The patch enables spread spectrum clocking (SSC) for MPU and LCD PLLs. As reported by the TI spruh73x/spruhl7x RM, SSC is only supported for the DISP/LCD and MPU PLLs on am33xx/am43xx. SSC is not supported for DDR, PER, and CORE PLLs. Calculating the required values and setting the registers accordingly was taken from the set_mpu_spreadspectrum routine contained in the arch/arm/mach-omap2/am33xx/clock_am33xx.c file of the u-boot project. In locked condition, DPLL output clock = CLKINP *[M/N]. In case of SSC enabled, the reference manual explains that there is a restriction of range of M values. Since the omap2_dpll_round_rate routine attempts to select the minimum possible N, the value of M obtained is not guaranteed to be within the range required. With the new "ti,min-div" parameter it is possible to increase N and consequently M to satisfy the constraint imposed by SSC. Signed-off-by: Dario Binacchi <dariobin@libero.it> Reviewed-by: Tero Kristo <kristo@kernel.org> Link: https://lore.kernel.org/r/20210606202253.31649-6-dariobin@libero.it Signed-off-by: Stephen Boyd <sboyd@kernel.org> |
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| .. | ||
| analogbits-wrpll-cln28hpc.h | ||
| at91_pmc.h | ||
| clk-conf.h | ||
| davinci.h | ||
| imx.h | ||
| mmp.h | ||
| mxs.h | ||
| renesas.h | ||
| samsung.h | ||
| spear.h | ||
| sunxi-ng.h | ||
| tegra.h | ||
| ti.h | ||
| zynq.h | ||