From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Fri, 18 Sep 2015 15:55:38 +0200 From: Maxime Ripard To: Arnd Bergmann Cc: linux-arm-kernel@lists.infradead.org, ulf.hansson@linaro.org, Mike Turquette , Stephen Boyd , linux-kernel@vger.kernel.org, Hans de Goede , linux-sunxi@googlegroups.com, Chen-Yu Tsai , linux-clk@vger.kernel.org Subject: Re: [PATCH 0/5] ARM: sunxi: Introduce CHIP support Message-ID: <20150918135538.GS4684@lukather> References: <1442566130-3497-1-git-send-email-maxime.ripard@free-electrons.com> <2353279.QTDzFUHVnF@wuerfel> <20150918121905.GO4684@lukather> <13485899.XsimukeSAF@wuerfel> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="Fh5LqGQwq8YwuKb/" In-Reply-To: <13485899.XsimukeSAF@wuerfel> Sender: linux-kernel-owner@vger.kernel.org List-ID: --Fh5LqGQwq8YwuKb/ Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Sep 18, 2015 at 03:18:57PM +0200, Arnd Bergmann wrote: > On Friday 18 September 2015 14:19:05 Maxime Ripard wrote: > >=20 > > There's actually two issues that are pretty orthogonal: > >=20 > > * the fact that the regulator to power the wifi chip needs to be > > enabled before it enumerates and the driver is probed. The MMC > > pwrseq stuff seems to fix that, even if it doesn't really fit in > > the usual DT model. >=20 > Ok. If there is anything missing in the pwrseq implementation or > binding at the moment, you'll have to work with Ulf to get it to > drive your hardware then. Yep. > > * The fact that that regulator on this board is actually two > > regulators in parallel that needs to be controlled in parallel > > too. Here, it will probably require a new regulator driver to > > combine two regulators into one. >=20 > I don't yet understand what it means to control them in parallel. > Do you mean the hardware uses two outputs to support a higher > current than you could do with one? Yes. > How critical is the timing? Would it be enough if the mmc > code knew how to set more than one regulator and do them > one at a time? I don't think it's critical as in both should happen exactly at the same time (but I've not really tried it either, so I'm not 100% sure). And I don't think it's something the MMC core should deal with. The device itself has a single pin to provide its power, it's the board that is wired that way. The way I was seeing it was more that I needed to create a regulator driver that would take two inputs, that the mmc core would use. Last time I discussed it with Mark (Brown), it semes like he was open to the idea, so I just need to find some time to do just that. Maxime --=20 Maxime Ripard, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com --Fh5LqGQwq8YwuKb/ Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJV/BfaAAoJEBx+YmzsjxAgwRUQAJGxrKNog0nAFfKQvn95TY25 MJ0EjVyXwfhwOvzhCoi2oifC3u9iZiWug9gcp8LZlzz68twtKm0tSi4/Cfmc1AUm uHquFzKkp4awBXkARbmFr289TUZ3WYns0GzIQofeuVAM3i3t9XAN/W2v2aAN6le7 pYfpTFLVfsJdzzQnFjzkK/VelnK5cPOOT1HHsDxdMn5qe+PfE4U2RG0bL4GJ89MY 02l4DrqeJpAqOT9EzuobPK0XRUmIQdhE4ddQpZbfs8eb8ZcriJ4zxyo4De8Slo+Q 5aQp6HvhHh+k7OcWlwHu4eF5hF8cCCQmuE5vZlt4TQMUyo9YpfkHxZN4tdwiC7Gj L8/CVPDZ6DTt1Cl5hy+deyBylo2/nPIXGn+pyuIn8fMDWOvxjrKhVR7NiACCoG23 /YEfdPmKnyBNjzoMyIE3EAYJLdbP6+Cc0SdbRDpZZGPVFKNdWWS+8q8KgECtEqdv yS8OjiuEsW3/Yi32zzi05rGf22wLd0yern8K11Y6VO0zYANZRy5DMhLNQNaNKG46 9ruTQdLip0nIyjX+iWy1CJbDRwv/lWDgDGxP98XmcFm+Xjxou2Q8gqjtPndy+GcU ZZCCzsnAj+O9It5/WGFuZQuYHz4BDYt31gmJmFJ568Z78APJ1BWot1ilKeUP8kE1 Fp4yzMTrwJ8F3SmbP4rE =Rb3T -----END PGP SIGNATURE----- --Fh5LqGQwq8YwuKb/--