Re: [PATCH 4/4] serial: sccnxp: Add DT support

["Alexander Shiyan" <shc_work@mail.ru>]

> On Wed, Jul 31, 2013 at 11:55:45AM +0100, Alexander Shiyan wrote:
> > Add DT support to the SCCNCP serial driver.
> > 
> > Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
> > ---
> >  .../bindings/tty/serial/sccnxp-serial.txt          | 53 ++++++++++++++++++++++
> >  drivers/tty/serial/sccnxp.c                        | 46 +++++++++++++++----
> >  include/linux/platform_data/serial-sccnxp.h        |  6 +--
> >  3 files changed, 93 insertions(+), 12 deletions(-)
> >  create mode 100644 Documentation/devicetree/bindings/tty/serial/sccnxp-serial.txt
> > 
> > diff --git a/Documentation/devicetree/bindings/tty/serial/sccnxp-serial.txt b/Documentation/devicetree/bindings/tty/serial/sccnxp-serial.txt
[...]
> > +Optional properties:
> > +- clocks: Phandle to input clock. If omitted, default IC frequency will be
> > +  used instead.
> > +- poll-interval: Poll interval time in nanoseconds.
> 
> Is there any reason this needs to be described at all? Is this interval
> a minimum/maximum bound required for some reason, or just a sensible
> value?
> 
> This feels like driver configuration than hardware description.

This is a exact value for driver in the polling mode.
Depends on desired response time and/or desired UART baudrate.

> > +- vcc-supply: The regulator supplying the VCC to drive the chip.
> > +- nxp,sccnxp-io-cfg: Array contains values for the emulated modem signals.
> > +  The number of values depends on the UART-number in the selected chip.
> > +  Each value should be composed according to the following rules:
> > +  (LINE1 << SIGNAL1) | ... | (LINEX << SIGNALX), where:
> > +   LINE - VALUE:
> > +    OP0 - 1
[...]
> > +    DIR - 24
> 
> I don't really understand what this is describing, but I'm not sure that
> the encoding (with an OR of shifted values) is the most sensible. Could
> you elaborate on what is being described and how it's used?

I have already described this property in a reply to Stephen Warren.
I'd like to do it differently, but I have no idea of another implementation of this.
Thanks.

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