Re: [PATCH v4 03/10] pinctrl: mvebu: kirkwood pinctrl driver

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 09/17/2012 03:55 AM, Nicolas Pitre wrote:
On Sun, 16 Sep 2012, Jason Cooper wrote:
On Sun, Sep 16, 2012 at 09:46:52AM +0200, Andrew Lunn wrote:
+++ b/Documentation/devicetree/bindings/pinctrl/marvell,kirkwood-pinctrl.txt
@@ -0,0 +1,279 @@
+* Marvell Kirkwood SoC pinctrl driver for mpp
+
+Please refer to marvell,mvebu-pinctrl.txt in this directory for common binding
+part and usage.
+
+Required properties:
+- compatible: "marvell,88f6180-pinctrl",
+              "marvell,88f6190-pinctrl", "marvell,88f6192-pinctrl",
+              "marvell,88f6281-pinctrl", "marvell,88f6282-pinctrl"
+
+This driver supports all kirkwood variants, i.e. 88f6180, 88f619x, and 88f628
>>> ...
If i wanted to mass convert all existing kirkwood DT boards over to
use pinctrl, im stuck at the very first step. I've no idea what chip
they use, it was not relevant before.

Let's try to do the DT correctly, and create a migration path for
kirkwood to work first, then migrate to using the DT fully.

Beware beware.

The DT should of course describe the hardware as accurately as possible.
That doesn't necessarily mean it should describe the hardware as
_extensively_ as possible.

And that doesn't mean that all the information found in the DT has to be
consumed by the kernel either.

Any information that can be *probed* at run time has no benefit being
stuffed in a DT.  That's true whether it is Linux or another operating
system.  The more that can be probed at run time the better.

I had a closer look at how kirkwood probes its id. I mentionend kirkwood_id()
earlier but in fact it is kirkwood_pcie_id(). I assume pcie registers are shut
down with pcie clk gated? That would require to have pcie running at least at
boot-time on all boards.

While it is still possible to grab the id and power down pcie later, I still
think that using five different compatible strings is better here. Of course,
there is some effort to obtain the kirkwood SoC variant for all boards.

Sebastian




--
To unsubscribe from this list: send the line "unsubscribe linux-doc" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [Kernel Newbies]     [Security]     [Netfilter]     [Bugtraq]     [Linux FS]     [Yosemite Forum]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Samba]     [Video 4 Linux]     [Device Mapper]     [Linux Resources]

  Powered by Linux