Re: [PATCH v2 03/12] xen/dt: Extend dt_device_match to possibly store data

From: Julien Grall <julien.grall@linaro.org>
To: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: xen-devel@lists.xenproject.org, tim@xen.org,
	ian.campbell@citrix.com, stefano.stabellini@citrix.com
Subject: Re: [PATCH v2 03/12] xen/dt: Extend dt_device_match to possibly store data
Date: Tue, 27 Jan 2015 16:07:16 +0000	[thread overview]
Message-ID: <54C7B7B4.2030405@linaro.org> (raw)
In-Reply-To: <alpine.DEB.2.02.1501271554080.9702@kaball.uk.xensource.com>

Hi Stefano,

On 27/01/15 15:57, Stefano Stabellini wrote:
>>  const struct dt_device_node *dt_get_parent(const struct dt_device_node *node)
>> diff --git a/xen/include/xen/device_tree.h b/xen/include/xen/device_tree.h
>> index 08db8bc..6502369 100644
>> --- a/xen/include/xen/device_tree.h
>> +++ b/xen/include/xen/device_tree.h
>> @@ -28,6 +28,7 @@ struct dt_device_match {
>>      const char *type;
>>      const char *compatible;
>>      const bool_t not_available;
>> +    const void *data;
> 
> Why are you adding this field? It doesn't seem to be required by the
> changes to dt_match_node you are making in this patch.

It's required for the SMMU drivers. The version of the SMMU is stored in
the field data.

+static const struct of_device_id arm_smmu_of_match[] = {
+	{ .compatible = "arm,smmu-v1", .data = (void *)ARM_SMMU_V1 },
+	{ .compatible = "arm,smmu-v2", .data = (void *)ARM_SMMU_V2 },
+	{ .compatible = "arm,mmu-400", .data = (void *)ARM_SMMU_V1 },
+	{ .compatible = "arm,mmu-401", .data = (void *)ARM_SMMU_V1 },
+	{ .compatible = "arm,mmu-500", .data = (void *)ARM_SMMU_V2 },
+	{ },
+};

The main goal of this patch is too add the field data. The change of
dt_match_node is only a side effect.

Regards,

-- 
Julien Grall