i2c keyboard

i2c keyboard

[Oleg Kravchenko]

Hello, everyone.
We are porting the Linux kernel to our PDA, Asus P525/P535. This device 
has a pca9535 gpio extender. The keyboard is connected to it. The 
extender has only one irq. At the moment, the pca9535 is handled by 
pca953x gpio driver. We need to have the access to its registers from 
our keyboard driver (so as not to read 13 gpios, but decode the register 
containing gpio states). If i try to read each of these 13 gpios after 
the interrupt from the extender comes, the kernel crashes. Is there a 
solution to read i2c client addresses when there is a client registered 
already?


http://www.kaa.org.ua/asus-p535/hardware.html

Re: i2c keyboard

[Marek Vasut]

On Monday 23 of February 2009 09:50:52 Oleg Kravchenko wrote:
> Hello, everyone.
> We are porting the Linux kernel to our PDA, Asus P525/P535. This device
> has a pca9535 gpio extender. The keyboard is connected to it. The
> extender has only one irq. At the moment, the pca9535 is handled by
> pca953x gpio driver. We need to have the access to its registers from
> our keyboard driver (so as not to read 13 gpios, but decode the register
> containing gpio states). If i try to read each of these 13 gpios after
> the interrupt from the extender comes, the kernel crashes. Is there a
> solution to read i2c client addresses when there is a client registered
> already?
>
There was some discussion about implementing batch GPIO reads in 
linux-arm-kernel mailing list, that's probably what you want.

>
> http://www.kaa.org.ua/asus-p535/hardware.html
> --
> To unsubscribe from this list: send the line "unsubscribe linux-input" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html