On Thu, Feb 17, 2022 at 01:25:23AM +0100, Marek Vasut wrote:
The chip contains fractional PLL, however the driver currently hard-codes one specific PLL setting. Implement generic PLL parameter calculation code, so any DPI panel with arbitrary pixel clock can be attached to this bridge.
The datasheet for this bridge is not available, the PLL behavior has been inferred from [1] and [2] and by analyzing the DPI pixel clock with scope. The PLL limits might be wrong, but at least the calculated values match all the example code available. This is better than one hard-coded pixel clock value anyway.
[1] https://github.com/rockchip-linux/kernel/blob/develop-4.19/drivers/gpu/drm/b... [2] https://github.com/tdjastrzebski/ICN6211-Configurator
Signed-off-by: Marek Vasut marex@denx.de Cc: Jagan Teki jagan@amarulasolutions.com Cc: Maxime Ripard maxime@cerno.tech Cc: Robert Foss robert.foss@linaro.org Cc: Sam Ravnborg sam@ravnborg.org Cc: Thomas Zimmermann tzimmermann@suse.de To: dri-devel@lists.freedesktop.org
Acked-by: Maxime Ripard maxime@cerno.tech
Maxime