[PATCH 2/2] cpufreq: cpu0: Extend support beyond CPU0
Viresh Kumar
viresh.kumar at linaro.org
Mon Jun 30 00:57:52 PDT 2014
On 27 June 2014 07:45, Viresh Kumar <viresh.kumar at linaro.org> wrote:
> On 27 June 2014 07:23, Mike Turquette <mturquette at linaro.org> wrote:
>>> but it isn't future-proof if/when the clock framework starts returning
>>> dynamically allocated clock pointers for each clk_get() invocation.
>>> Maybe we need a function in the common clock framework that tells us if
>>> the clocks are the same either via DT or by taking two clock pointers?
>>
>> I looked through the patch briefly and did not see why we would need to
>> do this. Any hint?
>
> We want to know which CPUs are sharing clock line, so that we can
> fill affected-cpus field of cpufreq core.
What about comparing "clocks" property in cpu DT nodes?
@Rob/Grant: I tried looking for an existing routine to do that, but couldn't
find it. And so wrote one.
I am not good at DT stuff and so I do hope there would be few correction
required here. Let me know if this can be added to drivers/of/base.c :
+/**
+ * of_property_match - Match property in two nodes
+ * @np1, np2: Nodes to match
+ * @list_name: property to match
+ *
+ * Returns 1 on match, 0 on no match, and error for missing property.
+ */
+static int of_property_match(const struct device_node *np1,
+ const struct device_node *np2,
+ const char *list_name)
+{
+ const __be32 *list1, *list2, *list1_end;
+ int size1, size2;
+ phandle phandle1, phandle2;
+
+ /* Retrieve the list property */
+ list1 = of_get_property(np1, list_name, &size1);
+ if (!list1)
+ return -ENOENT;
+
+ list2 = of_get_property(np2, list_name, &size2);
+ if (!list2)
+ return -ENOENT;
+
+ if (size1 != size2)
+ return 0;
+
+ list1_end = list1 + size1 / sizeof(*list1);
+
+ /* Loop over the phandles */
+ while (list1 < list1_end) {
+ phandle1 = be32_to_cpup(list1++);
+ phandle2 = be32_to_cpup(list2++);
+
+ if (phandle1 != phandle2)
+ return 0;
+ }
+
+ return 1;
+}
@Stephen: I have updated my tree with this change, in case you wanna
try.
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