lkml.org 
[lkml]   [2015]   [Jan]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    Subject[PATCH v2 0/7] extcon: usb: Introduce USB GPIO extcon driver. Fix DRA7 & AM57xx USB.
    Date
    Hi,

    Still hoping this can make into 3.20 else we have USB peripheral mode broken on
    DRA7-evm, DRA72-evm and AM57xx-beagle-x15.

    On DRA7 and AM57xx EVMs the USB ID pin is connected to a GPIO line.
    The USB drivers (dwc3 + dwc3-omap) depend on extcon framework to get the
    USB cable state (USB or USB-Host) to put the controller in the right mode.

    There were earlier attempts [1] to get this working by trying to patch up
    the existing GPIO extcon driver.

    This series attemts to take a different approach by introducing a new
    USB specific extcon driver to handle the USB ID GPIO pin and
    interpret a right USB cable state.

    The reasoning to introduce this new driver is:
    1) The existing GPIO extcon driver doesn't understand USB cable states
    and it can't handle more than one cable per instance.

    For the USB case we need to handle at least 2 cable states.
    a) USB (attach/detach)
    b) USB-Host (attach/detach)
    and could possible include more states like
    c) Fast-charger (attach/detach)
    d) Slow-charger (attach/detach)

    2) This USB specific driver can be easily updated in the future to
    handle VBUS events, or charger detect events, in case it happens
    to be available on GPIO for any platform.

    3) The DT implementation is very easy. You just need one extcon node per USB
    instead of one extcon node per cable state as in case of [1].

    4) The cable state string doesn't need to be encoded in the device tree
    as in case of [1].

    5) With only ID event available, you can simulate a USB-peripheral attach
    when USB-Host is detacted instead of hacking the USB driver to do the same.

    Tested on DRA7-evm, DRA72-evm and AM57xx-beagle-x15

    Changelog:
    v2
    - Addressed review comments.
    - Fixed auto load of extcon-usb-gpio driver when used as module.
    - Fixed up AM57xx USB.

    --
    cheers,
    -roger
    [1] - https://lkml.org/lkml/2014/11/3/513

    Roger Quadros (7):
    extcon: usb-gpio: Introduce gpio usb extcon driver
    usb: extcon: Fix USB-Host cable name
    ARM: dts: dra7-evm: Add extcon nodes for USB
    ARM: dts: dra72-evm: Add extcon nodes for USB
    ARM: dts: am57xx-beagle-x15: Add extcon nodes for USB
    ARM: dts: am57xx-beagle-x15: Fix USB2 mode
    ARM: omap2plus_defconfig: Enable EXTCON_GPIO_USB

    .../devicetree/bindings/extcon/extcon-usb-gpio.txt | 20 ++
    arch/arm/boot/dts/am57xx-beagle-x15.dts | 37 ++++
    arch/arm/boot/dts/dra7-evm.dts | 31 +++
    arch/arm/boot/dts/dra72-evm.dts | 31 +++
    arch/arm/configs/omap2plus_defconfig | 1 +
    drivers/extcon/Kconfig | 7 +
    drivers/extcon/Makefile | 1 +
    drivers/extcon/extcon-palmas.c | 18 +-
    drivers/extcon/extcon-usb-gpio.c | 214 +++++++++++++++++++++
    drivers/usb/dwc3/dwc3-omap.c | 6 +-
    drivers/usb/phy/phy-omap-otg.c | 4 +-
    drivers/usb/phy/phy-tahvo.c | 8 +-
    12 files changed, 360 insertions(+), 18 deletions(-)
    create mode 100644 Documentation/devicetree/bindings/extcon/extcon-usb-gpio.txt
    create mode 100644 drivers/extcon/extcon-usb-gpio.c

    --
    2.1.0



    \
     
     \ /
      Last update: 2015-01-26 13:21    [W:2.282 / U:0.044 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site