Hi,
> static int __devinit pmu_device_probe(struct platform_device *pdev)
> {
> + enum arm_pmu_type type = pdev->id;
>
> - if (pdev->id < 0 || pdev->id >= ARM_NUM_PMU_DEVICES) {
> + if (pdev->dev.of_node)
> + type = ARM_PMU_DEVICE_CPU;
> +
> + if (type < 0 || type >= 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[type])
> pr_warning("registering new PMU device type %d overwrites "
> - "previous registration!\n", pdev->id);
> + "previous registration!\n", type);
> else
> pr_info("registered new PMU device of type %d\n",
> - pdev->id);
> + type);
>
> - pmu_devices[pdev->id] = pdev;
> + pmu_devices[type] = pdev;
> return 0;
> }
I don't think this is the best way to handle the type when we've got an FDT
description:
* release_pmu hasn't been updated to match the type logic here, so it might do
anything when handed a platform_device initialised by FDT code.
* the warning message for an invalid registration still uses pdev->id rather
than type. This can't currently be reached when the PMU was handed to us via
FDT, but it may confuse refactoring later on.
* If we want to add a new PMU type, we'll have to add more logic to
pmu_device_probe. Given that work is going on to add support for system PMUs,
this doesn't seem particularly brilliant.
> +static struct of_device_id pmu_device_ids[] = {
> + { .compatible = "arm,cortex-a9-pmu" },
> + { .compatible = "arm,cortex-a8-pmu" },
> + { .compatible = "arm,arm1136-pmu" },
> + { .compatible = "arm,arm1176-pmu" },
> + {},
> +};
> +
> static struct platform_driver pmu_driver = {
> .driver = {
> .name = "arm-pmu",
> + .of_match_table = pmu_device_ids,
> },
> .probe = pmu_device_probe,
> };
This all seems fine for handling CPU PMUs.
I think that a better strategy would be to separate the type logic from the
registration. I have a patch for this:
http://lists.infradead.org/pipermail/linux-arm-kernel/2011-June/052455.html
With it, you won't need to change pmu_device_probe, and adding FDT support
should just be a matter of adding the of_match_table.
Mark
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