From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jaehoon Chung Subject: Re: [linux-sunxi] [PATCH v2 1/4] dt: bindings: mmc: Document the practice of using subnodes for slots Date: Mon, 02 Jun 2014 17:46:02 +0900 Message-ID: <538C39CA.4020301@samsung.com> References: <1401563014-13856-1-git-send-email-hdegoede@redhat.com> <1401563014-13856-2-git-send-email-hdegoede@redhat.com> <538AF124.9040106@redhat.com> <538C3812.9060705@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from mailout1.samsung.com ([203.254.224.24]:47727 "EHLO mailout1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752383AbaFBIqJ (ORCPT ); Mon, 2 Jun 2014 04:46:09 -0400 In-reply-to: <538C3812.9060705@samsung.com> Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Ulf Hansson , Hans de Goede Cc: Olof Johansson , linux-sunxi@googlegroups.com, Chris Ball , Sascha Hauer , Maxime Ripard , Arend van Spriel , Chen-Yu Tsai , "linux-arm-kernel@lists.infradead.org" , "linux-mmc@vger.kernel.org" , devicetree On 06/02/2014 05:38 PM, Jaehoon Chung wrote: > On 06/02/2014 05:29 PM, Ulf Hansson wrote: >> On 1 June 2014 11:23, Hans de Goede wrote: >>> Hi, >>> >>> >>> On 05/31/2014 10:13 PM, Olof Johansson wrote: >>>> >>>> On Sat, May 31, 2014 at 12:03 PM, Hans de Goede >>>> wrote: >>>>> >>>>> The following existing MMC host controller bindings use slot subnodes: >>>>> >>>>> Documentation/devicetree/bindings/mmc/synopsys-dw-mshc.txt >>>>> Documentation/devicetree/bindings/mmc/k3-dw-mshc.txt >>>>> Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt >>>>> Documentation/devicetree/bindings/mmc/socfpga-dw-mshc.txt >>>>> Documentation/devicetree/bindings/mmc/atmel-hsmci.txt >>>>> Documentation/devicetree/bindings/mmc/rockchip-dw-mshc.txt >>>>> >>>>> This commit documents this practice in the standard mmc bindings >>>>> documentation. >>>>> >>>>> Signed-off-by: Hans de Goede >>>> >>>> >>>> There are today only two drivers that use this kind of binding, dw_mmc >>>> and the at91 one. >>> >>> >>> Correct. >>> >>> >>>> Neither seems to actually ever have been used with >>>> more than one slot. I doubt anyone building an exynos-based system >>>> will ever do a multi-slot solution, and it seems that the at91 driver >>>> doesn't actually handle more than one slot. >>>> >>>> I'm personally not that excited about complicating the bindings by >>>> opening up for this -- I would rather work towards removing the >>>> concept of slots if it's one of those things that are going to remain >>>> unused. We have actually been talking about reworking the dw_mmc >>>> binding to remove the slot concept (and simplify the driver by doing >>>> so). >>> >>> >>> I'm fine with removing the slot subnode, I added it because of it being >>> brought up in the powerup sequence discussion. I explicitly asked there >>> if adding such a subnode level was seen as desirable but nobody >>> answered :| >>> >>> Anyways, either way works for me. I can do a v3 dropping the slot subnode >>> level again. I would really like to move forward with a decision on how-to >>> represent non probable info for sdio devices in device nodes. So do you >>> have any other remarks other then that the slot subnode should be dropped ? >>> And if not can you please review and ack (*) v3 of this patch-set once >>> I've send it? >>> >>> Chris Ball and Ulf Hansson, what is your take on this, are you willing to >>> take this patch set? And do you want it with or without the slot subnodes ? >> >> I certainly appreciate you working actively on this Hans, I will look >> into the patchset as soon as I can. >> >> I share Olof's view about the slot nodes, we must not add DT bindings >> that isn't really needed. >> >> Regarding the slot subnodes; Jaehoon Chung recently posted a patchset >> for adding the parsing of it, intended for dwmmc. I withdraw my ack >> for it, and let's try to go in the other direction instead. >> >> [PATCHv3 0/4] mmc: fixed the mmc_of_parse for dwmmc. >> >> Thus I suggest we should clean-up host drivers to support only one >> card per host, and entirely skip the slot concept. > > Well, almost platform is used the only one card per host, although some controller is supported the slot concept. > But we don't know that controller should be used the multi slot per host, in future. > So I think we can't skip the slot concept. If we need to change the dw-mmc controller, let me know, plz. I want to fix this problem before release the 3.16. Actually, i think it can remove the subnode, if ensure not to use multi-slot at dwmmc. Anyway, I will also consider to get more better