diff mbox

[1/2] input: touchscreen: ar1021_i2c: enable touch mode during open

Message ID 1493295756-17812-1-git-send-email-martin.kepplinger@ginzinger.com (mailing list archive)
State Accepted
Headers show

Commit Message

Martin Kepplinger April 27, 2017, 12:22 p.m. UTC
The device could as well be in command mode, in which this driver cannot
handle the device. When opening the device, let's make sure the device
will be in the mode we expect it to be for this driver.

Signed-off-by: Martin Kepplinger <martin.kepplinger@ginzinger.com>
---
 drivers/input/touchscreen/ar1021_i2c.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

Comments

Dmitry Torokhov April 28, 2017, 5:02 p.m. UTC | #1
On Thu, Apr 27, 2017 at 02:22:35PM +0200, Martin Kepplinger wrote:
> The device could as well be in command mode, in which this driver cannot
> handle the device. When opening the device, let's make sure the device
> will be in the mode we expect it to be for this driver.
> 
> Signed-off-by: Martin Kepplinger <martin.kepplinger@ginzinger.com>
> ---
>  drivers/input/touchscreen/ar1021_i2c.c | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)
> 
> diff --git a/drivers/input/touchscreen/ar1021_i2c.c b/drivers/input/touchscreen/ar1021_i2c.c
> index 1a94d8b..2a76231 100644
> --- a/drivers/input/touchscreen/ar1021_i2c.c
> +++ b/drivers/input/touchscreen/ar1021_i2c.c
> @@ -18,6 +18,12 @@
>  #define AR1021_MAX_X	4095
>  #define AR1021_MAX_Y	4095
>  
> +#define AR1021_CMD	0x55
> +#define AR1021_TOUCH	0x80
> +
> +#define AR1021_CMD_ENABLE_TOUCH		0x12
> +#define AR1021_CMD_DISABLE_TOUCH	0x13
> +
>  struct ar1021_i2c {
>  	struct i2c_client *client;
>  	struct input_dev *input;
> @@ -58,6 +64,15 @@ static int ar1021_i2c_open(struct input_dev *dev)
>  {
>  	struct ar1021_i2c *ar1021 = input_get_drvdata(dev);
>  	struct i2c_client *client = ar1021->client;
> +	int error;
> +	u8 cmd_enable_touch[3] = {AR1021_CMD,
> +				  0x01, /* number of bytes after this */
> +				  AR1021_CMD_ENABLE_TOUCH };

Changed to static const and applied, thank you.

> +
> +	error = i2c_master_send(ar1021->client, cmd_enable_touch,
> +				sizeof(cmd_enable_touch));
> +	if (error < 0)
> +		return error;
>  
>  	enable_irq(client->irq);
>  
> -- 
> 2.1.4
>
Christian Gmeiner Feb. 5, 2018, 10:07 a.m. UTC | #2
Hi all.

2017-04-27 14:22 GMT+02:00 Martin Kepplinger <martin.kepplinger@ginzinger.com>:
> The device could as well be in command mode, in which this driver cannot
> handle the device. When opening the device, let's make sure the device
> will be in the mode we expect it to be for this driver.
>

I run into issues caused by this change. It turns out that the device
is non-functional
after some warm-reboots and as a result I am not able to use xorg's
evdev driver.
So I have some questions about this change:

* Should we enable irq before calling i2c_master_send(..) as the chip raises an
  irq if the command was processed?

* Would it be enough to send this command only once during driver
lifetime? I can
  see that on my system open gets called 3 times during boot-up.

* What are the circumstances the touch device would be in an other state? In the
  official kernel driver the userspace can send commands via sysfs.
Also the driver
  does set the touch enable mode as this patch does.


> Signed-off-by: Martin Kepplinger <martin.kepplinger@ginzinger.com>
> ---
>  drivers/input/touchscreen/ar1021_i2c.c | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)
>
> diff --git a/drivers/input/touchscreen/ar1021_i2c.c b/drivers/input/touchscreen/ar1021_i2c.c
> index 1a94d8b..2a76231 100644
> --- a/drivers/input/touchscreen/ar1021_i2c.c
> +++ b/drivers/input/touchscreen/ar1021_i2c.c
> @@ -18,6 +18,12 @@
>  #define AR1021_MAX_X   4095
>  #define AR1021_MAX_Y   4095
>
> +#define AR1021_CMD     0x55
> +#define AR1021_TOUCH   0x80
> +
> +#define AR1021_CMD_ENABLE_TOUCH                0x12
> +#define AR1021_CMD_DISABLE_TOUCH       0x13
> +
>  struct ar1021_i2c {
>         struct i2c_client *client;
>         struct input_dev *input;
> @@ -58,6 +64,15 @@ static int ar1021_i2c_open(struct input_dev *dev)
>  {
>         struct ar1021_i2c *ar1021 = input_get_drvdata(dev);
>         struct i2c_client *client = ar1021->client;
> +       int error;
> +       u8 cmd_enable_touch[3] = {AR1021_CMD,
> +                                 0x01, /* number of bytes after this */
> +                                 AR1021_CMD_ENABLE_TOUCH };
> +
> +       error = i2c_master_send(ar1021->client, cmd_enable_touch,
> +                               sizeof(cmd_enable_touch));
> +       if (error < 0)
> +               return error;
>
>         enable_irq(client->irq);
>
> --
> 2.1.4
>
Martin Kepplinger Feb. 5, 2018, 10:40 a.m. UTC | #3




Martin Kepplinger | Entwicklung Software 

GINZINGER ELECTRONIC SYSTEMS GMBH

Tel.: +43 7723 5422 157
Mail: martin.kepplinger@ginzinger.com
Web: www.ginzinger.com




On 2018-02-05 11:07, Christian Gmeiner wrote:
> Hi all.
> 
> 2017-04-27 14:22 GMT+02:00 Martin Kepplinger <martin.kepplinger@ginzinger.com>:
>> The device could as well be in command mode, in which this driver cannot
>> handle the device. When opening the device, let's make sure the device
>> will be in the mode we expect it to be for this driver.
>>
> 
> I run into issues caused by this change. It turns out that the device
> is non-functional
> after some warm-reboots and as a result I am not able to use xorg's
> evdev driver.
> So I have some questions about this change:
> 
> * Should we enable irq before calling i2c_master_send(..) as the chip raises an
>   irq if the command was processed?
> 
> * Would it be enough to send this command only once during driver
> lifetime? I can
>   see that on my system open gets called 3 times during boot-up.

It would. See below for my thought on this change.

> 
> * What are the circumstances the touch device would be in an other state? In the
>   official kernel driver the userspace can send commands via sysfs.
> Also the driver
>   does set the touch enable mode as this patch does.

I did this change as the device was once non-functional unexpectedly
because it wasn't in touch mode. We can set touch mode during open() or
probe() but I figured during open() would keep the driver working even
when others would use the device in command mode.

Does your problem go away when you revert this change or put it into
probe()?

                                  martin
Dmitry Torokhov Feb. 6, 2018, 1:20 a.m. UTC | #4
On Mon, Feb 05, 2018 at 11:07:08AM +0100, Christian Gmeiner wrote:
> Hi all.
> 
> 2017-04-27 14:22 GMT+02:00 Martin Kepplinger <martin.kepplinger@ginzinger.com>:
> > The device could as well be in command mode, in which this driver cannot
> > handle the device. When opening the device, let's make sure the device
> > will be in the mode we expect it to be for this driver.
> >
> 
> I run into issues caused by this change. It turns out that the device
> is non-functional
> after some warm-reboots and as a result I am not able to use xorg's
> evdev driver.
> So I have some questions about this change:
> 
> * Should we enable irq before calling i2c_master_send(..) as the chip raises an
>   irq if the command was processed?

Well, we do not care about the response... However, what is your
interrupt trigger settings? Are you using edge by chance? If so, please
try switching to level.

> 
> * Would it be enough to send this command only once during driver
> lifetime? I can
>   see that on my system open gets called 3 times during boot-up.
> 
> * What are the circumstances the touch device would be in an other state? In the
>   official kernel driver the userspace can send commands via sysfs.
> Also the driver
>   does set the touch enable mode as this patch does.

What is "the official kernel driver"?

Thanks.
Christian Gmeiner Feb. 16, 2018, 4:38 p.m. UTC | #5
2018-02-05 11:40 GMT+01:00 Martin Kepplinger <martin.kepplinger@ginzinger.com>:
>
>
>
>
> Martin Kepplinger | Entwicklung Software
>
> GINZINGER ELECTRONIC SYSTEMS GMBH
>
> Tel.: +43 7723 5422 157
> Mail: martin.kepplinger@ginzinger.com
> Web: www.ginzinger.com
>
>
>
>
> On 2018-02-05 11:07, Christian Gmeiner wrote:
>> Hi all.
>>
>> 2017-04-27 14:22 GMT+02:00 Martin Kepplinger <martin.kepplinger@ginzinger.com>:
>>> The device could as well be in command mode, in which this driver cannot
>>> handle the device. When opening the device, let's make sure the device
>>> will be in the mode we expect it to be for this driver.
>>>
>>
>> I run into issues caused by this change. It turns out that the device
>> is non-functional
>> after some warm-reboots and as a result I am not able to use xorg's
>> evdev driver.
>> So I have some questions about this change:
>>
>> * Should we enable irq before calling i2c_master_send(..) as the chip raises an
>>   irq if the command was processed?
>>
>> * Would it be enough to send this command only once during driver
>> lifetime? I can
>>   see that on my system open gets called 3 times during boot-up.
>
> It would. See below for my thought on this change.
>
>>
>> * What are the circumstances the touch device would be in an other state? In the
>>   official kernel driver the userspace can send commands via sysfs.
>> Also the driver
>>   does set the touch enable mode as this patch does.
>
> I did this change as the device was once non-functional unexpectedly
> because it wasn't in touch mode. We can set touch mode during open() or
> probe() but I figured during open() would keep the driver working even
> when others would use the device in command mode.
>
> Does your problem go away when you revert this change or put it into
> probe()?

