On 08/10/2012 12:53 AM, dongsheng.w...@freescale.com wrote:
> From: Wang Dongsheng <dongsheng.w...@freescale.com>
>
> Add a description of the OPEN-PIC global timer in the OPEN-PIC document.
>
> Moidfy mpic-timer document. 1.Add a TFRR register region. This register
> is written by software to report the clocking frequency of the PIC timers.
> 2.Add a device_type. The global timer in line with the OPEN-PIC specification.
>
> Signed-off-by: Wang Dongsheng <dongsheng.w...@freescale.com>
> Signed-off-by: Li Yang <le...@freescale.com>
> ---
> Documentation/devicetree/bindings/open-pic.txt | 46
> ++++++++++++++++++++
> .../devicetree/bindings/powerpc/fsl/mpic-timer.txt | 21 +++++----
> arch/powerpc/boot/dts/fsl/pq3-mpic-timer-B.dtsi | 7 ++-
> arch/powerpc/boot/dts/fsl/pq3-mpic.dtsi | 7 ++-
> 4 files changed, 66 insertions(+), 15 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/open-pic.txt
> b/Documentation/devicetree/bindings/open-pic.txt
> index 909a902..045c2e9 100644
> --- a/Documentation/devicetree/bindings/open-pic.txt
> +++ b/Documentation/devicetree/bindings/open-pic.txt
> @@ -92,6 +92,52 @@ Example 2:
>
> * References
>
> +* Open PIC global timers
> +
> +Required properties:
> +- compatible: "open-pic,global-timer"
open-pic isn't a vendor (or software project that acts like a
pseudo-vendor) -- I'd go with "open-pic-global-timer".
> +- reg : Contains two regions. The first is the timer frequency reporting
> + register for the group. The second is the main timer register bank
> + (GTCCR, GTBCR, GTVPR, GTDR).
Why not just put clock-frequency in the node, instead of describing
TFRR? I don't think U-Boot currently sets TFRR.
> +- available-ranges: use <start count> style section to define which
> + timer interrupts can be used. This property is optional; without this,
> + all timers within the group can be used.
> +
> +- interrupts: one interrupt per timer in the group, in order, starting
> + with timer zero. If available-ranges is present, only the interrupts
> + that correspond to available timers shall be present.
> +
> +* Examples
> +
> +Example 1:
> +
> + /* Note that this requires #interrupt-cells to be 4 */
> + timer: timer@010f0 {
Unit addres shouldn't have leading zeroes.
> + compatible = "open-pic,global-timer";
> + device_type = "open-pic";
Remove device_type. Not only is it deprecated outside of real OF, it's
wrong -- this isn't an openpic, it's just a subset of it.
> + reg = <0x010f0 4 0x01100 0x100>;
> +
> + /* Another AMP partition is using timer */
> + available-ranges = <2 2>;
>
> +
> + interrupts = <2 0 3 0
> + 3 0 3 0>;
> + };
> +
> +Example 2:
> +
> + timer: timer@010f0 {
> + compatible = "open-pic,global-timer";
> + device_type = "open-pic";
> + reg = <0x010f0 4 0x01100 0x100>;
> + interrupts = <0 0 3 0
> + 1 0 3 0
> + 2 0 3 0
> + 3 0 3 0>;
> + };
4-cell interrupt specifiers are specific to Freescale MPICs. This means
there's no way to describe the timer interrupt on a non-Freescale
openpic. Again, I suggest we not bother with this in the absence of an
actual need to support the timer on non-Freescale openpic in partitioned
scenarios. The existing openpic node is sufficient to describe the
hardware in the absence of partitioning. We could have an
"openpic-no-timer" property to indicate that we're describing it
separately, so that the absence of a timer node isn't ambiguous as to
whether it's an old tree or a partitioned scenario. An fsl,mpic
compatible would imply openpic-no-timer.
Note that I believe many of the non-Freescale openpic nodes are going to
be found on systems with real Open Firmware, so we can't go changing the
device tree for them.
-Scott
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