Messages in this thread | | | From | Andrey Zhizhikin <> | Date | Mon, 28 Oct 2019 15:40:19 +0100 | Subject | Re: [PATCH 0/2] add regulator driver and mfd cell for Intel Cherry Trail Whiskey Cove PMIC |
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On Mon, Oct 28, 2019 at 1:42 PM Adrian Hunter <adrian.hunter@intel.com> wrote: > > On 25/10/19 10:55 AM, Andy Shevchenko wrote: > > On Fri, Oct 25, 2019 at 10:53:35AM +0300, Andy Shevchenko wrote: > >> On Thu, Oct 24, 2019 at 02:29:37PM +0000, Andrey Zhizhikin wrote: > >>> This patchset introduces additional regulator driver for Intel Cherry > >>> Trail Whiskey Cove PMIC. It also adds a cell in mfd driver for this > >>> PMIC, which is used to instantiate this regulator. > >>> > >>> Regulator support for this PMIC was present in kernel release from Intel > >>> targeted Aero platform, but was not entirely ported upstream and has > >>> been omitted in mainline kernel releases. Consecutively, absence of > >>> regulator caused the SD Card interface not to be provided with Vqcc > >>> voltage source needed to operate with UHS-I cards. > >>> > >>> Following patches are addessing this issue and making sd card interface > >>> to be fully operable with UHS-I cards. Regulator driver lists an ACPI id > >>> of the SD Card interface in consumers and exposes optional "vqmmc" > >>> voltage source, which mmc driver uses to switch signalling voltages > >>> between 1.8V and 3.3V. > >>> > >>> This set contains of 2 patches: one is implementing the regulator driver > >>> (based on a non upstreamed version from Intel Aero), and another patch > >>> registers this driver as mfd cell in exising Whiskey Cove PMIC driver. > >> > >> Thank you. > >> Hans, Cc'ed, has quite interested in these kind of patches. > >> Am I right, Hans? > > > > Since it's about UHS/SD, Cc to Adrian as well. > > > > My only concern is that the driver might conflict with ACPI methods trying > to do the same thing, e.g. there is one ACPI SDHC instance from GPDWin DSDT > with code like this: > [... cut ...]
That's a good point, and this is what I tried at first when I started to work on this problem. In my case INTEL_DSM_V18_SWITCH (fn=0x3) got executed in the mmc sub-system, but without the regulator or DSDT support the card did not get the proper voltage.
The DSDT on Intel Aero reference platform looks different here. Currently I don't have it on hands, but would be able to look it up next week.
-- Regards, Andrey.
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