clk: sunxi-ng: nkmp: Add constraint for maximum rate

Some, if not most, NKMP PLLs can be set to higher rate that is really
supported by HW.

Implement support for maximum frequency constrain for NKMP PLLs.

Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>

diff --git a/drivers/clk/sunxi-ng/ccu_nkmp.c b/drivers/clk/sunxi-ng/ccu_nkmp.c
index ebd9436d2c7cd382ed86a3bee1957a5db48b7530..9b49adb20d07c68ef8ddd01f8d35e73ed746f64f 100644 (file)
--- a/drivers/clk/sunxi-ng/ccu_nkmp.c
+++ b/drivers/clk/sunxi-ng/ccu_nkmp.c
@@ -137,6 +137,13 @@ static long ccu_nkmp_round_rate(struct clk_hw *hw, unsigned long rate,
        if (nkmp->common.features & CCU_FEATURE_FIXED_POSTDIV)
                rate *= nkmp->fixed_post_div;
 
+       if (nkmp->max_rate && rate > nkmp->max_rate) {
+               rate = nkmp->max_rate;
+               if (nkmp->common.features & CCU_FEATURE_FIXED_POSTDIV)
+                       rate /= nkmp->fixed_post_div;
+               return rate;
+       }
+
        _nkmp.min_n = nkmp->n.min ?: 1;
        _nkmp.max_n = nkmp->n.max ?: 1 << nkmp->n.width;
        _nkmp.min_k = nkmp->k.min ?: 1;

diff --git a/drivers/clk/sunxi-ng/ccu_nkmp.h b/drivers/clk/sunxi-ng/ccu_nkmp.h
index 6940503e7fc4665d36fd889e3ec25fa258a14f40..a9f8c116a7453b969019dfda27c4b340604e35dc 100644 (file)
--- a/drivers/clk/sunxi-ng/ccu_nkmp.h
+++ b/drivers/clk/sunxi-ng/ccu_nkmp.h
@@ -35,6 +35,7 @@ struct ccu_nkmp {
        struct ccu_div_internal         p;
 
        unsigned int            fixed_post_div;
+       unsigned int            max_rate;
 
        struct ccu_common       common;
 };