How to define gpio irq with device tree

How to define gpio irq with device tree

[Knut Wohlrab]

Hello,

I try the touch screen of a iMX6 SabreLite evaluation board. The used 
eGalax touch controller worked fine with a 3.2.x kernel [1]. As 
mentioned there [2] I merge the basic device tree support to the actual 
driver (see patch [4]) and add the touch definition to 
arch/arm/boot/dts/imx6q-sabrelite.dts [3].

The driver seems to start but the interrupt never occurs.

The pinmux and I2C configuration seems correct. I did a simple test with 
polling the interrupt gpio (see "POLLTEST" in patch [4]) and got 
coordinates matching to the movements on the screen.

How to configure the gpio irq correctly?

Anybody solved to work with the eGalax touch and iMX6 SabreLite with 
kernel > 3.2?

Thanks a lot for any information.


[1]
http://git.linaro.org/gitweb?p=landing-teams/working/freescale/kernel.git;a=shortlog;h=refs/heads/lt-3.2-imx6 


[2]
http://git.linaro.org/gitweb?p=landing-teams/working/freescale/kernel.git;a=blob;f=drivers/input/touchscreen/egalax_ts.c;h=58184dad7a2e1b6a42711acddb184d68ffceeb4c;hb=refs/heads/lt-3.2-imx6 


[3]
...
             i2c at 021a8000 { /* I2C3 */
                 status = "okay";
                 clock-frequency = <400000>;

                 egalax at 04 {
                     compatible = "eeti,egalax";
                     reg = <0x04>;
                     interrupt-parent = <&gpio1>;
                     interrupts = <9 0x08>;
                     interrupt-gpio = <&gpio1 9 0>;
                 };
...

[4]

diff --git a/drivers/input/touchscreen/egalax_ts.c b/drivers/input/touchscreen/egalax_ts.c
index 70524dd..653a97a 100644
--- a/drivers/input/touchscreen/egalax_ts.c
+++ b/drivers/input/touchscreen/egalax_ts.c
@@ -28,6 +28,9 @@
  #include <linux/slab.h>
  #include <linux/bitops.h>
  #include <linux/input/mt.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_gpio.h>
  
  /*
   * Mouse Mode: some panel may configure the controller to mouse mode,
@@ -62,6 +65,7 @@
  struct egalax_ts {
  	struct i2c_client		*client;
  	struct input_dev		*input_dev;
+	int 					gpio_irq;
  };
  
  static irqreturn_t egalax_ts_interrupt(int irq, void *dev_id)
@@ -122,7 +126,8 @@ static irqreturn_t egalax_ts_interrupt(int irq, void *dev_id)
  /* wake up controller by an falling edge of interrupt gpio.  */
  static int egalax_wake_up_device(struct i2c_client *client)
  {
-	int gpio = irq_to_gpio(client->irq);
+	struct egalax_ts *ts = i2c_get_clientdata(client);
+	int gpio = ts->gpio_irq;
  	int ret;
  
  	ret = gpio_request(gpio, "egalax_irq");
@@ -159,6 +164,7 @@ static int __devinit egalax_firmware_version(struct i2c_client *client)
  static int __devinit egalax_ts_probe(struct i2c_client *client,
  				       const struct i2c_device_id *id)
  {
+	struct device_node *n = client->dev.of_node;
  	struct egalax_ts *ts;
  	struct input_dev *input_dev;
  	int ret;
@@ -179,6 +185,13 @@ static int __devinit egalax_ts_probe(struct i2c_client *client,
  
  	ts->client = client;
  	ts->input_dev = input_dev;
+	ts->gpio_irq = of_get_named_gpio(n, "interrupt-gpio", 0);
+	if (!gpio_is_valid(ts->gpio_irq))
+		dev_warn(&client->dev, "invalid interrupt GPIO\n");
+	else
+		dev_info(&client->dev, "valid interrupt GPIO:%d\n", ts->gpio_irq);
+
+	i2c_set_clientdata(client, ts);
  
