[PATCH v3 03/25] clk: sunxi-ng: Add check for maximum rate to NKM PLLs

[Jagan Teki <jagan@amarulasolutions.com>]

Some NKM PLLs, frequency can be set above PLL working range.

Add a constraint for maximum supported rate. This way, drivers can
specify which is maximum allowed rate for PLL.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Tested-by: Jagan Teki <jagan@amarulasolutions.com>
---
Changes for v3:
- collect Stephen Ack
- add tested credit
Changes for v2:
- none

 drivers/clk/sunxi-ng/ccu_nkm.c | 7 +++++++
 drivers/clk/sunxi-ng/ccu_nkm.h | 1 +
 2 files changed, 8 insertions(+)

diff --git a/drivers/clk/sunxi-ng/ccu_nkm.c b/drivers/clk/sunxi-ng/ccu_nkm.c
index d17539dc88dd..574fd2cd2a79 100644
--- a/drivers/clk/sunxi-ng/ccu_nkm.c
+++ b/drivers/clk/sunxi-ng/ccu_nkm.c
@@ -132,6 +132,13 @@ static unsigned long ccu_nkm_round_rate(struct ccu_mux_internal *mux,
 		return rate;
 	}
 
+	if (nkm->max_rate && rate > nkm->max_rate) {
+		rate = nkm->max_rate;
+		if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV)
+			rate /= nkm->fixed_post_div;
+		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 ff5bd00f429f..c82590481188 100644
--- a/drivers/clk/sunxi-ng/ccu_nkm.h
+++ b/drivers/clk/sunxi-ng/ccu_nkm.h
@@ -36,6 +36,7 @@ struct ccu_nkm {
 
 	unsigned int		fixed_post_div;
 	unsigned int		min_rate;
+	unsigned int		max_rate;
 
 	struct ccu_common	common;
 };
-- 
2.18.0.321.gffc6fa0e3