Re: [PATCH 12/12] extcon: axp288: Set USB role where necessary

[Hans de Goede]

Hi,

On 16-02-18 14:19, Andy Shevchenko wrote:
> On Fri, Feb 16, 2018 at 12:47 PM, Hans de Goede <hdegoede@xxxxxxxxxx> wrote:
> > The AXP288 BC1.2 charger detection / extcon code may seem like a strange
> > place to add code to control the USB role-switch on devices with an AXP288,
> > but there are 2 reasons to do this inside the axp288 extcon code:
> >
> > 1) On many devices the USB role is controlled by ACPI AML code, but the AML
> >     code only switches between the host and none roles, because of Windows
> >     not really using device mode. To make device mode work we need to toggle
> >     between the none/device roles based on VBus presence, and the axp288
> >     extcon gets interrupts on VBus insertion / removal.
> >
> > 2) In order for our BC1.2 charger detection to work properly the role
> >     mux must be properly set to device mode before we do the detection.
> >
> > Also note the Kconfig help-text / obsolete depends on USB_PHY which are
> > remnants from older never upstreamed code also controlling the mux from
> > the axp288 extcon code.
> >
> > This commit also adds code to get notifications from the INT3496 extcon
> > device, which is used on some devices to notify the kernel about id-pin
> > changes instead of them being handled through AML code.
> >
> > This fixes:
> > -Device mode not working on most CHT devices with an AXP288
> > -Host mode not working on devices with an INT3496 ACPI device
> > -Charger-type misdetection (always SDP) on devices with an INT3496 when the
> >   USB role (always) gets initialized as host
> >
> > Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
>
> >   config EXTCON_AXP288
> >          tristate "X-Power AXP288 EXTCON support"
> > -       depends on MFD_AXP20X && USB_PHY
> > +       depends on MFD_AXP20X && USB_SUPPORT
> > +       select USB_ROLE_SWITCH
>
> Is it supposed to work outside of x86 world?..

No.

> > +#include <asm/cpu_device_id.h>
> > +#include <asm/intel-family.h>
>
> ...if yes, this should go under CONFIG_X86 along with accompanying parts.
>
> ...if no, put corresponding dependency to Kconfig.

Ack, added the dependency for v2 of the patch-set.

> > +       if (info->role_sw) {
> > +               ret = devm_add_action_or_reset(dev, axp288_put_role_sw, info);
> > +               if (ret)
> > +                       return ret;
> > +
> > +               if (acpi_dev_present("INT3496", NULL, -1)) {
> > +                       info->id_extcon = extcon_get_extcon_dev("INT3496:00");
>
> Please use instance found by acpi_dev_present(). Okay, actually new
> helper is here:
> acpi_dev_get_first_match_name().

Good call, I've switched to acpi_dev_get_first_match_name() for v2.


> > +                       if (!info->id_extcon)
> > +                               return -EPROBE_DEFER;
> > +
> > +                       dev_info(dev, "controlling USB role\n");
> > +               } else {
> > +                       dev_info(dev, "controlling USB role based on vbus presence\n");
> > +               }
> > +       }
> > +

Andy, Thank you for all the reviews!

Regards,

Hans