Re: [PATCH v1 3/3] dt-bindings: thermal: sun8i: Add binding for D1/T113s THS controller

From: Maxim Kiselev <bigunclemax@gmail.com>
To: Conor Dooley <conor@kernel.org>
Cc: linux-kernel@vger.kernel.org,
	Vasily Khoruzhick <anarsoul@gmail.com>,
	 Yangtao Li <tiny.windzz@gmail.com>,
	"Rafael J. Wysocki" <rafael@kernel.org>,
	 Daniel Lezcano <daniel.lezcano@linaro.org>,
	Amit Kucheria <amitk@kernel.org>,
	 Zhang Rui <rui.zhang@intel.com>,
	Rob Herring <robh+dt@kernel.org>,
	 Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Conor Dooley <conor+dt@kernel.org>,  Chen-Yu Tsai <wens@csie.org>,
	Jernej Skrabec <jernej.skrabec@gmail.com>,
	 Samuel Holland <samuel@sholland.org>,
	Paul Walmsley <paul.walmsley@sifive.com>,
	 Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	 Cristian Ciocaltea <cristian.ciocaltea@collabora.com>,
	linux-pm@vger.kernel.org,  devicetree@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	 linux-sunxi@lists.linux.dev, linux-riscv@lists.infradead.org
Subject: Re: [PATCH v1 3/3] dt-bindings: thermal: sun8i: Add binding for D1/T113s THS controller
Date: Sat, 10 Jun 2023 23:31:03 +0300	[thread overview]
Message-ID: <CALHCpMjFNvJAnd2_3-1n_L3QRz4eNc-Egm-BD6jcS6H694dSyg@mail.gmail.com> (raw)
In-Reply-To: <20230610-crumpet-spender-4133090a4728@spud>

сб, 10 июн. 2023 г. в 21:01, Conor Dooley <conor@kernel.org>:

...

> > > > +  - |
> > > > +    thermal-sensor@2009400 {
> > > > +          compatible = "allwinner,sun20i-d1-ths";
> > > > +          reg = <0x02009400 0x400>;
> > > > +          interrupts = <0 90 0>;
> > > > +          clocks = <&ccu 0>;
> > > > +          clock-names = "bus";
> > > > +          resets = <&ccu 2>;
> > > > +          nvmem-cells = <&ths_calibration>;
> > > > +          nvmem-cell-names = "calibration";
> > > > +          #thermal-sensor-cells = <0>;
> > > >
> > > >> Is this calibration required, or optional, for the d1?
> > >
> > > Calibration data for the D1 is optional as for the H6.
> > > (But without it, the sensor data will be inaccurate).
> >
> > Okay. Modulo the signoff:
> > Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
>
> Wait, that's not what I meant to say... Clearly turned my brain off for
> a moment. If it is not going to function correctly without the
> calibration data, why not make the calibration data required for the
> d1's ths?

I don't really know why, but the calibration data is optional for
other controllers.
So I just did it the same way.
Here is explanation comment about it from the driver:
        /*
         * Even if the external calibration data stored in sid is
         * not accessible, the THS hardware can still work, although
         * the data won't be so accurate.
         *
         * The default value of calibration register is 0x800 for
         * every sensor, and the calibration value is usually 0x7xx
         * or 0x8xx, so they won't be away from the default value
         * for a lot.
         *
         * So here we do not return error if the calibration data is
         * not available, except the probe needs deferring.
         */