On 10/5/22 17:13, Jagan Teki wrote:
Look like PLL PMS_P offset value varies between platforms that have Samsung DSIM IP. However, there is no clear evidence for it as both Exynos and i.MX 8M Mini Application Processor Reference Manual is still referring the PMS_P offset as 13. The offset 13 is not working for i.MX8M Mini SoCs but the downstream NXP sec-dsim.c driver is using offset 14 for i.MX8M Mini SoC platforms [1] [2]. PMS_P value set in sec_mipi_dsim_check_pll_out using PLLCTRL_SET_P() with offset 13 and then an additional offset of one bit added in sec_mipi_dsim_config_pll via PLLCTRL_SET_PMS(). Not sure whether it is reference manual documentation or something else but this patch trusts the downstream code and handle PLL_P offset via platform driver data so-that imx8mm driver data shall use pll_p_offset to 14. [1] https://source.codeaurora.org/external/imx/linux-imx/tree/drivers/gpu/drm/bridge/sec-dsim.c?h=imx_5.4.47_2.2.0#n210 [2] https://source.codeaurora.org/external/imx/linux-imx/tree/drivers/gpu/drm/bridge/sec-dsim.c?h=imx_5.4.47_2.2.0#n211
You also add to the commit message that all of 8M Mini/Nano/Plus have P=14 , unlike Exynos. It also seems like the PLL in the DSIM and the clock PLLs in the 8M are the same design from Samsung.
Reviewed-by: Marek Vasut <marex@xxxxxxx>
