Commit 7e4030e3 authored by Laurent Pinchart's avatar Laurent Pinchart Committed by Shawn Guo
Browse files

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: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: default avatarAlexander Stein <alexander.stein@ew.tq-group.com>
Tested-by: default avatarAlexander Stein <alexander.stein@ew.tq-group.com>
Signed-off-by: default avatarShawn Guo <shawnguo@kernel.org>
parent 2b52fd60

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

+4 −6
Original line number Diff line number Diff line
@@ -1687,7 +1687,7 @@ mipi_csi_0: csi@32e40000 { 
				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>,
@@ -1695,9 +1695,8 @@ mipi_csi_0: csi@32e40000 { 
				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";
@@ -1723,7 +1722,7 @@ mipi_csi_1: csi@32e50000 { 
				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>,
@@ -1731,9 +1730,8 @@ mipi_csi_1: csi@32e50000 { 
				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";