clk: sunxi-ng: nkm: Support finding closest rate

When finding the best rate for a NKM clock, consider rates that are
higher than the requested rate, if the CCU_FEATURE_CLOSEST_RATE flag is
set by using the helper function ccu_is_better_rate().

Accommodate ccu_mux_helper_determine_rate to this change.

Acked-by: Maxime Ripard <mripard@kernel.org>
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Frank Oltmanns <frank@oltmanns.dev>
Link: https://lore.kernel.org/r/20230807-pll-mipi_set_rate_parent-v6-7-f173239a4b59@oltmanns.dev
Signed-off-by: Chen-Yu Tsai <wens@csie.org>

diff --git a/drivers/clk/sunxi-ng/ccu_mux.c b/drivers/clk/sunxi-ng/ccu_mux.c
index 1d557e32316915787819b65959f1633e48e45d60..3ca695439620b1aabaf92fe00da4bad247b63e73 100644 (file)
--- a/drivers/clk/sunxi-ng/ccu_mux.c
+++ b/drivers/clk/sunxi-ng/ccu_mux.c
@@ -139,7 +139,7 @@ int ccu_mux_helper_determine_rate(struct ccu_common *common,
                        goto out;
                }
 
-               if ((req->rate - tmp_rate) < (req->rate - best_rate)) {
+               if (ccu_is_better_rate(common, req->rate, tmp_rate, best_rate)) {
                        best_rate = tmp_rate;
                        best_parent_rate = parent_rate;
                        best_parent = parent;

diff --git a/drivers/clk/sunxi-ng/ccu_nkm.c b/drivers/clk/sunxi-ng/ccu_nkm.c
index 2f60f3c33e30cda93c499d896ca3fbe90c189313..a714dcf0dfc1b45557b3f6e1149339b965f96349 100644 (file)
--- a/drivers/clk/sunxi-ng/ccu_nkm.c
+++ b/drivers/clk/sunxi-ng/ccu_nkm.c
@@ -16,7 +16,8 @@ struct _ccu_nkm {
        unsigned long   m, min_m, max_m;
 };
 
-static unsigned long ccu_nkm_find_best_with_parent_adj(struct clk_hw *parent_hw,
+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,
                                                       struct _ccu_nkm *nkm)
 {
@@ -32,10 +33,8 @@ static unsigned long ccu_nkm_find_best_with_parent_adj(struct clk_hw *parent_hw,
                                tmp_parent = clk_hw_round_rate(parent_hw, rate * _m / (_n * _k));
 
                                tmp_rate = tmp_parent * _n * _k / _m;
-                               if (tmp_rate > rate)
-                                       continue;
 
-                               if ((rate - tmp_rate) < (rate - best_rate)) {
+                               if (ccu_is_better_rate(common, rate, tmp_rate, best_rate)) {
                                        best_rate = tmp_rate;
                                        best_parent_rate = tmp_parent;
                                        best_n = _n;
@@ -56,7 +55,7 @@ static unsigned long ccu_nkm_find_best_with_parent_adj(struct clk_hw *parent_hw,
 }
 
 static unsigned long ccu_nkm_find_best(unsigned long parent, unsigned long rate,
-                                      struct _ccu_nkm *nkm)
+                                      struct _ccu_nkm *nkm, struct ccu_common *common)
 {
        unsigned long best_rate = 0;
        unsigned long best_n = 0, best_k = 0, best_m = 0;
@@ -69,9 +68,7 @@ static unsigned long ccu_nkm_find_best(unsigned long parent, unsigned long rate,
 
                                tmp_rate = parent * _n * _k / _m;
 
-                               if (tmp_rate > rate)
-                                       continue;
-                               if ((rate - tmp_rate) < (rate - best_rate)) {
+                               if (ccu_is_better_rate(common, rate, tmp_rate, best_rate)) {
                                        best_rate = tmp_rate;
                                        best_n = _n;
                                        best_k = _k;
@@ -164,9 +161,10 @@ static unsigned long ccu_nkm_round_rate(struct ccu_mux_internal *mux,
                rate *= nkm->fixed_post_div;
 
        if (!clk_hw_can_set_rate_parent(&nkm->common.hw))
-               rate = ccu_nkm_find_best(*parent_rate, rate, &_nkm);
+               rate = ccu_nkm_find_best(*parent_rate, rate, &_nkm, &nkm->common);
        else
-               rate = ccu_nkm_find_best_with_parent_adj(parent_hw, parent_rate, rate, &_nkm);
+               rate = ccu_nkm_find_best_with_parent_adj(&nkm->common, parent_hw, parent_rate, rate,
+                                                        &_nkm);
 
        if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV)
                rate /= nkm->fixed_post_div;
@@ -201,7 +199,7 @@ static int ccu_nkm_set_rate(struct clk_hw *hw, unsigned long rate,
        _nkm.min_m = 1;
        _nkm.max_m = nkm->m.max ?: 1 << nkm->m.width;
 
-       ccu_nkm_find_best(parent_rate, rate, &_nkm);
+       ccu_nkm_find_best(parent_rate, rate, &_nkm, &nkm->common);
 
        spin_lock_irqsave(nkm->common.lock, flags);