Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.34 as permitted sender) client-ip=23.128.96.34;
From:   Flavio Suligoi <f.suligoi@asem.it>
To:     Daniel Thompson <daniel.thompson@linaro.org>
CC:     Lee Jones <lee@kernel.org>, Jingoo Han <jingoohan1@gmail.com>,
        Helge Deller <deller@gmx.de>, Pavel Machek <pavel@ucw.cz>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor+dt@kernel.org>,
        "dri-devel@lists.freedesktop.org" <dri-devel@lists.freedesktop.org>,
        "linux-leds@vger.kernel.org" <linux-leds@vger.kernel.org>,
        "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
        "linux-fbdev@vger.kernel.org" <linux-fbdev@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Rob Herring <robh@kernel.org>
Subject: RE: [PATCH v3 1/2] dt-bindings: backlight: Add MPS MP3309C
Thread-Topic: [PATCH v3 1/2] dt-bindings: backlight: Add MPS MP3309C
Thread-Index: AQHZ76uO1Fb/EPNT/k67j1TrFzld37AtE7aAgAmVcBCAAT5MAIAAXgAg
Date:   Tue, 3 Oct 2023 16:00:32 +0000
Message-ID: <DU2PR01MB80349344FB8CB1415BFA917DF9C4A@DU2PR01MB8034.eurprd01.prod.exchangelabs.com>
References: <20230925122609.78849-1-f.suligoi@asem.it>
 <20230926130113.GB4356@aspen.lan>
 <DU2PR01MB8034F448F6E66BAC3823CDB1F9C4A@DU2PR01MB8034.eurprd01.prod.exchangelabs.com>
 <20231003102138.GB69443@aspen.lan>
In-Reply-To: <20231003102138.GB69443@aspen.lan>
Accept-Language: it-IT, en-US
Content-Language: en-US
x-ms-exchange-antispam-messagedata-chunkcount: 1
x-ms-exchange-antispam-messagedata-0: =?us-ascii?Q?lJu/9rToUgFnyxLxTdoJ/gyCTk6jHQcI4oyXXqWTZgDyMoTaDWrf5JHFwx4n?=
 =?us-ascii?Q?GgvL4UYlp+9JbLpYvuK95Pnon+FIuYKrwHCOB11f7VZRy/UXv+q2pNUUdRLy?=
 =?us-ascii?Q?WkskGrOKFGPO5OpePh4bcDNpwT4YkbNEyjCIHMoQk6ppxGKt/O+3SVKHA7Z3?=
 =?us-ascii?Q?6x8OkjPRg2yKTnAfrQ0pDyH3Qyn9b9E//REEQeenVEoYBHTlGJ7IHEr+xzTg?=
 =?us-ascii?Q?lXc8QvvrS5YXsI36/GrF9HEAW8hD6B0GNVhs5oAGSte119ktjQ2lURFt4f55?=
 =?us-ascii?Q?trrGBLg0bPntyBtqwuPXndn94LD/W8EsuulFsSGC93Eht0qzBMVQgyVIuEPv?=
 =?us-ascii?Q?EFl4+XRCOhcbpVnnPPEN1Q4qnozZkDngMrnNZ71HcAuRiw+sWb3taFKOwJ4I?=
 =?us-ascii?Q?k29WLLgdhx1rLeMXmp9pqk2Umb1c5XDiBaRWJEdm4J4PonkMOTEVjfATKrvv?=
 =?us-ascii?Q?0L3kc4TZa9JOCBWfPKT9hQzEdFsYx3tx2q8VV9bnTLCsenpNsUIvutD8U48q?=
 =?us-ascii?Q?RX9wJbsHxHg4+5J/TYx2WTIDEKqHm0VVZmQOrUs4CC9IgmUA39Uld+6hyuvM?=
 =?us-ascii?Q?YuiOw1sLS5T1hJDxKKKLUDSJk6vZglp2sM8Aky7LMlo4d1Pxad4eNu81u4q1?=
 =?us-ascii?Q?m1TLqFdkDT4zwvtSVcKhkCM0BWI7FAQexhGbwENwUoyPpBKslzE+dhWNIGJc?=
 =?us-ascii?Q?8X++uFgWiAnPscXuQA/G/T/9ysFFYojVi1RAmPYhRZmsRXJ+EKWj9NJFat73?=
 =?us-ascii?Q?8x6qtj7kvC9YwUAQO7HTRSkROon9EoYuN0VgpPoXqfMhikDVf//V8u5YFU60?=
 =?us-ascii?Q?qbCY2vAgexBKeOMKtT0Olz+BJndb69S1OKzRYwRDX2rnCJlDTumAD1gjL5Ek?=
 =?us-ascii?Q?emw9t6T0gusmMSdyqslEa06pYXFiE9ah6HlQ4NNbuEOCxuD6PSbAus7jm1Wi?=
 =?us-ascii?Q?6FgCwKz9ucRvtbf5VqZG+wDMyC9pw3jelVehMqhF5E2UQcoPTCWMzN0bZpkD?=
 =?us-ascii?Q?hnD8aitu/bUbM+hFhbLrueBCmePClE7wkPY7pZ0y8QnW/IvKvNt76KebH3hX?=
 =?us-ascii?Q?eoYw5oCjasmVPT3Hi26K6FuGvwmQ2T5M6DHSVAEe90JNB7Scjsk32dWhZFiB?=
 =?us-ascii?Q?OvJRjY965rKXAlqS48xWDwioYt3fSrfj5aXQqtc4coOvyVftPwOH03LKKRQ7?=
 =?us-ascii?Q?35rgymGVpvJU6C2/PMzUZ5FSp9ru46lSaRf33ZyXt/u8j9C6qlSCYzyYcdcR?=
 =?us-ascii?Q?0qte6GD6tV2vbePVvWMqZjRqE5qAdYURD1L57wzk/bJCUDzX4rwu5Pzmmdnl?=
 =?us-ascii?Q?taOViKAgeQfIwGplgIOpCFSpl5NRZNCQ7vATb53QA49RmPWYSYG8V9Yodmz+?=
 =?us-ascii?Q?t5FI7wy38USxgE7bZqRIYf5Y/jfSun8m5+RWSjqAivyu1TCPzXnsdRkDfLEa?=
 =?us-ascii?Q?7N70wFkZy1ndy8RdhRuLh6+8sZSRF0MKaZnSO+LCCa6ibFlRNqATOfudbKLc?=
 =?us-ascii?Q?zzqtFphAaHe7mQNeTipjrAuRV5T9iUVEHWnMzpzr7f5B/R2B/zAkX4t4DzaM?=
 =?us-ascii?Q?WhOqoZ0d3bGmEoH/1Uo=3D?=
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-OriginatorOrg: asem.it
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-AuthSource: DU2PR01MB8034.eurprd01.prod.exchangelabs.com
X-MS-Exchange-CrossTenant-Network-Message-Id: bd36f944-de3d-405f-a678-08dbc429df4e
X-MS-Exchange-CrossTenant-originalarrivaltime: 03 Oct 2023 16:00:32.1839
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: d0a766c6-7992-4344-a4a2-a467a7bb1ed2
X-MS-Exchange-CrossTenant-mailboxtype: HOSTED
X-MS-Exchange-CrossTenant-userprincipalname: LPxyVnC2mSC7UtP3T5UsTN22axMyizDcqkJsSZNAtrTwbvlWdCFwkFJfIwvZndAz9bmUiZ9myCBZDIjw9mVlfw==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: DB9PR01MB9246
X-Spam-Status: No, score=-2.7 required=5.0 tests=BAYES_00,DKIM_SIGNED,
        DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_BLOCKED,
        RCVD_IN_MSPIKE_H2,SPF_HELO_PASS,SPF_PASS autolearn=ham
        autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
        lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.6.4 (howler.vger.email [0.0.0.0]); Tue, 03 Oct 2023 09:00:52 -0700 (PDT)