  	/* controller may be in sleep, wake it up. */
  	egalax_wake_up_device(client);
@@ -214,13 +227,31 @@ static int __devinit egalax_ts_probe(struct i2c_client *client,
  	if (error < 0) {
  		dev_err(&client->dev, "Failed to register interrupt\n");
  		goto err_free_dev;
+	}else{
+		dev_info(&client->dev, "register interrupt: %d\n", client->irq);
  	}
  
  	error = input_register_device(ts->input_dev);
  	if (error)
  		goto err_free_irq;
  
-	i2c_set_clientdata(client, ts);
+//#define POLLTEST
+#ifdef POLLTEST
+	while(1){
+		if(!gpio_get_value(ts->gpio_irq)){
+			u8 buf[MAX_I2C_DATA_LEN];
+			int i, ret, tries = 0;
+			do {
+				ret = i2c_master_recv(client, buf, MAX_I2C_DATA_LEN);
+
+				for(i=0; i<ret; ++i)
+					printk("0x%02X ", buf[i]);
+
+				printk("\n");
+			} while (ret == -EAGAIN && tries++ < EGALAX_MAX_TRIES);
+		}
+	}
+#endif
  	return 0;
  
  err_free_irq:
@@ -251,6 +282,12 @@ static const struct i2c_device_id egalax_ts_id[] = {
  };
  MODULE_DEVICE_TABLE(i2c, egalax_ts_id);
  
+static struct of_device_id egalax_dt_ids[] = {
+	{ .compatible = "eeti,egalax" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, imx_uart_dt_ids);
+
  #ifdef CONFIG_PM_SLEEP
  static int egalax_ts_suspend(struct device *dev)
  {
@@ -279,6 +316,7 @@ static struct i2c_driver egalax_ts_driver = {
  		.name	= "egalax_ts",
  		.owner	= THIS_MODULE,
  		.pm	= &egalax_ts_pm_ops,
+		.of_match_table	= egalax_dt_ids,
  	},
  	.id_table	= egalax_ts_id,
  	.probe		= egalax_ts_probe,

How to define gpio irq with device tree

[Shawn Guo]

On Fri, Aug 10, 2012 at 02:30:59PM +0200, Knut Wohlrab wrote:
> Hello,
> 
> I try the touch screen of a iMX6 SabreLite evaluation board. The
> used eGalax touch controller worked fine with a 3.2.x kernel [1]. As
> mentioned there [2] I merge the basic device tree support to the
> actual driver (see patch [4]) and add the touch definition to
> arch/arm/boot/dts/imx6q-sabrelite.dts [3].
> 
> The driver seems to start but the interrupt never occurs.
> 
> The pinmux and I2C configuration seems correct. I did a simple test
> with polling the interrupt gpio (see "POLLTEST" in patch [4]) and
> got coordinates matching to the movements on the screen.
> 
> How to configure the gpio irq correctly?
> 
> Anybody solved to work with the eGalax touch and iMX6 SabreLite with
> kernel > 3.2?
> 
I'm not interested in reviewing those out-of-tree codes to see what
goes wrong there.  But I just quickly enabled the driver for
imx6q-sabrelite board with the following changes against latest
mainline.  And the interrupt seems working for me.

Regards,
Shawn

--8<---

diff --git a/arch/arm/boot/dts/imx6q-sabrelite.dts b/arch/arm/boot/dts/imx6q-sabrelite.dts
index 72f30f3..c8511c1 100644
--- a/arch/arm/boot/dts/imx6q-sabrelite.dts
+++ b/arch/arm/boot/dts/imx6q-sabrelite.dts
@@ -115,6 +115,21 @@
 					VDDIO-supply = <&reg_3p3v>;
 				};
 			};
+
+			i2c at 021a8000 { /* I2C3 */
+				status = "okay";
+				clock-frequency = <400000>;
+				pinctrl-names = "default";
+				pinctrl-0 = <&pinctrl_i2c3_1>;
+
+				egalax at 04 {
+					compatible = "eeti,egalax";
+					reg = <0x04>;
+					interrupt-parent = <&gpio1>;
+					interrupts = <9 0x8>;
+					wakeup-gpios = <&gpio1 9 0>;
+				};
+			};
 		};
 	};
 
diff --git a/arch/arm/boot/dts/imx6q.dtsi b/arch/arm/boot/dts/imx6q.dtsi
index 3d3c64b..bbf5196 100644
--- a/arch/arm/boot/dts/imx6q.dtsi
+++ b/arch/arm/boot/dts/imx6q.dtsi
@@ -545,6 +545,13 @@
 					};
 				};
 
