target/linux/sunxi/patches-3.14/187-clk-sunxi-automatic-reparenting.patch

   1 From b416520f239aeaa4207ebe84c22247cff2da444f Mon Sep 17 00:00:00 2001
   2 From: =?UTF-8?q?Emilio=20L=C3=B3pez?= <emilio@elopez.com.ar>
   3 Date: Thu, 5 Sep 2013 19:52:41 -0300
   4 Subject: [PATCH] clk: sunxi: factors: automatic reparenting support
   5 MIME-Version: 1.0
   6 Content-Type: text/plain; charset=UTF-8
   7 Content-Transfer-Encoding: 8bit
   8
   9 This commit implements .determine_rate, so that our factor clocks can be
  10 reparented when needed.
  11
  12 Signed-off-by: Emilio López <emilio@elopez.com.ar>
  13 ---
  14  drivers/clk/sunxi/clk-factors.c | 36 ++++++++++++++++++++++++++++++++++++
  15  1 file changed, 36 insertions(+)
  16
  17 --- a/drivers/clk/sunxi/clk-factors.c
  18 +++ b/drivers/clk/sunxi/clk-factors.c
  19 @@ -77,6 +77,41 @@ static long clk_factors_round_rate(struc
  20         return rate;
  21  }
  22
  23 +static long clk_factors_determine_rate(struct clk_hw *hw, unsigned long rate,
  24 +                                      unsigned long *best_parent_rate,
  25 +                                      struct clk **best_parent_p)
  26 +{
  27 +       struct clk *clk = hw->clk, *parent, *best_parent = NULL;
  28 +       int i, num_parents;
  29 +       unsigned long parent_rate, best = 0, child_rate, best_child_rate = 0;
  30 +
  31 +       /* find the parent that can help provide the fastest rate <= rate */
  32 +       num_parents = __clk_get_num_parents(clk);
  33 +       for (i = 0; i < num_parents; i++) {
  34 +               parent = clk_get_parent_by_index(clk, i);
  35 +               if (!parent)
  36 +                       continue;
  37 +               if (__clk_get_flags(clk) & CLK_SET_RATE_PARENT)
  38 +                       parent_rate = __clk_round_rate(parent, rate);
  39 +               else
  40 +                       parent_rate = __clk_get_rate(parent);
  41 +
  42 +               child_rate = clk_factors_round_rate(hw, rate, &parent_rate);
  43 +
  44 +               if (child_rate <= rate && child_rate > best_child_rate) {
  45 +                       best_parent = parent;
  46 +                       best = parent_rate;
  47 +                       best_child_rate = child_rate;
  48 +               }
  49 +       }
  50 +
  51 +       if (best_parent)
  52 +               *best_parent_p = best_parent;
  53 +       *best_parent_rate = best;
  54 +
  55 +       return best_child_rate;
  56 +}
  57 +
  58  static int clk_factors_set_rate(struct clk_hw *hw, unsigned long rate,
  59                                 unsigned long parent_rate)
  60  {
  61 @@ -113,6 +148,7 @@ static int clk_factors_set_rate(struct c
  62  }
  63
  64  const struct clk_ops clk_factors_ops = {
  65 +       .determine_rate = clk_factors_determine_rate,
  66         .recalc_rate = clk_factors_recalc_rate,
  67         .round_rate = clk_factors_round_rate,
  68         .set_rate = clk_factors_set_rate,