Commit c4e634ce authored by Eric Anholt's avatar Eric Anholt Committed by Stephen Boyd
Browse files

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: default avatarEric Anholt <eric@anholt.net>
Signed-off-by: default avatarStephen Boyd <sboyd@codeaurora.org>
parent 1c703225

drivers/clk/bcm/clk-bcm2835.c

+4 −7
Original line number Original line Diff line number Diff line
@@ -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,

static long bcm2835_pll_round_rate(struct clk_hw *hw, unsigned long rate,

				   unsigned long *parent_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;

	u32 ndiv, fdiv;





	rate = clamp(rate, data->min_rate, data->max_rate);



	bcm2835_pll_choose_ndiv_and_fdiv(rate, *parent_rate, &ndiv, &fdiv);

	bcm2835_pll_choose_ndiv_and_fdiv(rate, *parent_rate, &ndiv, &fdiv);





	return bcm2835_pll_rate_from_divisors(*parent_rate, ndiv, fdiv, 1);

	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];

	u32 ana[4];

	int i;

	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) {

	if (rate > data->max_fb_rate) {

		use_fb_prediv = true;

		use_fb_prediv = true;

		rate /= 2;

		rate /= 2;

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