Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752905AbcCJPXp (ORCPT ); Thu, 10 Mar 2016 10:23:45 -0500 Received: from comal.ext.ti.com ([198.47.26.152]:46949 "EHLO comal.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752368AbcCJPXl (ORCPT ); Thu, 10 Mar 2016 10:23:41 -0500 Subject: Re: [PATCH v3 1/6] memory: omap-gpmc: Store handle to GPMC dev To: "Franklin S Cooper Jr." , , , , , , , , References: <1457582861-20619-1-git-send-email-fcooper@ti.com> <1457582861-20619-2-git-send-email-fcooper@ti.com> <56E16B20.5070001@ti.com> <56E17932.6090304@ti.com> From: Roger Quadros Message-ID: <56E19148.9060207@ti.com> Date: Thu, 10 Mar 2016 17:22:48 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.5.1 MIME-Version: 1.0 In-Reply-To: <56E17932.6090304@ti.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2550 Lines: 66 Franklin, On 10/03/16 15:40, Franklin S Cooper Jr. wrote: > > > On 03/10/2016 06:40 AM, Roger Quadros wrote: >> Franklin, >> >> On 10/03/16 06:07, Franklin S Cooper Jr wrote: >>> The dma channel information is located within the GPMC node. The NAND >>> driver requires a handle to the GPMC's dev to properly parse the DMA >>> properties. Therefore, store a handle to the dev so it can be referenced >>> within the NAND driver. >>> >>> Signed-off-by: Franklin S Cooper Jr >>> --- >>> drivers/memory/omap-gpmc.c | 1 + >>> include/linux/platform_data/mtd-nand-omap2.h | 2 ++ >>> 2 files changed, 3 insertions(+) >>> >>> diff --git a/drivers/memory/omap-gpmc.c b/drivers/memory/omap-gpmc.c >>> index 6515dfc..2932d13 100644 >>> --- a/drivers/memory/omap-gpmc.c >>> +++ b/drivers/memory/omap-gpmc.c >>> @@ -1796,6 +1796,7 @@ static int gpmc_probe_nand_child(struct platform_device *pdev, >>> >>> gpmc_nand_data->cs = val; >>> gpmc_nand_data->of_node = child; >>> + gpmc_nand_data->gpmc_dev = &pdev->dev; >>> >>> /* Detect availability of ELM module */ >>> gpmc_nand_data->elm_of_node = of_parse_phandle(child, "ti,elm-id", 0); >>> diff --git a/include/linux/platform_data/mtd-nand-omap2.h b/include/linux/platform_data/mtd-nand-omap2.h >>> index 090bbab..534b984 100644 >>> --- a/include/linux/platform_data/mtd-nand-omap2.h >>> +++ b/include/linux/platform_data/mtd-nand-omap2.h >>> @@ -80,5 +80,7 @@ struct omap_nand_platform_data { >>> /* for passing the partitions */ >>> struct device_node *of_node; >>> struct device_node *elm_of_node; >>> + >>> + struct device *gpmc_dev; >>> }; >>> #endif >>> >> Why do you need this? Can't we just use dev->parent in the omap2-nand driver? > > The omap2-nand platform_device is created by > platform_device_alloc. The created platform_device dev > parent isn't by default set to the GPMC dev. I didn't think > this was the right approach to manually set the parent > property. However, taking a look at other usages of > platform_device_alloc it seems this is actually pretty > common. If your ok with this then I can go that route. After my DT cleanup we no longer use platform_dev_alloc for DT cases. As Nand node is child of GPMC node, omap2 nand's parent is guaranteed to be the GPMC device. But for legacy boot we still use gpmc_nand_init() which calls platform_device_add() without setting pdev->parent and so it will set the parent to platform bus. Maybe we could patch gpmc_nand_init() to set NAND's parent to GPMC device? cheers, -roger