On Saturday 05 November 2011 02:55 AM, Cousson, Benoit wrote:

quoted

quoted

+Required properties:
+- compatible: Should be "ti,omap-hsmmc<n>", "ti,omap2-hsmmc";
+n is controller instance starting 0, for OMAP2/3 controllers

No, no, no. You should not have to specify the unit-address in the
compatible
field. They are all programmed the same way, right?

AFAIR, 2 instances contain a DMA engine, but that should anyway be
detected using a "ti,had-dma-engine" extra property and not like that.

Checking the code in #2, it is used to get the instance of the MMC.

+static unsigned int of_get_hsmmc_instance(struct device_node *np)
+{
+    int i;
+    char comp[32];
+
+    for (; i < OMAP_MMC_DEV_MAX; i++) {
+        snprintf(comp, 32, "ti,omap-hsmmc%d", i);
+        if (of_device_is_compatible(np, comp))
+            break;
+    }
+    return i;
+}

Which does not seems to be a good usage of the compatible property anyway.
For a similar issue someone on the list suggested using the "cell-index"
property. But the definition I found in some binding documentation seems
to reserve that to: "enumerate logical devices within an IP core."
Ideally the driver should probably get rid of the need for an index.
I didn't check the original driver, but that should be needed for some
legacy reason.

yes, there are a bunch of things done inside the driver based on the
instance id which seem wrong, but I agree, encoding the instance
in the compatible property seems really bad and non-scalable.
Will look at how some of this legacy code in the driver can be
removed/cleaned up.