Re: [PATCH V3] clk: bcm: Add driver for Northstar ILP clock

[Ray Jui <ray.jui@broadcom.com>]

On 8/10/2016 10:28 AM, Rafał Miłecki wrote:
> On 10 August 2016 at 19:22, Jon Mason <jon.mason@broadcom.com> wrote:
>> On Wed, Aug 10, 2016 at 8:05 AM, Rafał Miłecki <zajec5@gmail.com> wrote:
>>> diff --git a/Documentation/devicetree/bindings/clock/brcm,ns-ilp.txt b/Documentation/devicetree/bindings/clock/brcm,ns-ilp.txt
>>> new file mode 100644
>>> index 0000000..a18c73f
>>> --- /dev/null
>>> +++ b/Documentation/devicetree/bindings/clock/brcm,ns-ilp.txt
>>> @@ -0,0 +1,40 @@
>>> +Broadcom Northstar ILP clock
>>> +============================
>>> +
>>> +This binding uses the common clock binding:
>>> +    Documentation/devicetree/bindings/clock/clock-bindings.txt
>>> +
>>> +This binding is used for ILP clock (sometimes referred as "slow clock")
>>> +on Broadcom Northstar devices using Corex-A7 CPU.
>>> +
>>> +This clock is part of PMU (Power Management Unit), a Broadcom's device
>>> +handing power-related aspects. Please note PMU contains more subdevices,
>>> +ILP is only one of them.
>>> +
>>> +ILP's rate has to be calculated on runtime and it depends on ALP clock
>>> +which has to be referenced.
>>> +
>>> +Required properties:
>>> +- compatible: "brcm,ns-ilp"
>>> +- reg: iomem address range of PMU (Power Management Unit)
>>> +- reg-names: "pmu", the only needed & supported reg right now
>>> +- clocks: has to reference an ALP clock
>>> +- #clock-cells: should be <0>
>>> +
>>> +Example:
>>> +
>>> +pmu@18012000 {
>>> +       compatible = "simple-bus";
>>> +       ranges = <0x00000000 0x18012000 0x00001000>;
>>
>> I don't see a corresponding DT entry in this patch, but 18012000 is
>> the PCI block.  So, I am concerned this will collide if used there.
>>
>> I looked at the NS register reference guide, and I cannot find the
>> registers you are trying to reference.  Is this supposed to be
>> referencing the LCPLL clock registers in DMU?  If so, there is already
>> a driver in there for this (see drivers/clk/bcm/clk-nsp.c).
>
> This patch is for BCM53573 family, not BCM4708 family you are looking at.
>
> Found chip with id 53573, rev 0x02 and package 0x01
> Core 0 found: ChipCommon (manuf 0x4BF, id 0x800, rev 0x36, class 0x0)
> Core 1 found: IEEE 802.11 (manuf 0x4BF, id 0x812, rev 0x38, class 0x0)
> Core 2 found: PCIe Gen 2 (manuf 0x4BF, id 0x501, rev 0x05, class 0x0)
> Core 3 found: ARM CA7 (manuf 0x4BF, id 0x847, rev 0x00, class 0x0)
> Core 4 found: USB 2.0 Host (manuf 0x4BF, id 0x819, rev 0x05, class 0x0)
> Core 5 found: GBit MAC (manuf 0x4BF, id 0x82D, rev 0x08, class 0x0)
> Core 6 found: I2S (manuf 0x4BF, id 0x834, rev 0x06, class 0x0)
> Core 7 found: CNDS DDR2/3 memory controller (manuf 0x4BF, id 0x846,
> rev 0x00, class 0x0)
> Core 8 found: NAND flash controller (manuf 0x4BF, id 0x509, rev 0x01, class 0x0)
> Core 9 found: IEEE 802.11 (manuf 0x4BF, id 0x812, rev 0x38, class 0x0)
> Core 10 found: GBit MAC (manuf 0x4BF, id 0x82D, rev 0x08, class 0x0)
> Core 11 found: I2S (manuf 0x4BF, id 0x834, rev 0x06, class 0x0)
> Core 12 found: GCI (manuf 0x4BF, id 0x840, rev 0x08, class 0x0)
> Core 13 found: PMU (manuf 0x4BF, id 0x827, rev 0x1C, class 0x0)
>

Out of curiosity, I searched the datasheet and found this is a wireless 
router SoC done by the WLAN team. It happens to share some peripherals 
with other iProc based SoCs.

I cannot find a code name for this SoC from our internal documents. I 
guess that name "Northstar" used here has confused both Jon and me.

Thanks,

Ray