Messages in this thread | | | Date | Mon, 17 Apr 2023 00:07:16 +0200 | Subject | Re: [PATCH 2/6] drm: bridge: samsung-dsim: Fix PMS Calculator on imx8m[mnp] | From | Marek Vasut <> |
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On 4/15/23 12:40, Adam Ford wrote: > According to Table 13-45 of the i.MX8M Mini Reference Manual, the min > and max values for M and the frequency range for the VCO_out > calculator were incorrect. This also appears to be the case for the > imx8mn and imx8mp. > > To fix this, make new variables to hold the min and max values of m > and the minimum value of VCO_out, and update the PMS calculator to > use these new variables instead of using hard-coded values to keep > the backwards compatibility with other parts using this driver.
[...]
> static const struct samsung_dsim_driver_data imx8mm_dsi_driver_data = { > @@ -470,6 +485,9 @@ static const struct samsung_dsim_driver_data imx8mm_dsi_driver_data = { > */ > .pll_p_offset = 14, > .reg_values = imx8mm_dsim_reg_values, > + .m_min = 64, > + .m_max = 1023, > + .vco_min = 1050,
You might want to call this 'min_freq' since there is a 'max_freq' which seems to indicate what VCO max frequency is.
Note that the same datasheet contains the following information: " MIPI_DPHY_M_PLLPMS field descriptions
12–4 PMS_M Specifies the PLL PMS value for the M divider NOTE: The programmable divider range should be within 25 to 125 to ensure PLL stability. NOTE: The M and P divider values should be considered together to ensure VCO ouput frequency (VCO_out) range is between 350 MHz to 750 MHz. Please refer to the topic DPHY PLL for more information. "
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