1 files changed, 107 insertions, 7 deletions

diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c
index 5543b7df8e16..d95f120af5c5 100644
--- a/drivers/clk/clk-divider.c
+++ b/drivers/clk/clk-divider.c
@@ -24,7 +24,7 @@
  * Traits of this clock:
  * prepare - clk_prepare only ensures that parents are prepared
  * enable - clk_enable only ensures that parents are enabled
- * rate - rate is adjustable.  clk->rate = parent->rate / divisor
+ * rate - rate is adjustable.  clk->rate = DIV_ROUND_UP(parent->rate / divisor)
  * parent - fixed parent.  No clk_set_parent support
  */
 
@@ -43,6 +43,17 @@ static unsigned int _get_table_maxdiv(const struct clk_div_table *table)
 	return maxdiv;
 }
 
+static unsigned int _get_table_mindiv(const struct clk_div_table *table)
+{
+	unsigned int mindiv = UINT_MAX;
+	const struct clk_div_table *clkt;
+
+	for (clkt = table; clkt->div; clkt++)
+		if (clkt->div < mindiv)
+			mindiv = clkt->div;
+	return mindiv;
+}
+
 static unsigned int _get_maxdiv(struct clk_divider *divider)
 {
 	if (divider->flags & CLK_DIVIDER_ONE_BASED)
@@ -115,7 +126,7 @@ static unsigned long clk_divider_recalc_rate(struct clk_hw *hw,
 		return parent_rate;
 	}
 
-	return parent_rate / div;
+	return DIV_ROUND_UP(parent_rate, div);
 }
 
 /*
@@ -144,6 +155,91 @@ static bool _is_valid_div(struct clk_divider *divider, unsigned int div)
 	return true;
 }
 
+static int _round_up_table(const struct clk_div_table *table, int div)
+{
+	const struct clk_div_table *clkt;
+	int up = INT_MAX;
+
+	for (clkt = table; clkt->div; clkt++) {
+		if (clkt->div == div)
+			return clkt->div;
+		else if (clkt->div < div)
+			continue;
+
+		if ((clkt->div - div) < (up - div))
+			up = clkt->div;
+	}
+
+	return up;
+}
+
+static int _round_down_table(const struct clk_div_table *table, int div)
+{
+	const struct clk_div_table *clkt;
+	int down = _get_table_mindiv(table);
+
+	for (clkt = table; clkt->div; clkt++) {
+		if (clkt->div == div)
+			return clkt->div;
+		else if (clkt->div > div)
+			continue;
+
+		if ((div - clkt->div) < (div - down))
+			down = clkt->div;
+	}
+
+	return down;
+}
+
+static int _div_round_up(struct clk_divider *divider,
+		unsigned long parent_rate, unsigned long rate)
+{
+	int div = DIV_ROUND_UP(parent_rate, rate);
+
+	if (divider->flags & CLK_DIVIDER_POWER_OF_TWO)
+		div = __roundup_pow_of_two(div);
+	if (divider->table)
+		div = _round_up_table(divider->table, div);
+
+	return div;
+}
+
+static int _div_round_closest(struct clk_divider *divider,
+		unsigned long parent_rate, unsigned long rate)
+{
+	int up, down, div;
+
+	up = down = div = DIV_ROUND_CLOSEST(parent_rate, rate);
+
+	if (divider->flags & CLK_DIVIDER_POWER_OF_TWO) {
+		up = __roundup_pow_of_two(div);
+		down = __rounddown_pow_of_two(div);
+	} else if (divider->table) {
+		up = _round_up_table(divider->table, div);
+		down = _round_down_table(divider->table, div);
+	}
+
+	return (up - div) <= (div - down) ? up : down;
+}
+
+static int _div_round(struct clk_divider *divider, unsigned long parent_rate,
+		unsigned long rate)
+{
+	if (divider->flags & CLK_DIVIDER_ROUND_CLOSEST)
+		return _div_round_closest(divider, parent_rate, rate);
+
+	return _div_round_up(divider, parent_rate, rate);
+}
+
+static bool _is_best_div(struct clk_divider *divider,
+		unsigned long rate, unsigned long now, unsigned long best)
+{
+	if (divider->flags & CLK_DIVIDER_ROUND_CLOSEST)
+		return abs(rate - now) < abs(rate - best);
+
+	return now <= rate && now > best;
+}
+
 static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate,
 		unsigned long *best_parent_rate)
 {
@@ -159,7 +255,7 @@ static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate,
 
 	if (!(__clk_get_flags(hw->clk) & CLK_SET_RATE_PARENT)) {
 		parent_rate = *best_parent_rate;
-		bestdiv = DIV_ROUND_UP(parent_rate, rate);
+		bestdiv = _div_round(divider, parent_rate, rate);
 		bestdiv = bestdiv == 0 ? 1 : bestdiv;
 		bestdiv = bestdiv > maxdiv ? maxdiv : bestdiv;
 		return bestdiv;
@@ -185,8 +281,8 @@ static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate,
 		}
 		parent_rate = __clk_round_rate(__clk_get_parent(hw->clk),
 				MULT_ROUND_UP(rate, i));
-		now = parent_rate / i;
-		if (now <= rate && now > best) {
+		now = DIV_ROUND_UP(parent_rate, i);
+		if (_is_best_div(divider, rate, now, best)) {
 			bestdiv = i;
 			best = now;
 			*best_parent_rate = parent_rate;
@@ -207,7 +303,7 @@ static long clk_divider_round_rate(struct clk_hw *hw, unsigned long rate,
 	int div;
 	div = clk_divider_bestdiv(hw, rate, prate);
 
-	return *prate / div;
+	return DIV_ROUND_UP(*prate, div);
 }
 
 static int clk_divider_set_rate(struct clk_hw *hw, unsigned long rate,
@@ -218,7 +314,11 @@ static int clk_divider_set_rate(struct clk_hw *hw, unsigned long rate,
 	unsigned long flags = 0;
 	u32 val;
 
-	div = parent_rate / rate;
+	div = DIV_ROUND_UP(parent_rate, rate);
+
+	if (!_is_valid_div(divider, div))
+		return -EINVAL;
+
 	value = _get_val(divider, div);
 
 	if (value > div_mask(divider))