Add WLAN support to device tree

[hansemro]

Resources:

• https://github.com/hansemro/kernel_omap_otter-common/blob/84763bbf0a9138cb0ba7b42411cd8d0405c1c684/arch/arm/mach-omap2/board-4430kc1-tablet.c#L320-L376
• arch/arm/boot/dts/omap4-var-som-om44-wlan.dtsi
• https://github.com/TI-OpenLink/firmwares : wl12xx firmware blobs
• http://www.armadeus.org/wiki/index.php?title=Wl12xx_driver

Based off board files, the kindle fire will share many similarities to 4430 SDP. In short, the following modifications will need to be made:

GPIO_WIFI_PMENA: 54
GPIO_WIFI_IRQ: 53

• Add 1.8V fixed voltage regulator for wlan device
• Set appropriate pins (mmc5 + irq pins)
• Add mmc5 device
• Add UART2 (?)
• Pass module loading
• Pass firmware loading
• Pass wireless connection
• Enable 32kHz clock (clk32kg) (achieved by patch 0006)
• Set MAC Address

[hansemro]

arch/arm/boot/dts/omap4-kc1.dts

/ {
	...
	/* regulator for wl12xx on sdio5 */
	wl12xx_vmmc: wl12xx_vmmc {
		pinctrl-names = "default";
		pinctrl-0 = <&wl12xx_gpio>;
		compatible = "regulator-fixed";
		regulator-name = "vwl1271";
		regulator-min-microvolt = <1800000>;
		regulator-max-microvolt = <1800000>;
		gpio = <&gpio2 22 GPIO_ACTIVE_HIGH>; /* gpio_54 */
		startup-delay-us = <70000>;
		enable-active-high;
	};
	...
};
...
&omap4_pmx_core {
	...
	uart2_pins: pinmux_uart2_pins {
		pinctrl-single,pins = <
			OMAP4_IOPAD(0x118, PIN_INPUT_PULLUP | MUX_MODE0)	/* uart2_cts.uart2_cts */
			OMAP4_IOPAD(0x11a, PIN_OUTPUT | MUX_MODE0)		/* uart2_rts.uart2_rts */
			OMAP4_IOPAD(0x11c, PIN_INPUT_PULLUP | MUX_MODE0)	/* uart2_rx.uart2_rx */
			OMAP4_IOPAD(0x11e, PIN_OUTPUT | MUX_MODE0)		/* uart2_tx.uart2_tx */
		>;
	};

	/* wl12xx GPIO output: WLAN_IRQ */
	wl12xx_gpio: pinmux_wl12xx_gpio {
		pinctrl-single,pins = <
			OMAP4_IOPAD(0x07a, PIN_OUTPUT | MUX_MODE3)		/* gpmc_ncs3.gpio_53 */
		>;
	};

	/* wl12xx GPIO inputs and WLAN_EN */
	wl12xx_pins: pinmux_wl12xx_pins {
		pinctrl-single,pins = <
			OMAP4_IOPAD(0x07c, PIN_INPUT | MUX_MODE3)		/* gpmc_nwp.gpio_54 */
			OMAP4_IOPAD(0x148, PIN_INPUT_PULLUP | MUX_MODE0)	/* sdmmc5_clk.sdmmc5_clk */
			OMAP4_IOPAD(0x14a, PIN_INPUT_PULLUP | MUX_MODE0)	/* sdmmc5_cmd.sdmmc5_cmd */
			OMAP4_IOPAD(0x14c, PIN_INPUT_PULLUP | MUX_MODE0)	/* sdmmc5_dat0.sdmmc5_dat0 */
			OMAP4_IOPAD(0x14e, PIN_INPUT_PULLUP | MUX_MODE0)	/* sdmmc5_dat1.sdmmc5_dat1 */
			OMAP4_IOPAD(0x150, PIN_INPUT_PULLUP | MUX_MODE0)	/* sdmmc5_dat2.sdmmc5_dat2 */
			OMAP4_IOPAD(0x152, PIN_INPUT_PULLUP | MUX_MODE0)	/* sdmmc5_dat3.sdmmc5_dat3 */
		>;
	};
	...
};
...
&uart2 {
	pinctrl-names = "default";
	pinctrl-0 = <&uart2_pins>;
	status = "okay";
};

&mmc5 {
	pinctrl-names = "default";
	pinctrl-0 = <&wl12xx_pins>;
	status = "okay";
	vmmc-supply = <&wl12xx_vmmc>;
	non-removable;
	bus-width = <4>;
	cap-power-off-card;

