Re: [PATCH V2 1/3] dma: add Qualcomm Technologies HIDMA management driver

From: Timur Tabi
Date: Mon Nov 02 2015 - 12:26:56 EST


On 11/02/2015 10:20 AM, Sinan Kaya wrote:

Is there a good example I can look or a wiki about the device-tree
naming conventions?

I'm more of an ACPI person than DTS.

I think Rob is talking about something like this:

compatible="qcom,hidma-mgmt-1.0", "qcom,hidma-mgmt"

This specifies that this is the v1.0 of the HIDMA management engine (or, the management engine for the 1.0 HIDMA device). That way, if in the future there's a v1.1, you can do this:

compatible="qcom,hidma-mgmt-1.1", "qcom,hidma-mgmt"

The driver will probe only on ""qcom,hidma-mgmt", but in the probe function, it can query the version number and act accordingly.

Alternatively, the driver can probe on both:

static const struct of_device_id hidma_match[] = {
{ .compatible = "qcom,hidma-mgmt-1.0", &v10_struct},
{ .compatible = "qcom,hidma-mgmt-1.1", &v11_struct},
{},
};
MODULE_DEVICE_TABLE(of, hidma_match);

And then the probe function will automatically get a pointer to either v10_struct or v11_struct.

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