Patchwork [v2,15/37] Input: tsc2007: Add device tree support.

login
register
mail settings
Submitter Denis Carikli
Date Oct. 17, 2013, 3:02 p.m.
Message ID <1382022155-21954-16-git-send-email-denis@eukrea.com>
Download mbox | patch
Permalink /patch/284247/
State New
Headers show

Comments

Denis Carikli - Oct. 17, 2013, 3:02 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: Eric Bénard <eric@eukrea.com>
Signed-off-by: Denis Carikli <denis@eukrea.com>
---
 .../bindings/input/touchscreen/tsc2007.txt         |   44 +++++
 drivers/input/touchscreen/tsc2007.c                |  200 +++++++++++++++-----
 2 files changed, 201 insertions(+), 43 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/input/touchscreen/tsc2007.txt
Lothar Waßmann - Oct. 18, 2013, 8:36 a.m.
Hi,

Denis Carikli <denis@eukrea.com> 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..d67b33f
> --- /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]).
> +- x-plate-ohms: X-plate resistance in ohms.
> +
There is already a property 'ti,x-plate-ohms' (used for ads7846).
Should this be used here too instead of inventing a new one?

[...]
> @@ -175,10 +192,10 @@ static irqreturn_t tsc2007_soft_irq(int irq, void *handle)
>  
>  		/* pen is down, continue with the measurement */
>  		tsc2007_read_values(ts, &tc);
> -
>  		rt = tsc2007_calculate_pressure(ts, &tc);
>  
> -		if (rt == 0 && !ts->get_pendown_state) {
> +		if ((ts->of && rt == 0 && ts->gpio < 0) ||
... && !gpio_is_valid(ts->gpio)) ||
for consistency?

> @@ -273,34 +294,64 @@ 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, "x-plate-ohms", &val32)) {
> +		ts->x_plate_ohms = val32;
> +	} else {
> +		dev_err(&client->dev,
> +			"x-plate-ohms is not set up in the devicetree."
> +			" (err %d).", err);
>
It's a bad habit to split messages like this, since it makes it harder
to grep the kernel source for a message in a logfile.

>  		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);
>  
dito (at least you should be consistent putting the space either in the
end of the first line or in the beginning of the next line!)

[...]
> @@ -309,13 +360,59 @@ 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;
> +		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 = kzalloc(sizeof(struct tsc2007), GFP_KERNEL);
>
devm_kzalloc()?

> @@ -389,10 +494,19 @@ 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 */ },
>
the redundant comma after the last entry in a struct initializer is
useful to ease adding more entries lateron. Since the empty entry
always has to be the last one, the comma doesn't make any sense here.


Lothar Waßmann

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..d67b33f
--- /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]).
+- 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>;
+			x-plate-ohms = <180>;
+		};
+
+		/* ... */
+	};
diff --git a/drivers/input/touchscreen/tsc2007.c b/drivers/input/touchscreen/tsc2007.c
index 0b67ba4..b1ab6c0 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 +90,14 @@  struct tsc2007 {
 	void			(*clear_penirq)(void);
 };
 
+static int tsc2007_get_pendown_state_dt(struct tsc2007  *ts)
+{
+	if (gpio_is_valid(ts->gpio))
+		return !gpio_get_value(ts->gpio);
+	else
+		return true;
+}
+
 static inline int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd)
 {
 	s32 data;
@@ -158,6 +172,9 @@  static bool tsc2007_is_pen_down(struct tsc2007 *ts)
 	 * to fall back on the pressure reading.
 	 */
 
+	if (ts->of)
+		return tsc2007_get_pendown_state_dt(ts);
+
 	if (!ts->get_pendown_state)
 		return true;
 
@@ -175,10 +192,10 @@  static irqreturn_t tsc2007_soft_irq(int irq, void *handle)
 
 		/* pen is down, continue with the measurement */
 		tsc2007_read_values(ts, &tc);
-
 		rt = tsc2007_calculate_pressure(ts, &tc);
 
-		if (rt == 0 && !ts->get_pendown_state) {
+		if ((ts->of && rt == 0 && ts->gpio < 0) ||
+			(!ts->of && rt == 0 && !ts->get_pendown_state)) {
 			/*
 			 * If pressure reported is 0 and we don't have
 			 * callback to check pendown state, we have to
@@ -198,7 +215,6 @@  static irqreturn_t tsc2007_soft_irq(int irq, void *handle)
 			input_report_abs(input, ABS_PRESSURE, rt);
 
 			input_sync(input);
-
 		} else {
 			/*
 			 * Sample found inconsistent by debouncing or pressure is
@@ -217,7 +233,6 @@  static irqreturn_t tsc2007_soft_irq(int irq, void *handle)
 	input_report_key(input, BTN_TOUCH, 0);
 	input_report_abs(input, ABS_PRESSURE, 0);
 	input_sync(input);
-
 	if (ts->clear_penirq)
 		ts->clear_penirq();
 
@@ -228,11 +243,17 @@  static irqreturn_t tsc2007_hard_irq(int irq, void *handle)
 {
 	struct tsc2007 *ts = handle;
 
-	if (!ts->get_pendown_state || likely(ts->get_pendown_state()))
-		return IRQ_WAKE_THREAD;
+	if (!ts->of) {
+		if (!ts->get_pendown_state || likely(ts->get_pendown_state()))
+			return IRQ_WAKE_THREAD;
 
-	if (ts->clear_penirq)
-		ts->clear_penirq();
+		if (ts->clear_penirq)
+			ts->clear_penirq();
+	} else {
+		if ((!gpio_is_valid(ts->gpio)) ||
+		    likely(tsc2007_get_pendown_state_dt(ts)))
+			return IRQ_WAKE_THREAD;
+	}
 
 	return IRQ_HANDLED;
 }
@@ -273,34 +294,64 @@  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, "x-plate-ohms", &val32)) {
+		ts->x_plate_ohms = val32;
+	} else {
+		dev_err(&client->dev,
+			"x-plate-ohms is not set up in the devicetree."
+			" (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 +360,59 @@  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;
+		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 = kzalloc(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)
+		goto err_free_mem;
+
+	if (!i2c_check_functionality(client->adapter,
+				     I2C_FUNC_SMBUS_READ_WORD_DATA)) {
+		err = -EIO;
 		goto err_free_mem;
 	}
 
+	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 +457,29 @@  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);
+ err_free_mem:
 	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 +494,19 @@  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,