diff options
Diffstat (limited to 'drivers/clk/clk-divider.c')
| -rw-r--r-- | drivers/clk/clk-divider.c | 25 |
1 files changed, 23 insertions, 2 deletions
diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c index 6d9674160430..6d55eb2cb959 100644 --- a/drivers/clk/clk-divider.c +++ b/drivers/clk/clk-divider.c @@ -150,6 +150,7 @@ static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate, struct clk_divider *divider = to_clk_divider(hw); int i, bestdiv = 0; unsigned long parent_rate, best = 0, now, maxdiv; + unsigned long parent_rate_saved = *best_parent_rate; if (!rate) rate = 1; @@ -173,6 +174,15 @@ static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate, for (i = 1; i <= maxdiv; i++) { if (!_is_valid_div(divider, i)) continue; + if (rate * i == parent_rate_saved) { + /* + * It's the most ideal case if the requested rate can be + * divided from parent clock without needing to change + * parent rate, so return the divider immediately. + */ + *best_parent_rate = parent_rate_saved; + return i; + } parent_rate = __clk_round_rate(__clk_get_parent(hw->clk), MULT_ROUND_UP(rate, i)); now = parent_rate / i; @@ -217,8 +227,12 @@ 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 +259,13 @@ 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) { |