• Archit Taneja's avatar
    drm/msm: Set CLK_IGNORE_UNUSED flag for PLL clocks · 73b65b19
    Archit Taneja authored
    The DSI/HDMI PLLs in MSM require resources like interface clocks, power
    domains to be enabled before we can access their registers.
    
    The clock framework doesn't have a mechanism at the moment where we can
    tie such resources to a clock, so we make sure that the KMS driver enables
    these resources whenever a PLL is expected to be in use.
    
    One place where we can't ensure the resource dependencies are met is when
    the clock framework tries to disable unused clocks. The KMS driver doesn't
    know when the clock framework calls the is_enabled clk_op, and hence can't
    enable interface clocks/power domains beforehand.
    
    We set the CLK_IGNORE_UNUSED flag for PLL clocks for now. This needs to be
    revisited, since bootloaders can enable display, and we would want to
    disable the PLL clocks if there isn't a display driver using them.
    
    Cc: Stephen Boyd <sboyd@codeaurora.org>
    Signed-off-by: default avatarArchit Taneja <architt@codeaurora.org>
    Acked-by: default avatarStephen Boyd <sboyd@codeaurora.org>
    Signed-off-by: default avatarRob Clark <robdclark@gmail.com>
    73b65b19
dsi_pll_28nm.c 18.7 KB