1 files changed, 23 insertions, 2 deletions

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) {