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

Hans de Goede
2018-02-25T13:49:59Z

Hi,

On 16-02-18 14:19, Andy Shevchenko wrote:
> 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?..

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