• Jernej Skrabec's avatar
    clk: sunxi-ng: h3: h5: Add minimal rate for video PLL · 4fd8ae91
    Jernej Skrabec authored
    Although user manuals for H3 and H5 SoCs state that minimal rate
    supported by video PLL is around 30 MHz, it seems that in reality
    minimal rate is around 192 MHz.
    
    Experiments showed that any rate below 96 MHz doesn't produce any video
    output at all. Even at this frequency, stable output depends on right
    factors. For example, when N = 4 and M = 1, output is stable and when N
    = 8 and M = 2, it's not.
    
    BSP clock driver suggest that minimum stable frequency is 192 MHz. That
    would also be in line with A64 SoC, which has similar periphery.
    
    Set minimal video PLL rate for H3/H5 to 192 MHz.
    Signed-off-by: default avatarJernej Skrabec <jernej.skrabec@siol.net>
    Signed-off-by: default avatarMaxime Ripard <maxime.ripard@bootlin.com>
    4fd8ae91
ccu-sun8i-h3.c 37.8 KB