pdata = client->dev.platform_data;
 
 	free_irq(ts->irq, ts);
 
-	if (pdata->exit_platform_hw)
-		pdata->exit_platform_hw();
+	if (!np) {
+		if (pdata->exit_platform_hw)
+			pdata->exit_platform_hw();
+	}
 
 	input_unregister_device(ts->input);
 	kfree(ts);
@@ -389,10 +492,19 @@  static const struct i2c_device_id tsc2007_idtable[] = {
 
 MODULE_DEVICE_TABLE(i2c, tsc2007_idtable);
 
+#ifdef CONFIG_OF
+static const struct of_device_id tsc2007_of_match[] = {
+	{ .compatible = "ti,tsc2007" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, tsc2007_of_match);
+#endif
+
 static struct i2c_driver tsc2007_driver = {
 	.driver = {
 		.owner	= THIS_MODULE,
-		.name	= "tsc2007"
+		.name	= "tsc2007",
+		.of_match_table = of_match_ptr(tsc2007_of_match),
 	},
 	.id_table	= tsc2007_idtable,
 	.probe		= tsc2007_probe,