[PATCH 1/6] clk: imx8mp: add 700 MHz rate entry for VIDEO_PLL1
Ahmad Fatoum
a.fatoum at pengutronix.de
Tue Jun 2 00:04:31 PDT 2026
On 6/2/26 6:09 AM, Johannes Schneider wrote:
> From: Thomas Haemmerle <thomas.haemmerle at leica-geosystems.com>
>
> The LVDS serializer requires link_freq = pixel_clock × 7. For a 25 MHz
> pixel clock the link frequency is 175 MHz. VIDEO_PLL1 must be set to
> 700 MHz so the divider chain (VIDEO_PLL1 / 4 = 175 MHz) produces an
> exact match; without it clk_set_rate() rounds down to 650 MHz, yielding
> only 162.5 MHz and causing the LVDS transmitter to output ~743 pixels
> per line instead of 800 — visible as a black strip on the right edge.
>
> PLL parameters: Fin=24 MHz, P=3, S=2, K=0 → 24 × 350 / (3 × 4) = 700 MHz.
>
> Assisted-by: Claude:claude-sonnet-4-6
> Signed-of-by: Thomas Haemmerle <thomas.haemmerle at leica-geosystems.com>
Reviewed-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
> ---
> drivers/clk/imx/clk-pll14xx.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/clk/imx/clk-pll14xx.c b/drivers/clk/imx/clk-pll14xx.c
> index 6716a6f555..db7e744e87 100644
> --- a/drivers/clk/imx/clk-pll14xx.c
> +++ b/drivers/clk/imx/clk-pll14xx.c
> @@ -61,6 +61,7 @@ static const struct imx_pll14xx_rate_table imx_pll1416x_tbl[] = {
> };
>
> static const struct imx_pll14xx_rate_table imx_pll1443x_tbl[] = {
> + PLL_1443X_RATE(700000000U, 350, 3, 2, 0),
> PLL_1443X_RATE(650000000U, 325, 3, 2, 0),
> PLL_1443X_RATE(594000000U, 198, 2, 2, 0),
> PLL_1443X_RATE(393216000U, 262, 2, 3, 9437),
>
> base-commit: 81fbe2e8d0d445032498a0bfecf9fd270f00985a
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