+				i2c3 {
+					pinctrl_i2c3_1: i2c3grp-1 {
+						fsl,pins = <1013 0x4001b8b1	/* MX6Q_PAD_GPIO_5__I2C3_SCL */
+							    1037 0x4001b8b1>;	/* MX6Q_PAD_GPIO_16__I2C3_SDA */
+					};
+				};
+
 				serial2 {
 					pinctrl_serial2_1: serial2grp-1 {
 						fsl,pins = <183 0x1b0b1		/* MX6Q_PAD_EIM_D26__UART2_TXD */
diff --git a/drivers/input/touchscreen/egalax_ts.c b/drivers/input/touchscreen/egalax_ts.c
index 70524dd..013011d 100644
--- a/drivers/input/touchscreen/egalax_ts.c
+++ b/drivers/input/touchscreen/egalax_ts.c
@@ -28,6 +28,8 @@
 #include <linux/slab.h>
 #include <linux/bitops.h>
 #include <linux/input/mt.h>
+#include <linux/of_device.h>
+#include <linux/of_gpio.h>
 
 /*
  * Mouse Mode: some panel may configure the controller to mouse mode,
@@ -122,7 +124,7 @@ static irqreturn_t egalax_ts_interrupt(int irq, void *dev_id)
 /* wake up controller by an falling edge of interrupt gpio.  */
 static int egalax_wake_up_device(struct i2c_client *client)
 {
-	int gpio = irq_to_gpio(client->irq);
+	int gpio = of_get_named_gpio(client->dev.of_node, "wakeup-gpios", 0);
 	int ret;
 
 	ret = gpio_request(gpio, "egalax_irq");
@@ -251,6 +253,12 @@ static const struct i2c_device_id egalax_ts_id[] = {
 };
 MODULE_DEVICE_TABLE(i2c, egalax_ts_id);
 
+static struct of_device_id egalax_ts_dt_ids[] = {
+	{ .compatible = "eeti,egalax" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, egalax_ts_dt_ids);
+
 #ifdef CONFIG_PM_SLEEP
 static int egalax_ts_suspend(struct device *dev)
 {
@@ -279,6 +287,7 @@ static struct i2c_driver egalax_ts_driver = {
 		.name	= "egalax_ts",
 		.owner	= THIS_MODULE,
 		.pm	= &egalax_ts_pm_ops,
+		.of_match_table	= egalax_ts_dt_ids,
 	},
 	.id_table	= egalax_ts_id,
 	.probe		= egalax_ts_probe,
-- 
1.7.5.4

How to define gpio irq with device tree

[Hui Wang]

Shawn Guo wrote:
> On Fri, Aug 10, 2012 at 02:30:59PM +0200, Knut Wohlrab wrote:
>   
>> Hello,
>>
>> I try the touch screen of a iMX6 SabreLite evaluation board. The
>> used eGalax touch controller worked fine with a 3.2.x kernel [1]. As
>> mentioned there [2] I merge the basic device tree support to the
>> actual driver (see patch [4]) and add the touch definition to
>> arch/arm/boot/dts/imx6q-sabrelite.dts [3].
>>
>> The driver seems to start but the interrupt never occurs.
>>
>> The pinmux and I2C configuration seems correct. I did a simple test
>> with polling the interrupt gpio (see "POLLTEST" in patch [4]) and
>> got coordinates matching to the movements on the screen.
>>
>> How to configure the gpio irq correctly?
>>
>> Anybody solved to work with the eGalax touch and iMX6 SabreLite with
>> kernel > 3.2?
>>
>>     
> I'm not interested in reviewing those out-of-tree codes to see what
> goes wrong there.  But I just quickly enabled the driver for
> imx6q-sabrelite board with the following changes against latest
> mainline.  And the interrupt seems working for me.
>
>   
I generated a similar patch on the last week, only the linux-input part. 
please refer to https://patchwork.kernel.org/patch/1293451/

