On Tue, May 30, 2017 at 10:16:01PM +0200, christopher.spinrath@xxxxxxxxxxxxxx wrote: > From: Christopher Spinrath <christopher.spinrath@xxxxxxxxxxxxxx> > > The cm-fx6 module has an on-board AW-NH387 WiFi/BT module which is > based on Marvell's SD8787 chip and is connected to the usdhc1 > controller. > > Unfortunately, the chip gets unresponsive if the Bluetooth AMP > (Alternate Mac/Phy) function gets probed but the loaded firmware > doesn't support it. For instance, this is the case for the most > recent firmware in linux-firmware (Version 14.66.35.p52). > > Thus, just add the required nodes but leave the usdhc1 node disabled > explicitly. Users who disabled the Bluetooth (AMP) support of their > OS can then conveniently enable WiFi (or even plain Bluetooth) support > with a simple device tree overlay/bootloader configuration. > > Signed-off-by: Christopher Spinrath <christopher.spinrath@xxxxxxxxxxxxxx> > --- > > Hi all, > > some more information on the Bluetooth AMP dilemma: the vendor (CompuLab) just > remove Bluetooth AMP support from the kernel. However, this is not an option > here, since it would introduce a regression for its actual users. > > Neither is degrading the firmware a good option: recent firmare (without AMP > support) provides WiFi that is more stable (in particular, for access points). > > I wrote a RFC to linux-bluetooth [1] two weeks ago about this problem and the > only feedback I got was that Marvell has to provide information about how to > detect whether the firmware supports AMP properly -- but this is unlikely given > Marvell's information policy (in particular, since the sd8787 seems to be > unsupported as of now). > > IMHO this patch is currently the best option, since it allows users in a > convenient way to enable WiFi support (e.g. no pinctrl handling in overlays), > even when they are using distribution kernels/device trees. Furthermore, the > hardware description is entirely accurate -- we have a driver/firmware problem > here. Hi Valentin, Igor, Are you guys fine with the patch? Shawn > > Thanks, > Christopher > > [1] https://www.spinics.net/lists/linux-bluetooth/msg70493.html > > arch/arm/boot/dts/imx6q-cm-fx6.dts | 41 ++++++++++++++++++++++++++++++++++++++ > 1 file changed, 41 insertions(+) > > diff --git a/arch/arm/boot/dts/imx6q-cm-fx6.dts b/arch/arm/boot/dts/imx6q-cm-fx6.dts > index a8af382..fe6ab0a 100644 > --- a/arch/arm/boot/dts/imx6q-cm-fx6.dts > +++ b/arch/arm/boot/dts/imx6q-cm-fx6.dts > @@ -64,6 +64,14 @@ > }; > }; > > + awnh387_pwrseq: pwrseq { > + pinctrl-names = "default"; > + pinctrl-0 = <&pinctrl_pwrseq>; > + compatible = "mmc-pwrseq-sd8787"; > + powerdown-gpios = <&gpio7 12 GPIO_ACTIVE_HIGH>; > + reset-gpios = <&gpio6 16 GPIO_ACTIVE_HIGH>; > + }; > + > reg_pcie_power_on_gpio: regulator-pcie-power-on-gpio { > compatible = "regulator-fixed"; > regulator-name = "regulator-pcie-power-on-gpio"; > @@ -304,6 +312,13 @@ > >; > }; > > + pinctrl_pwrseq: pwrseqgrp { > + fsl,pins = < > + MX6QDL_PAD_GPIO_17__GPIO7_IO12 0x1b0b0 > + MX6QDL_PAD_NANDF_CS3__GPIO6_IO16 0x1b0b0 > + >; > + }; > + > pinctrl_spdif: spdifgrp { > fsl,pins = < > MX6QDL_PAD_GPIO_16__SPDIF_IN 0x1b0b0 > @@ -330,6 +345,17 @@ > MX6QDL_PAD_EIM_D22__GPIO3_IO22 0x130b0 > >; > }; > + > + pinctrl_usdhc1: usdhc1grp { > + fsl,pins = < > + MX6QDL_PAD_SD1_CMD__SD1_CMD 0x17071 > + MX6QDL_PAD_SD1_CLK__SD1_CLK 0x10071 > + MX6QDL_PAD_SD1_DAT0__SD1_DATA0 0x17071 > + MX6QDL_PAD_SD1_DAT1__SD1_DATA1 0x17071 > + MX6QDL_PAD_SD1_DAT2__SD1_DATA2 0x17071 > + MX6QDL_PAD_SD1_DAT3__SD1_DATA3 0x17071 > + >; > + }; > }; > > &pcie { > @@ -382,3 +408,18 @@ > dr_mode = "otg"; > status = "okay"; > }; > + > +&usdhc1 { > + pinctrl-names = "default"; > + pinctrl-0 = <&pinctrl_usdhc1>; > + mmc-pwrseq = <&awnh387_pwrseq>; > + non-removable; > + /* > + * If the OS probes the Bluetooth AMP function advertised on this bus > + * but the firmware in place does not support it, the WiFi/BT module > + * gets unresponsive. > + * Users who configured their OS properly can enable this node to gain > + * WiFi and/or plain Bluetooth support. > + */ > + status = "disabled"; > +}; > -- > 2.10.2 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
