Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1752856AbcDOQok (ORCPT <rfc822;w@1wt.eu>);
	Fri, 15 Apr 2016 12:44:40 -0400
Received: from mail-pf0-f172.google.com ([209.85.192.172]:33979 "EHLO
	mail-pf0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1751285AbcDOQoi (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Fri, 15 Apr 2016 12:44:38 -0400
Date: Fri, 15 Apr 2016 09:44:33 -0700
From: Bjorn Andersson <bjorn.andersson@linaro.org>
To: Timur Tabi <timur@codeaurora.org>
Cc: Vikram Sethi <vikrams@codeaurora.org>,
        Florian Fainelli <f.fainelli@gmail.com>, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org, devicetree@vger.kernel.org,
        linux-arm-msm@vger.kernel.org, sdharia@codeaurora.org,
        Shanker Donthineni <shankerd@codeaurora.org>,
        Greg Kroah-Hartman <greg@kroah.com>, cov@codeaurora.org,
        gavidov@codeaurora.org, Rob Herring <robh+dt@kernel.org>,
        andrew@lunn.ch, Mark Langsdorf <mlangsdo@redhat.com>,
        Jon Masters <jcm@redhat.com>, Andy Gross <agross@codeaurora.org>,
        "David S. Miller" <davem@davemloft.net>
Subject: Re: [PATCH 1/2] [v4] net: emac: emac gigabit ethernet controller
 driver
Message-ID: <20160415164433.GV391@tuxbot>
References: <1460570393-19838-1-git-send-email-timur@codeaurora.org>
 <570EC541.6080603@gmail.com>
 <570FFB6B.5060305@codeaurora.org>
 <57100962.40404@gmail.com>
 <571012E6.6050303@codeaurora.org>
 <57102920.7000104@codeaurora.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <57102920.7000104@codeaurora.org>
User-Agent: Mutt/1.5.23 (2014-03-12)
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
Content-Length: 816
Lines: 32

On Thu 14 Apr 16:34 PDT 2016, Timur Tabi wrote:

[..]
> So I think the solution is to create a device tree (and ACPI) property that
> holds the mask.
> 
> 	dma-mask = <0 0xffffffff>;
> 
> or
> 
> 	dma-mask = <0xffffffff 0xffffffff>;
> 
> The driver will then do this:
> 
> 	u64 dma_mask;
> 	device_property_read_u64(&pdev->dev, "dma-mask", &dma_mask);
> 	dma_coerce_mask_and_coherent(&pdev->dev, dma_mask);
> 
> What I'm not sure yet is whether I should call
> dma_coerce_mask_and_coherent() or dma_set_coherent_mask().
> 

For platform devices being populated via from DT you will pass:
of_platform_bus_create()
  of_platform_device_create_pdata()
    of_dma_configure()

Which calls of_dma_get_range() to acquire this information from the
dma-ranges property and set up the dma ops and properties.

Regards,
Bjorn