6.10-stable review patch. If anyone has any objections, please let me know.
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From: Adam Ford aford173@gmail.com
[ Upstream commit 78c4c0011bb577a29906d8ca135795af2293c49e ]
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 Reviewed-by: Marek Vasut marex@denx.de Tested-by: Marek Szyprowski m.szyprowski@samsung.com Signed-off-by: Robert Foss rfoss@kernel.org Link: https://patchwork.freedesktop.org/patch/msgid/20240601144103.198299-1-aford1... Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/bridge/samsung-dsim.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/bridge/samsung-dsim.c index 95fedc68b0ae5..8476650c477c2 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)); + p_max = fin / (driver_data->pll_fin_min * MHZ);
for (_p = p_min; _p <= p_max; ++_p) { for (_s = 0; _s <= 5; ++_s) {