lkml.org 
[lkml]   [2017]   [Jun]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH v4 1/3] pinctrl: Add sleep related configuration
    On 一,  6月 26, 2017 at 11:13:48上午 -0500, Rob Herring wrote:
    > On Wed, Jun 21, 2017 at 07:55:37PM +0800, Baolin Wang wrote:
    > > In some scenarios, we should set some pins as input/output/pullup/pulldown
    > > when the specified system goes into deep sleep mode, then when the system
    > > goes into deep sleep mode, these pins will be set automatically by hardware.
    > >
    > > Usually we can set the "sleep" state to set sleep related config, but one SoC
    > > usually has not only one system (especially for mobile SoC), some systems on
    > > the SoC which did not run linux kernel, they can not select the "sleep" state
    > > when they go into deep sleep mode.
    >
    > The wording here is not very clear. I think what you mean is some pins
    > are not controlled by any specific driver in the OS, but need to be
    > controlled when entering sleep mode.

    Yes, that is what I meaning, sorry for confusing.

    >
    > > Thus we introduce some sleep related config into pinconf-generic for users to
    > > configure.
    > >
    > > Signed-off-by: Baolin Wang <baolin.wang@spreadtrum.com>
    > > ---
    > > - Add this patch since v4.
    > > ---
    > > .../bindings/pinctrl/pinctrl-bindings.txt | 12 ++++++++++++
    > > drivers/pinctrl/pinconf-generic.c | 10 ++++++++++
    > > include/linux/pinctrl/pinconf-generic.h | 14 ++++++++++++++
    > > 3 files changed, 36 insertions(+)
    > >
    > > diff --git a/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt b/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
    > > index bf3f7b0..e098059 100644
    > > --- a/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
    > > +++ b/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
    > > @@ -236,6 +236,18 @@ low-power-enable - enable low power mode
    > > low-power-disable - disable low power mode
    > > output-low - set the pin to output mode with low level
    > > output-high - set the pin to output mode with high level
    > > +sleep-bias-pull-up - pull up the pin when the specified system goes into
    > > + deep sleep mode
    > > +sleep-bias-pull-down - pull down the pin when the specified system goes into
    > > + deep sleep mode
    > > +sleep-input-enable - enable input on pin when the specified system goes
    > > + into deep sleep mode (no effect on output)
    > > +sleep-intput-disable - disable input on pin when the specified system goes
    > > + into deep sleep mode (no effect on output)
    > > +sleep-output-low - set the pin to output mode with low level when the
    > > + specified system goes into deep sleep mode
    > > +sleep-output-high - set the pin to output mode with high level when the
    > > + specified system goes into deep sleep mode
    > > slew-rate - set the slew rate
    >
    > I don't really like having 2 ways to define pin setup and this doesn't
    > scale if I need to define 3 states. Couldn't we create pin state
    > definitions and have a pinctrl-n property within the pin controller
    > node to handle all the unhandled pins?

    As LinusW also suggest we can create one "sleep" state and program them
    into registers at early point (like: after probing pinctrl driver). So I
    think I can introduce one called "early-sleep" state which need select it
    after initializing pinctrl driver.

    >
    > Rob

    \
     
     \ /
      Last update: 2017-06-27 10:27    [W:4.257 / U:0.032 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site