From mboxrd@z Thu Jan 1 00:00:00 1970 From: maxime.ripard@free-electrons.com (Maxime Ripard) Date: Fri, 16 Dec 2016 13:47:48 +0100 Subject: [PATCH] ARM: dts: sun8i-q8-common: enable bluetooth on SDIO Wi-Fi In-Reply-To: <20161213233658.atGuNCNY@smtp1h.mail.yandex.net> References: <20161213233658.atGuNCNY@smtp1h.mail.yandex.net> Message-ID: <20161216124748.rkvnnlo4x5onzpvk@lukather> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Fri, Dec 09, 2016 at 07:49:00PM +0800, Icenowy Zheng wrote: > > 2016?12?9? ??4:07? Maxime Ripard ??? > > > > On Tue, Dec 06, 2016 at 04:08:38PM +0800, Icenowy Zheng wrote: > > > Some SDIO Wi-Fi chips (such as RTL8703AS) have a UART bluetooth, which > > > has a dedicated enable pin (PL8 in the reference design). > > > > > > Enable the pin in the same way as the WLAN enable pins. > > > > > > Tested on an A33 Q8 tablet with RTL8703AS. > > > > > > Signed-off-by: Icenowy Zheng > > > --- > > > > > > This patch should be coupled with the uart1 node patch I send before: > > > http://lists.infradead.org/pipermail/linux-arm-kernel/2016-December/471997.html > > > > > > For RTL8703AS, the rtl8723bs bluetooth code is used, which can be retrieve from: > > > https://github.com/lwfinger/rtl8723bs_bt > > > > > >? arch/arm/boot/dts/sun8i-q8-common.dtsi | 2 +- > > >? 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > diff --git a/arch/arm/boot/dts/sun8i-q8-common.dtsi b/arch/arm/boot/dts/sun8i-q8-common.dtsi > > > index c676940..4aeb5bb 100644 > > > --- a/arch/arm/boot/dts/sun8i-q8-common.dtsi > > > +++ b/arch/arm/boot/dts/sun8i-q8-common.dtsi > > > @@ -88,7 +88,7 @@ > > >? > > >? &r_pio { > > >? wifi_pwrseq_pin_q8: wifi_pwrseq_pin at 0 { > > > - pins = "PL6", "PL7", "PL11"; > > > + pins = "PL6", "PL7", "PL8", "PL11"; > > >? function = "gpio_in"; > > >? bias-pull-up; > > >? }; > > > > There's several things wrong here. The first one is that you rely > > solely on the pinctrl state to maintain a reset line. This is very > > fragile (especially since the GPIO pinctrl state are likely to go away > > at some point), but it also means that if your driver wants to recover > > from that situation at some point, it won't work. > > > > The other one is that the bluetooth and wifi chips are two devices in > > linux, and you assign that pin to the wrong device (wifi). > > > > rfkill-gpio is made just for that, so please use it. > > The GPIO is not for the radio, but for the full Bluetooth part. I know. > If it's set to 0, then the bluetooth part will reset, and the > hciattach will fail. Both rfkill-gpio and rfkill-regulator will shutdown when called (either by poking the reset pin or shutting down the regulator), so that definitely seems like an expected behavior to put the device in reset. > The BSP uses this as a rfkill, and the result is that the bluetooth > on/off switch do not work properly. Then rfkill needs fixing, but working around it by hoping that the core will probe an entirely different device, and enforcing a default that the rest of the kernel might or might not change is both fragile and wrong. Maxime -- Maxime Ripard, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 801 bytes Desc: not available URL: