2008-02-27 02:59:06     bf527-ezkit; no max1233 touch controller driver?

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2008-02-27 02:59:06     bf527-ezkit; no max1233 touch controller driver?

John Soerensen (DENMARK)

Message: 51698    Hi all,

 

I've got a bf527-ezkit board running with ucLinux. I use SDL as GUI and it all works fine.  :-)

 

But, is there any driver I can use to get the touch screen and keypad working?

It seems like there is no driver yet. Is there any work going on to make a kernel driver, or should I try to make a user space driver via the SPIDEV driver?

 

Unfortunately I don't have a lot of time time to write the driver myself, and I havn't much knowlege (yet) on Linux drivers. So any help an suggestions are very much appreciated.  :-)

 

Thanks

joesoe

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2008-02-27 03:56:53     Re: bf527-ezkit; no max1233 touch controller driver?

Yi Li (CHINA)

Message: 51701    I used touchscreen in SDL long time ago (http://docs.blackfin.uclinux.org/doku.php?id=touchscreen#using_touch_screen_with_sdl).

But many things (sdl, touchscreen driver) has changed since then and this document is outdated. I am not sure SDL has built-in support for touchscreen or not currently.

 

But you can refer to touchscreen used in nanox: http://docs.blackfin.uclinux.org/doku.php?id=ad7877_touchscreen_input_device_driver.

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2008-02-27 04:00:40     Re: bf527-ezkit; no max1233 touch controller driver?

Yi Li (CHINA)

Message: 51702    Sorry, I saw you are using max1233, the above document all use ad7877.

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2008-02-27 04:09:15     Re: bf527-ezkit; no max1233 touch controller driver?

Mike Frysinger (UNITED STATES)

Message: 51703    right ... the ad7877 is what we use on the BF548-EZKIT and it works great today

 

there are no drivers at the moment for the BF527-EZKIT touchpad

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2008-02-27 10:29:11     Re: bf527-ezkit; no max1233 touch controller driver?

Robin Getz (UNITED STATES)

Message: 51741    John:

 

Yeah, as Mike and Yi indicated, there are touchscreen drivers for the AD7877 in the kernel (which is the one found on the BF548 EZKit) - which doesn't help you (or anyone with the 527 Kits) much.

 

Is it possible to use the AD7877 in your design instead? It might be faster to replace the chip on the EZKit - or prototype the touchscreen portions of your application on the 548 EZKit.

 

-Robin

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2008-02-28 02:01:48     Re: bf527-ezkit; no max1233 touch controller driver?

John Soerensen (DENMARK)

Message: 51758    Thank you for your answers.  :-)

 

Robin, I think you are right that it would be better to consider the AD7877 in our design. But at this stage, I am making a kind of demo application on the ezkit board, so I can show my bosses the possibilities with Linux on Blackfin.

 

In the VisualDSP++ download, there is a driver and example program of the max1233.

I am considering the possibility to convert the driver to Linux. I havn't made drivers to Linux before, but by using the SPIDEV kernel driver, it might be possible.

 

Does anyone of you have knowlege of the SPIDEV driver?

 

Thanks

John

 

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2008-02-28 04:51:01     Re: bf527-ezkit; no max1233 touch controller driver?

Mike Frysinger (UNITED STATES)

Message: 51796    converting VisualDSP drivers really isnt feasible.  they're OK for looking at how to talk to the part, but that's about it.

 

this document gives an intro to the spidev device:

http://docs.blackfin.uclinux.org/doku.php?id=spi

 

it's pretty simple to use

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2008-02-28 09:22:24     Re: bf527-ezkit; no max1233 touch controller driver?

Robin Getz (UNITED STATES)

Message: 51803    John:

 

The best thing to do would be to take the existing AD877 driver - found at  linux-2.6.x/drivers/input/touchscreen/ad7877.c and modify it so it works.

 

You really can't use the SPIDEV, since you want it to be exposed to the kernel as a generic touchscreen - not as a generic SPI device.

 

As Mike indicated - looking at the VDSP driver, other than the low level register map (which you should be able to get from the datasheet) is not worth your time when it comes to making things work properly in Linux.

 

For a demo - showing the possibilities of Linux on Blackfin - use the 548 EZkit - it is better supported, and a little more stable, since we have more hardware to test on, and there are less issues on early silicon. (As of today, there are USB bugs in 527 that make it flakey - that do not exist on 548).

 

-Robin

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2008-02-29 02:39:22     Re: bf527-ezkit; no max1233 touch controller driver?

John Soerensen (DENMARK)

Message: 51872    Hi Mike and Robin,

 

Thank you for your advices. Now I only will use the VisualDSP driver for max1233 specific code. :-)

 

Now I'll will try and look at the AD7877 and see if I can figure out how to make a simelar driver for the max1233.

I will stick to the bf527-ezkit, mainly because it is the board we have got, and the Blackfin 527 is better suited than the 548 for our development.

 

Well, this will be my first attemt to write a Linux driver, so I think I will have a lot of reading to do this week-end. :-)

Hopefully I can get something working soon that can be included in the distribution (if interested of course).

 

John

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