clk: sunxi-ng: nkm: add support for fixed post-divider
SATA PLL on Allwinner R40 is of type (parent) * N * K / M / 6 where 6 is
the fixed post-divider.
Add post-divider support for NKM type clock.
Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
[wens@csie.org: Fixed application of post-divider in set_rate callback]
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
diff --git a/drivers/clk/sunxi-ng/ccu_nkm.c b/drivers/clk/sunxi-ng/ccu_nkm.c
index 44b16dc..841840e 100644
--- a/drivers/clk/sunxi-ng/ccu_nkm.c
+++ b/drivers/clk/sunxi-ng/ccu_nkm.c
@@ -75,7 +75,7 @@
unsigned long parent_rate)
{
struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
- unsigned long n, m, k;
+ unsigned long n, m, k, rate;
u32 reg;
reg = readl(nkm->common.base + nkm->common.reg);
@@ -98,7 +98,12 @@
if (!m)
m++;
- return parent_rate * n * k / m;
+ rate = parent_rate * n * k / m;
+
+ if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV)
+ rate /= nkm->fixed_post_div;
+
+ return rate;
}
static unsigned long ccu_nkm_round_rate(struct ccu_mux_internal *mux,
@@ -117,9 +122,17 @@
_nkm.min_m = 1;
_nkm.max_m = nkm->m.max ?: 1 << nkm->m.width;
+ if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV)
+ rate *= nkm->fixed_post_div;
+
ccu_nkm_find_best(*parent_rate, rate, &_nkm);
- return *parent_rate * _nkm.n * _nkm.k / _nkm.m;
+ rate = *parent_rate * _nkm.n * _nkm.k / _nkm.m;
+
+ if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV)
+ rate /= nkm->fixed_post_div;
+
+ return rate;
}
static int ccu_nkm_determine_rate(struct clk_hw *hw,
@@ -139,6 +152,9 @@
unsigned long flags;
u32 reg;
+ if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV)
+ rate *= nkm->fixed_post_div;
+
_nkm.min_n = nkm->n.min ?: 1;
_nkm.max_n = nkm->n.max ?: 1 << nkm->n.width;
_nkm.min_k = nkm->k.min ?: 1;
diff --git a/drivers/clk/sunxi-ng/ccu_nkm.h b/drivers/clk/sunxi-ng/ccu_nkm.h
index 3458089..cc6efb7 100644
--- a/drivers/clk/sunxi-ng/ccu_nkm.h
+++ b/drivers/clk/sunxi-ng/ccu_nkm.h
@@ -34,6 +34,8 @@
struct ccu_div_internal m;
struct ccu_mux_internal mux;
+ unsigned int fixed_post_div;
+
struct ccu_common common;
};