[RFC PATCH] ARM: pmu: add OF match support

[Rob Herring <robherring2-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

From: Rob Herring <rob.herring-bsGFqQB8/DxBDgjK7y7TUQ@public.gmane.org>

Add OF match table to enable OF style driver binding. The dts entry is like
this:

pmu {
	compatible = "arm,pmu";
	interrupts = <100 101>;
};

The use of pdev->id as an index breaks with OF device binding. Change to use
a counter instead. If more than 1 pmu device is ever really supported, a
better solution to match users with particular pmu is probably needed.

Signed-off-by: Rob Herring <rob.herring-bsGFqQB8/DxBDgjK7y7TUQ@public.gmane.org>
---
 arch/arm/kernel/pmu.c |   13 ++++++++++---
 1 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/arch/arm/kernel/pmu.c b/arch/arm/kernel/pmu.c
index b8af96e..7084057 100644
--- a/arch/arm/kernel/pmu.c
+++ b/arch/arm/kernel/pmu.c
@@ -24,30 +24,37 @@
 static volatile long pmu_lock;
 
 static struct platform_device *pmu_devices[ARM_NUM_PMU_DEVICES];
+static int pmu_device_count;
 
 static int __devinit pmu_device_probe(struct platform_device *pdev)
 {
 
-	if (pdev->id < 0 || pdev->id >= ARM_NUM_PMU_DEVICES) {
+	if (pmu_device_count >= ARM_NUM_PMU_DEVICES) {
 		pr_warning("received registration request for unknown "
 				"device %d\n", pdev->id);
 		return -EINVAL;
 	}
 
-	if (pmu_devices[pdev->id])
+	if (pmu_devices[pmu_device_count])
 		pr_warning("registering new PMU device type %d overwrites "
 				"previous registration!\n", pdev->id);
 	else
 		pr_info("registered new PMU device of type %d\n",
 				pdev->id);
 
-	pmu_devices[pdev->id] = pdev;
+	pmu_devices[pmu_device_count++] = pdev;
 	return 0;
 }
 
+static struct of_device_id pmu_device_ids[] = {
+	{ .compatible = "arm,pmu" },
+	{},
+};
+
 static struct platform_driver pmu_driver = {
 	.driver		= {
 		.name	= "arm-pmu",
+		.of_match_table = pmu_device_ids,
 	},
 	.probe		= pmu_device_probe,
 };
-- 
1.7.1