From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932650AbcFJRbD (ORCPT ); Fri, 10 Jun 2016 13:31:03 -0400 Received: from mail-oi0-f66.google.com ([209.85.218.66]:34612 "EHLO mail-oi0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750848AbcFJRa6 (ORCPT ); Fri, 10 Jun 2016 13:30:58 -0400 Date: Fri, 10 Jun 2016 12:30:56 -0500 From: Rob Herring To: Krzysztof Kozlowski Cc: Mark Brown , Ulf Hansson , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , Sebastian Reichel , Dmitry Eremin-Solenikov , David Woodhouse , Liam Girdwood , Greg Kroah-Hartman , Hans de Goede , Jean-Christophe Plagniol-Villard , Tomi Valkeinen , Heiko Stuebner , linux-mmc@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, linux-pm@vger.kernel.org, linux-usb@vger.kernel.org, linux-fbdev@vger.kernel.org, hzpeterchen@gmail.com, Bartlomiej Zolnierkiewicz Subject: Re: [RFC v4 01/14] regulator: of: Add helper for getting all supplies Message-ID: <20160610173056.GA16503@rob-hp-laptop> References: <1465465471-28740-1-git-send-email-k.kozlowski@samsung.com> <1465465471-28740-2-git-send-email-k.kozlowski@samsung.com> <20160609102925.GS7510@sirena.org.uk> <5759560A.70107@samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5759560A.70107@samsung.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 09, 2016 at 01:42:02PM +0200, Krzysztof Kozlowski wrote: > On 06/09/2016 12:29 PM, Mark Brown wrote: > > On Thu, Jun 09, 2016 at 11:44:18AM +0200, Krzysztof Kozlowski wrote: > >> Few drivers have a need of getting regulator supplies without knowing > >> their names: > >> 1. The Simple Framebuffer driver works on setup provided by bootloader > >> (outside of scope of kernel); > >> 2. Generic power sequence driver may be attached to any device node. > >> > >> Add a Device Tree helper for parsing "-supply" properties and returning > >> allocated bulk regulator consumers. > > > > I'm still very concerned that this is just an invitation to people to > > write half baked regulator consumers and half baked DTs to go along with > > it, making it a standard API that doesn't have big red flags on it that > > will flag up when "normal" drivers use it is not good. Right now this > > just looks like a standard API and people are going to just start using > > it. If we are going to do this perhaps we need a separate header or > > something to help flag this up. > > No problem, I can move it to a special header. Actually, if you dislike > this as an API, it does not have to be in header at all. I can just > duplicate the simplefb code. > > > In the case of power sequences I'd expect the sequences to perform > > operations on named supplies - the core shouldn't know what the supplies > > are but the thing specifying the sequence should. > > Hm, so maybe passing names like: > > usb3503@08 { > reset-gpios = <&gpx3 5 GPIO_ACTIVE_HIGH>; > initial-mode = <1>; > vdd-supply = <&buck8_reg>; > foo-supply = <&buck9_reg>; > > power-sequence; > power-sequence-supplies = "vdd", "foo"; This alone would be fine as it is just one property, but then what's next? power-sequence-delay, power-sequence-clocks, etc. What if you need to express ordering relationship of supplies, clocks, gpios? We end up with a scripting language in DT and we don't want to have that. Rob From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rob Herring Subject: Re: [RFC v4 01/14] regulator: of: Add helper for getting all supplies Date: Fri, 10 Jun 2016 12:30:56 -0500 Message-ID: <20160610173056.GA16503@rob-hp-laptop> References: <1465465471-28740-1-git-send-email-k.kozlowski@samsung.com> <1465465471-28740-2-git-send-email-k.kozlowski@samsung.com> <20160609102925.GS7510@sirena.org.uk> <5759560A.70107@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <5759560A.70107@samsung.com> Sender: linux-pm-owner@vger.kernel.org To: Krzysztof Kozlowski Cc: Mark Brown , Ulf Hansson , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , Sebastian Reichel , Dmitry Eremin-Solenikov , David Woodhouse , Liam Girdwood , Greg Kroah-Hartman , Hans de Goede , Jean-Christophe Plagniol-Villard , Tomi Valkeinen , Heiko Stuebner , linux-mmc@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, linux-pm@vger.kernel.org, linux-usb@vger.kernel.org, linux-fbdev@vger.kernel.org, hzpeterchen@gmail.com, Bartlomiej List-Id: devicetree@vger.kernel.org On Thu, Jun 09, 2016 at 01:42:02PM +0200, Krzysztof Kozlowski wrote: > On 06/09/2016 12:29 PM, Mark Brown wrote: > > On Thu, Jun 09, 2016 at 11:44:18AM +0200, Krzysztof Kozlowski wrote: > >> Few drivers have a need of getting regulator supplies without knowing > >> their names: > >> 1. The Simple Framebuffer driver works on setup provided by bootloader > >> (outside of scope of kernel); > >> 2. Generic power sequence driver may be attached to any device node. > >> > >> Add a Device Tree helper for parsing "-supply" properties and returning > >> allocated bulk regulator consumers. > > > > I'm still very concerned that this is just an invitation to people to > > write half baked regulator consumers and half baked DTs to go along with > > it, making it a standard API that doesn't have big red flags on it that > > will flag up when "normal" drivers use it is not good. Right now this > > just looks like a standard API and people are going to just start using > > it. If we are going to do this perhaps we need a separate header or > > something to help flag this up. > > No problem, I can move it to a special header. Actually, if you dislike > this as an API, it does not have to be in header at all. I can just > duplicate the simplefb code. > > > In the case of power sequences I'd expect the sequences to perform > > operations on named