[PATCH v2 2/2] phy: mediatek: hdmi: mt8195: fix wrong pll calculus

From: Guillaume Ranquet
Date: Fri Apr 14 2023 - 12:13:12 EST


The clock rate calculus in mtk_hdmi_pll_calc() was wrong when it has
been replaced by 'div_u64'.

Fix the issue by multiplying the values in the denominator instead of
dividing them.

Fixes: 45810d486bb44 ("phy: mediatek: add support for phy-mtk-hdmi-mt8195")
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
Signed-off-by: Guillaume Ranquet <granquet@xxxxxxxxxxxx>
---
drivers/phy/mediatek/phy-mtk-hdmi-mt8195.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/phy/mediatek/phy-mtk-hdmi-mt8195.c b/drivers/phy/mediatek/phy-mtk-hdmi-mt8195.c
index 054b73cb31ee..caa953780bee 100644
--- a/drivers/phy/mediatek/phy-mtk-hdmi-mt8195.c
+++ b/drivers/phy/mediatek/phy-mtk-hdmi-mt8195.c
@@ -271,7 +271,7 @@ static int mtk_hdmi_pll_calc(struct mtk_hdmi_phy *hdmi_phy, struct clk_hw *hw,
* [32,24] 9bit integer, [23,0]:24bit fraction
*/
pcw = div_u64(((u64)ns_hdmipll_ck) << PCW_DECIMAL_WIDTH,
- da_hdmitx21_ref_ck / PLL_FBKDIV_HS3);
+ da_hdmitx21_ref_ck * PLL_FBKDIV_HS3);

if (pcw > GENMASK_ULL(32, 0))
return -EINVAL;
@@ -288,7 +288,7 @@ static int mtk_hdmi_pll_calc(struct mtk_hdmi_phy *hdmi_phy, struct clk_hw *hw,
posdiv2 = 1;

/* Digital clk divider, max /32 */
- digital_div = div_u64((u64)ns_hdmipll_ck, posdiv1 / posdiv2 / pixel_clk);
+ digital_div = div_u64(ns_hdmipll_ck, posdiv1 * posdiv2 * pixel_clk);
if (!(digital_div <= 32 && digital_div >= 1))
return -EINVAL;


--
2.40.0