From mboxrd@z Thu Jan 1 00:00:00 1970 From: Viresh Kumar Subject: Re: [RFC v2 5/6] drivers: boot_constraint: Add initial DT bindings Date: Thu, 13 Jul 2017 10:39:34 +0530 Message-ID: <20170713050934.GB352@vireshk-i7> References: <0610277aef9830cff53b7b53cf41cc54886fdc7f.1499770771.git.viresh.kumar@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Chen-Yu Tsai Cc: Rob Herring , Mark Rutland , "devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Vincent Guittot , Greg Kroah-Hartman , Stephen Boyd , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Mark Brown , Rajendra Nayak , Shiraz Hashim , "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" List-Id: devicetree@vger.kernel.org On 13-07-17, 10:52, Chen-Yu Tsai wrote: > I'm afraid the regulator case still doesn't make sense. The voltage > constraints should be set within each supplies device node. This was > explained in the discussion in v1 [1]. I thought we were discussing about something I mentioned in one of my example but never to a point that the regulator problem doesn't exist at all. Perhaps I misunderstood your concerns. Anyway, lemme try once more with a better example. Regulator shared by: LCD and MMC (both can do DVFS) and the min/max constraint that can be set by the consumers of the regulator (both LCD/MMC) are: 1.5 V to 3 V. The bootloader has programmed the LCD to work at the highest pixel frequency, which needs the voltage to be in range from 2.5 - 3 V. Now MMC can get probed first and it can try to bring the voltages below 2.5 V. Though, 1.5 - 2.5 is a valid range for the LCD, but not at the current pixel frequency. Does that sound like a valid problem? -- viresh -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html