From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lee Jones Subject: Re: [PATCH v2 06/10] mmc: omap_hsmmc: add support for pbias configuration in dt Date: Thu, 13 Jun 2013 11:47:15 +0100 Message-ID: <20130613104715.GC16677@laptop> References: <20130523184045.GD13507@atomide.com> <1370546059-24181-1-git-send-email-balajitk@ti.com> <1370546059-24181-7-git-send-email-balajitk@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-omap-owner@vger.kernel.org To: Linus Walleij Cc: Balaji T K , Laurent Pinchart , Linux-OMAP , "linux-mmc@vger.kernel.org" , Chris Ball , ext Tony Lindgren , "Cousson, Benoit" , "devicetree-discuss@lists.ozlabs.org" , Mark Brown , Ulf Hansson List-Id: devicetree@vger.kernel.org On Thu, 13 Jun 2013, Linus Walleij wrote: > On Thu, Jun 6, 2013 at 9:14 PM, Balaji T K wrote: >=20 > > PBIAS register configuration is based on the regulator voltage > > which supplies these pbias cells, sd i/o pads. > > With PBIAS register address and bit definitions different across > > omap[3,4,5], Simplify PBIAS configuration under three different > > regulator voltage levels - O V, 1.8 V, 3 V. Corresponding pinctrl s= tates > > are defined as pbias_off, pbias_1v8, pbias_3v. > > > > pinctrl state mmc_init is used for configuring speed mode, loopback= clock > > (in devconf0/devconf1/prog_io1 register for omap3) and pull strengt= h > > configuration (in control_mmc1 for omap4) > > > > Signed-off-by: Balaji T K >=20 > You *need* Lee Jones and Mark Brown to review this. > Maybe Laurent has something to add too. >=20 > Ux500 had the very same thing, and there this was solved using > a GPIO regulator for "vqmmc" a level-shifter. I vaguely remember > Laurent doing something similar with the SH stuff. I haven't seem much of this patch-set, but this certainly looks like it should be handled by a GPIO regulator instead of pinctrl. States are easily declared in a 'struct gpio_regulator_state', which the framework then uses to set the correct pins for the required voltage. And yes, 'vqmmc' is a good place to store the this regulator. --=20 Lee Jones Linaro ST-Ericsson Landing Team Lead Linaro.org =E2=94=82 Open source software for ARM SoCs =46ollow Linaro: Facebook | Twitter | Blog -- To unsubscribe from this list: send the line "unsubscribe linux-omap" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html