lkml.org 
[lkml]   [2017]   [Jan]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [STLinux Kernel] [PATCH 8/8] ARM: dts: STiH407-family: Enable HW flow-control
    On Wed, 25 Jan 2017, Peter Griffin wrote:
    > On Wed, 25 Jan 2017, Peter Griffin wrote:
    > > On Tue, 24 Jan 2017, Lee Jones wrote:
    > >
    > > > Hardware flow-control capability must be specified at a platform
    > > > level in order to inform the ASC driver that the platform is capable
    > > > (i.e. are the lines wired up, etc). STiH4{07,10} devices are indeed
    > > > capable, so let's provide the property.
    > > >
    > > > Signed-off-by: Lee Jones <lee.jones@linaro.org>
    > > > ---
    > > > arch/arm/boot/dts/stih407-family.dtsi | 2 +-
    > > > 1 file changed, 1 insertion(+), 1 deletion(-)
    > > >
    > > > diff --git a/arch/arm/boot/dts/stih407-family.dtsi b/arch/arm/boot/dts/stih407-family.dtsi
    > > > index 9789978..7ada8ea 100644
    > > > --- a/arch/arm/boot/dts/stih407-family.dtsi
    > > > +++ b/arch/arm/boot/dts/stih407-family.dtsi
    > > > @@ -226,7 +226,7 @@
    > > > pinctrl-0 = <&pinctrl_serial0_flowctrl>;
    > > > pinctrl-1 = <&pinctrl_serial0>;
    > > > clocks = <&clk_s_c0_flexgen CLK_EXT2F_A9>;
    > > > -
    > > > + st,hw-flow-control;
    > >
    > > There is a generic serial binding for this already. As this ST property
    > > hasn't been used upstream, it seems like it would be worth dropping it
    > > and switching to the generic uart-has-rtscts one.
    > >
    > > See Documentation/devicetree/bindings/serial/serial.txt
    > >
    > > - uart-has-rtscts: The presence of this property indicates that the
    > > UART has dedicated lines for RTS/CTS hardware flow control, and that
    > > they are available for use (wired and enabled by pinmux configuration).
    > > This depends on both the UART hardware and the board wiring.
    > > Note that this property is mutually-exclusive with "cts-gpios" and
    > > "rts-gpios" above.
    >
    > Thinking some more this generic binding definition is a bit restrictive,
    > particularly the "Note that this property is mutually-exclusive with "cts-gpios"
    > and "rts-gpios"" part.
    >
    > As with this series we will have dynamic on-the-fly changing from hw flow
    > control to gpio control for other configs which the HW IP doesn't support.
    >
    > IMO the uart-has-rtscts definition should be updated to reflect that they can
    > be used together in certain circumstances.

    Ah, you noticed that too. Yes, will update the doc.

    --
    Lee Jones
    Linaro STMicroelectronics Landing Team Lead
    Linaro.org │ Open source software for ARM SoCs
    Follow Linaro: Facebook | Twitter | Blog

    \
     
     \ /
      Last update: 2017-01-27 12:36    [W:4.842 / U:0.288 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site