From mboxrd@z Thu Jan  1 00:00:00 1970
From: Timur Tabi <timur@codeaurora.org>
Subject: Re: [PATCH V2 1/3] dma: add Qualcomm Technologies HIDMA management
 driver
Date: Mon, 2 Nov 2015 11:26:46 -0600
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To: Sinan Kaya <okaya@codeaurora.org>, Rob Herring <robh+dt@kernel.org>
Cc: dmaengine@vger.kernel.org, Christopher Covington <cov@codeaurora.org>, "jcm@redhat.com" <jcm@redhat.com>, Pawel Moll <pawel.moll@arm.com>, Mark Rutland <mark.rutland@arm.com>, Ian Campbell <ijc+devicetree@hellion.org.uk>, Kumar Gala <galak@codeaurora.org>, Vinod Koul <vinod.koul@intel.com>, Dan Williams <dan.j.williams@intel.com>, "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
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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.
	
-- 
Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the
Code Aurora Forum, a Linux Foundation Collaborative Project.