arm64: dts: imx8mp: Clarify csis clock frequency

The DT nodes for the MIPI CSI-2 receivers (MIPI_CSI) configure the
CAM1_PIX and CAM2_PIX clocks to 266 MHz through the assigned-clock-rates
property, and report that frequency in the clock-frequency property. The
i.MX8MP reference manual and datasheet list 266 MHz as a nominal
frequency when using both CSI-2 receivers, so all looks normal.

In reality, the clock is actually set to 250 MHz, as the selected
parent, IMX8MP_SYS_PLL2_1000M, has a 1/4 output that is selected as the
closest frequency to 266 MHz. This doesn't break operation of the
device, but is clearly misleading.

Clarify the clock configuration by selecting the IMX8MP_SYS_PLL2_250M
parent, dropping the redundant assigned-clock-rates, and setting
clock-frequency to 250 MHz. This doesn't cause any functional change.

Signed-off-by: Laurent Pinchart <[email protected]>
Reviewed-by: Alexander Stein <[email protected]>
Tested-by: Alexander Stein <[email protected]>
Signed-off-by: Shawn Guo <[email protected]>

arch/arm64/boot/dts/freescale/imx8mp.dtsi

@@ -1687,17 +1687,16 @@
 				compatible = "fsl,imx8mp-mipi-csi2", "fsl,imx8mm-mipi-csi2";
 				reg = <0x32e40000 0x10000>;
 				interrupts = <GIC_SPI 17 IRQ_TYPE_LEVEL_HIGH>;
-				clock-frequency = <266000000>;
+				clock-frequency = <250000000>;
 				clocks = <&clk IMX8MP_CLK_MEDIA_APB_ROOT>,
 					 <&clk IMX8MP_CLK_MEDIA_CAM1_PIX_ROOT>,
 					 <&clk IMX8MP_CLK_MEDIA_MIPI_PHY1_REF_ROOT>,
 					 <&clk IMX8MP_CLK_MEDIA_AXI_ROOT>;
 				clock-names = "pclk", "wrap", "phy", "axi";
 				assigned-clocks = <&clk IMX8MP_CLK_MEDIA_CAM1_PIX>,
 						  <&clk IMX8MP_CLK_MEDIA_MIPI_PHY1_REF>;
-				assigned-clock-parents = <&clk IMX8MP_SYS_PLL2_1000M>,
+				assigned-clock-parents = <&clk IMX8MP_SYS_PLL2_250M>,
 							 <&clk IMX8MP_CLK_24M>;
-				assigned-clock-rates = <266000000>;
 				power-domains = <&media_blk_ctrl IMX8MP_MEDIABLK_PD_MIPI_CSI2_1>;
 				status = "disabled";
 
@@ -1723,17 +1722,16 @@
 				compatible = "fsl,imx8mp-mipi-csi2", "fsl,imx8mm-mipi-csi2";
 				reg = <0x32e50000 0x10000>;
 				interrupts = <GIC_SPI 80 IRQ_TYPE_LEVEL_HIGH>;
-				clock-frequency = <266000000>;
+				clock-frequency = <250000000>;
 				clocks = <&clk IMX8MP_CLK_MEDIA_APB_ROOT>,
 					 <&clk IMX8MP_CLK_MEDIA_CAM2_PIX_ROOT>,
 					 <&clk IMX8MP_CLK_MEDIA_MIPI_PHY1_REF_ROOT>,
 					 <&clk IMX8MP_CLK_MEDIA_AXI_ROOT>;
 				clock-names = "pclk", "wrap", "phy", "axi";
 				assigned-clocks = <&clk IMX8MP_CLK_MEDIA_CAM2_PIX>,
 						  <&clk IMX8MP_CLK_MEDIA_MIPI_PHY1_REF>;
-				assigned-clock-parents = <&clk IMX8MP_SYS_PLL2_1000M>,
+				assigned-clock-parents = <&clk IMX8MP_SYS_PLL2_250M>,
 							 <&clk IMX8MP_CLK_24M>;
-				assigned-clock-rates = <266000000>;
 				power-domains = <&media_blk_ctrl IMX8MP_MEDIABLK_PD_MIPI_CSI2_2>;
 				status = "disabled";