2017-11-03 11:29 GMT+08:00 Vincent Yang <vincent.cw.yang@xxxxxxxxx>: > 2017-11-02 19:00 GMT+08:00 Ulf Hansson <ulf.hansson@xxxxxxxxxx>: >> + Vincent Yang (several emails, don't know which works) >> >> On 2 November 2017 at 11:49, Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> wrote: >>> On 2 November 2017 at 10:48, Ulf Hansson <ulf.hansson@xxxxxxxxxx> wrote: >>>> On 2 November 2017 at 01:12, Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> wrote: >>>>> On 2 November 2017 at 00:08, Rob Herring <robh@xxxxxxxxxx> 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 <ard.biesheuvel@xxxxxxxxxx> >>>>>>> --- >>>>>>> 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 >> >> Yes. >> >>> way of testing whether it still works on other SoCs that use this IP. >> >> Me neither! > > Hi all, I can not yet get contact with IP owner because it is a > holiday in Japan. > Around two years ago, F_SDH30_CMD_DAT_DELAY was a new feature of this IP. > I will update the latest information as soon as I get it. > I got a response from IP owner. He explains F_SDH30_CMD_DAT_DELAY is intended to adjust signal timing of CMD/DAT lines, and it is necessary to change its value according to SoC/board design. So he advises us to make F_SDH30_CMD_DAT_DELAY adjustable by a DT binding. Kind regards Vincent >> >> Apparently there are no DTS in the kernel git that uses the >> "fujitsu,mb86s70-sdhci-3.0". > > Around two years ago, sdhci_f_sdh30_driver was a portion for mb86s70 SoC > patch series, but finally the patch series did not fully go upstream. > > Kind regards > Vincent > >> >> I looped in Vincent Yang, let's hope he can provide us with some more >> information. >> >> Kind regards >> Uffe -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
