[PATCH v2 02/15] clk: sunxi-ng: Add check for minimal rate to NKM PLLs
From: Maxime Ripard <hidden>
Date: 2018-10-24 18:04:50
Also in:
dri-devel, linux-clk, linux-devicetree, lkml
On Tue, Oct 23, 2018 at 09:20:22PM +0530, Jagan Teki wrote:
quoted hunk ↗ jump to hunk
Some NKM PLLs doesn't work well when their output clock rate is set below certain rate. So, add support for minimal rate for relevant PLLs. Signed-off-by: Jagan Teki <jagan@amarulasolutions.com> --- Changes for v2: - new patch drivers/clk/sunxi-ng/ccu_nkm.c | 7 +++++++ drivers/clk/sunxi-ng/ccu_nkm.h | 1 + 2 files changed, 8 insertions(+)diff --git a/drivers/clk/sunxi-ng/ccu_nkm.c b/drivers/clk/sunxi-ng/ccu_nkm.c index 841840e35e61..d17539dc88dd 100644 --- a/drivers/clk/sunxi-ng/ccu_nkm.c +++ b/drivers/clk/sunxi-ng/ccu_nkm.c@@ -125,6 +125,13 @@ static unsigned long ccu_nkm_round_rate(struct ccu_mux_internal *mux, if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV) rate *= nkm->fixed_post_div; + if (rate < nkm->min_rate) { + rate = nkm->min_rate; + if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV) + rate /= nkm->fixed_post_div;
I'm not sure this is right. Is the post divider taken into account to calculate the minimum, or is the minimum on the rate before the fixed post divider. How did you test this? Maxime -- Maxime Ripard, Bootlin Embedded Linux and Kernel engineering https://bootlin.com