Dne nedelja, 31. december 2023 ob 10:10:40 CET je Frank Oltmanns napisal(a): > > On 2023-12-19 at 17:54:19 +0100, Jernej Škrabec <jernej.skra...@gmail.com> > wrote: > > Dne ponedeljek, 18. december 2023 ob 14:35:22 CET je Frank Oltmanns > > napisal(a): > >> The Allwinner A64 manual lists the following constraint for the > >> PLL-VIDEO0 clock: 8 <= N/M <= 25 > >> > >> Use this constraint. > >> > >> Signed-off-by: Frank Oltmanns <fr...@oltmanns.dev> > >> --- > >> drivers/clk/sunxi-ng/ccu-sun50i-a64.c | 8 ++++++-- > >> 1 file changed, 6 insertions(+), 2 deletions(-) > >> > >> diff --git a/drivers/clk/sunxi-ng/ccu-sun50i-a64.c > >> b/drivers/clk/sunxi-ng/ccu-sun50i-a64.c > >> index c034ac027d1c..75d839da446c 100644 > >> --- a/drivers/clk/sunxi-ng/ccu-sun50i-a64.c > >> +++ b/drivers/clk/sunxi-ng/ccu-sun50i-a64.c > >> @@ -68,7 +68,8 @@ static > >> SUNXI_CCU_NM_WITH_SDM_GATE_LOCK(pll_audio_base_clk, "pll-audio-base", > >> BIT(28), /* lock */ > >> CLK_SET_RATE_UNGATE); > >> > >> -static SUNXI_CCU_NM_WITH_FRAC_GATE_LOCK_MIN_MAX_CLOSEST(pll_video0_clk, > >> "pll-video0", > >> +static > >> SUNXI_CCU_NM_WITH_FRAC_GATE_LOCK_MIN_MAX_FEAT_NM_RATIO(pll_video0_clk, > >> + "pll-video0", > >> "osc24M", 0x010, > >> 192000000, /* Minimum rate > >> */ > >> 1008000000, /* Maximum rate > >> */ > > I just realized that adding the whole ratio limits for ccu_nm is > superfluous as you could just as well express them in for of a minimum > and maximum range: > Since 8 <= N/M <= 25 and parent_rate = 24 MHz, therefore > 192 MHz <= rate <= 600 MHz.
Good point! > > These absolute limits are also listed in Allwinner's A64 manual. > > BUT, here the upper limit was raised to 1008 MHz: > 5de39acaf34604bd04834f092479cf4dcc946dd "clk: sunxi-ng: a64: Add max. > rate constraint to video PLL" > > With this upper limit the ratio limitation is effectively: > 8 <= N/M <= 42 > > Icenowy Zheng (added to CC) had the reasonable explanation that this was > used in the BSP kernel, so we should probably stick to that and ditch > the two PLL-VIDEO0 related patches. What are your thoughts on that? Ok, it seems that these patches are really superfluous. Remove them for v2. Best regards, Jernej > > >> @@ -80,7 +81,10 @@ static > >> SUNXI_CCU_NM_WITH_FRAC_GATE_LOCK_MIN_MAX_CLOSEST(pll_video0_clk, "pll-vid > >> 297000000, /* frac rate 1 > >> */ > >> BIT(31), /* gate */ > >> BIT(28), /* lock */ > >> - CLK_SET_RATE_UNGATE); > >> + CLK_SET_RATE_UNGATE, > >> + CCU_FEATURE_FRACTIONAL | > >> + CCU_FEATURE_CLOSEST_RATE, > > > > Above flags are unrelated change, put them in new patch if needed. > > > > Best regards, > > Jernej > > > >> + 8, 25); /* min/max nm > >> ratio */ > >> > >> static SUNXI_CCU_NM_WITH_FRAC_GATE_LOCK(pll_ve_clk, "pll-ve", > >> "osc24M", 0x018, > >> > >> >
