Messages in this thread | | | Date | Sun, 21 Apr 2024 16:05:08 +0200 | Subject | Re: [PATCH V2 1/2] drm/bridge: samsung-dsim: Set P divider based on min/max of fin pll | From | Marek Vasut <> |
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On 2/12/24 12:09 AM, Adam Ford wrote: > The P divider should be set based on the min and max values of > the fin pll which may vary between different platforms. > These ranges are defined per platform, but hard-coded values > were used instead which resulted in a smaller range available > on the i.MX8M[MNP] than what was possible. > > As noted by Frieder, there are descripencies between the reference > manuals of the Mini, Nano and Plus, so I reached out to my NXP > rep and got the following response regarding the varing notes > in the documentation. > > "Yes it is definitely wrong, the one that is part of the NOTE in > MIPI_DPHY_M_PLLPMS register table against PMS_P, PMS_M and PMS_S is > not correct. I will report this to Doc team, the one customer should > be take into account is the Table 13-40 DPHY PLL Parameters and the > Note above." > > With this patch, the clock rates now match the values used in NXP's > downstream kernel. > > Fixes: 846307185f0f ("drm/bridge: samsung-dsim: update PLL reference clock") > Signed-off-by: Adam Ford <aford173@gmail.com> > Reviewed-by: Frieder Schrempf <frieder.schrempf@kontron.de> > Tested-by: Frieder Schrempf <frieder.schrempf@kontron.de> > --- > V2: Only update the commit message to reflect why these values > were chosen. No code change present > > diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/bridge/samsung-dsim.c > index 95fedc68b0ae..8476650c477c 100644 > --- a/drivers/gpu/drm/bridge/samsung-dsim.c > +++ b/drivers/gpu/drm/bridge/samsung-dsim.c > @@ -574,8 +574,8 @@ static unsigned long samsung_dsim_pll_find_pms(struct samsung_dsim *dsi, > u16 _m, best_m; > u8 _s, best_s; > > - p_min = DIV_ROUND_UP(fin, (12 * MHZ)); > - p_max = fin / (6 * MHZ); > + p_min = DIV_ROUND_UP(fin, (driver_data->pll_fin_max * MHZ));
The parenthesis around driver_data... are not needed.
With that fixed:
Reviewed-by: Marek Vasut <marex@denx.de>
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