From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfram Sang Subject: Re: [PATCH v4 2/3] mmc: sh_mobile_sdhi: explain clock bindings Date: Fri, 20 Jan 2017 23:41:39 +0100 Message-ID: <20170120224137.GD1438@katana> References: <20170120194332.1683-1-chris.brandt@renesas.com> <20170120194332.1683-3-chris.brandt@renesas.com> <20170120213901.GC1438@katana> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="LKTjZJSUETSlgu2t" Return-path: Received: from www.zeus03.de ([194.117.254.33]:60418 "EHLO mail.zeus03.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752058AbdATWlm (ORCPT ); Fri, 20 Jan 2017 17:41:42 -0500 Content-Disposition: inline In-Reply-To: Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Chris Brandt Cc: Ulf Hansson , Rob Herring , Mark Rutland , Simon Horman , Wolfram Sang , Geert Uytterhoeven , "devicetree@vger.kernel.org" , "linux-mmc@vger.kernel.org" , "linux-renesas-soc@vger.kernel.org" --LKTjZJSUETSlgu2t Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable > It sounds like your suggestion is to just put the HW description in > the DT bindings, but move the dirty details into the driver. >=20 > Keep in DT: >=20 > +- clocks: Most controllers only have 1 clock source per channel. However= , on > + some variations of this controller, the internal card detection > + logic that exists in this controller is sectioned off to be run by a > + separate second clock source to allow the main core clock to be turned > + off to save power. > + If 2 clocks are specified by the hardware, you must name them as > + "core" and "cd". > + If the controller only has 1 clock, naming is not required. >=20 >=20 >=20 > Move somewhere in the driver (maybe where the 2nd clock is detected): >=20 > + Unfortunately, the existing driver architecture > + does not support such a separation of clocks. "such" is not explained. Maybe "does not support a seperation of clocks. It doesn't work with Runtime PM because ..."? > + Additionally, it is prohibited to supply a clock to the core but not > + to the card detect circuit. That leaves you with if separate clocks > + are presented, you must treat them both as 1. >=20 >=20 > Is this what you were thinking? Exactly. --LKTjZJSUETSlgu2t Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIbBAEBAgAGBQJYgpIhAAoJEBQN5MwUoCm21iEP9ivLnVX3LgSHxtqx8UYvJpKJ 3Q+v2sD61HZUcVzzoXCDr9sUCEVFq1juoor1TaNgzLWGx31cgCD0pFl+MEZ2S9A+ +rJz6xsYPOC/IITYAJvmC/8+GdK7pxkc+KWMFvlcBR/OAcZpzWHziMnkpQKKoW7o kR+B411kA/8kwoQpta5U+hL8Jk4Z/aQXOfiTyEDVDeZjHDUGm3+EAcSXLH2SGLd0 EcZ5vyDbdQwAhljGtazfpnShkDM9Z4c0Jiuz+V2D9/lBYPWQBuiJmlJBf3SHKH2v rfd4ZVPKM1in8vGqDTNpUcON9koTIa3E/rXeWddxlCXGPiprwmuLsgyTjIZcVBl7 EXqlvA2DQoqddXs6kulq/WAy4IeSDv8ePxe2h2R5z2opGiUXApXqm0vt7te0ert7 tsJ6VphnJ1kpZIv4SQCa05HNhiKscBV8c4Al5MmyMbz6bpn2YJQ31pH+MXMqTN7G +OIZIQJ6ddz5L5XzEtMapXdjfGYUGw5zguQHNUjLywg8YYTTbYPsaHQFODT/CJ6I P2uoqBhUIclhdStOFgWLsZZZr/vL9Mr40r2H7BfrSRB9Fg8gDVRSgtmW96/EUwv5 +/4NvjCqY06SSCbEIm89ccUhZ9Q3UEugUGPhjPTxN8wjfnHvzJKSTWKPlIfeE3y+ ItQGojn/LZaSPo2cXpU= =HVRM -----END PGP SIGNATURE----- --LKTjZJSUETSlgu2t--