	#address-cells = <1>;
	#size-cells = <0>;
	wlcore: wlcore@2 {
		compatible = "ti,wl1271";
		reg = <2>;
		interrupt-parent = <&gpio2>;
		interrupts = <21 IRQ_TYPE_LEVEL_HIGH>; /* gpio 53 */
		ref-clock-frequency = <38400000>;
		/*tcxo-clock-frequency = <26000000>;*/
	};
};

Issues:

• wl12xx modules do not get loaded.
• cfg80211 fails to load regulatory.db

5.11.0 dmesg

[    5.221221] reg-fixed-voltage wl12xx_vmmc: GPIO lookup for consumer (null)
[    5.230529] reg-fixed-voltage wl12xx_vmmc: using device tree for GPIO lookup
[    5.246887] of_get_named_gpiod_flags: can't parse 'gpios' property of node '/wl12xx_vmmc[0]'
[    5.256683] of_get_named_gpiod_flags: parsed 'gpio' property of node '/wl12xx_vmmc[0]' - status (0)
[    5.274414] vwl1271: 1800 mV, disabled
[    5.274414] reg-fixed-voltage wl12xx_vmmc: vwl1271 supplying 1800000uV
...
[   36.961303] vwl1271: disabling

[mj-sakellaropoulos]

Forced wl12xx_vmmc to always on

installed firmware via apk add linux-firmware-ti-connectivity

modprobe -a wlcore wl12xx wlcore_sdio
Modules are loaded, regulatory.db loaded (I think) all with no errors.

But no /dev/wlan , nothing in sysfs either - no wlan device is created, no driver probe in dmesg, no firmware load attempt - nothing

[hansemro]

But no /dev/wlan , nothing in sysfs either - no wlan device is created

Something is wrong with the device tree. wl127x driver does not get loaded automatically

[mj-sakellaropoulos]

compatible string is right for sure

the rest seems pretty standard too

[mj-sakellaropoulos]

refclock is wrong , should be 38.4 MHz

• https://github.com/hansemro/kernel_omap_otter-common/blob/84763bbf0a9138cb0ba7b42411cd8d0405c1c684/include/linux/wl12xx.h
• https://github.com/torvalds/linux/blob/e4adffb8daf476a01e7b4a55f586dc8c26e81392/arch/arm/boot/dts/omap4-var-som-om44-wlan.dtsi#L73

[hansemro]

Yeah, you're right.

[mj-sakellaropoulos]

Actually, per https://github.com/torvalds/linux/blob/e4adffb8daf476a01e7b4a55f586dc8c26e81392/Documentation/devicetree/bindings/net/wireless/ti%2Cwlcore.txt#L26-L27

Since the clock is _XTAL , does the mean eXTernAL ? Then perhaps there are more nodes required for the clock setup

[hansemro]

xtal usually means crystal oscillator for clock

[mj-sakellaropoulos]

Enabled very verbose dmesg - I haven't seen anything interesting

• boot log
• after modprobe

[hansemro]

Related issue with what I encountered with 3.4.48 kernel: https://bugzilla.kernel.org/show_bug.cgi?id=119331
https://forum.digikey.com/t/pandaboard-a4-wifi-module-not-found/2951/5

It mentions TWL6030 driver not supporting 32kHz clock may cause issues.

[hansemro]

So the patch in the digikey post actually makes the wlcore/wl12xx modules load.

[   13.349822] wlcore: WARNING Detected unconfigured mac address in nvs, derive from fuse instead.
[   13.359558] wlcore: WARNING Your device performance is not optimized.
[   13.366455] wlcore: WARNING Please use the calibrator tool to configure your device.
[   13.374694] wlcore: WARNING Fuse mac address is zero. using random mac
[   13.381713] wlcore: WARNING NIC part of the MAC address wraps around!
[   13.402008] wlcore: loaded
[   17.395355] wlcore: firmware booted (Rev 6.3.10.0.142)

wlan0 also starts up! It needs to be calibrated, but I think we are getting closer.

https://web.archive.org/web/20160311003302/http://processors.wiki.ti.com/index.php/WL12xx_NLCP_Calibration_Process

[hansemro]

Building calibrator (on kindle):

apk add patch
wget http://www.infradead.org/~tgr/libnl/files/libnl-2.0.tar.gz
cd libnl-2.0
./configure
make
make install
cd ..
git clone https://github.com/TI-OpenLink/ti-utils
cd ti-utils
wget https://git.buildroot.net/buildroot/plain/package/ti-utils/0001-plt.h-fix-build-with-gcc-10.patch
patch -p1 < 0001-plt*.patch
make