For mach dts part:

diff --git a/arch/arm/boot/dts/imx6q-sabrelite.dts 
b/arch/arm/boot/dts/imx6q-sabrelite.dts
index d42e851..71fcd12 100644
--- a/arch/arm/boot/dts/imx6q-sabrelite.dts
+++ b/arch/arm/boot/dts/imx6q-sabrelite.dts
@@ -53,6 +53,7 @@
fsl,pins = <
144 0x80000000 /* MX6Q_PAD_EIM_D22__GPIO_3_22 */
121 0x80000000 /* MX6Q_PAD_EIM_D19__GPIO_3_19 */
+ 972 0x10 /* MX6Q_PAD_GPIO_9__GPIO_1_9 */
 >;
};
};
@@ -114,6 +115,21 @@
VDDIO-supply = <&reg_3p3v>;
};
};
+
+ i2c at 021a8000 { /* I2C3 */
+ status = "okay";
+ clock-frequency = <100000>;
+ pinctrl-names = "default";
+ pinctrl-0 = <&pinctrl_i2c3_1>;
+
+ egalax_ts at 04 {
+ compatible = "eeti,egalax_ts";
+ reg = <0x04>;
+ interrupt-parent = <&gpio1>;
+ interrupts = <9 2>;
+ irq-gpio = <&gpio1 9 0>;
+ };
+ };
};
};

diff --git a/arch/arm/boot/dts/imx6q.dtsi b/arch/arm/boot/dts/imx6q.dtsi
index 3d3c64b..ebbd624 100644
--- a/arch/arm/boot/dts/imx6q.dtsi
+++ b/arch/arm/boot/dts/imx6q.dtsi
@@ -545,6 +545,14 @@
};
};

+
+ i2c3 {
+ pinctrl_i2c3_1: i2c3grp-1 {
+ fsl,pins = <1013 0x4001b8b1 /* MX6Q_PAD_GPIO_5__I2C3_SCL */
+ 1037 0x4001b8b1>; /* MX6Q_PAD_GPIO_16__I2C3_SDA */
+ };
+ };
+
serial2 {
pinctrl_serial2_1: serial2grp-1 {
fsl,pins = <183 0x1b0b1 /* MX6Q_PAD_EIM_D26__UART2_TXD */

