[v5,01/17] clk: sunxi-ng: Add check for minimal rate to NKM PLLs

Message ID 20181210161729.29720-2-jagan@amarulasolutions.com
State New
Headers show
Series
  • drm/sun4i: Allwinner A64 MIPI-DSI support
Related show

Commit Message

Jagan Teki Dec. 10, 2018, 4:17 p.m. UTC
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@amarulasolutions.com>
Acked-by: Stephen Boyd <sboyd@kernel.org>
---
 drivers/clk/sunxi-ng/ccu_nkm.c | 5 +++++
 drivers/clk/sunxi-ng/ccu_nkm.h | 1 +
 2 files changed, 6 insertions(+)

Patch

diff --git a/drivers/clk/sunxi-ng/ccu_nkm.c b/drivers/clk/sunxi-ng/ccu_nkm.c
index 841840e35e61..096ff4f4839a 100644
--- a/drivers/clk/sunxi-ng/ccu_nkm.c
+++ b/drivers/clk/sunxi-ng/ccu_nkm.c
@@ -125,6 +125,11 @@  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) {
+		rate = nkm->min_rate;
+		return 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;
 };