clk: sunxi-ng: div: Add support for fixed post-divider

SATA clock on sun4i/sun7i is of type (parent) / M / 6 where
6 is fixed post-divider.
Signed-off-by: Priit Laes <plaes@plaes.org>
Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
Signed-off-by: Chen-Yu Tsai <wens@csie.org>

drivers/clk/sunxi-ng/ccu_div.c

@@ -21,10 +21,18 @@ static unsigned long ccu_div_round_rate(struct ccu_mux_internal *mux,
 {
 	struct ccu_div *cd = data;
 
-	return divider_round_rate_parent(&cd->common.hw, parent,
+	if (cd->common.features & CCU_FEATURE_FIXED_POSTDIV)
+		rate *= cd->fixed_post_div;
+
+	rate = divider_round_rate_parent(&cd->common.hw, parent,
 					 rate, parent_rate,
 					 cd->div.table, cd->div.width,
 					 cd->div.flags);
+
+	if (cd->common.features & CCU_FEATURE_FIXED_POSTDIV)
+		rate /= cd->fixed_post_div;
+
+	return rate;
 }
 
 static void ccu_div_disable(struct clk_hw *hw)
@@ -62,8 +70,13 @@ static unsigned long ccu_div_recalc_rate(struct clk_hw *hw,
 	parent_rate = ccu_mux_helper_apply_prediv(&cd->common, &cd->mux, -1,
 						  parent_rate);
 
-	return divider_recalc_rate(hw, parent_rate, val, cd->div.table,
+	val = divider_recalc_rate(hw, parent_rate, val, cd->div.table,
 				  cd->div.flags);
+
+	if (cd->common.features & CCU_FEATURE_FIXED_POSTDIV)
+		val /= cd->fixed_post_div;
+
+	return val;
 }
 
 static int ccu_div_determine_rate(struct clk_hw *hw,
@@ -86,6 +99,9 @@ static int ccu_div_set_rate(struct clk_hw *hw, unsigned long rate,
 	parent_rate = ccu_mux_helper_apply_prediv(&cd->common, &cd->mux, -1,
 						  parent_rate);
 
+	if (cd->common.features & CCU_FEATURE_FIXED_POSTDIV)
+		rate *= cd->fixed_post_div;
+
 	val = divider_get_val(rate, parent_rate, cd->div.table, cd->div.width,
 			      cd->div.flags);
 

drivers/clk/sunxi-ng/ccu_div.h

@@ -89,6 +89,7 @@ struct ccu_div {
 	struct ccu_div_internal	div;
 	struct ccu_mux_internal	mux;
 	struct ccu_common	common;
+	unsigned int		fixed_post_div;
 };
 
 #define SUNXI_CCU_DIV_TABLE_WITH_GATE(_struct, _name, _parent, _reg,	\