X-Git-Url: https://git.karo-electronics.de/?a=blobdiff_plain;f=drivers%2Fclk%2Fclk-divider.c;h=6d55eb2cb959baafc949cae9db15097f38c51c76;hb=bfffbea1aaeeb1eb6500c83ff9653416daa5b490;hp=6d9674160430db7456b58c1697272a801b68ba52;hpb=aad760136537fdfa10e5ac76bd3c79bde2100863;p=karo-tx-linux.git

diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c
index 6d9674160430..6d55eb2cb959 100644
--- a/drivers/clk/clk-divider.c
+++ b/drivers/clk/clk-divider.c
@@ -150,6 +150,7 @@ 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_saved = *best_parent_rate;
 
 	if (!rate)
 		rate = 1;
@@ -173,6 +174,15 @@ static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate,
 	for (i = 1; i <= maxdiv; i++) {
 		if (!_is_valid_div(divider, i))
 			continue;
+		if (rate * i == parent_rate_saved) {
+			/*
+			 * It's the most ideal case if the requested rate can be
+			 * divided from parent clock without needing to change
+			 * parent rate, so return the divider immediately.
+			 */
+			*best_parent_rate = parent_rate_saved;
+			return i;
+		}
 		parent_rate = __clk_round_rate(__clk_get_parent(hw->clk),
 				MULT_ROUND_UP(rate, i));
 		now = parent_rate / i;
@@ -217,8 +227,12 @@ static int clk_divider_set_rate(struct clk_hw *hw, unsigned long rate,
 	if (divider->lock)
 		spin_lock_irqsave(divider->lock, flags);
 
-	val = readl(divider->reg);
-	val &= ~(div_mask(divider) << divider->shift);
+	if (divider->flags & CLK_DIVIDER_HIWORD_MASK) {
+		val = div_mask(divider) << (divider->shift + 16);
+	} else {
+		val = readl(divider->reg);
+		val &= ~(div_mask(divider) << divider->shift);
+	}
 	val |= value << divider->shift;
 	writel(val, divider->reg);
 
@@ -245,6 +259,13 @@ static struct clk *_register_divider(struct device *dev, const char *name,
 	struct clk *clk;
 	struct clk_init_data init;
 
+	if (clk_divider_flags & CLK_DIVIDER_HIWORD_MASK) {
+		if (width + shift > 16) {
+			pr_warn("divider value exceeds LOWORD field\n");
+			return ERR_PTR(-EINVAL);
+		}
+	}
+
 	/* allocate the divider */
 	div = kzalloc(sizeof(struct clk_divider), GFP_KERNEL);
 	if (!div) {