linux/include/drm/bridge
Michael Tretter 846307185f drm/bridge: samsung-dsim: update PLL reference clock
The PLL requires a clock frequency in a certain platform-dependent range
after the pre-divider. The reference clock for the PLL may change due to
changes to it's parent clock. Thus, the frequency may be out of range or
unsuited for generating the high speed clock for MIPI DSI.

Try to keep the pre-devider small, and set the reference clock close to
the upper limit before recalculating the PLL configuration. Use a
divider with a power of two for the reference clock as this seems to
work best in my tests.

Reviewed-by: Marco Felsch <m.felsch@pengutronix.de>
Tested-by: Frieder Schrempf <frieder.schrempf@kontron.de> # Kontron BL i.MX8MM + Waveshare 10.1inch HDMI LCD (E)
Signed-off-by: Michael Tretter <m.tretter@pengutronix.de>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/20230818-samsung-dsim-v2-3-846603df0e0a@pengutronix.de
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230818-samsung-dsim-v2-3-846603df0e0a@pengutronix.de
2023-10-09 11:06:22 +02:00
..
analogix_dp.h drm/bridge: analogix_dp: Split bind() into probe() and real bind() 2020-04-09 10:29:35 +02:00
dw_hdmi.h drm/bridge: dw-hdmi: change YUV420 selection logic at clock setup 2023-06-27 09:51:31 +02:00
dw_mipi_dsi.h drm/bridge/synopsys: dsi: extend the prototype of mode_valid() 2022-01-04 12:53:59 +01:00
mhl.h drm/bridge/mhl.h: Replace zero-length array with flexible-array member 2020-03-06 11:52:01 +01:00
samsung-dsim.h drm/bridge: samsung-dsim: update PLL reference clock 2023-10-09 11:06:22 +02:00