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

Andy Shevchenko
2018-02-16T13:19:53Z

On Fri, Feb 16, 2018 at 12:47 PM, Hans de Goede <hdegoede@redhat.com> 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@redhat.com>

> 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?..

> +#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.

> + 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().

> + 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");
> + }
> + }
> +

--
With Best Regards,
Andy Shevchenko