[PATCH v7 06/14] usb: phy-mxs: Add anatop regmap

On Tue, Dec 24, 2013 at 09:20:11AM +0800, Peter Chen wrote:

quoted

quoted

@@ -226,6 +235,16 @@ static int mxs_phy_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, mxs_phy);
 
+	if (mxs_phy->data->flags & MXS_PHY_HAS_ANATOP) {
+		mxs_phy->regmap_anatop = syscon_regmap_lookup_by_phandle
+			(np, "fsl,anatop");
+		if (IS_ERR(mxs_phy->regmap_anatop)) {
+			dev_dbg(&pdev->dev,
+				"failed to find regmap for anatop\n");
+			return PTR_ERR(mxs_phy->regmap_anatop);

I'm looking at the merge dependency that Felipe mentions, and just think
of the DTB compatibility thing.  Does the above code mean that USB will
be broken if someone runs the new kernel with an old DTB on his board?

We're entering the stage where we need to maintain the DTB compatibility
in kernel.  That said, if users choose to upgrade their kernel only
(running with an old DTB), it's okay we do not give them new
features, but we shouldn't cause any regression/breakage for them.

Then, this patch needs to change for old imx6 DTB. I will use of_find_property 
like my previous version patch, do you think so?

http://marc.info/?l=linux-usb&m=138361742123380&w=2

Yes.  Basically, we need to add the new property as optional one and
keep the driver work in the existing way if the property is absent.

Shawn