From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Anholt Subject: Re: [PATCH RFC 3/3] ARM64: bcm2837-rpi: Fix pwm and i2c pin control Date: Mon, 27 Feb 2017 14:36:48 -0800 Message-ID: <87a897tg5b.fsf@eliezer.anholt.net> References: <1487280047-29608-1-git-send-email-stefan.wahren@i2se.com> <1487280047-29608-4-git-send-email-stefan.wahren@i2se.com> <87r32j8ial.fsf@eliezer.anholt.net> <1798682438.259359.1488229985933@email.1und1.de> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha512; protocol="application/pgp-signature" Return-path: Received: from anholt.net ([50.246.234.109]:43362 "EHLO anholt.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751372AbdB0WjN (ORCPT ); Mon, 27 Feb 2017 17:39:13 -0500 In-Reply-To: <1798682438.259359.1488229985933@email.1und1.de> Sender: linux-i2c-owner@vger.kernel.org List-Id: linux-i2c@vger.kernel.org To: Stefan Wahren , Peter Robinson , Wolfram Sang Cc: Will Deacon , Frank Rowand , Martin Sperl , Rob Herring , linux-i2c@vger.kernel.org, Catalin Marinas , Florian Fainelli , linux-rpi-kernel@lists.infradead.org, Noralf =?utf-8?Q?Tr=C3=B8nnes?= , devicetree@vger.kernel.org --=-=-= Content-Type: text/plain Content-Transfer-Encoding: quoted-printable Stefan Wahren writes: >> Eric Anholt hat am 27. Februar 2017 um 21:56 geschrieb= en: >>=20 >>=20 >> Stefan Wahren writes: >>=20 >> > According to the firmware DT blob [1] the RPi 3 uses different >> > pins for i2c0 and pwm. >> > >> > [1] - https://github.com/raspberrypi/firmware/blob/master/extra/dt-blo= b.dts >> > >> > Fixes: 9d56c22a7861 ("ARM: bcm2835: Add devicetree for the Raspberry P= i 3.") >> > Signed-off-by: Stefan Wahren >>=20 >> Interesting. The dt-blob does, I think, basically reflect the state >> that the pins will be in when the firmware hands off to us. Note that >> the firmware also, at boot, sets ID_SDA/SCL to function 0 (i2c0), probes >> for a HAT ROM and saves it, then restores those pins to whatever mux >> they had before (presumably the dt-blob pin_config values). >>=20 >> Linux doesn't have any HAT probing code itself, so leaving pins 0/1 as >> GPIO input (most boards) or i2c0 (rev2) should be fine. I think this >> patch should effectively be a no-op, unless you've enabled the pwm node. >>=20 >> My only suggestion for change is: These pin configurations are >> board-specific, so could we just move them into the specific board >> files, instead?=20 > > Yes, that would be better. In case of pin configurations do you mean > only those affected by this patch or all pin configurations? I was just thinking about the ones you're changing in this patch. >> Basically leave bcm2835-rpi.dtsi as the "generic >> configuration of bcm283x for the rpi firmware" rather than "things >> common to bcm2835/6 with rpi firmware but not bcm2837 with rpi >> firmware". > > If this our intension, shouldn't we rename it to bcm283x-rpi.dtsi? That sounds good to me. --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCgAdFiEE/JuuFDWp9/ZkuCBXtdYpNtH8nugFAli0qgAACgkQtdYpNtH8 nuiM0w//b7PK7izl2lHMAiIfqGVOFyCJl9sSQ/G0UsxQChlpXwK/FCyuZNafks+R 7xUzuaDbnXmRbKSgwICZ2hK0whcY8wqAdwKI6PNQXIsX97CiNTC41lg8bE0Z7Klo w7nYPg/VG9enwBX/TfbO1JmbhcDcKtt5DsWfIe9/zvuj6qIxBVX2ULKsF/Fbks6r iZOS07ifPnE4WvEfF6vjgcmQ8qRd1KsuAZsoW8zS08RVsHPlCT4StrIG/1jf+ceQ GFpjFHQGUD+yt4DnCYkm6FzH7aZ+O/tt6c49TGZr3or4smJimm1KSxU6QoZy3lHr lHBNTfPHpWwpI7MHD+oFrp1+cQZbBikzcDguVA1M3sLq3kz6KjAs7pS5aG71b/ZF iU4irjAawQ1+hZy2aVETjSC03natMwBdRJn618hwUdXqM1fZDgYakTCMsw0GPtwt xX0U/4XbkOVarH0ItaB2IjmarJ5YZWhTB07Lic5YXqJtSvZiRAZXoLZ9Xu75DTld XLXYTDMmCsrmzEYAXYeZSm2WjNIeBB9D+eB8Ou4MS7+JI3P5kDyvhIpy4s+NMsUc 6uiobWoJRwx4uAuIf9irNPNoxkainTEsAuq8C6nRKVSMLgilP/R/u9nKMCgl9gWI lAoIzu/wNzWaYueWoKxVl21VJZmPOLzxWTrYX79NaVMeEe4/h4s= =LGNi -----END PGP SIGNATURE----- --=-=-=--