Official Atmel Touchscreen Driver on GitHub

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Hello XDA developers,

As you know, Atmel maXTouch touchscreen controllers are used in a large percentage of Android phones and tablets out there.

I wanted to let you know that the latest patches for the official Atmel maXTouch Linux driver are available on GitHub. This will allow you to get the latest up to date changes before they make it into the mainline kernel.

On GitHub, search for user "atmel-maxtouch"

Happy hacking

Best regards,
Sherif
Product Marketing Manager - Atmel

thank u for ur valuable information, well can u pls post what are the latest changes and updates. that will help the devs much more.

Hi showlyshah,

The latest updates include the following:

- Support for Atmel's mXT224E, mXT768E, and mXT540E chipsets
- Support for both protocol A and protocol B reporting
- Support for kernel 3.0 in addition to kernel 2.6.35

More details are available on GitHub in the release notes.

Regards,
Sherif

Is https://github.com/atmel-maxtouch the correct URL?

Unfortunately, if it is, the drivers in this repository are structured completely differently from the ones included in many vendor source drops, and unfortunately this causes great negative impact on their usefulness.

See, for example:
https://github.com/Entropy512/linux_...ut/touchscreen - This includes the mxt224 drivers as implemented by Samsung on their device (Galaxy S II)

https://github.com/atmel-maxtouch/li...ut/touchscreen - mxt224_u1.c is completely missing, indicating that the driver here is incomplete or structured very differently from the one used by Samsung, making it very difficult to use. Also, the few files there that do pertain to Atmel MXT such as atmel_mxt_ts.c in there appear identical to the mainline Linux repo.

Originally Posted by Entropy512

Is https://github.com/atmel-maxtouch the correct URL?

Unfortunately, if it is, the drivers in this repository are structured completely differently from the ones included in many vendor source drops, and unfortunately this causes great negative impact on their usefulness.

But it's not Atmel who are to blame. Atmel are doing a great job working directly with upstream so that all the users of mainline linux can benefit. I have been using the drivers from the vanilla kernel for quite a while on both my tegra tablet (with chromium kernel) and galaxy s2, and they work just fine, supporting multitouch in xorg in ubuntu.

The problem is OEMs who do crap like hardcoding/hacking drivers instead of using platform data, use machine-specific hacks, custom interfaces and a lot of copy-paste. That's the essence of modern consumer electronics business - no one cares for quality, only about releasing early.

Originally Posted by Entropy512

Unfortunately, if it is, the drivers in this repository are structured completely differently from the ones included in many vendor source drops, and unfortunately this causes great negative impact on their usefulness.

See, for example:
linux_kernel_sgh-i777/tree/master/drivers/input/touchscreen - This includes the mxt224 drivers as implemented by Samsung on their device (Galaxy S II)

atmel-maxtouch/linux/tree/master/drivers/input/touchscreen - mxt224_u1.c is completely missing, indicating that the driver here is incomplete or structured very differently from the one used by Samsung, making it very difficult to use. Also, the few files there that do pertain to Atmel MXT such as atmel_mxt_ts.c in there appear identical to the mainline Linux repo.

I think you're looking at the unchanged mainline branch: the driver releases are as tags.

The advantage of these drivers is that they are generic for all chips in the maxtouch series. mxt224_u1.c is just a renamed atmel_mxt_ts.c, it contains lots of mxt224 specific configuration and it's unlikely that it will go upstream.

You will also find some user-space tools for extracting config files in a format the kernel driver can load, on the same github account.

Missed the tags, thanks for the additional info!

I'll look into maybe playing with this when ICS time rolls around. It's getting late in the game to do a major driver rework on the Gingerbread kernel I maintain.

Originally Posted by sherifhanna

Hi showlyshah,

The latest updates include the following:

- Support for Atmel's mXT224E, mXT768E, and mXT540E chipsets
- Support for both protocol A and protocol B reporting
- Support for kernel 3.0 in addition to kernel 2.6.35

More details are available on GitHub in the release notes.

Regards,
Sherif

Hi Sherif,

I found the project in Github, but am not able to find the the release notes. Does this driver support the Atmel mXT336S at this time?

Thank you

Hi omaha64,

Support for mXT336S is in progress.

Regards,
Sherif

Question,

I am trying to back-port the 2.6.35.7 driver to 2.6.32. I have mostly succeeded, but probe() fails because of missing platform_data. Digging through the driver code, I found the platform data structure in include/linux/i2c/atmel_mxt_ts.h:

struct mxt_platform_data {
        unsigned long irqflags;
        u8(*read_chg) (void);
};

So I assume that in my board file (where my i2c_board_info arrays live) I would want to create a static instance of the above struct and store a pointer to it in the .platform_data member of the i2c_board_info struct, right? But what is the preferred initialization, and what is read_chg supposed to actually do? What's the consequences of just setting it to NULL? (I know it won't crash because the driver checks it before calling it)