> Regards,
> Shawn
>
> --8<---
>
> diff --git a/arch/arm/boot/dts/imx6q-sabrelite.dts b/arch/arm/boot/dts/imx6q-sabrelite.dts
> index 72f30f3..c8511c1 100644
> --- a/arch/arm/boot/dts/imx6q-sabrelite.dts
> +++ b/arch/arm/boot/dts/imx6q-sabrelite.dts
> @@ -115,6 +115,21 @@
>  					VDDIO-supply = <&reg_3p3v>;
>  				};
>  			};
> +
> +			i2c at 021a8000 { /* I2C3 */
> +				status = "okay";
> +				clock-frequency = <400000>;
> +				pinctrl-names = "default";
> +				pinctrl-0 = <&pinctrl_i2c3_1>;
> +
> +				egalax at 04 {
> +					compatible = "eeti,egalax";
> +					reg = <0x04>;
> +					interrupt-parent = <&gpio1>;
> +					interrupts = <9 0x8>;
> +					wakeup-gpios = <&gpio1 9 0>;
> +				};
> +			};
>  		};
>  	};
>  
> diff --git a/arch/arm/boot/dts/imx6q.dtsi b/arch/arm/boot/dts/imx6q.dtsi
> index 3d3c64b..bbf5196 100644
> --- a/arch/arm/boot/dts/imx6q.dtsi
> +++ b/arch/arm/boot/dts/imx6q.dtsi
> @@ -545,6 +545,13 @@
>  					};
>  				};
>  
> +				i2c3 {
> +					pinctrl_i2c3_1: i2c3grp-1 {
> +						fsl,pins = <1013 0x4001b8b1	/* MX6Q_PAD_GPIO_5__I2C3_SCL */
> +							    1037 0x4001b8b1>;	/* MX6Q_PAD_GPIO_16__I2C3_SDA */
> +					};
> +				};
> +
>  				serial2 {
>  					pinctrl_serial2_1: serial2grp-1 {
>  						fsl,pins = <183 0x1b0b1		/* MX6Q_PAD_EIM_D26__UART2_TXD */
> diff --git a/drivers/input/touchscreen/egalax_ts.c b/drivers/input/touchscreen/egalax_ts.c
> index 70524dd..013011d 100644
> --- a/drivers/input/touchscreen/egalax_ts.c
> +++ b/drivers/input/touchscreen/egalax_ts.c
> @@ -28,6 +28,8 @@
>  #include <linux/slab.h>
>  #include <linux/bitops.h>
>  #include <linux/input/mt.h>
> +#include <linux/of_device.h>
> +#include <linux/of_gpio.h>
>  
>  /*
>   * Mouse Mode: some panel may configure the controller to mouse mode,
> @@ -122,7 +124,7 @@ static irqreturn_t egalax_ts_interrupt(int irq, void *dev_id)
>  /* wake up controller by an falling edge of interrupt gpio.  */
>  static int egalax_wake_up_device(struct i2c_client *client)
>  {
> -	int gpio = irq_to_gpio(client->irq);
> +	int gpio = of_get_named_gpio(client->dev.of_node, "wakeup-gpios", 0);
>  	int ret;
>  
>  	ret = gpio_request(gpio, "egalax_irq");
> @@ -251,6 +253,12 @@ static const struct i2c_device_id egalax_ts_id[] = {
>  };
>  MODULE_DEVICE_TABLE(i2c, egalax_ts_id);
>  
> +static struct of_device_id egalax_ts_dt_ids[] = {
> +	{ .compatible = "eeti,egalax" },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, egalax_ts_dt_ids);
> +
>  #ifdef CONFIG_PM_SLEEP
>  static int egalax_ts_suspend(struct device *dev)
>  {
> @@ -279,6 +287,7 @@ static struct i2c_driver egalax_ts_driver = {
>  		.name	= "egalax_ts",
>  		.owner	= THIS_MODULE,
>  		.pm	= &egalax_ts_pm_ops,
> +		.of_match_table	= egalax_ts_dt_ids,
>  	},
>  	.id_table	= egalax_ts_id,
>  	.probe		= egalax_ts_probe,
>   

How to define gpio irq with device tree

[Shawn Guo]

On Tue, Aug 14, 2012 at 01:46:46PM +0800, Hui Wang wrote:
> I generated a similar patch on the last week, only the linux-input
> part. please refer to https://patchwork.kernel.org/patch/1293451/
> 
Ok.  But can you rename property "irq-gpio" to "wakeup-gpios"?
Firstly, the idiom of gpio naming in DT is *-gpios, even though
most of time, it could be just one gpio.  Secondly, as the pin is
accessed as a gpio only in egalax_wake_up_device for waking up the
device, "wakeup-gpios" sounds better?

-- 
Regards,
Shawn

How to define gpio irq with device tree

[Hui Wang]

Shawn Guo wrote:
> On Tue, Aug 14, 2012 at 01:46:46PM +0800, Hui Wang wrote:
>   
>> I generated a similar patch on the last week, only the linux-input
>> part. please refer to https://patchwork.kernel.org/patch/1293451/
>>
>>     
> Ok.  But can you rename property "irq-gpio" to "wakeup-gpios"?
> Firstly, the idiom of gpio naming in DT is *-gpios, even though
> most of time, it could be just one gpio.  Secondly, as the pin is
> accessed as a gpio only in egalax_wake_up_device for waking up the
> device, "wakeup-gpios" sounds better?
>
>   
Both accepted.

Thanks,
Hui.