[PATCH v4 02/26] clk: sunxi-ng: Add check for minimal rate to NKM PLLs

From: Jagan Teki
Date: Tue Nov 13 2018 - 06:17:06 EST


Some NKM PLLs doesn't work well when their output clock rate is set below
certain rate.

So, add support for minimal rate for relevant PLLs.

Signed-off-by: Jagan Teki <jagan@xxxxxxxxxxxxxxxxxxxx>
Acked-by: Stephen Boyd <sboyd@xxxxxxxxxx>
---
drivers/clk/sunxi-ng/ccu_nkm.c | 3 +++
drivers/clk/sunxi-ng/ccu_nkm.h | 1 +
2 files changed, 4 insertions(+)

diff --git a/drivers/clk/sunxi-ng/ccu_nkm.c b/drivers/clk/sunxi-ng/ccu_nkm.c
index 841840e35e61..6b5ad990f802 100644
--- a/drivers/clk/sunxi-ng/ccu_nkm.c
+++ b/drivers/clk/sunxi-ng/ccu_nkm.c
@@ -125,6 +125,9 @@ static unsigned long ccu_nkm_round_rate(struct ccu_mux_internal *mux,
if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV)
rate *= nkm->fixed_post_div;

+ if (rate < nkm->min_rate)
+ return nkm->min_rate;
+
ccu_nkm_find_best(*parent_rate, rate, &_nkm);

rate = *parent_rate * _nkm.n * _nkm.k / _nkm.m;
diff --git a/drivers/clk/sunxi-ng/ccu_nkm.h b/drivers/clk/sunxi-ng/ccu_nkm.h
index cc6efb70a102..ff5bd00f429f 100644
--- a/drivers/clk/sunxi-ng/ccu_nkm.h
+++ b/drivers/clk/sunxi-ng/ccu_nkm.h
@@ -35,6 +35,7 @@ struct ccu_nkm {
struct ccu_mux_internal mux;

unsigned int fixed_post_div;
+ unsigned int min_rate;

struct ccu_common common;
};
--
2.18.0.321.gffc6fa0e3