• Vivek Gautam's avatar
    phy: exynos5-usbdrd: Calibrate LOS levels for exynos5420/5800 · d8c80bb3
    Vivek Gautam authored
    Adding phy calibration sequence for USB 3.0 DRD PHY present on
    Exynos5420/5800 systems.
    This calibration facilitates setting certain PHY parameters viz.
    the Loss-of-Signal (LOS) Detector Threshold Level, as well as
    Tx-Vboost-Level for Super-Speed operations.
    Additionally we also set proper time to wait for RxDetect measurement,
    for desired PHY reference clock, so as to solve issue with enumeration
    of few USB 3.0 devices, like Samsung SUM-TSB16S 3.0 USB drive
    on the controller.
    
    We are using CR_port for this purpose to send required data
    to override the LOS values.
    
    On testing with USB 3.0 devices on USB 3.0 port present on
    SMDK5420, and peach-pit boards should see following message:
    usb 2-1: new SuperSpeed USB device number 2 using xhci-hcd
    
    and without this patch, should see below shown message:
    usb 1-1: new high-speed USB device number 2 using xhci-hcd
    
    [Also removed unnecessary extra lines in the register macro definitions]
    Signed-off-by: default avatarVivek Gautam <gautam.vivek@samsung.com>
    [adapted to use phy_calibrate as entry point]
    Signed-off-by: default avatarAndrzej Pietrasiewicz <andrzej.p@samsung.com>
    Acked-by: default avatarFelipe Balbi <felipe.balbi@linux.intel.com>
    Signed-off-by: default avatarKishon Vijay Abraham I <kishon@ti.com>
    Signed-off-by: default avatarKishon Vijay Abraham I <kishon@ti.com>
    d8c80bb3
phy-exynos5-usbdrd.c 25.6 KB