lkml.org 
[lkml]   [2021]   [Dec]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH] mmc: meson: initial ocr available by default value
On Mon, Dec 13, 2021 at 2:25 PM Jerome Brunet <jbrunet@baylibre.com> wrote:
>
>
> On Mon 13 Dec 2021 at 19:50, "rong.chen@amlogic.com" <rong.chen@amlogic.com> wrote:
>
> > Hello,
> > If 3.3V always-on power source for vmmc is supplied by hardware boards fixed, don't need regulator in software, so .dts unnecessary the link between regulator
> > and MMC controller vmmc/vqmmc.
>
> Controllable or not, your vmmc/vqmmc regulators should be described in
> DT.
I agree with Jerome. Here are the two reasons why I think that it's
best to describe these regulators in device-tree:
- device-tree is there to describe the hardware. It's especially
useful for non-discoverable information (USB and PCI IDs are
discoverable examples), for example: voltage supply of an MMC
controller, UART IRQ line, ...
- reviewing board.dts would be a lot harder if we rely on defaults
(defaults which cannot be described in a device-tree schema). For
meson-g12a-radxa-zero.dts this means we could omit the vmmc/vqmmc
regulators for the SD card slot but we need them for the eMMC (because
vqmmc is fixed at 1.8V).


Best regards,
Martin

\
 
 \ /
  Last update: 2021-12-13 20:03    [W:0.088 / U:1.004 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site