Re: [PATCH v2 6/6] mfd: iqs62x: Do not change clock frequency during ATI

From: Lee Jones
Date: Wed Jan 20 2021 - 04:00:38 EST


On Sun, 17 Jan 2021, Jeff LaBundy wrote:

> After a reset event, the device automatically triggers ATI at the
> default core clock frequency (16 MHz). Soon afterward, the driver
> loads firmware which may attempt to lower the frequency.
>
> If this initial ATI cycle is still in progress when the frequency
> is changed, however, the device incorrectly reports channels 0, 1
> and 2 to be in a state of touch once ATI finally completes.
>
> To solve this problem, wait until ATI is complete before lowering
> the frequency. Because this particular ATI cycle occurs following
> a reset event, its duration is predictable and a simple delay can
> suffice.
>
> Signed-off-by: Jeff LaBundy <jeff@xxxxxxxxxxx>
> Acked-for-MFD-by: Lee Jones <lee.jones@xxxxxxxxxx>
> ---
> Changes in v2:
> - Added Acked-for-MFD-by trailer
>
> drivers/mfd/iqs62x.c | 9 +++++++++
> 1 file changed, 9 insertions(+)

Applied, thanks.

--
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog