clk: bcm2835: Clamp the PLL's requested rate to the hardware limits.

Fixes setting low-resolution video modes on HDMI.  Now the PLLH_PIX
divider adjusts itself until the PLLH is within bounds.

Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

diff --git a/drivers/clk/bcm/clk-bcm2835.c b/drivers/clk/bcm/clk-bcm2835.c
index b68bf57..8c7763f 100644 (file)
--- a/drivers/clk/bcm/clk-bcm2835.c
+++ b/drivers/clk/bcm/clk-bcm2835.c
@@ -502,8 +502,12 @@ static long bcm2835_pll_rate_from_divisors(unsigned long parent_rate,
 static long bcm2835_pll_round_rate(struct clk_hw *hw, unsigned long rate,
                                   unsigned long *parent_rate)
 {
+       struct bcm2835_pll *pll = container_of(hw, struct bcm2835_pll, hw);
+       const struct bcm2835_pll_data *data = pll->data;
        u32 ndiv, fdiv;
 
+       rate = clamp(rate, data->min_rate, data->max_rate);
+
        bcm2835_pll_choose_ndiv_and_fdiv(rate, *parent_rate, &ndiv, &fdiv);
 
        return bcm2835_pll_rate_from_divisors(*parent_rate, ndiv, fdiv, 1);
@@ -608,13 +612,6 @@ static int bcm2835_pll_set_rate(struct clk_hw *hw,
        u32 ana[4];
        int i;
 
-       if (rate < data->min_rate || rate > data->max_rate) {
-               dev_err(cprman->dev, "%s: rate out of spec: %lu vs (%lu, %lu)\n",
-                       clk_hw_get_name(hw), rate,
-                       data->min_rate, data->max_rate);
-               return -EINVAL;
-       }
-
        if (rate > data->max_fb_rate) {
                use_fb_prediv = true;
                rate /= 2;