summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--drivers/clk/zynqmp/divider.c46
1 files changed, 46 insertions, 0 deletions
diff --git a/drivers/clk/zynqmp/divider.c b/drivers/clk/zynqmp/divider.c
index da6903197fc7..c6af0c454997 100644
--- a/drivers/clk/zynqmp/divider.c
+++ b/drivers/clk/zynqmp/divider.c
@@ -89,6 +89,42 @@ static unsigned long zynqmp_clk_divider_recalc_rate(struct clk_hw *hw,
return DIV_ROUND_UP_ULL(parent_rate, value);
}
+static void zynqmp_get_divider2_val(struct clk_hw *hw,
+ unsigned long rate,
+ unsigned long parent_rate,
+ struct zynqmp_clk_divider *divider,
+ int *bestdiv)
+{
+ int div1;
+ int div2;
+ long error = LONG_MAX;
+ struct clk_hw *parent_hw = clk_hw_get_parent(hw);
+ struct zynqmp_clk_divider *pdivider = to_zynqmp_clk_divider(parent_hw);
+
+ if (!pdivider)
+ return;
+
+ *bestdiv = 1;
+ for (div1 = 1; div1 <= pdivider->max_div;) {
+ for (div2 = 1; div2 <= divider->max_div;) {
+ long new_error = ((parent_rate / div1) / div2) - rate;
+
+ if (abs(new_error) < abs(error)) {
+ *bestdiv = div2;
+ error = new_error;
+ }
+ if (divider->flags & CLK_DIVIDER_POWER_OF_TWO)
+ div2 = div2 << 1;
+ else
+ div2++;
+ }
+ if (pdivider->flags & CLK_DIVIDER_POWER_OF_TWO)
+ div1 = div1 << 1;
+ else
+ div1++;
+ }
+}
+
/**
* zynqmp_clk_divider_round_rate() - Round rate of divider clock
* @hw: handle between common and hardware-specific interfaces
@@ -126,6 +162,16 @@ static long zynqmp_clk_divider_round_rate(struct clk_hw *hw,
bestdiv = zynqmp_divider_get_val(*prate, rate);
+ /*
+ * In case of two divisors, compute best divider values and return
+ * divider2 value based on compute value. div1 will be automatically
+ * set to optimum based on required total divider value.
+ */
+ if (div_type == TYPE_DIV2 &&
+ (clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT)) {
+ zynqmp_get_divider2_val(hw, rate, *prate, divider, &bestdiv);
+ }
+
if ((clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT) && divider->is_frac)
bestdiv = rate % *prate ? 1 : bestdiv;
*prate = rate * bestdiv;