target/linux/brcm2708/patches-4.4/0521-clk-bcm2835-Clamp-the-PLL-s-requested-rate-to-the-ha.patch

   1 From d9ab4b6b57e450db6a03df299079e8d80093ef45 Mon Sep 17 00:00:00 2001
   2 From: Eric Anholt <eric@anholt.net>
   3 Date: Wed, 28 Sep 2016 17:58:52 -0700
   4 Subject: [PATCH] clk: bcm2835: Clamp the PLL's requested rate to the hardware
   5  limits.
   6
   7 Fixes setting low-resolution video modes on HDMI.  Now the PLLH_PIX
   8 divider adjusts itself until the PLLH is within bounds.
   9
  10 Signed-off-by: Eric Anholt <eric@anholt.net>
  11 ---
  12  drivers/clk/bcm/clk-bcm2835.c | 11 ++++-------
  13  1 file changed, 4 insertions(+), 7 deletions(-)
  14
  15 --- a/drivers/clk/bcm/clk-bcm2835.c
  16 +++ b/drivers/clk/bcm/clk-bcm2835.c
  17 @@ -523,8 +523,12 @@ static long bcm2835_pll_rate_from_diviso
  18  static long bcm2835_pll_round_rate(struct clk_hw *hw, unsigned long rate,
  19                                    unsigned long *parent_rate)
  20  {
  21 +       struct bcm2835_pll *pll = container_of(hw, struct bcm2835_pll, hw);
  22 +       const struct bcm2835_pll_data *data = pll->data;
  23         u32 ndiv, fdiv;
  24
  25 +       rate = clamp(rate, data->min_rate, data->max_rate);
  26 +
  27         bcm2835_pll_choose_ndiv_and_fdiv(rate, *parent_rate, &ndiv, &fdiv);
  28
  29         return bcm2835_pll_rate_from_divisors(*parent_rate, ndiv, fdiv, 1);
  30 @@ -629,13 +633,6 @@ static int bcm2835_pll_set_rate(struct c
  31         u32 ana[4];
  32         int i;
  33
  34 -       if (rate < data->min_rate || rate > data->max_rate) {
  35 -               dev_err(cprman->dev, "%s: rate out of spec: %lu vs (%lu, %lu)\n",
  36 -                       clk_hw_get_name(hw), rate,
  37 -                       data->min_rate, data->max_rate);
  38 -               return -EINVAL;
  39 -       }
  40 -
  41         if (rate > data->max_fb_rate) {
  42                 use_fb_prediv = true;
  43                 rate /= 2;