solution. Thanks for pointing out. Best Regards, Jaehoon Chung > > Best Regards, > Jaehoon Chung > >> >> Kind regards >> Uffe >> >>> >>> Thanks & Regards, >>> >>> Hans >>> >>> >>> *) Assuming you don't find any issues >> > From mboxrd@z Thu Jan 1 00:00:00 1970 From: jh80.chung@samsung.com (Jaehoon Chung) Date: Mon, 02 Jun 2014 17:46:02 +0900 Subject: [linux-sunxi] [PATCH v2 1/4] dt: bindings: mmc: Document the practice of using subnodes for slots In-Reply-To: <538C3812.9060705@samsung.com> References: <1401563014-13856-1-git-send-email-hdegoede@redhat.com> <1401563014-13856-2-git-send-email-hdegoede@redhat.com> <538AF124.9040106@redhat.com> <538C3812.9060705@samsung.com> Message-ID: <538C39CA.4020301@samsung.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 06/02/2014 05:38 PM, Jaehoon Chung wrote: > On 06/02/2014 05:29 PM, Ulf Hansson wrote: >> On 1 June 2014 11:23, Hans de Goede wrote: >>> Hi, >>> >>> >>> On 05/31/2014 10:13 PM, Olof Johansson wrote: >>>> >>>> On Sat, May 31, 2014 at 12:03 PM, Hans de Goede >>>> wrote: >>>>> >>>>> The following existing MMC host controller bindings use slot subnodes: >>>>> >>>>> Documentation/devicetree/bindings/mmc/synopsys-dw-mshc.txt >>>>> Documentation/devicetree/bindings/mmc/k3-dw-mshc.txt >>>>> Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt >>>>> Documentation/devicetree/bindings/mmc/socfpga-dw-mshc.txt >>>>> Documentation/devicetree/bindings/mmc/atmel-hsmci.txt >>>>> Documentation/devicetree/bindings/mmc/rockchip-dw-mshc.txt >>>>> >>>>> This commit documents this practice in the standard mmc bindings >>>>> documentation. >>>>> >>>>> Signed-off-by: Hans de Goede >>>> >>>> >>>> There are today only two drivers that use this kind of binding, dw_mmc >>>> and the at91 one. >>> >>> >>> Correct. >>> >>> >>>> Neither seems to actually ever have been used with >>>> more than one slot. I doubt anyone building an exynos-based system >>>> will ever do a multi-slot solution, and it seems that the at91 driver >>>> doesn't actually handle more than one slot. >>>> >>>> I'm personally not that excited about complicating the bindings by >>>> opening up for this -- I would rather work towards removing the >>>> concept of slots if it's one of those things that are going to remain >>>> unused. We have actually been talking about reworking the dw_mmc >>>> binding to remove the slot concept (and simplify the driver by doing >>>> so). >>> >>> >>> I'm fine with removing the slot subnode, I added it because of it being >>> brought up in the powerup sequence discussion. I explicitly asked there >>> if adding such a subnode level was seen as desirable but nobody >>> answered :| >>> >>> Anyways, either way works for me. I can do a v3 dropping the slot subnode >>> level again. I would really like to move forward with a decision on how-to >>> represent non probable info for sdio devices in device nodes. So do you >>> have any other remarks other then that the slot subnode should be dropped ? >>> And if not can you please review and ack (*) v3 of this patch-set once >>> I've send it? >>> >>> Chris Ball and Ulf Hansson, what is your take on this, are you willing to >>> take this patch set? And do you want it with or without the slot subnodes ? >> >> I certainly appreciate you working actively on this Hans, I will look >> into the patchset as soon as I can. >> >> I share Olof's view about the slot nodes, we must not add DT bindings >> that isn't really needed. >> >> Regarding the slot subnodes; Jaehoon Chung recently posted a patchset >> for adding the parsing of it, intended for dwmmc. I withdraw my ack >> for it, and let's try to go in the other direction instead. >> >> [PATCHv3 0/4] mmc: fixed the mmc_of_parse for dwmmc. >> >> Thus I suggest we should clean-up host drivers to support only one >> card per host, and entirely skip the slot concept. > > Well, almost platform is used the only one card per host, although some controller is supported the slot concept. > But we don't know that controller should be used the multi slot per host, in future. > So I think we can't skip the slot concept. If we need to change the dw-mmc controller, let me know, plz. I want to fix this problem before release the 3.16. Actually, i think it can remove the subnode, if ensure not to use multi-slot at dwmmc. Anyway, I will also consider to get more better solution. Thanks for pointing out. Best Regards, Jaehoon Chung > > Best Regards, > Jaehoon Chung > >> >> Kind regards >> Uffe >> >>> >>> Thanks & Regards, >>> >>> Hans >>> >>> >>> *) Assuming you don't find any issues >> >