supplies - the core shouldn't know what the supplies > > are but the thing specifying the sequence should. > > Hm, so maybe passing names like: > > usb3503@08 { > reset-gpios = <&gpx3 5 GPIO_ACTIVE_HIGH>; > initial-mode = <1>; > vdd-supply = <&buck8_reg>; > foo-supply = <&buck9_reg>; > > power-sequence; > power-sequence-supplies = "vdd", "foo"; This alone would be fine as it is just one property, but then what's next? power-sequence-delay, power-sequence-clocks, etc. What if you need to express ordering relationship of supplies, clocks, gpios? We end up with a scripting language in DT and we don't want to have that. Rob From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rob Herring Date: Fri, 10 Jun 2016 17:30:56 +0000 Subject: Re: [RFC v4 01/14] regulator: of: Add helper for getting all supplies Message-Id: <20160610173056.GA16503@rob-hp-laptop> List-Id: References: <1465465471-28740-1-git-send-email-k.kozlowski@samsung.com> <1465465471-28740-2-git-send-email-k.kozlowski@samsung.com> <20160609102925.GS7510@sirena.org.uk> <5759560A.70107@samsung.com> In-Reply-To: <5759560A.70107@samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-arm-kernel@lists.infradead.org On Thu, Jun 09, 2016 at 01:42:02PM +0200, Krzysztof Kozlowski wrote: > On 06/09/2016 12:29 PM, Mark Brown wrote: > > On Thu, Jun 09, 2016 at 11:44:18AM +0200, Krzysztof Kozlowski wrote: > >> Few drivers have a need of getting regulator supplies without knowing > >> their names: > >> 1. The Simple Framebuffer driver works on setup provided by bootloader > >> (outside of scope of kernel); > >> 2. Generic power sequence driver may be attached to any device node. > >> > >> Add a Device Tree helper for parsing "-supply" properties and returning > >> allocated bulk regulator consumers. > > > > I'm still very concerned that this is just an invitation to people to > > write half baked regulator consumers and half baked DTs to go along with > > it, making it a standard API that doesn't have big red flags on it that > > will flag up when "normal" drivers use it is not good. Right now this > > just looks like a standard API and people are going to just start using > > it. If we are going to do this perhaps we need a separate header or > > something to help flag this up. > > No problem, I can move it to a special header. Actually, if you dislike > this as an API, it does not have to be in header at all. I can just > duplicate the simplefb code. > > > In the case of power sequences I'd expect the sequences to perform > > operations on named supplies - the core shouldn't know what the supplies > > are but the thing specifying the sequence should. > > Hm, so maybe passing names like: > > usb3503@08 { > reset-gpios = <&gpx3 5 GPIO_ACTIVE_HIGH>; > initial-mode = <1>; > vdd-supply = <&buck8_reg>; > foo-supply = <&buck9_reg>; > > power-sequence; > power-sequence-supplies = "vdd", "foo"; This alone would be fine as it is just one property, but then what's next? power-sequence-delay, power-sequence-clocks, etc. What if you need to express ordering relationship of supplies, clocks, gpios? We end up with a scripting language in DT and we don't want to have that. Rob From mboxrd@z Thu Jan 1 00:00:00 1970 From: robh@kernel.org (Rob Herring) Date: Fri, 10 Jun 2016 12:30:56 -0500 Subject: [RFC v4 01/14] regulator: of: Add helper for getting all supplies In-Reply-To: <5759560A.70107@samsung.com> References: <1465465471-28740-1-git-send-email-k.kozlowski@samsung.com> <1465465471-28740-2-git-send-email-k.kozlowski@samsung.com> <20160609102925.GS7510@sirena.org.uk> <5759560A.70107@samsung.com> Message-ID: <20160610173056.GA16503@rob-hp-laptop> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, Jun 09, 2016 at 01:42:02PM +0200, Krzysztof Kozlowski wrote: > On 06/09/2016 12:29 PM, Mark Brown wrote: > > On Thu, Jun 09, 2016 at 11:44:18AM +0200, Krzysztof Kozlowski wrote: > >> Few drivers have a need of getting regulator supplies without knowing > >> their names: > >> 1. The Simple Framebuffer driver works on setup provided by bootloader > >> (outside of scope of kernel); > >> 2. Generic power sequence driver may be attached to any device node. > >> > >> Add a Device Tree helper for parsing "-supply" properties and returning > >> allocated bulk regulator consumers. > > > > I'm still very concerned that this is just an invitation to people to > > write half baked regulator consumers and half baked DTs to go along with > > it, making it a standard API that doesn't have big red flags on it that > > will flag up when "normal" drivers use it is not good. Right now this > > just looks like a standard API and people are going to just start using > > it. If we are going to do this perhaps we need a separate header or > > something to help flag this up. > > No problem, I can move it to a special header. Actually, if you dislike > this as an API, it does not have to be in header at all. I can just > duplicate the simplefb code. > > > In the case of power sequences I'd expect the sequences to perform > > operations on named supplies - the core shouldn't know what the supplies > > are but the thing specifying the sequence should. > > Hm, so maybe passing names like: > > usb3503 at 08 { > reset-gpios = <&gpx3 5 GPIO_ACTIVE_HIGH>; > initial-mode = <1>; > vdd-supply = <&buck8_reg>; > foo-supply = <&buck9_reg>; > > power-sequence; > power-sequence-supplies = "vdd", "foo"; This alone would be fine as it is just one property, but then what's next? power-sequence-delay, power-sequence-clocks, etc. What if you need to express ordering relationship of supplies, clocks, gpios? We end up with a scripting language in DT and we don't want to have that. Rob