From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ard Biesheuvel Subject: Re: [PATCH] sdhci-fujitsu: add support for setting the CMD_DAT_DELAY attribute Date: Thu, 2 Nov 2017 10:49:42 +0000 Message-ID: References: <20171101002132.13500-1-ard.biesheuvel@linaro.org> <20171102000814.ih2ggtfpmfsx3xap@rob-hp-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Return-path: In-Reply-To: Sender: linux-mmc-owner@vger.kernel.org To: Ulf Hansson Cc: Rob Herring , Mark Rutland , Adrian Hunter , "linux-mmc@vger.kernel.org" , "devicetree@vger.kernel.org" List-Id: devicetree@vger.kernel.org On 2 November 2017 at 10:48, Ulf Hansson wrote: > On 2 November 2017 at 01:12, Ard Biesheuvel wrote: >> On 2 November 2017 at 00:08, Rob Herring wrote: >>> On Wed, Nov 01, 2017 at 12:21:32AM +0000, Ard Biesheuvel wrote: >>>> The Socionext SynQuacer SoC inherits this IP from Fujitsu, but >>>> requires the F_SDH30_CMD_DAT_DELAY bit to be set in the >>>> F_SDH30_ESD_CONTROL control register. >>>> >>>> So let's add an optional property to this device's binding, and >>>> set the attribute if it is present in the DT node. >>>> >>>> Signed-off-by: Ard Biesheuvel >>>> --- >>>> Documentation/devicetree/bindings/mmc/sdhci-fujitsu.txt | 2 ++ >>>> drivers/mmc/host/sdhci_f_sdh30.c | 18 +++++++++++++++++- >>>> 2 files changed, 19 insertions(+), 1 deletion(-) >>>> >>>> diff --git a/Documentation/devicetree/bindings/mmc/sdhci-fujitsu.txt b/Documentation/devicetree/bindings/mmc/sdhci-fujitsu.txt >>>> index de2c53cff4f1..9ad02f743ad0 100644 >>>> --- a/Documentation/devicetree/bindings/mmc/sdhci-fujitsu.txt >>>> +++ b/Documentation/devicetree/bindings/mmc/sdhci-fujitsu.txt >>>> @@ -15,6 +15,8 @@ Required properties: >>>> Optional properties: >>>> - vqmmc-supply: phandle to the regulator device tree node, mentioned >>>> as the VCCQ/VDD_IO supply in the eMMC/SD specs. >>>> +- cmd-dat-delay-select: boolean property indicating that this host requires >>>> + the CMD_DAT_DELAY control to be enabled. >>> >>> Needs a vendor prefix unless this is a standard SDHCI bit (in which >>> case it should be documented in a common spot). >>> >> >> I suspect this is a non-standard thing, so I'll add the fujitsu prefix. Ulf? > > This is specific to the Fujitsu variant. > > However, what puzzles me is why this bit is needed for the Socionext > SynQuacer SoC, but not for other SoCs that uses this IP. That seems > weird (probably wrong). > > Moreover, the F_SDH30_CMD_DAT_DELAY register define is already there, > so I would rather suspect that it's something that did got fully > implemented. In other words, I don't think you need a new DT binding, > but rather try to implement it generically for the sdhci-f_sdh30 > driver. Do you think that will work? > Do you mean set it unconditionally? That works for me, but I have no way of testing whether it still works on other SoCs that use this IP.