drm/mgag200: Split PLL setup into compute and update functions
The _set_plls() functions compute a pixel clock's PLL values and program the hardware accordingly. This happens during atomic commits. For atomic modesetting, it's better to separate computation and programming from each other. This will allow to compute the PLL value during atomic checks and catch unsupported modes early. Split the PLL setup into a compute and an update functions, and call them one after the other. Computed PLL values are store in struct mgag200_pll_values. There are four parameters for the PLL, m, n, p and s. Every compute function stores a value for each of these parameters, and the rsp update function makes the register bits from them. The values stored by the compute function are either plain values or register bits. An additional change is required to always store plain values. No functional changes. Signed-off-by:Thomas Zimmermann <tzimmermann@suse.de> Acked-by: