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Groups > linux.kernel > #1224014
| From | Ulf Hansson <ulf.hansson@linaro.org> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [RFC 2/3] mmc: sdhci: add host_ops->voltage_switch callback for all other voltages |
| Date | 2015-09-14 12:40 +0200 |
| Message-ID | <q8zl0-3Cs-13@gated-at.bofh.it> (permalink) |
| References | (3 earlier) <q4bAD-82i-17@gated-at.bofh.it> <q4bKi-8dy-11@gated-at.bofh.it> <q4eI9-3YQ-1@gated-at.bofh.it> <q8yoX-2gE-33@gated-at.bofh.it> <q8yyB-2rV-5@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On 14 September 2015 at 11:42, Vaibhav Hiremath <vaibhav.hiremath@linaro.org> wrote: > > > On Monday 14 September 2015 03:00 PM, Ulf Hansson wrote: >> >> [...] >> >>>>>> >>>>>> Could this be implemented by regulator API? From patch set 3/3, the >>>>>> pxa1928 >>>>>> voltage_switch hook is to operate the IO pad registers, this seems not >>>>>> belong >>>>>> to the SDHC IP core. >>>>>> >>>>> >>>>> Not quite sure whether regulator would be right fit for this. >>>> >>>> >>>> >>>> From the patche[3/3], this can be achieved by abstracting the IO PAD >>>> as >>>> regulators >>>> then, we may not need to touch the core sdhci.c. But I'm not sure >>>> whether >>>> this >>>> is the good solution or not. >>> >>> >>> >>> Exactly... >>> >>>> sdhci Maintainers and experts may have better >>>> suggestions. >>>> >>> >>> Thats is the reason I stamped it as a RFC :) >>> >> >> [...] >> >> From an mmc core perspective it would be preferred if you implement >> this as a regulator (vqmmc). >> >> Especially since we will soon have an API for how to set the I/O >> voltages - and the intelligence within that API is not something we >> would like to implement for each and every host driver. >> https://lkml.org/lkml/2015/8/31/367 >> > > > I would still consider this as a regulator specific and may not address > the IO configuration within the SoC which are module specific. > The API regulator_set_voltage_triplet() will not have intelligence to > differentiate whether the call is coming from MMC or somewhere else. > > Note that, the IO pad voltage configuration which I am referring to is > MMC specific and applicable only when pad is configured in MMC mode. So > technically it is not simply common pad voltage configuration. > > > And I am still not sure regulator framework would be right fit for > this. Pinctrl would have been right fit, but...since I saw f_sdh30 > driver is already doing this, which is easy fit; so adopted the same. Pinctrl would work as well, or perhaps a combination of both pinctrl and a regulator. What I don't like is the solution you have suggested in patch3. Kind regards Uffe -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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Re: [RFC 2/3] mmc: sdhci: add host_ops->voltage_switch callback for all other voltages Ulf Hansson <ulf.hansson@linaro.org> - 2015-09-14 11:40 +0200
Re: [RFC 2/3] mmc: sdhci: add host_ops->voltage_switch callback for all other voltages Vaibhav Hiremath <vaibhav.hiremath@linaro.org> - 2015-09-14 11:50 +0200
Re: [RFC 2/3] mmc: sdhci: add host_ops->voltage_switch callback for all other voltages Ulf Hansson <ulf.hansson@linaro.org> - 2015-09-14 12:40 +0200
Re: [RFC 2/3] mmc: sdhci: add host_ops->voltage_switch callback for all other voltages Vaibhav Hiremath <vaibhav.hiremath@linaro.org> - 2015-09-14 14:50 +0200
Re: [RFC 2/3] mmc: sdhci: add host_ops->voltage_switch callback for all other voltages Vaibhav Hiremath <vaibhav.hiremath@linaro.org> - 2015-09-14 14:50 +0200
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