Subject: [PATCH v2 2/5] devicetree: serial: Document msm_serial bindings

From: [email-masked] (Stephen Boyd)
Date: Wed, 21 Aug 2013 09:32:32 -0700

On 08/21, Kumar Gala wrote:
> 
> On Aug 21, 2013, at 1:48 AM, Stephen Boyd wrote:
> 
> > The msm serial device bindings were added to the DTS files but
> > never documented. Let's document them now and also fix things up
> > so that it's clearer what hardware is supported. Instead of using
> > hsuart (for high speed uart), let's use uartdm because that
> > matches the actual name of the hardware. Also, let's add the
> > version information in case we need to differentiate between
> > different versions of the hardware in the future.
> > 
> > Cc: David Brown <[email-masked]>
> > Cc: <[email-masked]>
> > Signed-off-by: Stephen Boyd <[email-masked]>
> > ---
> > .../devicetree/bindings/serial/qcom,msm-uart.txt   | 25 +++++++++++
> > .../devicetree/bindings/serial/qcom,msm-uartdm.txt | 52 ++++++++++++++++++++++
> > 2 files changed, 77 insertions(+)
> > create mode 100644 Documentation/devicetree/bindings/serial/qcom,msm-uart.txt
> > create mode 100644 Documentation/devicetree/bindings/serial/qcom,msm-uartdm.txt
> 
> Should we remove bindings/tty/serial/msm_serial.txt ?

Yes, although I'm confused why there is a tty/serial/ and a serial/
binding directory.

> 
> > diff --git a/Documentation/devicetree/bindings/serial/qcom,msm-uart.txt b/Documentation/devicetree/bindings/serial/qcom,msm-uart.txt
> > new file mode 100644
> > index 0000000..ce8c901
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/serial/qcom,msm-uart.txt
> > @@ -0,0 +1,25 @@
> > +* MSM Serial UART
> > +
> > +The MSM serial UART hardware is designed for low-speed use cases where a
> > +dma-engine isn't needed. From a software perspective it's mostly compatible
> > +with the MSM serial UARTDM except that it only supports reading and writing one
> > +character at a time.
> > +
> > +Required properties:
> > +- compatible: Should contain "qcom,msm-uart"
> > +- reg: Should contain UART register location and length.
> > +- interrupts: Should contain UART interrupt.
> > +- clocks: Should contain the core clock.
> > +- clock-names: Should be "core".
> > +
> > +Example:
> > +
> > +A uart device at 0xa9c00000 with interrupt 11.
> > +
> > +serial at a9c00000 {
> > +	compatible = "qcom,msm-uart";
> > +	reg = <0xa9c00000 0x1000>;
> > +	interrupts = <11>;
> > +	clocks = <&uart_cxc>;
> > +	clock-names = "core";
> > +};
> > diff --git a/Documentation/devicetree/bindings/serial/qcom,msm-uartdm.txt b/Documentation/devicetree/bindings/serial/qcom,msm-uartdm.txt
> > new file mode 100644
> > index 0000000..1a4d681
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/serial/qcom,msm-uartdm.txt
> > @@ -0,0 +1,52 @@
> > +* MSM Serial UARTDM
> > +
> > +The MSM serial UARTDM hardware is designed for high-speed use cases where the
> > +transmit and/or receive channels can be offloaded to a dma-engine. From a
> > +software perspective it's mostly compatible with the MSM serial UART except
> > +that it supports reading and writing multiple characters at a time.
> > +
> > +Required properties:
> > +- compatible: Should contain at least "qcom,msm-uartdm".
> > +              A more specific property should be specified as follows depending
> > +	      on the version:
> > +		"qcom,msm-uartdm-v1.1"
> > +		"qcom,msm-uartdm-v1.2"
> > +		"qcom,msm-uartdm-v1.3"
> > +		"qcom,msm-uartdm-v1.4"
> > +- reg: Should contain UART register locations and lengths. The first
> > +       register shall specify the main control registers. An optional second
> > +       register location shall specify the GSBI control region.
> 
> Can we add something like:
> 
> "qcom,msm-uartdm-v1.3" is the only compatible that might optionally need the GSBI control region.

Ok. I will remove the part from the example.

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