Merge tag 'v4.7-rc5' into perf/core, to pick up fixes

[cascardo/linux.git] / drivers / gpu / drm / sun4i / sun4i_dotclock.c

diff --git a/drivers/gpu/drm/sun4i/sun4i_dotclock.c b/drivers/gpu/drm/sun4i/sun4i_dotclock.c
index 3ff668c..5b34631 100644 (file)
--- a/drivers/gpu/drm/sun4i/sun4i_dotclock.c
+++ b/drivers/gpu/drm/sun4i/sun4i_dotclock.c
@@ -72,14 +72,40 @@ static unsigned long sun4i_dclk_recalc_rate(struct clk_hw *hw,
 static long sun4i_dclk_round_rate(struct clk_hw *hw, unsigned long rate,
                                  unsigned long *parent_rate)
 {
-       return *parent_rate / DIV_ROUND_CLOSEST(*parent_rate, rate);
+       unsigned long best_parent = 0;
+       u8 best_div = 1;
+       int i;
+
+       for (i = 6; i < 127; i++) {
+               unsigned long ideal = rate * i;
+               unsigned long rounded;
+
+               rounded = clk_hw_round_rate(clk_hw_get_parent(hw),
+                                           ideal);
+
+               if (rounded == ideal) {
+                       best_parent = rounded;
+                       best_div = i;
+                       goto out;
+               }
+
+               if ((rounded < ideal) && (rounded > best_parent)) {
+                       best_parent = rounded;
+                       best_div = i;
+               }
+       }
+
+out:
+       *parent_rate = best_parent;
+
+       return best_parent / best_div;
 }
 
 static int sun4i_dclk_set_rate(struct clk_hw *hw, unsigned long rate,
                               unsigned long parent_rate)
 {
        struct sun4i_dclk *dclk = hw_to_dclk(hw);
-       int div = DIV_ROUND_CLOSEST(parent_rate, rate);
+       u8 div = parent_rate / rate;
 
        return regmap_update_bits(dclk->regmap, SUN4I_TCON0_DCLK_REG,
                                  GENMASK(6, 0), div);
@@ -127,10 +153,14 @@ int sun4i_dclk_create(struct device *dev, struct sun4i_tcon *tcon)
        const char *clk_name, *parent_name;
        struct clk_init_data init;
        struct sun4i_dclk *dclk;
+       int ret;
 
        parent_name = __clk_get_name(tcon->sclk0);
-       of_property_read_string_index(dev->of_node, "clock-output-names", 0,
-                                     &clk_name);
+       ret = of_property_read_string_index(dev->of_node,
+                                           "clock-output-names", 0,
+                                           &clk_name);
+       if (ret)
+               return ret;
 
        dclk = devm_kzalloc(dev, sizeof(*dclk), GFP_KERNEL);
        if (!dclk)
@@ -140,6 +170,7 @@ int sun4i_dclk_create(struct device *dev, struct sun4i_tcon *tcon)
        init.ops = &sun4i_dclk_ops;
        init.parent_names = &parent_name;
        init.num_parents = 1;
+       init.flags = CLK_SET_RATE_PARENT;
 
        dclk->regmap = tcon->regs;
        dclk->hw.init = &init;