Re: [PATCH 1/2] iio: adc: aspeed: Remove the trim valid dts property.

From: Billy Tsai
Date: Sun Nov 06 2022 - 21:35:17 EST


On 2022/11/6, 10:50 PM, "Jonathan Cameron" <jic23@xxxxxxxxxx> wrote:

On Mon, 31 Oct 2022 19:32:07 +0800
Billy Tsai <billy_tsai@xxxxxxxxxxxxxx> wrote:

> > The dts property "aspeed,trim-data-valid" is used to determin whether to
> > read the OTP register. If the image with the aspeed,trim-data-vali
> > install to the chip without valid trimming data the adc controller will
> > become confused. This patch use the default otp value 0 as a criterion
> > for determining whether trimming data is valid instead of the dts
> > property. The chip with actually trimming value is 0 should be filter out.

> Hi Billy,

> I'm not sure I correctly follow the patch description. Would the following
> be an accurate description?

> The dts property "aspeed,trim-data-valid" is currently used to determine
> whether to read trimming data from the OTP register. If this is set on
> a device without valid trimming data in the OTP the ADC will not function
> correctly. This patch drops he use of this property and instead uses the
> default (unprogrammed) OTP value of 0 to detect when a fallback value of
> 0x8 should be used rather then the value read from the OTP.
Hi Jonathan,

Yes, it's correct.

> Also, is this a bug fix we need to backport? If so please provide a fixes
> tag.

I will provide the fixes tag in next version of patch.

Thanks

Best Regards,
Billy Tsai