DESK-MX8M-L/Peripherals/WiFI

History
Issue Date	Notes
2024/04/08	DESK-MX8M-L-4.1.0 release

Peripheral WiFi

Device tree configuration

Here below an example of device tree configuration used on standard DAVE's kit for the MITO 8M Mini:

From imx8mm-mito8mmini.dts:

...
...
	pcie0_refclk: pcie0-refclk {
		compatible = "fixed-clock";
		#clock-cells = <0>;
		clock-frequency = <100000000>;
	};
...
...
	regulators {
...
		reg_pcie_pwr: pcie_pwr {
			compatible = "regulator-fixed";
			regulator-name = "PCIe_PWREN";
			regulator-min-microvolt = <3300000>;
			regulator-max-microvolt = <3300000>;
			regulator-always-on;
			gpio = <&gpio2 20 GPIO_ACTIVE_HIGH>;
			enable-active-high;
		};
...
...
&pcie0 {
	pinctrl-names = "default";
	pinctrl-0 = <&pinctrl_pcie0>;
	disable-gpio = <&gpio5 20 GPIO_ACTIVE_LOW>;
	reset-gpio = <&gpio5 21 GPIO_ACTIVE_LOW>;
	wake-gpio = <&gpio3 20 GPIO_ACTIVE_HIGH>;
	clocks = <&clk IMX8MM_CLK_PCIE1_ROOT>,
		 <&clk IMX8MM_CLK_PCIE1_AUX>,
		 <&clk IMX8MM_CLK_PCIE1_PHY>,
		 <&pcie0_refclk>;
	clock-names = "pcie", "pcie_aux", "pcie_phy", "pcie_bus";
	assigned-clocks = <&clk IMX8MM_CLK_PCIE1_AUX>,
			  <&clk IMX8MM_CLK_PCIE1_PHY>,
			  <&clk IMX8MM_CLK_PCIE1_CTRL>;
	assigned-clock-rates = <10000000>, <100000000>, <250000000>;
	assigned-clock-parents = <&clk IMX8MM_SYS_PLL2_50M>,
				 <&clk IMX8MM_SYS_PLL2_100M>,
				 <&clk IMX8MM_SYS_PLL2_250M>;
	ext_osc = <0>;
	status = "okay";
};
...
...
&iomuxc {
...
...
	pinctrl_pcie0: pcie0grp {
		fsl,pins = <
			MX8MM_IOMUXC_I2C4_SCL_GPIO5_IO20			   0x19
			MX8MM_IOMUXC_I2C4_SDA_GPIO5_IO21			   0x19
			MX8MM_IOMUXC_SD2_WP_GPIO2_IO20				   0x19
			MX8MM_IOMUXC_SAI5_RXC_GPIO3_IO20				0x19
		>;
	};
...
...

Accessing the peripheral

Linux messages at boot time

PCIe driver initialized:

...
...                                                                                  
[    1.131579] ehci-pci: EHCI PCI platform driver
[    1.147680] ohci-pci: OHCI PCI platform driver                                                                      
[    3.234024] imx6q-pcie 33800000.pcie: supply epdev_on not found, using dummy regulator
[    3.242348] imx6q-pcie 33800000.pcie: PLL REF_CLK is used!.              
[    3.276463] imx6q-pcie 33800000.pcie: PCIe PLL is locked.        
[    3.284714] imx6q-pcie 33800000.pcie: iATU unroll: enabled               
[    3.295015] imx6q-pcie 33800000.pcie: Detected iATU regions: 4 outbound, 4 inbound
[    3.309648] imx6q-pcie 33800000.pcie: host bridge /soc@0/pcie@33800000 ranges:
[    3.316925] imx6q-pcie 33800000.pcie:       IO 0x001ff80000..0x001ff8ffff -> 0x0000000000
[    3.330476] imx6q-pcie 33800000.pcie:      MEM 0x0018000000..0x001fefffff -> 0x0018000000
[    3.342505] imx6q-pcie 33800000.pcie: iATU unroll: enabled               
[    3.351821] imx6q-pcie 33800000.pcie: Detected iATU regions: 4 outbound, 4 inbound
[    3.444200] imx6q-pcie 33800000.pcie: Link up
...
...

Check which are the devices connected to the PCIe.

root@desk-mx8mm:~# lspci
00:00.0 PCI bridge: Synopsys, Inc. DWC_usb3 / PCIe bridge (rev 01)
01:00.0 Network controller: Intel Corporation Wireless 7260 (rev bb)
root@desk-mx8mm:~#