Merge tag 'lsk-v3.10-android-14.12'

[firefly-linux-kernel-4.4.55.git] / drivers / clk / clk-divider.c

diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c
index 2ce22447d76e97b660c1fc7ea7a024dc411c0a51..6769f509fd2bc187ce0f333836e4d368bf50f95f 100644 (file)
--- a/drivers/clk/clk-divider.c
+++ b/drivers/clk/clk-divider.c
@@ -24,7 +24,7 @@
  * Traits of this clock:
  * prepare - clk_prepare only ensures that parents are prepared
  * enable - clk_enable only ensures that parents are enabled
- * rate - rate is adjustable.  clk->rate = parent->rate / divisor
+ * rate - rate is adjustable.  clk->rate = DIV_ROUND_UP(parent->rate / divisor)
  * parent - fixed parent.  No clk_set_parent support
  */
 
@@ -43,6 +43,17 @@ static unsigned int _get_table_maxdiv(const struct clk_div_table *table)
        return maxdiv;
 }
 
+static unsigned int _get_table_mindiv(const struct clk_div_table *table)
+{
+       unsigned int mindiv = UINT_MAX;
+       const struct clk_div_table *clkt;
+
+       for (clkt = table; clkt->div; clkt++)
+               if (clkt->div < mindiv)
+                       mindiv = clkt->div;
+       return mindiv;
+}
+
 static unsigned int _get_maxdiv(struct clk_divider *divider)
 {
        if (divider->flags & CLK_DIVIDER_ONE_BASED)
@@ -115,7 +126,7 @@ static unsigned long clk_divider_recalc_rate(struct clk_hw *hw,
                return parent_rate;
        }
 
-       return parent_rate / div;
+       return DIV_ROUND_UP(parent_rate, div);
 }
 
 /*
@@ -144,6 +155,91 @@ static bool _is_valid_div(struct clk_divider *divider, unsigned int div)
        return true;
 }
 
+static int _round_up_table(const struct clk_div_table *table, int div)
+{
+       const struct clk_div_table *clkt;
+       int up = INT_MAX;
+
+       for (clkt = table; clkt->div; clkt++) {
+               if (clkt->div == div)
+                       return clkt->div;
+               else if (clkt->div < div)
+                       continue;
+
+               if ((clkt->div - div) < (up - div))
+                       up = clkt->div;
+       }
+
+       return up;
+}
+
+static int _round_down_table(const struct clk_div_table *table, int div)
+{
+       const struct clk_div_table *clkt;
+       int down = _get_table_mindiv(table);
+
+       for (clkt = table; clkt->div; clkt++) {
+               if (clkt->div == div)
+                       return clkt->div;
+               else if (clkt->div > div)
+                       continue;
+
+               if ((div - clkt->div) < (div - down))
+                       down = clkt->div;
+       }
+
+       return down;
+}
+
+static int _div_round_up(struct clk_divider *divider,
+               unsigned long parent_rate, unsigned long rate)
+{
+       int div = DIV_ROUND_UP(parent_rate, rate);
+
+       if (divider->flags & CLK_DIVIDER_POWER_OF_TWO)
+               div = __roundup_pow_of_two(div);
+       if (divider->table)
+               div = _round_up_table(divider->table, div);
+
+       return div;
+}
+
+static int _div_round_closest(struct clk_divider *divider,
+               unsigned long parent_rate, unsigned long rate)
+{
+       int up, down, div;
+
+       up = down = div = DIV_ROUND_CLOSEST(parent_rate, rate);
+
+       if (divider->flags & CLK_DIVIDER_POWER_OF_TWO) {
+               up = __roundup_pow_of_two(div);
+               down = __rounddown_pow_of_two(div);
+       } else if (divider->table) {
+               up = _round_up_table(divider->table, div);
+               down = _round_down_table(divider->table, div);
+       }
+
+       return (up - div) <= (div - down) ? up : down;
+}
+
+static int _div_round(struct clk_divider *divider, unsigned long parent_rate,
+               unsigned long rate)
+{
+       if (divider->flags & CLK_DIVIDER_ROUND_CLOSEST)
+               return _div_round_closest(divider, parent_rate, rate);
+
+       return _div_round_up(divider, parent_rate, rate);
+}
+
+static bool _is_best_div(struct clk_divider *divider,
+               unsigned long rate, unsigned long now, unsigned long best)
+{
+       if (divider->flags & CLK_DIVIDER_ROUND_CLOSEST)
+               return abs(rate - now) < abs(rate - best);
+
+       return now <= rate && now > best;
+}
+
 static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate,
                unsigned long *best_parent_rate)
 {
@@ -158,7 +254,7 @@ static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate,
 
        if (!(__clk_get_flags(hw->clk) & CLK_SET_RATE_PARENT)) {
                parent_rate = *best_parent_rate;
-               bestdiv = DIV_ROUND_UP(parent_rate, rate);
+               bestdiv = _div_round(divider, parent_rate, rate);
                bestdiv = bestdiv == 0 ? 1 : bestdiv;
                bestdiv = bestdiv > maxdiv ? maxdiv : bestdiv;
                return bestdiv;
@@ -175,8 +271,8 @@ static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate,
                        continue;
                parent_rate = __clk_round_rate(__clk_get_parent(hw->clk),
                                MULT_ROUND_UP(rate, i));
-               now = parent_rate / i;
-               if (now <= rate && now > best) {
+               now = DIV_ROUND_UP(parent_rate, i);
+               if (_is_best_div(divider, rate, now, best)) {
                        bestdiv = i;
                        best = now;
                        *best_parent_rate = parent_rate;
@@ -197,7 +293,7 @@ static long clk_divider_round_rate(struct clk_hw *hw, unsigned long rate,
        int div;
        div = clk_divider_bestdiv(hw, rate, prate);
 
-       return *prate / div;
+       return DIV_ROUND_UP(*prate, div);
 }
 
 static int clk_divider_set_rate(struct clk_hw *hw, unsigned long rate,
@@ -208,7 +304,11 @@ static int clk_divider_set_rate(struct clk_hw *hw, unsigned long rate,
        unsigned long flags = 0;
        u32 val;
 
-       div = parent_rate / rate;
+       div = DIV_ROUND_UP(parent_rate, rate);
+
+       if (!_is_valid_div(divider, div))
+               return -EINVAL;
+
        value = _get_val(divider, div);
 
        if (value > div_mask(divider))
@@ -217,8 +317,12 @@ 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 +349,13 @@ 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) {