Hi Daniel,

...
> > > > +required:
> > > > +  - compatible
> > > > +  - reg
> > > > +  - max-brightness
> > >
> > > Why is this mandatory?
> > >
> > > There's no point in setting max-brightness when running in I2C mode
> > > (max- brightness should default to 31 in that case).
> > >
> > >
> > > > +  - default-brightness
> > >
> > > Again. I'm not clear why this needs to be mandatory.
> > >
> > >
> >
> > Ok, you are right, I'll remove max-brightness and default-brightness
> > from required properties list. I think to change these properties, for
> > the pwm dimming, into a clearer:
> >
> > - brightness-levels (uint32)
> > - default-brightness-levels (uint32).
> >
> > For example:
> >
> >   brightness-levels:
> >     description:
> >       Number of brightness levels. The actual brightness
> >       level (PWM duty cycle) will be interpolated from 0 to this value.
> >       0 means a  0% duty cycle (darkest/off), while the brightness-leve=
ls
> represents
> >       a 100% duty cycle (brightest).
> >     $ref: /schemas/types.yaml#/definitions/uint32
> >
> >   default-brightness-level:
> >     description:
> >       The default brightness level (from 0 to brightness-levels)
> >     $ref: /schemas/types.yaml#/definitions/uint32
> >
> > Example:
> > brightness-levels =3D <10>;
> > default-brightness-level =3D <6>;
> >
> > What do you think about this solution?
>=20
> If you want to introduce a brightness-levels property then I would expect=
 it to
> be defined with the same meaning as pwm-backlight (it's not relevant to t=
he
> bindings but ideally it would be implemented by refactoring and reusing t=
he
> code from pwm_bl.c).

ok, I'll use the brightness-levels property as used in pwm-backlight

>=20
> Same with default-brightness-level although I'm not sure why one wouldn't
> just use default-brightness for new bindings (doesn't default-brightness-=
level
> simply do exactly the same thing as default-brightness).

ok for default-brightness instead of default-brightness-level

>=20
>=20
> Daniel.

Thanks an best regards,
Flavio