I needed to postprone further research and reverted this commit locally as
a new software release gets releases soon. The good this that I have
an automated way to run a test to trigger this issue quite easily.

Will have a deeper look after release time.
Christian Gmeiner Feb. 16, 2018, 4:46 p.m. UTC | #6
2018-02-06 2:20 GMT+01:00 Dmitry Torokhov <dmitry.torokhov@gmail.com>:
> On Mon, Feb 05, 2018 at 11:07:08AM +0100, Christian Gmeiner wrote:
>> Hi all.
>>
>> 2017-04-27 14:22 GMT+02:00 Martin Kepplinger <martin.kepplinger@ginzinger.com>:
>> > The device could as well be in command mode, in which this driver cannot
>> > handle the device. When opening the device, let's make sure the device
>> > will be in the mode we expect it to be for this driver.
>> >
>>
>> I run into issues caused by this change. It turns out that the device
>> is non-functional
>> after some warm-reboots and as a result I am not able to use xorg's
>> evdev driver.
>> So I have some questions about this change:
>>
>> * Should we enable irq before calling i2c_master_send(..) as the chip raises an
>>   irq if the command was processed?
>
> Well, we do not care about the response... However, what is your
> interrupt trigger settings? Are you using edge by chance? If so, please
> try switching to level.
>

We may should take care of the response. I have seen strange responses
after the third open of the device.

&i2c2 {
       ar1021@4d {
               compatible = "microchip,ar1021-i2c";
               reg = <0x4d>;
               interrupt-parent = <&gpio3>;
               interrupts = <26 IRQ_TYPE_EDGE_RISING>;
       };
};

I am not sure if this is really the cause of the problem! As without this commit
my device survives one week of a automated touch-press-test done with some
mechanical gear and with the help of an SPS.

>>
>> * Would it be enough to send this command only once during driver
>> lifetime? I can
>>   see that on my system open gets called 3 times during boot-up.
>>
>> * What are the circumstances the touch device would be in an other state? In the
>>   official kernel driver the userspace can send commands via sysfs.
>> Also the driver
>>   does set the touch enable mode as this patch does.
>
> What is "the official kernel driver"?
>

http://ww1.microchip.com/downloads/en/DeviceDoc/AR1020-AR1021-LINUX-SPI-I2C-V102.tar.gz

As it is release time at my company I had to stop finding the root
cause but will look into the issue
again in 2-3 weeks.
diff mbox

Patch

diff --git a/drivers/input/touchscreen/ar1021_i2c.c b/drivers/input/touchscreen/ar1021_i2c.c
index 1a94d8b..2a76231 100644
--- a/drivers/input/touchscreen/ar1021_i2c.c
+++ b/drivers/input/touchscreen/ar1021_i2c.c
@@ -18,6 +18,12 @@ 
 #define AR1021_MAX_X	4095
 #define AR1021_MAX_Y	4095
 
+#define AR1021_CMD	0x55
+#define AR1021_TOUCH	0x80
+
+#define AR1021_CMD_ENABLE_TOUCH		0x12
+#define AR1021_CMD_DISABLE_TOUCH	0x13
+
 struct ar1021_i2c {
 	struct i2c_client *client;
 	struct input_dev *input;
@@ -58,6 +64,15 @@  static int ar1021_i2c_open(struct input_dev *dev)
 {
 	struct ar1021_i2c *ar1021 = input_get_drvdata(dev);
 	struct i2c_client *client = ar1021->client;
+	int error;
+	u8 cmd_enable_touch[3] = {AR1021_CMD,
+				  0x01, /* number of bytes after this */
+				  AR1021_CMD_ENABLE_TOUCH };
+
+	error = i2c_master_send(ar1021->client, cmd_enable_touch,
+				sizeof(cmd_enable_touch));
+	if (error < 0)
+		return error;
 
 	enable_irq(client->irq);