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>
This commit is contained in:
Icenowy Zheng 2017-08-12 20:43:51 +08:00 committed by Chen-Yu Tsai
parent 721353c030
commit a6653773d6
2 changed files with 21 additions and 3 deletions

View File

@ -75,7 +75,7 @@ static unsigned long ccu_nkm_recalc_rate(struct clk_hw *hw,
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 @@ static unsigned long ccu_nkm_recalc_rate(struct clk_hw *hw,
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 @@ static unsigned long ccu_nkm_round_rate(struct ccu_mux_internal *mux,
_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 @@ static int ccu_nkm_set_rate(struct clk_hw *hw, unsigned long rate,
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;

View File

@ -34,6 +34,8 @@ struct ccu_nkm {
struct ccu_div_internal m;
struct ccu_mux_internal mux;
unsigned int fixed_post_div;
struct ccu_common common;
};