| Message ID | 1441232406-32628-1-git-send-email-amstan@chromium.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Alex, On Wed, Sep 2, 2015 at 3:20 PM, Alexandru M Stan <amstan@chromium.org> wrote: > The flow control lines from a user accessible UART are optional, > the user might not have anything connected to those pins. > In order to prevent random interrupts happening and noise affecting > that pin it should be pulled up. > > Note that the default state for those pins on the rk3288 is pulled up, > so this patch merely restores them. > > Suggested-by: Neil Hendin <nhendin@chromium.org> > Signed-off-by: Alexandru M Stan <amstan@chromium.org> > --- > arch/arm/boot/dts/rk3288.dtsi | 16 ++++++++-------- > 1 file changed, 8 insertions(+), 8 deletions(-) > > diff --git a/arch/arm/boot/dts/rk3288.dtsi b/arch/arm/boot/dts/rk3288.dtsi > index 906e938..a059367 100644 > --- a/arch/arm/boot/dts/rk3288.dtsi > +++ b/arch/arm/boot/dts/rk3288.dtsi > @@ -1211,11 +1211,11 @@ > }; > > uart0_cts: uart0-cts { > - rockchip,pins = <4 18 RK_FUNC_1 &pcfg_pull_none>; > + rockchip,pins = <4 18 RK_FUNC_1 &pcfg_pull_up>; > }; > > uart0_rts: uart0-rts { > - rockchip,pins = <4 19 RK_FUNC_1 &pcfg_pull_none>; > + rockchip,pins = <4 19 RK_FUNC_1 &pcfg_pull_up>; I would probably do just CTS. That would match the TX / RX lines where the RX is pulled but not the TX. You might also mention in the commit message that this really should be safe since we're already doing something similar for RX. -Doug
diff --git a/arch/arm/boot/dts/rk3288.dtsi b/arch/arm/boot/dts/rk3288.dtsi index 906e938..a059367 100644 --- a/arch/arm/boot/dts/rk3288.dtsi +++ b/arch/arm/boot/dts/rk3288.dtsi @@ -1211,11 +1211,11 @@ }; uart0_cts: uart0-cts { - rockchip,pins = <4 18 RK_FUNC_1 &pcfg_pull_none>; + rockchip,pins = <4 18 RK_FUNC_1 &pcfg_pull_up>; }; uart0_rts: uart0-rts { - rockchip,pins = <4 19 RK_FUNC_1 &pcfg_pull_none>; + rockchip,pins = <4 19 RK_FUNC_1 &pcfg_pull_up>; }; }; @@ -1226,11 +1226,11 @@ }; uart1_cts: uart1-cts { - rockchip,pins = <5 10 RK_FUNC_1 &pcfg_pull_none>; + rockchip,pins = <5 10 RK_FUNC_1 &pcfg_pull_up>; }; uart1_rts: uart1-rts { - rockchip,pins = <5 11 RK_FUNC_1 &pcfg_pull_none>; + rockchip,pins = <5 11 RK_FUNC_1 &pcfg_pull_up>; }; }; @@ -1249,11 +1249,11 @@ }; uart3_cts: uart3-cts { - rockchip,pins = <7 9 RK_FUNC_1 &pcfg_pull_none>; + rockchip,pins = <7 9 RK_FUNC_1 &pcfg_pull_up>; }; uart3_rts: uart3-rts { - rockchip,pins = <7 10 RK_FUNC_1 &pcfg_pull_none>; + rockchip,pins = <7 10 RK_FUNC_1 &pcfg_pull_up>; }; }; @@ -1264,11 +1264,11 @@ }; uart4_cts: uart4-cts { - rockchip,pins = <5 14 3 &pcfg_pull_none>; + rockchip,pins = <5 14 3 &pcfg_pull_up>; }; uart4_rts: uart4-rts { - rockchip,pins = <5 15 3 &pcfg_pull_none>; + rockchip,pins = <5 15 3 &pcfg_pull_up>; }; };
The flow control lines from a user accessible UART are optional, the user might not have anything connected to those pins. In order to prevent random interrupts happening and noise affecting that pin it should be pulled up. Note that the default state for those pins on the rk3288 is pulled up, so this patch merely restores them. Suggested-by: Neil Hendin <nhendin@chromium.org> Signed-off-by: Alexandru M Stan <amstan@chromium.org> --- arch/arm/boot/dts/rk3288.dtsi | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-)