linux-kernel - [PATCH 2/2] clk: divider: handle minimum divider

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Date:	Tue, 22 Jan 2013 22:10:43 +0530
From:	Afzal Mohammed <afzal@...com>
To:	<linux-omap@...r.kernel.org>,
	<linux-arm-kernel@...ts.infradead.org>,
	<linux-kernel@...r.kernel.org>
Subject: [PATCH 2/2] clk: divider: handle minimum divider

Some of clocks can have a limit on minimum divider value that can be
programmed. Modify basic clock divider to take care of this aspect.

Signed-off-by: Afzal Mohammed <afzal@...com>
---
 drivers/clk/clk-divider.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c
index 0b34992..2de9ff5 100644
--- a/drivers/clk/clk-divider.c
+++ b/drivers/clk/clk-divider.c
@@ -32,6 +32,11 @@
 #define div_mask(d)	((1 << (d->width)) - 1)
 #define is_power_of_two(i)	!(i & ~i)
 
+static unsigned int _get_mindiv(struct clk_divider *divider)
+{
+	return divider->min_div;
+}
+
 static unsigned int _get_table_maxdiv(const struct clk_div_table *table)
 {
 	unsigned int maxdiv = 0;
@@ -148,17 +153,18 @@ static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate,
 {
 	struct clk_divider *divider = to_clk_divider(hw);
 	int i, bestdiv = 0;
-	unsigned long parent_rate, best = 0, now, maxdiv;
+	unsigned long parent_rate, best = 0, now, maxdiv, mindiv;
 
 	if (!rate)
 		rate = 1;
 
 	maxdiv = _get_maxdiv(divider);
+	mindiv = _get_mindiv(divider);
 
 	if (!(__clk_get_flags(hw->clk) & CLK_SET_RATE_PARENT)) {
 		parent_rate = *best_parent_rate;
 		bestdiv = DIV_ROUND_UP(parent_rate, rate);
-		bestdiv = bestdiv == 0 ? 1 : bestdiv;
+		bestdiv = bestdiv == 0 ? mindiv : bestdiv;
 		bestdiv = bestdiv > maxdiv ? maxdiv : bestdiv;
 		return bestdiv;
 	}
@@ -169,7 +175,7 @@ static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate,
 	 */
 	maxdiv = min(ULONG_MAX / rate, maxdiv);
 
-	for (i = 1; i <= maxdiv; i++) {
+	for (i = mindiv; i <= maxdiv; i++) {
 		if (!_is_valid_div(divider, i))
 			continue;
 		parent_rate = __clk_round_rate(__clk_get_parent(hw->clk),
-- 
1.7.12

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