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>
This commit is contained in:
Eric Anholt 2016-09-30 10:07:27 -07:00 committed by Stephen Boyd
parent 1c7032258d
commit c4e634ce41

View file

@ -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;