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From: Marcelo Schmitt <marcelo.schmitt1@gmail.com>
To: Jorijn van der Graaf <jorijnvdgraaf@catcrafts.net>
Cc: "Jonathan Cameron" <jic23@kernel.org>,
	linux-iio@vger.kernel.org,
	"David Lechner" <dlechner@baylibre.com>,
	"Nuno Sá" <nuno.sa@analog.com>,
	"Andy Shevchenko" <andy@kernel.org>,
	"Andy Shevchenko" <andriy.shevchenko@intel.com>,
	"Rob Herring" <robh@kernel.org>,
	"Krzysztof Kozlowski" <krzk+dt@kernel.org>,
	"Conor Dooley" <conor+dt@kernel.org>,
	devicetree@vger.kernel.org, "Kees Cook" <kees@kernel.org>,
	"Gustavo A. R. Silva" <gustavoars@kernel.org>,
	linux-hardening@vger.kernel.org, linux-kernel@vger.kernel.org,
	"Luca Weiss" <luca.weiss@fairphone.com>
Subject: Re: [PATCH v2 5/5] iio: light: stk3310: support the Sensortek STK36C61
Date: Sun, 30 Aug 2026 12:03:29 -0300	[thread overview]
Message-ID: <apRGQVfPKWHvE2Ct@debian-BULLSEYE-live-builder-AMD64> (raw)
In-Reply-To: <20260828154705.11962-1-jorijnvdgraaf@catcrafts.net>

On 08/28, Jorijn van der Graaf wrote:
> On Fri, Aug 28, 2026 at 01:18:18AM -0300, Marcelo Schmitt wrote:
> > > @@ -417,10 +459,10 @@ static int stk3310_read_raw(struct iio_dev *indio_dev,
> > >  		mutex_unlock(&data->lock);
> > >  		return IIO_VAL_INT;
> > >  	case IIO_CHAN_INFO_INT_TIME:
> > > -		if (chan->type == IIO_LIGHT)
> > > -			ret = regmap_field_read(data->reg_als_it, &index);
> > > -		else
> > > +		if (chan->type == IIO_PROXIMITY)
> > >  			ret = regmap_field_read(data->reg_ps_it, &index);
> > > +		else
> > > +			ret = regmap_field_read(data->reg_als_it, &index);
> > The above seems unnecessary. Why changing the comparison from IIO_LIGHT to IIO_PROXIMITY?
> > After the proposed update we would have the integration time for both light and
> > intensity channels being read from the same register field?
> 
> These arms now see three channel types instead of two, so the two-way
> branch has to put the intensity channels on one side or the other:
> keyed on IIO_LIGHT they would fall into the else and read or write the
> proximity fields. Proximity is the odd one out - its engine has its
> own integration-time and gain fields - so the comparison keys on it
> (the write_raw arms route identically, hence the same change there).
> 
> And yes, light and intensity read the same field: the chip measures
> the colour channels in the same engine run as the ALS data, over the
> ALS integration time. Stepping that field through the driver doubles
> the ALS count and all four colour counts together (measured on the
> device: ALS 30/59/120 across three settings, C 83/167/334, R/G/B
> likewise).

Ah, so both STK3310 and STK36C61 have register 0x02 for integration time and
gain configurations that applies for all light/color channels. I think changing
to compare with IIO_PROXIMITY makes sense then.

Having a closer look at the data sheet I found for STK36C61, I noticed registers
0x13 and 0x14 are not listed. Does the newer part has ambient light sensing
besides the clear channel?


With best regards,
Marcelo

  reply	other threads:[~2026-08-30 15:02 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-08-26 17:54 [PATCH v2 0/5] iio: light: stk3310: per-chip match data and STK36C61 support Jorijn van der Graaf
2026-08-26 17:54 ` [PATCH v2 1/5] iio: light: stk3310: lower-case the i2c device ID names Jorijn van der Graaf
2026-08-27  6:45   ` Andy Shevchenko
2026-08-26 17:54 ` [PATCH v2 2/5] dt-bindings: iio: light: stk33xx: document the Sensortek STK36C61 Jorijn van der Graaf
2026-08-26 17:54 ` [PATCH v2 3/5] iio: light: stk3310: move the data registers into the channel address Jorijn van der Graaf
2026-08-27  6:47   ` Andy Shevchenko
2026-08-26 17:54 ` [PATCH v2 4/5] iio: light: stk3310: add per-chip match data Jorijn van der Graaf
2026-08-27  7:47   ` Andy Shevchenko
2026-08-26 17:54 ` [PATCH v2 5/5] iio: light: stk3310: support the Sensortek STK36C61 Jorijn van der Graaf
2026-08-27  7:53   ` Andy Shevchenko
2026-08-28  4:18   ` Marcelo Schmitt
2026-08-28 15:47     ` Jorijn van der Graaf
2026-08-30 15:03       ` Marcelo Schmitt [this message]
2026-08-30 20:19         ` Jorijn van der Graaf
2026-08-31  7:53           ` Luca Weiss
2026-09-01  0:54             ` Marcelo Schmitt
2026-09-01  1:28               ` Marcelo Schmitt
2026-09-01  2:55                 ` Jorijn van der Graaf
2026-09-01  6:57                   ` Luca Weiss
2026-08-30 23:48 ` [PATCH v2 0/5] iio: light: stk3310: per-chip match data and STK36C61 support Jonathan Cameron

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