diff options
| author | Frank Oltmanns <frank@oltmanns.dev> | 2024-03-10 16:21:13 +0300 |
|---|---|---|
| committer | Jernej Skrabec <jernej.skrabec@gmail.com> | 2024-04-16 00:23:09 +0300 |
| commit | 5723879c145255d2502a3f8f3a21a16332b24366 (patch) | |
| tree | b3876ce829aed94cda7ac3c70066a0306010af89 | |
| parent | 4cece764965020c22cff7665b18a012006359095 (diff) | |
| download | linux-5723879c145255d2502a3f8f3a21a16332b24366.tar.xz | |
clk: sunxi-ng: nkm: Support constraints on m/n ratio and parent rate
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.
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Frank Oltmanns <frank@oltmanns.dev>
Link: https://lore.kernel.org/r/20240310-pinephone-pll-fixes-v4-3-46fc80c83637@oltmanns.dev
Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>
| -rw-r--r-- | drivers/clk/sunxi-ng/ccu_nkm.c | 21 | ||||
| -rw-r--r-- | drivers/clk/sunxi-ng/ccu_nkm.h | 2 |
2 files changed, 23 insertions, 0 deletions
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; }; |