On Sun, Nov 13, 2016 at 11:48 AM, Chen-Yu Tsai [off-list ref] wrote:

On Wed, Nov 9, 2016 at 1:23 AM, Maxime Ripard
[off-list ref] wrote:

It'd be better if you mentioned what clock needs this.

quoted

Signed-off-by: Maxime Ripard <redacted>
---
 drivers/clk/sunxi-ng/ccu_nkm.c | 17 ++++++++++++++---
 drivers/clk/sunxi-ng/ccu_nkm.h |  2 ++
 2 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/drivers/clk/sunxi-ng/ccu_nkm.c b/drivers/clk/sunxi-ng/ccu_nkm.c
index 9b840a47a94d..fd3c6a9d987c 100644
--- a/drivers/clk/sunxi-ng/ccu_nkm.c
+++ b/drivers/clk/sunxi-ng/ccu_nkm.c

@@ -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 rate, n, m, k;
        u32 reg;

        reg = readl(nkm->common.base + nkm->common.reg);

@@ -89,7 +89,11 @@ static unsigned long ccu_nkm_recalc_rate(struct clk_hw *hw,
        m = reg >> nkm->m.shift;
        m &= (1 << nkm->m.width) - 1;

-       return parent_rate * (n + 1) * (k + 1) / (m + 1);
+       rate = parent_rate * (n + 1) * (k + 1) / (m + 1);
+       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,

@@ -100,6 +104,9 @@ static unsigned long ccu_nkm_round_rate(struct ccu_mux_internal *mux,
        struct ccu_nkm *nkm = data;
        struct _ccu_nkm _nkm;

+       if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV)
+               rate *= nkm->fixed_post_div;
+
        _nkm.min_n = nkm->n.min;
        _nkm.max_n = 1 << nkm->n.width;
        _nkm.min_k = nkm->k.min;

@@ -109,7 +116,11 @@ static unsigned long ccu_nkm_round_rate(struct ccu_mux_internal *mux,

        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 = rate / nkm->fixed_post_div;
+
+       return rate;
 }

You also need to handle this in the set_rate callback. You might need
to read back
the parent index value to determine if the post divider applies, as
this clock supports
a mux. Or don't support mux + post-div, and leave a TODO note.

Was thinking pre-dividers... sorry. Please ignore the second parent
index part.

ChenYu

ChenYu

quoted

 static int ccu_nkm_determine_rate(struct clk_hw *hw,

diff --git a/drivers/clk/sunxi-ng/ccu_nkm.h b/drivers/clk/sunxi-ng/ccu_nkm.h
index 34580894f4d1..0f1dbca25719 100644
--- a/drivers/clk/sunxi-ng/ccu_nkm.h
+++ b/drivers/clk/sunxi-ng/ccu_nkm.h

@@ -32,6 +32,8 @@ struct ccu_nkm {
        struct ccu_mult_internal        n;
        struct ccu_mult_internal        k;
        struct ccu_div_internal         m;
+
+       unsigned int            fixed_post_div;
        struct ccu_mux_internal mux;

        struct ccu_common       common;
--

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