clk: st: STiH410: Fix pdiv and fdiv divisor when setting rate

[linux-beck.git] / drivers / clk / st / clk-flexgen.c

diff --git a/drivers/clk/st/clk-flexgen.c b/drivers/clk/st/clk-flexgen.c
index 2282cef9f2ffb0d834b84be7b2b00c32190bde15..3a484b3cb448616f10578f7e6e2d064a8bf67cbd 100644 (file)
--- a/drivers/clk/st/clk-flexgen.c
+++ b/drivers/clk/st/clk-flexgen.c
@@ -138,16 +138,27 @@ static int flexgen_set_rate(struct clk_hw *hw, unsigned long rate,
        struct flexgen *flexgen = to_flexgen(hw);
        struct clk_hw *pdiv_hw = &flexgen->pdiv.hw;
        struct clk_hw *fdiv_hw = &flexgen->fdiv.hw;
-       unsigned long primary_div = 0;
+       unsigned long div = 0;
        int ret = 0;
 
        pdiv_hw->clk = hw->clk;
        fdiv_hw->clk = hw->clk;
 
-       primary_div = clk_best_div(parent_rate, rate);
+       div = clk_best_div(parent_rate, rate);
 
-       clk_divider_ops.set_rate(fdiv_hw, parent_rate, parent_rate);
-       ret = clk_divider_ops.set_rate(pdiv_hw, rate, rate * primary_div);
+       /*
+       * pdiv is mainly targeted for low freq results, while fdiv
+       * should be used for div <= 64. The other way round can
+       * lead to 'duty cycle' issues.
+       */
+
+       if (div <= 64) {
+               clk_divider_ops.set_rate(pdiv_hw, parent_rate, parent_rate);
+               ret = clk_divider_ops.set_rate(fdiv_hw, rate, rate * div);
+       } else {
+               clk_divider_ops.set_rate(fdiv_hw, parent_rate, parent_rate);
+               ret = clk_divider_ops.set_rate(pdiv_hw, rate, rate * div);
+       }
 
        return ret;
 }