Hi Jernej, On 2024-02-05 at 18:45:27 +0100, Jernej Škrabec <jernej.skrabec@xxxxxxxxx> wrote: > Dne ponedeljek, 05. februar 2024 ob 16:22:24 CET je Frank Oltmanns napisal(a): >> The Allwinner A64 manual lists the following constraints for the >> PLL-MIPI clock: >> - M/N <= 3 >> - (PLL_VIDEO0)/M >= 24MHz >> >> The PLL-MIPI clock is implemented as ccu_nkm. Therefore, add support for >> these constraints. >> >> Signed-off-by: Frank Oltmanns <frank@xxxxxxxxxxxx> > > Haven't we discussed that this patch is unnecessary because same effect can > be reached by limiting minimum frequency? The patch for ccu_nm was unnecessary: https://lore.kernel.org/all/87jzoug2jz.fsf@xxxxxxxxxxxx/ Unfortunately, we still need this one. Best regards, Frank > > Best regards, > Jernej > >> --- >> drivers/clk/sunxi-ng/ccu_nkm.c | 21 +++++++++++++++++++++ >> drivers/clk/sunxi-ng/ccu_nkm.h | 2 ++ >> 2 files changed, 23 insertions(+) >> >> diff --git a/drivers/clk/sunxi-ng/ccu_nkm.c b/drivers/clk/sunxi-ng/ccu_nkm.c >> index 853f84398e2b..1168d894d636 100644 >> --- a/drivers/clk/sunxi-ng/ccu_nkm.c >> +++ b/drivers/clk/sunxi-ng/ccu_nkm.c >> @@ -16,6 +16,20 @@ struct _ccu_nkm { >> unsigned long m, min_m, max_m; >> }; >> >> +static bool ccu_nkm_is_valid_rate(struct ccu_common *common, unsigned long parent, >> + unsigned long n, unsigned long m) >> +{ >> + struct ccu_nkm *nkm = container_of(common, struct ccu_nkm, common); >> + >> + if (nkm->max_m_n_ratio && (m > nkm->max_m_n_ratio * n)) >> + return false; >> + >> + if (nkm->min_parent_m_ratio && (parent < nkm->min_parent_m_ratio * m)) >> + return false; >> + >> + return true; >> +} >> + >> static unsigned long ccu_nkm_find_best_with_parent_adj(struct ccu_common *common, >> struct clk_hw *parent_hw, >> unsigned long *parent, unsigned long rate, >> @@ -31,6 +45,10 @@ static unsigned long ccu_nkm_find_best_with_parent_adj(struct ccu_common *common >> unsigned long tmp_rate, tmp_parent; >> >> tmp_parent = clk_hw_round_rate(parent_hw, rate * _m / (_n * _k)); >> + >> + if (!ccu_nkm_is_valid_rate(common, tmp_parent, _n, _m)) >> + continue; >> + >> tmp_rate = tmp_parent * _n * _k / _m; >> >> if (ccu_is_better_rate(common, rate, tmp_rate, best_rate) || >> @@ -64,6 +82,9 @@ static unsigned long ccu_nkm_find_best(unsigned long parent, unsigned long rate, >> for (_k = nkm->min_k; _k <= nkm->max_k; _k++) { >> for (_n = nkm->min_n; _n <= nkm->max_n; _n++) { >> for (_m = nkm->min_m; _m <= nkm->max_m; _m++) { >> + if (!ccu_nkm_is_valid_rate(common, parent, _n, _m)) >> + continue; >> + >> unsigned long tmp_rate; >> >> tmp_rate = parent * _n * _k / _m; >> diff --git a/drivers/clk/sunxi-ng/ccu_nkm.h b/drivers/clk/sunxi-ng/ccu_nkm.h >> index 6601defb3f38..c409212ee40e 100644 >> --- a/drivers/clk/sunxi-ng/ccu_nkm.h >> +++ b/drivers/clk/sunxi-ng/ccu_nkm.h >> @@ -27,6 +27,8 @@ struct ccu_nkm { >> struct ccu_mux_internal mux; >> >> unsigned int fixed_post_div; >> + unsigned long max_m_n_ratio; >> + unsigned long min_parent_m_ratio; >> >> struct ccu_common common; >> }; >> >>
